Drainage basin soluble organic carbon source analysis method, device, equipment and medium

Abstract

The invention provides a drainage basin soluble organic carbon source analysis method, device, equipment and medium, and the drainage basin soluble organic carbon source analysis method comprises the following steps: obtaining river network data, water flow direction data and gridding model parameters of a preset drainage basin, and the content of gridding soil organic matters in a soil pool; inputting the gridding model parameters, the river network data and the water flow direction data into a variable infiltration capacity model to obtain hydrological information of a preset time scale and gridding precision in a preset drainage basin, and inputting the hydrological information and the gridding soil organic matter content in the soil pool into a soluble organic carbon output migration model to obtain a soluble organic carbon output migration model; obtaining a gridding soluble organic carbon output quantity, a gridding soluble organic carbon transport path and a gridding soluble organic carbon contribution proportion of the preset watershed in a preset time scale; the spatial-temporal resolution and quantitative precision of dissolved organic carbon source analysis are remarkably improved, and technical support is provided for precise prevention and control of drainage basin dissolved organic carbon.

Description

Technical Field

[0001] The present application relates to the field of environmental science and technology, and in particular to methods, devices, equipment and media for analyzing the sources of dissolved organic carbon in a watershed. Background Art

[0002] Dissolved organic carbon (DOC) is a type of heterogeneous organic mixture with a continuous molecular weight distribution and a multifunctional group structure. It includes all organic compounds that can dissolve in water and is defined as organic matter that can pass through a 0.45μm (or 0.20μm) microporous filter membrane. Dissolved organic carbon can efficiently participate in physical, chemical, and biological reactions in the aquatic environment. Its source, existence form, and migration and transformation processes are closely related to all stages of the life cycle of aquatic organisms and have a significant impact on the life activities of aquatic organisms. Therefore, it is of great significance to carry out work to prevent and control dissolved organic carbon pollution.

[0003] The primary goal of dissolved organic carbon pollution prevention and control efforts is to achieve breakthroughs in key technologies for "source control and emission reduction" in water bodies. Identifying the sources of pollutants is a prerequisite for achieving this goal. Therefore, accurately analyzing the sources of dissolved organic carbon is crucial for achieving water pollution prevention and control goals. Small and medium-sized watersheds exhibit significant environmental variability and are often considered the fundamental spatial units for regional ecosystems and water resource management. In certain mountainous areas, small and medium-sized watersheds have vast spatial extents and significant upstream and downstream gradients, along with complex climatic, geological, and hydrological conditions. These factors collectively influence the sources, migration, and transformation of dissolved organic carbon, making it more challenging to identify their sources.

[0004] Currently, the main technologies for characterizing and tracing dissolved organic carbon (DOC) include ultraviolet-visible absorption spectroscopy (UV-Vis), three-dimensional fluorescence spectroscopy (EEMs), stable isotope tracing, biomarkers, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Although these technologies differ in their principles for characterizing and tracing DOM (Dissolved Organic Matter), they still have significant technical limitations in key areas such as DOM source identification (source), tracking migration and transformation processes (flow), and analyzing multi-source mixing and fate (sink): First, the labeling of specific sources is insufficient, making them easily confused, and the ability to capture dynamic source information is weak, making it impossible to effectively correlate the temporal dynamics of specific sources; second, there are deficiencies in tracking migration and transformation processes; and third, there are deficiencies in analyzing multi-source mixing and fate, resulting in inaccurate spatiotemporal resolution and quantitative analysis of dissolved organic carbon. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present application provides a method, device, equipment and medium for analyzing the source of dissolved organic carbon in a watershed to solve the above-mentioned technical problems.

[0006] According to one aspect of an embodiment of the present application, a method for analyzing the source of dissolved organic carbon in a watershed is provided, the method comprising: obtaining river network data, water flow direction data, and gridding model parameters of a preset watershed, as well as gridded soil organic matter content in a soil pool, the gridding model parameters comprising: gridded soil parameters, gridded vegetation parameters, gridded vegetation reservoir parameters, gridded snow elevation zone parameters, and gridded meteorological driving parameters; inputting the gridding model parameters, the river network data, and the water flow direction data into a variable infiltration capacity model to obtain hydrological information of a preset time scale and gridding accuracy within the preset watershed; the variable infiltration capacity model is based on samples of the preset watershed. The gridded model parameters are obtained by adjusting the parameters in the preset variable infiltration capacity model; the hydrological information includes: surface runoff, underground runoff, moisture content of each soil layer and water flow direction; the hydrological information and the gridded soil organic matter content in the soil pool are input into the dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon transport path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale; the dissolved organic carbon output and transport model is obtained by adjusting the parameters in the preset dissolved organic carbon output and transport model based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool.

[0007] In one embodiment of the present application, if the preset variable infiltration capacity model includes a land surface process unit and a confluence process unit, the parameters in the preset variable infiltration capacity model are adjusted based on the sample gridding model parameters of the preset watershed, and the process of obtaining the variable infiltration capacity model includes: inputting the sample gridding model parameters into the land surface process unit to obtain the hydrological information of each grid sample within the preset time scale; obtaining sample river network data and sample water flow direction data, inputting the hydrological information of each grid sample, the sample river network data and the sample water flow direction data into the confluence process unit to obtain the simulated flow data of the preset watershed; setting the mouth section in the preset watershed as a control node, taking the difference between the simulated flow data and the measured flow data of the control node as the first difference, and determining the first Nash efficiency coefficient based on the first difference. ; The first Nash efficiency coefficient is negatively correlated with the first difference; the measured flow data and the simulated flow data belong to the same time scale; if the first Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the preset variable infiltration capacity model is used as the variable infiltration capacity model; if the first Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the parameters in the land surface process unit and the parameters in the confluence process unit are adjusted until the first Nash efficiency coefficient determined by the difference between the adjusted simulated flow data and the flow measurement data is greater than or equal to the preset Nash efficiency coefficient threshold, and the combination of the adjusted land surface process unit and the adjusted confluence process unit is used as the variable infiltration capacity model; the adjusted simulated flow data is the simulated flow data of the control node output by the adjusted confluence process unit.

[0008] In one embodiment of the present application, before obtaining the river network data, water flow direction data and grid model parameters of the preset watershed, the method further includes: obtaining the boundary vector data, fishing net vector data, soil parameters, vegetation parameters, vegetation library parameters, snow elevation zone parameters and meteorological driving parameters of the preset watershed; using the preset grid size as the division unit, discretizing the boundary vector data and the fishing net vector data to obtain multiple grid units, and using each grid unit as the basic calculation unit of the variable infiltration capacity model; performing spatial interpolation calculation on the soil parameters to obtain the soil parameters of each basic calculation unit, and using the soil parameters of all basic calculation units as the gridded soil parameters; performing spatial interpolation calculation on the vegetation parameters to obtain the vegetation of each basic calculation unit. Parameters, and the vegetation parameters of all basic calculation units are used as the gridded vegetation parameters; spatial interpolation calculation is performed on the vegetation library parameters to obtain the vegetation library parameters of each basic calculation unit, and the vegetation library parameters of all basic calculation units are used as the gridded vegetation library parameters; spatial interpolation calculation is performed on the snow elevation band parameters to obtain the snow elevation band parameters of each basic calculation unit, and the snow elevation band parameters of all basic calculation units are used as the gridded snow elevation band parameters; spatial interpolation calculation is performed on the meteorological driving parameters to obtain the meteorological driving parameters of each basic calculation unit, and the meteorological driving parameters of all basic calculation units are used as the gridded meteorological driving parameters; and the river network data and the water flow direction data are extracted from the digital elevation data of preset resolution.

[0009] In one embodiment of the present application, based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool, the parameters in the preset dissolved organic carbon output and transport model are adjusted to obtain the process of the dissolved organic carbon output and transport model, which includes: obtaining the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded dissolved organic carbon concentration soil adsorption coefficient, the gridded sample soil heterotrophic respiration, the gridded dissolved organic carbon total amount, and the gridded soil aqueous solution temperature; and obtaining the water content of each layer of the sample soil, the sample surface runoff, and the sample underground runoff from the sample hydrological information, wherein the gridded dissolved organic carbon concentration in the sample soil aqueous solution is determined by the ratio of the preset soil organic carbon in the soil organic matter, the preset soil organic carbon in the soil organic carbon, and the gridded dissolved organic carbon concentration in the sample soil aqueous solution. The ratio of dissolved organic carbon, the water content of each layer of the sample soil, the gridded soil organic matter content and the grid area in the sample soil pool are determined; the gridded dissolved organic carbon concentration soil adsorption coefficient is determined by the gridded dissolved organic carbon concentration in the sample soil, the adsorption affinity of the gridded sample soil and dissolved organic carbon, and the desorption parameters of the gridded sample soil and dissolved organic carbon; the gridded sample soil heterotrophic respiration is determined by the preset gridded sample soil heterotrophic respiration rate, the preset gridded sample soil heterotrophic respiration temperature sensitivity and the gridded soil temperature; based on the sample surface runoff, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration and the gridded soil temperature, the gridded sample soil heterotrophic respiration is determined by the preset gridded sample soil heterotrophic respiration rate, the preset gridded sample soil heterotrophic respiration temperature sensitivity and the gridded soil temperature. The dissolved organic carbon output driven by surface runoff in each grid is calculated based on the soil adsorption coefficient of dissolved organic carbon concentration; the dissolved organic carbon output driven by underground runoff in each grid is calculated based on the underground runoff of the sample, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration and the gridded dissolved organic carbon concentration soil adsorption coefficient; the dissolved organic carbon output driven by surface runoff in each grid and the dissolved organic carbon output driven by underground runoff in each grid are determined; the dissolved organic carbon output of each grid is determined based on the water flow direction, the position of each grid in the water flow direction, the preset gridded dissolved organic carbon degradation rate, the preset dissolved organic carbon content in the water body of the basin, and the dissolved organic carbon content in the grid. The preset gridded decomposition stability sensitivity coefficient of organic carbon, the gridded soil water solution temperature and the gridded total dissolved organic carbon are used to determine the dissolved organic carbon attenuation between grids; based on the water flow direction, the position of each grid in the water flow direction, the dissolved organic carbon output and the dissolved organic carbon attenuation, the dissolved organic carbon migration between grids is determined, and the gridded dissolved organic carbon migration path is determined according to the dissolved organic carbon migration between grids; based on the water flow direction, the dissolved organic carbon attenuation between grids and the dissolved organic carbon migration between grids, the simulated flux of the sampling point is determined; based on the simulated flux and the dissolved organic carbon migration between grids, the gridded dissolved organic carbon contribution ratio is determined;The simulated flux is used to characterize the dissolved organic carbon sink at the sampling point; the difference between the simulated flux and the dissolved organic carbon measurement at the sampling point is used as a second difference, and a second Nash efficiency coefficient is determined based on the second difference; the second Nash efficiency coefficient is negatively correlated with the second difference; the dissolved organic carbon measurement and the simulated flux belong to the same time scale; if the second Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the preset dissolved organic carbon output transport model is used as the dissolved organic carbon output transport model; if the second Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the parameters in the preset dissolved organic carbon output transport model are adjusted until the second Nash efficiency coefficient determined by the difference between the adjusted simulated flux and the dissolved organic carbon measurement is greater than or equal to the preset Nash efficiency coefficient threshold, and the adjusted dissolved organic matter output transport model is used as the dissolved organic carbon output transport model; the adjusted simulated flux is the dissolved organic carbon sink at the sampling point output by the adjusted dissolved organic matter output transport model.

[0010] In one embodiment of the present application, based on the surface runoff, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration, and the gridded dissolved organic carbon concentration soil adsorption coefficient, the process of calculating the dissolved organic carbon output driven by the surface runoff in each grid includes: the calculation formula of the dissolved organic carbon output driven by the surface runoff in each grid includes: DOC runoff,i =[DOC] i ×K absorb,i ×Q surf,i -SR i , among which, DOC runoff,i represents the output of dissolved organic carbon driven by surface runoff in the i-th grid, [DOC] i represents the dissolved organic carbon concentration in the i-th grid of the sample soil aqueous solution. The dissolved organic carbon concentrations in all grids of the sample soil aqueous solution constitute the gridded dissolved organic carbon concentration in the sample soil aqueous solution. K absorb,i It represents the soil adsorption coefficient of dissolved organic carbon concentration in the i-th grid. The soil adsorption coefficients of dissolved organic carbon concentration in all grids constitute the gridded soil adsorption coefficient of dissolved organic carbon concentration. Q surf,i represents the sample surface runoff of the i-th grid, SR i It represents the heterotrophic respiration of the sample soil in the i-th grid, and the heterotrophic respiration of the sample soil in all grids constitutes the gridded sample soil heterotrophic respiration.

[0011] In one embodiment of the present application, based on the water flow direction, the position of each grid in the water flow direction, the preset gridded dissolved organic carbon degradation rate, the preset gridded decomposition stability sensitivity coefficient of dissolved organic carbon in the preset watershed water body, the gridded soil aqueous solution temperature and the gridded total dissolved organic carbon, the process of determining the dissolved organic carbon attenuation between grids includes: obtaining the position of the current grid in the water flow direction; if the current grid is the starting grid in the water flow direction, setting the dissolved organic carbon attenuation between the starting grid and the next grid to the preset attenuation; if the current grid is the intermediate grid in the water flow direction, calculating the dissolved organic carbon attenuation between the intermediate grid and the next grid based on the preset gridded dissolved organic carbon degradation rate, the preset gridded decomposition stability sensitivity coefficient, the gridded soil aqueous solution temperature and the gridded total dissolved organic carbon; the calculation formula for the dissolved organic carbon attenuation between the intermediate grid and the next grid includes: Among them, DOC i,j represents the attenuation of dissolved organic carbon between the i-th grid and the j-th grid, SR w,i represents the dissolved organic carbon degradation rate of the i-th grid. The dissolved organic carbon degradation rates of all grids constitute the preset gridded dissolved organic carbon degradation rate. Q 10w,i Represents the decomposed stable sensitivity coefficient of the i-th grid, and the decomposed stable sensitivity coefficients of all grids constitute the preset gridded decomposed stable sensitivity coefficient, T i represents the soil water solution temperature of the ith grid. The soil water solution temperature of all grids constitutes the gridded soil water solution temperature. Tw represents the reference value of soil absorption. SDOC i represents the total dissolved organic carbon of the i-th grid, and the total dissolved organic carbon of all grids constitutes the gridded total dissolved organic carbon.

[0012] In one embodiment of the present application, the process of determining the dissolved organic carbon migration amount between grids based on the water flow direction, the position of each grid in the water flow direction, the dissolved organic carbon output and the dissolved organic carbon attenuation includes: if the current grid is the starting grid in the water flow direction, then based on the dissolved organic carbon output of the starting grid, the output ratio of the starting grid and the preset attenuation, the dissolved organic carbon migration amount between the starting grid and the next grid is determined; if the current grid is the middle grid in the water flow direction, then based on the dissolved organic carbon migration amount between the previous grid and the middle grid, and the dissolved organic carbon attenuation between the middle grid and the next grid, the dissolved organic carbon migration amount between the middle grid and the next grid is calculated.

[0013] According to one aspect of an embodiment of the present application, a device for analyzing the source of dissolved organic carbon in a watershed is provided, including: a data acquisition module for obtaining river network data, water flow direction data and gridding model parameters of a preset watershed, as well as gridded soil organic matter content in a soil pool, wherein the gridding model parameters include: gridded soil parameters, gridded vegetation parameters, gridded vegetation reservoir parameters, gridded snow elevation zone parameters and gridded meteorological driving parameters; a hydrological information output module for inputting the gridding model parameters, the river network data and the water flow direction data into a variable infiltration capacity model to obtain hydrological information of a preset time scale and gridding accuracy in the preset watershed; the variable infiltration capacity model is based on the preset watershed. The sample grid model parameters are obtained by adjusting the parameters in the preset variable infiltration capacity model; the hydrological information includes: surface runoff, underground runoff, moisture content of each soil layer and water flow direction; the result output module is used to input the hydrological information and the gridded soil organic matter content in the soil pool into the dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon transport path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale; the dissolved organic carbon output and transport model is obtained by adjusting the parameters in the preset dissolved organic carbon output and transport model based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool.

[0014] According to one aspect of an embodiment of the present application, an electronic device is provided, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the electronic device implements the method for analyzing the sources of dissolved organic carbon in a watershed as described above.

[0015] According to one aspect of an embodiment of the present application, a computer-readable storage medium is provided, on which computer-readable instructions are stored. When the computer-readable instructions are executed by a processor of a computer, the computer executes the method for analyzing the sources of dissolved organic carbon in a watershed as described above.

[0016] Beneficial effects of the present application: The present application obtains river network data, water flow direction data and grid model parameters of a preset watershed, as well as grid soil organic matter content in a soil pool, and inputs the grid model parameters, river network data and water flow direction data into a variable infiltration capacity model. Capacity, VIC model) is used to obtain hydrological information of a preset time scale and gridding accuracy in a preset watershed. The hydrological information and the gridded soil organic matter content in the soil pool are input into the dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale. The above process, through the coupling of the variable infiltration capacity model and the dissolved organic carbon output and transport model, simulates the entire "source-flow-sink" process of dissolved organic carbon in the water body of the preset watershed, and can obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale, which significantly improves the temporal and spatial resolution and quantitative accuracy of the dissolved organic carbon source analysis, and provides technical support for the precise prevention and control of dissolved organic carbon in the watershed.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and a person of ordinary skill in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0019] Figure 1 is a schematic diagram of an exemplary system architecture shown in an exemplary embodiment of the present application;

[0020] Figure 2 is a flow chart of a method for source apportionment of dissolved organic carbon in a watershed, as shown in an exemplary embodiment of the present application;

[0021] Figure 3 is a flow chart of a method for source apportionment of dissolved organic carbon in a watershed, shown in another exemplary embodiment of the present application;

[0022] Figure 4 is a schematic diagram showing an exemplary embodiment of the present application after boundary extraction of a preset watershed;

[0023] Figure 5is a schematic diagram of gridding a preset watershed as shown in an exemplary embodiment of the present application;

[0024] Figure 6 is a schematic diagram of gridded dissolved organic carbon output according to an exemplary embodiment of the present application;

[0025] Figure 7 is a schematic diagram of a gridded dissolved organic carbon migration pathway shown in an exemplary embodiment of the present application;

[0026] Figure 8 is a schematic diagram of a gridded dissolved organic carbon contribution ratio shown in an exemplary embodiment of the present application;

[0027] Figure 9 is a block diagram of a watershed dissolved organic carbon source apportionment device shown in another exemplary embodiment of the present application;

[0028] Figure 10 A schematic diagram of the structure of a computer system suitable for implementing an electronic device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0030] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0031] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0032] In this application, "plurality" refers to two or more. "And / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0033] The technical solutions of the embodiments of this application involve related technologies such as material loading and unloading management, and are specifically described through the following embodiments:

[0034] Figure 1 It is a schematic diagram of an exemplary system architecture shown in an exemplary embodiment of the present application.

[0035] Reference Figure 1 As shown, the system architecture may include a storage device 101 and a computer device 102. The computer device 102 may be at least one of a desktop graphics processing unit (GPU) computer, a GPU computing cluster, a neural network computer, etc. Relevant technicians can use the computer device 102 to obtain river network data, water flow direction data, and grid model parameters of a preset watershed, as well as the gridded soil organic matter content in the soil pool, and input the gridded model parameters, river network data, and water flow direction data into a variable infiltration capacity model to obtain hydrological information of a preset time scale and gridding accuracy in the preset watershed. The hydrological information and the gridded soil organic matter content in the soil pool are input into a dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon transport path, and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale. The storage device 101 is used to store the river network data, water flow direction data, grid model parameters, and grid soil organic matter content of a preset watershed, as well as the grid soil organic matter content in the soil pool. In this embodiment, the storage device 101 uses a random access memory (RAM) or the like to store the river network data, water flow direction data, grid model parameters, and grid soil organic matter content of the preset watershed, and provides the data to the computer device 102 for processing.

[0036] Schematically, after obtaining the river network data, water flow direction data and grid model parameters of the preset watershed, as well as the gridded soil organic matter content in the soil pool from the storage device 101, the computer device 102 inputs the gridded model parameters, river network data and water flow direction data into the variable infiltration capacity model to obtain hydrological information of the preset watershed at a preset time scale and gridding accuracy, and inputs the hydrological information and the gridded soil organic matter content in the soil pool into the dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridding accuracy and gridding accuracy of the preset watershed within the preset time scale. The gridded dissolved organic carbon migration pathway and gridded dissolved organic carbon contribution ratio. The above process, through the coupling of the variable infiltration capacity model and the dissolved organic carbon output and migration model, simulates the entire process of "source-flow-sink" of dissolved organic carbon in the water body of the preset basin, and can obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon migration pathway and gridded dissolved organic carbon contribution ratio of the preset basin within the preset time scale, which significantly improves the spatiotemporal resolution and quantitative accuracy of dissolved organic carbon source analysis, and provides technical support for the precise prevention and control of dissolved organic carbon in the basin.

[0037] It should be noted that the method for source analysis of dissolved organic carbon in a watershed provided in the embodiment of the present application is generally executed by the computer device 102 , and accordingly, the device for source analysis of dissolved organic carbon in a watershed is generally provided in the computer device 102 .

[0038] The following is a detailed description of the implementation details of the technical solution of the embodiment of the present application:

[0039] Figure 2 This is a flow chart of a method for source analysis of dissolved organic carbon in a watershed, as shown in an exemplary embodiment of the present application. The method for source analysis of dissolved organic carbon in a watershed can be performed by a computing and processing device, which can be Figure 1 The computer device 102 shown in FIG. Figure 2 As shown, the method for source apportionment of dissolved organic carbon in a watershed includes at least steps S210 to S230, which are described in detail as follows:

[0040] In step S210, river network data, water flow direction data, and gridded model parameters for a preset watershed are obtained, as well as the gridded soil organic matter content in the soil pool. In one embodiment of the present application, the gridded model parameters include: gridded soil parameters, gridded vegetation parameters, gridded vegetation pool parameters, gridded snow elevation zone parameters, and gridded meteorological driving parameters. The preset watershed can be selected as needed, for example, the Yanjin River Basin.

[0041] In step S220, the grid model parameters, river network data and water flow direction data are input into the variable infiltration capacity model to obtain hydrological information of a preset time scale and grid accuracy in a preset watershed. In one embodiment of the present application, the variable infiltration capacity model is obtained by adjusting the parameters in the preset variable infiltration capacity model based on the sample grid model parameters of the preset watershed; the hydrological information includes: surface runoff, underground runoff, water content of each soil layer and water flow direction. The preset variable infiltration capacity model is a large-scale distributed hydrological model based on the idea of ​​SVATS (Soil Vegetation Atmospheric Transfer Schemes), which is often used to simulate hydrological processes at the watershed scale.

[0042] In step S230, the hydrological information and the gridded soil organic matter content in the soil pool are input into a dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon transport pathway, and gridded dissolved organic carbon contribution ratio for a predetermined watershed within a predetermined time scale. In one embodiment of the present application, the dissolved organic carbon output and transport model is obtained by adjusting the parameters of a predetermined dissolved organic carbon output and transport model based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool.

[0043] In one embodiment of the present application, by coupling a variable infiltration capacity model and a dissolved organic carbon output and migration model, the entire process of "source-flow-sink" of dissolved organic carbon in a preset watershed water body is simulated, and the gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon contribution ratio of the preset watershed within a preset time scale can be obtained, which significantly improves the spatiotemporal resolution and quantitative accuracy of dissolved organic carbon source analysis, and provides technical support for the precise prevention and control of dissolved organic carbon in the watershed.

[0044] In one embodiment of the present application, if the preset variable infiltration capacity model includes a land surface process unit and a confluence process unit, the process of adjusting the parameters in the preset variable infiltration capacity model based on the sample grid model parameters of the preset watershed to obtain the variable infiltration capacity model includes:

[0045] The sample grid model parameters are input into the land surface process unit to obtain the hydrological information of each grid sample within the preset time scale. In one embodiment of the present application, the preset time scale can be set according to the actual situation. For example, every day, the hydrological information of each grid sample includes: the surface runoff of each grid sample, the underground runoff of each grid sample, the moisture content of each layer of soil of each grid sample, and the water flow direction of each grid. Before inputting the sample grid model parameters into the land surface process unit, the range of the sample grid model parameters needs to be set. The sample grid model parameters include: grid sample soil parameters, grid sample vegetation parameters, grid sample vegetation library parameters, grid sample snow elevation zone parameters, and grid sample meteorological driving parameters. The preparation process of the sample grid model parameters is the same as the preparation process of the grid model parameters.

[0046] Obtain sample river network data and sample water flow direction data, input the sample hydrological information of each grid, sample river network data and sample water flow direction data into the confluence process unit to obtain the simulated flow data of the preset watershed. In one embodiment of the present application, the sample river network data and sample water flow direction data are extracted from the 90m resolution digital elevation data of the geospatial data cloud by the flow direction tool in ARCGIS. ARCGIS is a comprehensive geographic information system platform that provides users with a complete set of tools and applications for the collection, storage, management, analysis and visualization of geographic data. The confluence process unit realizes the dynamic calculation of the watershed hydrological process based on the distributed confluence algorithm of the flow direction (for example, single flow direction method, multi-flow direction method, hydrological method, hydraulic method).

[0047] A mouth section in a preset watershed is set as a control node, and the difference between the simulated flow data and the measured flow data at the control node is used as a first difference. Based on the first difference, a first Nash efficiency coefficient is determined. In one embodiment of the present application, the first Nash efficiency coefficient is negatively correlated with the first difference; the larger the first Nash efficiency coefficient, the smaller the first difference, and the smaller the first Nash efficiency coefficient, the larger the first difference. The measured flow data and the simulated flow data belong to the same time scale, and if the preset time scale is a day, the measured flow data and the simulated flow data belong to the same day.

[0048] If the first Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the preset variable infiltration capacity model is used as the variable infiltration capacity model. In one embodiment of the present application, the preset Nash efficiency coefficient threshold is set according to actual conditions. For example, the preset Nash efficiency coefficient threshold is set to 0.5. When the first Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, it indicates that the preset variable infiltration capacity model has a high accuracy and the simulation results output by the preset variable infiltration capacity model can be guaranteed.

[0049] If the first Nash efficiency coefficient is less than a preset Nash efficiency coefficient threshold, the parameters in the land surface process unit and the parameters in the confluence process unit are adjusted until the first Nash efficiency coefficient determined by the difference between the adjusted simulated flow data and the measured flow data is greater than or equal to the preset Nash efficiency coefficient threshold. The combination of the adjusted land surface process unit and the adjusted confluence process unit is then used as the variable infiltration capacity model. In one embodiment of the present application, the adjusted simulated flow data is the simulated flow data of the control node output by the adjusted confluence process unit.

[0050] In one embodiment of the present application, before obtaining river network data, water flow direction data, and grid model parameters for a preset watershed, the method for elucidating dissolved organic carbon sources in the watershed further includes:

[0051] Obtain boundary vector data, fishing net vector data, soil parameters, vegetation parameters, vegetation library parameters, snow elevation zone parameters, and meteorological driving parameters of a preset watershed. In one embodiment of the present application, boundary vector data refers to geographic boundary information stored in a vector format, which is generally used to describe spatial ranges such as administrative regions, natural regions, and land use zones. Vector data represents spatial objects through geometric elements such as points, lines, and surfaces, and has the characteristics of high precision, strong editability, and clear topological relationships. Fishnet vector data is vector data generated by dividing a preset watershed into a regular grid (fishing net).

[0052] Using a preset grid size as a division unit, the boundary vector data and the fishing net vector data are discretized to obtain multiple grid cells, each of which serves as a basic calculation unit for the variable infiltration capacity model. In one embodiment of the present application, the size of the preset grid size affects the spatiotemporal resolution and the calculation accuracy of the basic calculation unit. The preset grid size is set based on actual conditions.

[0053] The soil parameters are spatially interpolated to obtain the soil parameters of each basic calculation unit, and the soil parameters of all basic calculation units are used as gridded soil parameters. In one embodiment of the present application, the soil parameters are derived from the IGBP-SOIL (International Geosphere-Biosphere Programme-SOIL) dataset. The spatial interpolation of the soil parameters can be performed using global polynomial interpolation, universal kriging, or the like.

[0054] Spatial interpolation is performed on the vegetation parameters to obtain the vegetation parameters for each basic calculation unit, and the vegetation parameters of all basic calculation units are used as gridded vegetation parameters. In one embodiment of the present application, the vegetation parameters are derived from 1km resolution land cover data from the University of Maryland. The spatial interpolation of the vegetation parameters can be performed using global polynomial interpolation, universal kriging, etc.

[0055] Spatial interpolation is performed on the vegetation library parameters to obtain the vegetation library parameters for each basic calculation unit, and the vegetation library parameters of all basic calculation units are used as the gridded vegetation library parameters. In one embodiment of the present application, the vegetation library parameters are derived from 1km resolution land cover data from the University of Maryland. The spatial interpolation calculation of the vegetation library parameters can be performed using global polynomial interpolation, universal kriging, etc.

[0056] Spatial interpolation is performed on the snow elevation band parameters to obtain the snow elevation band parameters for each basic calculation unit. The snow elevation band parameters of all basic calculation units are then used as gridded snow elevation band parameters. In one embodiment of the present application, the snow elevation band parameters are derived from preset watershed gridded elevation data. Spatial interpolation of the snow elevation band parameters can be performed using global polynomial interpolation, universal kriging, or other methods.

[0057] The meteorological driving parameters are spatially interpolated to obtain the meteorological driving parameters for each basic calculation unit, and the meteorological driving parameters of all basic calculation units are used as gridded meteorological driving parameters. In one embodiment of the present application, the meteorological driving parameters are derived from a high-resolution meteorological driving parameter set for the Chinese region (the latitude and longitude interval of the data grid is 0.1 degrees) and observation data from meteorological stations around the basin. The spatial interpolation of the meteorological driving parameters can be performed using global polynomial interpolation, universal kriging, etc.

[0058] Furthermore, river network data and water flow direction data are extracted from the digital elevation data at a preset resolution. In one embodiment of the present application, river network data and water flow direction data are extracted from the digital elevation data at a preset resolution in the geospatial data cloud using the Flow Direction tool in ARCGIS. The preset resolution can be selected based on actual conditions, for example, 90m resolution.

[0059] In one embodiment of the present application, based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool, the parameters in the preset dissolved organic carbon output and transport model are adjusted to obtain the dissolved organic carbon output and transport model. The process includes:

[0060] Obtain the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded dissolved organic carbon concentration soil adsorption coefficient, the gridded sample soil heterotrophic respiration, the gridded dissolved organic carbon total amount, and the gridded soil aqueous solution temperature; and obtain the water content of each layer of the sample soil, the sample surface runoff, and the sample underground runoff from the sample hydrological information. In one embodiment of the present application, the gridded dissolved organic carbon concentration in the sample soil aqueous solution is determined by the ratio of preset soil organic carbon in soil organic matter, the ratio of preset dissolved organic carbon in soil organic carbon, the water content of each layer of the sample soil, the gridded soil organic matter content in the sample soil pool, and the grid area. Taking the dissolved organic carbon concentration in the i-th grid of the sample soil aqueous solution as an example, the calculation formula for the dissolved organic carbon concentration in the i-th grid of the sample soil aqueous solution is as follows:

[0061]

[0062] Among them, [DOC] i Represents the dissolved organic carbon concentration in the i-th grid of the sample soil water solution. The dissolved organic carbon concentrations in all grids of the sample soil water solution constitute the gridded dissolved organic carbon concentration in the sample soil water solution. NS DOC,i Represents the background content of dissolved organic carbon in the i-th grid in the sample soil pool, in units of (g C / grid), WS tot_soil,i Represents the water content of each layer of the sample soil in the i-th grid, in units of (kg H2O).

[0063] The calculation formula for the background content of dissolved organic carbon in the i-th grid in the soil pool is as follows:

[0064] NS DOC,i =NS SOM,i ×K SOC,i ×K DOC,i Formula (2)

[0065] Among them, NS DOC,i Represents the background content of dissolved organic carbon in the i-th grid in the sample soil pool, NS SOM,i represents the soil organic matter content in the i-th grid in the sample soil pool, in units of (g / grid), K SOC,i represents the proportion of preset soil organic carbon in the soil organic matter in the i-th grid, K DOC,i Represents the proportion of preset dissolved organic carbon in the soil organic carbon in the i-th grid.

[0066] The calculation formula for the moisture content of each layer of sample soil in the i-th grid is as follows:

[0067] WS tot_soil,i =(L1 i +L2 i +L3i )×A i Formula (3)

[0068] Among them, WS tot_soil,i Indicates the water content of each layer of the sample soil in the i-th grid, in units of (kg H2O), L1 i Indicates the soil moisture content of the first layer in the i-th grid, in units of (mm), L2 i Indicates the soil moisture content of the second layer in the i-th grid, in units of (mm), L3 i represents the soil moisture content of the third layer in the i-th grid, in units of (mm), A i Represents the grid area of ​​the i-th grid, in units of (m 2 ).

[0069] The gridded dissolved organic carbon concentration soil adsorption coefficient is determined by the gridded dissolved organic carbon concentration in the sample soil, the adsorption affinity between the gridded sample soil and dissolved organic carbon, and the desorption parameters between the gridded sample soil and dissolved organic carbon. Taking the soil adsorption coefficient of dissolved organic carbon concentration in the i-th grid as an example, the calculation formula of the soil adsorption coefficient of dissolved organic carbon concentration in the i-th grid is as follows:

[0070]

[0071] Among them, X i Indicates the dissolved organic carbon concentration in the i-th grid of the sample soil, in units of (mg C / g soil), m i is the adsorption affinity between sample soil and dissolved organic carbon in the i-th grid. The adsorption affinity between sample soil and dissolved organic carbon in all grids constitutes the adsorption affinity between gridded sample soil and dissolved organic carbon. b i Represents the desorption parameter of the soil and dissolved organic carbon sample within the i-th grid, in units of (mg C / g soil). The desorption parameters of the soil and dissolved organic carbon sample within all grids constitute the gridded sample soil and dissolved organic carbon desorption parameter. The soil adsorption coefficient of the dissolved organic carbon concentration within all grids constitutes the gridded dissolved organic carbon concentration soil adsorption coefficient. The dissolved organic carbon concentration within all grids in the sample soil constitutes the gridded dissolved organic carbon concentration in the sample soil.

[0072] The heterotrophic respiration of the gridded sample soil is determined by the preset gridded sample soil heterotrophic respiration rate, the preset gridded sample soil heterotrophic respiration temperature sensitivity, and the gridded soil temperature. Taking the heterotrophic respiration of the sample soil in the i-th grid as an example, the calculation formula for the heterotrophic respiration of the sample soil in the i-th grid is as follows:

[0073]

[0074] Among them, SR i Represents the heterotrophic respiration of the sample soil in the i-th grid. The heterotrophic respiration of the sample soil in all grids constitutes the gridded sample soil heterotrophic respiration. R 10,i represents the preset soil heterotrophic respiration rate in the ith grid at 10°C, in units of (g C / grid / day). The preset soil heterotrophic respiration rates in all grids at 10°C constitute the preset gridded sample soil heterotrophic respiration rate, Q S10,i Represents the preset soil heterotrophic respiration temperature sensitivity in the i-th grid. The preset soil heterotrophic respiration temperature sensitivity in all grids constitutes the preset gridded sample soil heterotrophic respiration temperature sensitivity, T i1 Represents the soil temperature in the i-th grid, in degrees Celsius. The soil temperatures in all grids constitute the gridded soil temperature.

[0075] Based on the surface runoff, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration, and the gridded dissolved organic carbon concentration soil adsorption coefficient, the dissolved organic carbon output driven by the surface runoff in each grid is calculated. In one embodiment of the present application, taking the dissolved organic carbon output driven by the surface runoff in the i-th grid as an example, the calculation formula for the dissolved organic carbon output driven by the surface runoff in the i-th grid is as follows:

[0076] DOC runoff,i =[DOC] i ×K absorb,i ×Q surf,i -SR i Formula (6)

[0077] Among them, DOC runoff,i represents the output of dissolved organic carbon driven by surface runoff in the ith grid, in units of (g C / grid / day), [DOC] i represents the dissolved organic carbon concentration in the i-th grid of the sample soil aqueous solution. The dissolved organic carbon concentrations in all grids of the sample soil aqueous solution constitute the gridded dissolved organic carbon concentration in the sample soil aqueous solution. K absorb,i It represents the soil adsorption coefficient of dissolved organic carbon concentration in the i-th grid. The soil adsorption coefficients of dissolved organic carbon concentration in all grids constitute the gridded soil adsorption coefficient of dissolved organic carbon concentration. Q surf,i represents the sample surface runoff of the i-th grid, in units of (kg H2O / grid / day), SR i Represents the heterotrophic respiration of the soil sample in the i-th grid. The heterotrophic respiration of the soil samples in all grids constitutes the gridded sample soil heterotrophic respiration.

[0078] Based on the underground runoff, the gridded dissolved organic carbon concentration, the gridded sample soil heterotrophic respiration, and the gridded dissolved organic carbon concentration soil adsorption coefficient, the dissolved organic carbon output driven by underground runoff in each grid is calculated. In one embodiment of the present application, taking the dissolved organic carbon output driven by underground runoff in the i-th grid as an example, the calculation formula for the dissolved organic carbon output driven by underground runoff in the i-th grid is as follows:

[0079] DOC leaching,i =[DOC] i ×K absorb,i ×Q dis,i -SR i Formula (7)

[0080] Among them, DOC leaching,i represents the output of dissolved organic carbon driven by subsurface runoff in the ith grid, in units of (g C / grid / day), [DOC] i represents the dissolved organic carbon concentration in the i-th grid of the sample soil aqueous solution. The dissolved organic carbon concentrations in all grids of the sample soil aqueous solution constitute the gridded dissolved organic carbon concentration in the sample soil aqueous solution. K absorb,i It represents the soil adsorption coefficient of dissolved organic carbon concentration in the i-th grid. The soil adsorption coefficients of dissolved organic carbon concentration in all grids constitute the gridded soil adsorption coefficient of dissolved organic carbon concentration. Q dis,i represents the sample underground runoff of the ith grid, in units of (kg H2O / grid / day), SR i Represents the heterotrophic respiration of the soil sample in the i-th grid. The heterotrophic respiration of the soil samples in all grids constitutes the gridded sample soil heterotrophic respiration.

[0081] Based on the dissolved organic carbon output driven by surface runoff in each grid and the dissolved organic carbon output driven by underground runoff in each grid, the dissolved organic carbon output of each grid is determined. In one embodiment of the present application, taking the dissolved organic carbon output of the i-th grid as an example, the calculation formula for the dissolved organic carbon output of the i-th grid is as follows:

[0082] DOC shu,i =DOC runoff,i +DOC leaching,i Formula (8)

[0083] Among them, DOC shu,i represents the output of dissolved organic carbon in the ith grid, in units of (g C / grid / day), DOC runoff,i represents the output of dissolved organic carbon driven by surface runoff in the i-th grid, DOC leaching,i represents the output of dissolved organic carbon driven by subsurface runoff in the i-th grid.

[0084] The dissolved organic carbon attenuation between grids is determined based on the water flow direction, the position of each grid in the water flow direction, the preset gridded dissolved organic carbon degradation rate, the preset gridded decomposition stability sensitivity coefficient of dissolved organic carbon in the preset basin water body, the gridded soil water solution temperature and the gridded total dissolved organic carbon. In one embodiment of the present application, based on the water flow direction, the position of each grid in the water flow direction, the preset gridded dissolved organic carbon degradation rate, the preset gridded decomposition stability sensitivity coefficient of the dissolved organic carbon in the preset watershed water body, the gridded soil aqueous solution temperature, and the gridded dissolved organic carbon total amount, the process of determining the dissolved organic carbon attenuation between grids includes: obtaining the position of the current grid in the water flow direction; if the current grid is the starting grid in the water flow direction, setting the dissolved organic carbon attenuation between the starting grid and the next grid to the preset attenuation, which can be set to 0 or other values; if the current grid is the middle grid in the water flow direction, calculating the dissolved organic carbon attenuation between the middle grid and the next grid based on the preset gridded dissolved organic carbon degradation rate, the preset gridded decomposition stability sensitivity coefficient, the gridded soil aqueous solution temperature, and the gridded dissolved organic carbon total amount; the calculation formula for the dissolved organic carbon attenuation between the middle grid and the next grid includes:

[0085]

[0086] Among them, DOC i,j represents the attenuation of dissolved organic carbon between the i-th grid and the j-th grid, SR w,i Represents the degradation rate of dissolved organic carbon in the ith grid, in (s -1 ), the dissolved organic carbon degradation rates of all grids constitute the preset grid-based dissolved organic carbon degradation rate, Q 10w,i Represents the decomposed stable sensitivity coefficient of the i-th grid. The decomposed stable sensitivity coefficients of all grids constitute the preset gridded decomposed stable sensitivity coefficients. i It represents the soil water solution temperature of the ith grid. The soil water solution temperature of all grids constitutes the gridded soil water solution temperature. Tw represents the reference value of soil absorption, which is 20. SDOC i represents the total dissolved organic carbon of the ith grid, in units of (g C). The total dissolved organic carbon of all grids constitutes the gridded total dissolved organic carbon.

[0087] Based on the water flow direction, the position of each grid in the water flow direction, the dissolved organic carbon output and the dissolved organic carbon attenuation, the dissolved organic carbon migration amount between the grids is determined, and based on the dissolved organic carbon migration amount between the grids, the gridded dissolved organic carbon migration path is determined. In one embodiment of the present application, based on the water flow direction, the position of each grid in the water flow direction, the dissolved organic carbon output and the dissolved organic carbon attenuation, the process of determining the dissolved organic carbon migration amount between the grids includes: if the current grid is the starting grid in the water flow direction, then based on the dissolved organic carbon output of the starting grid, the output ratio of the starting grid and the preset attenuation, the dissolved organic carbon migration amount between the starting grid and the next grid is determined, and the calculation formula of the dissolved organic carbon migration amount between the starting grid and the next grid is as follows:

[0088] L DOC,aj =DOC shu,a ×DOC bi,a -DOC shuai Formula (10)

[0089] Among them, L DOC,aj Indicates the amount of dissolved organic carbon migration between the starting grid a and the next grid j, DOC shu,a Indicates the output of dissolved organic carbon at the starting grid a, DOCb i,a Indicates the output ratio of the starting grid a, DOC shuai Indicates the preset attenuation amount.

[0090] If the current grid is the middle grid in the direction of water flow, the dissolved organic carbon transfer amount between the middle grid and the next grid is calculated based on the dissolved organic carbon transfer amount between the previous grid and the middle grid and the dissolved organic carbon decay amount between the middle grid and the next grid. In one embodiment of the present application, the dissolved organic carbon transfer amount between the middle grid and the next grid is the difference between the dissolved organic carbon transfer amount between the previous grid and the middle grid and the dissolved organic carbon decay amount between the middle grid and the next grid.

[0091] In one embodiment of the present application, a water flow is composed of multiple runoffs. Based on the water flow direction and the amount of dissolved organic carbon migration between grids, the gridded dissolved organic carbon migration path can be obtained. In one embodiment of the present application, the starting grid is a grid that generates surface runoff and underground runoff. If there are multiple grids that generate surface runoff and underground runoff in the water flow direction, the grids that generate surface runoff and underground runoff are respectively used as the starting grids of a runoff, and the inter-grid dissolved organic carbon output and inter-grid dissolved organic carbon attenuation in each runoff are calculated respectively. Finally, the partial dissolved organic carbon excesses belonging to the same grid in each runoff are superimposed to obtain the total dissolved organic carbon in each grid. For example, if a grid is used as the starting grid in a certain runoff, the partial dissolved organic carbon excess of the grid is the difference between the dissolved organic carbon output of the grid and the dissolved organic carbon migration amount between the grid and the next grid. If the grid is used as the intermediate grid in another runoff, the other partial dissolved organic carbon excess of the grid is 0 (the dissolved organic carbon after attenuation is all migrated to the next grid). Therefore, the total dissolved organic carbon in the grid is the sum of the two partial dissolved organic carbon excesses.

[0092] Based on the water flow direction, the dissolved organic carbon attenuation between grids, and the dissolved organic carbon migration between grids, the simulated flux of the sampling point is determined; based on the simulated flux and the dissolved organic carbon migration between grids, the gridded dissolved organic carbon contribution ratio is determined; in one embodiment of the present application, the simulated flux is used to characterize the dissolved organic carbon accumulation at the sampling point; based on the water flow direction, the dissolved organic carbon attenuation between grids, and the dissolved organic carbon migration between grids, the process of determining the simulated flux of the sampling point includes: determining the grid position corresponding to the sampling point, and determining the upstream grid of the grid corresponding to the sampling point based on the water flow direction and the dissolved organic carbon migration between grids; and obtaining the simulated flux of the sampling point based on the dissolved organic carbon migration from the upstream grid to the downstream grid. The process of determining the gridded dissolved organic carbon contribution ratio based on the simulated flux and the dissolved organic carbon migration amount between grids includes: the dissolved organic carbon migration amount between grids and the gridded dissolved organic carbon migration path are used to obtain the dissolved organic carbon contribution of each upstream grid to the grid corresponding to the sampling point; the ratio of the dissolved organic carbon contribution of each upstream grid to the grid corresponding to the sampling point to the simulated flux is used as the dissolved organic carbon contribution ratio of each upstream grid to the grid corresponding to the sampling point, and the dissolved organic carbon contribution ratios of all upstream grids to the grid corresponding to the sampling point are used as the gridded dissolved organic carbon contribution ratio.

[0093] The difference between the simulated flux and the measured dissolved organic carbon at the sampling point is used as the second difference, and a second Nash efficiency coefficient is determined based on the second difference. In one embodiment of the present application, the second Nash efficiency coefficient is negatively correlated with the second difference; the larger the second difference, the smaller the second Nash efficiency coefficient; and the smaller the second difference, the larger the second Nash efficiency coefficient. The measured dissolved organic carbon and the simulated flux belong to the same time scale. If the preset time scale is daily, the measured dissolved organic carbon and the simulated flux belong to the same day.

[0094] If the second Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the preset dissolved organic carbon output and transport model is used as the dissolved organic carbon output and transport model. In one embodiment of the present application, if the second Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, it indicates that the preset dissolved organic carbon output and transport model has a high accuracy, and the simulation results output by the preset dissolved organic carbon output and transport model can be guaranteed.

[0095] If the second Nash efficiency coefficient is less than a preset Nash efficiency coefficient threshold, the parameters of the preset dissolved organic carbon output transport model are adjusted until the second Nash efficiency coefficient, determined by the difference between the adjusted simulated flux and the measured dissolved organic carbon amount, is greater than or equal to the preset Nash efficiency coefficient threshold. The adjusted dissolved organic matter output transport model is then used as the dissolved organic carbon output transport model. In one embodiment of the present application, the adjusted simulated flux is the dissolved organic carbon accumulation at the sampling point output by the adjusted dissolved organic matter output transport model. If the second Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the preset proportion of soil organic carbon in soil organic matter, the preset proportion of dissolved organic carbon in soil organic carbon, the preset gridded sample soil heterotrophic respiration rate, the preset gridded sample soil heterotrophic respiration temperature sensitivity, the preset gridded dissolved organic carbon degradation rate, and the preset gridded decomposition stability sensitivity coefficient of dissolved organic carbon in the preset watershed water body in the preset dissolved organic carbon output and transport model are adjusted until the second Nash efficiency coefficient determined by the difference between the adjusted simulated flux and the dissolved organic carbon measurement is greater than or equal to the preset Nash efficiency coefficient threshold, and the adjusted dissolved organic matter output and transport model is used as the dissolved organic carbon output and transport model, thereby ensuring the output precision and accuracy of the adjusted dissolved organic matter output and transport model.

[0096] In another embodiment of the present application, the preset soil organic carbon ratio in the soil organic matter is in the range of 0.455-0.6, the preset dissolved organic carbon ratio in the soil organic carbon is in the range of 0.05-0.21, the preset grid sample soil heterotrophic respiration rate is in the range of 0.0000084-0.0000588, in units of g C / m2 / s, the preset grid sample soil heterotrophic respiration temperature sensitivity is in the range of 2-6.3, and the preset grid dissolved organic carbon degradation rate is in the range of 6.9×10 -9 -6.4×10 -8 , unit is s -1 The preset grid decomposition stability sensitivity coefficient of dissolved organic carbon in the preset basin water body ranges from 1.47 to 2.88.

[0097] Figure 3 is a flow chart of a method for source apportionment of dissolved organic carbon in a watershed, as shown in another exemplary embodiment of the present application. Figure 3The method for analyzing the source of dissolved organic carbon in the watershed includes: (301) watershed extraction and grid unit division: obtaining the boundary vector data, fishing net vector data and sample model parameters of the preset watershed, the sample model parameters include: sample soil parameters, sample vegetation parameters, sample vegetation library parameters, sample snow elevation zone parameters and sample meteorological driving parameters, using the preset grid size as the division unit, discretizing the boundary vector data and fishing net vector data to obtain multiple grid units, and using each grid unit as the basic calculation unit of the variable infiltration capacity model; (302) grid parameter preparation: preparing the sample soil parameters, sample vegetation parameters, sample vegetation library parameters, sample snow elevation zone parameters and sample meteorological driving parameters respectively. The spatial difference calculation of dynamic parameters is performed to obtain sample grid soil parameters, sample grid vegetation parameters, sample grid vegetation library parameters, sample grid snow elevation zone parameters and sample grid meteorological driving parameters; (303) Land surface process simulation: set the parameter range of sample grid soil parameters, sample grid vegetation parameters, sample grid vegetation library parameters, sample grid snow elevation zone parameters and sample grid meteorological driving parameters; input the sample grid soil parameters, sample grid vegetation parameters, sample grid vegetation library parameters, sample grid snow elevation zone parameters and sample grid meteorological driving parameters into the land surface process unit to obtain the hydrological information of each grid sample; (304) Confluence process simulation: input the sample grid soil parameters, sample grid vegetation parameters, sample grid vegetation library parameters, sample grid snow elevation zone parameters and sample grid meteorological driving parameters into the land surface process unit to obtain the hydrological information of each grid sample; The grid sample hydrological information, sample river network data and sample water flow direction data are input into the confluence process unit to obtain the simulated flow data of the preset basin; (305) Calibration and verification of the preset variable infiltration capacity model: the mouth section in the preset basin is set as the control node, the difference between the simulated flow data and the measured flow data of the control node is used as the first difference, and based on the first difference, the first Nash efficiency coefficient is determined, and according to the comparison result between the first Nash efficiency coefficient and the preset Nash efficiency coefficient threshold, it is judged whether to adjust the parameters in the preset variable infiltration capacity model; (306) Reliability judgment of the preset variable infiltration capacity model: if the first Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the first Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold. value, the preset variable infiltration capacity model is used as the variable infiltration capacity model; if the first Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the parameters in the land surface process unit and the parameters in the confluence process unit are adjusted until the first Nash efficiency coefficient determined by the difference between the adjusted simulated flow data and the flow measurement data is greater than or equal to the preset Nash efficiency coefficient threshold, and the combination of the adjusted land surface process unit and the adjusted confluence process unit is used as the variable infiltration capacity model; (307) hydrological information output: after obtaining the variable infiltration capacity model, the sample grid model parameters, sample river network data and sample water flow direction data are input into the variable infiltration capacity model to obtain sample hydrological information;(308) Calculate the dissolved organic carbon output of each grid: Based on the sample surface runoff, the grid-based dissolved organic carbon concentration in the sample soil aqueous solution, the grid-based sample soil heterotrophic respiration and the grid-based dissolved organic carbon concentration soil adsorption coefficient, calculate the dissolved organic carbon output driven by the surface runoff in each grid; Based on the sample underground runoff, the grid-based dissolved organic carbon concentration in the sample soil aqueous solution, the grid-based sample soil heterotrophic respiration and the grid-based dissolved organic carbon concentration soil adsorption coefficient, calculate the dissolved organic carbon output driven by the underground runoff in each grid; Based on the dissolved organic carbon output driven by the surface runoff in each grid and the dissolved organic carbon output driven by the underground runoff in each grid, determine the dissolved organic carbon output of each grid. (309) Calculate the dissolved organic carbon migration and dissolved organic carbon attenuation between grids: Determine the dissolved organic carbon attenuation between grids based on the flow direction, the position of each grid in the flow direction, the preset grid-based dissolved organic carbon degradation rate, the preset grid-based decomposition stability sensitivity coefficient of dissolved organic carbon in the preset watershed water body, the grid-based soil water solution temperature and the grid-based dissolved organic carbon total amount; Determine the dissolved organic carbon migration between grids based on the flow direction, the position of each grid in the flow direction, the dissolved organic carbon output and the dissolved organic carbon attenuation; (310) Calibrate and validate the preset dissolved organic carbon output migration model: Determine the dissolved organic carbon migration between grids based on the flow direction, the dissolved organic carbon attenuation between grids, the grid-based The amount of dissolved organic carbon migration between the two samples is used to determine the simulated flux of the sampling point; the difference between the simulated flux and the dissolved organic carbon measurement at the sampling point is used as the second difference, and the second Nash efficiency coefficient is determined based on the second difference. According to the comparison result of the second Nash efficiency coefficient and the preset Nash efficiency coefficient threshold, it is determined whether to adjust the parameters in the preset dissolved organic carbon output migration model; (311) Reliability judgment of the preset dissolved organic carbon output migration model: if the second Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the preset dissolved organic carbon output migration model is used as the dissolved organic carbon output migration model; if the second Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the preset dissolved organic carbon output migration model is adjusted. The parameters in the DOE are adjusted until the second Nash efficiency coefficient determined by the difference between the adjusted simulated flux and the dissolved organic carbon measurement is greater than or equal to the preset Nash efficiency coefficient threshold, and the adjusted dissolved organic matter output transport model is used as the dissolved organic carbon output transport model; (312) dynamic data of dissolved organic carbon in the preset watershed are output: the dynamic data of dissolved organic carbon in the preset watershed include: gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon contribution ratio; (313) the source of dissolved organic carbon in the preset watershed is determined: the source of dissolved organic carbon in the preset watershed is determined based on the gridded dissolved organic carbon migration path and the dissolved organic carbon migration between grids.

[0098] In some embodiments of the present application, the Yanjin River basin is gridded with a pixel size of 0.009°, and then gridded soil parameters, gridded vegetation parameters, gridded snow elevation zone parameters and gridded meteorological driving parameters are prepared. Then, the gridded model parameters, river network data and water flow direction data are input into the variable infiltration capacity model. The Nash efficiency coefficient of the variable infiltration capacity model reaches 0.61. The hydrological information and the gridded soil organic matter content in the soil pool are input into the dissolved organic carbon output migration model to calculate the dissolved organic carbon attenuation and dissolved organic carbon migration between grids. At the same time, the water flow direction matrix and the time unit line division method in the confluence process unit are applied to the simulation of the dissolved organic carbon output migration process, thereby realizing the coupling of the variable infiltration capacity model and the dissolved organic carbon output migration model. Within a fixed time period, a total of 10 samplings were carried out in the Yanjin River basin. The sampling point at the Yanjin River mouth section was calibrated using a coupled model (a combination of a variable infiltration capacity model and a dissolved organic carbon output and transport model). The actual DOC measurements at the sampling point were compared with the simulated flux to complete the model calibration, and the Nash efficiency coefficient reached 0.77. Subsequently, three sewage treatment plant outlets were selected as three sampling points for model verification, and the obtained Nash efficiency coefficients were 0.71, 0.64 and 0.55, respectively, verifying the reliability of the model.

[0099] This application is based on the gridded hydrological dynamic data of the watershed simulated by the variable infiltration capacity model, combined with the quantitative calculation of the dissolved organic carbon output and migration model, to achieve dynamic analysis of the source of dissolved organic carbon. Specifically, by integrating the gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon attenuation characteristics of each grid unit, a gridded dissolved organic carbon source analysis model for the entire "source-stream-sink" process (i.e., a combination of the variable infiltration capacity model and the dissolved organic carbon output and migration model) is constructed. The gridded dissolved organic carbon source analysis model can: (1) identify the main source grids of dissolved organic carbon based on grid unit division; (2) track the spatial migration path and attenuation of dissolved organic carbon through the migration process; (3) quantify the contribution ratio of different source grids to the dissolved organic carbon of the downstream confluence grid through multi-source mixing, and significantly improve the spatiotemporal resolution and quantitative accuracy of dissolved organic carbon source analysis, providing technical support for the precise prevention and control of dissolved organic carbon in the preset watershed.

[0100] Figure 4 This is a schematic diagram of an exemplary embodiment of the present application showing the extraction of the boundary of a preset watershed. Taking the preset watershed as the Yanjin River Basin as an example, the main river of the Yanjin River is 37.6 kilometers long and has a drainage area of ​​316 square kilometers. It is a typical small watershed. The boundary outline of the Yanjin River Basin obtained by extracting the boundary of the Yanjin River Basin is as follows: Figure 4 shown.

[0101] Figure 5 This is a schematic diagram of gridding a preset watershed as shown in an exemplary embodiment of the present application. Taking the preset watershed as the Yanjin River Basin as an example, Figure 5 The gridding of the boundary outline of the Yanjin River Basin is shown in Figure 1, and the gridded boundary outline of the Yanjin River Basin is obtained.

[0102] Figure 6 is a schematic diagram of the gridded dissolved organic carbon output shown in an exemplary embodiment of the present application. Figure 6 In the figure, the horizontal axis is longitude, the vertical axis is latitude, and different color depths in the grid correspond to different dissolved organic carbon outputs.

[0103] Figure 7 is a schematic diagram of a gridded dissolved organic carbon migration path shown in an exemplary embodiment of the present application. Figure 7 In the figure, the horizontal axis is longitude and the vertical axis is latitude. Different colors represent the migration paths of dissolved organic carbon in different runoffs. In the same migration path, the dot in the grid represents the starting grid, and the end grid of the migration path represents the convergence point of dissolved organic carbon in the migration path.

[0104] Figure 8 is a schematic diagram of the gridded dissolved organic carbon contribution ratio shown in an exemplary embodiment of the present application. Figure 8 In the example, the horizontal axis is longitude and the vertical axis is latitude. Figure 7 and Figure 8 Combined, it can be seen that different colors in the grid represent the contribution ratio to the end point grid of the migration path.

[0105] The following describes an apparatus embodiment of the present application, which can be used to perform the method for source apportionment of dissolved organic carbon in a watershed described in the above-mentioned embodiments of the present application. For details not disclosed in the apparatus embodiment of the present application, please refer to the embodiment of the method for source apportionment of dissolved organic carbon in a watershed described in the above-mentioned embodiments of the present application.

[0106] Figure 9 This is a block diagram of a watershed dissolved organic carbon source analysis device shown in an exemplary embodiment of the present application. The device can be applied to Figure 1 The implementation environment shown is specifically configured in the computer device 102. The apparatus may also be applicable to other exemplary implementation environments and specifically configured in other devices. This embodiment does not limit the implementation environment to which the apparatus is applicable.

[0107] like Figure 9 As shown, the exemplary watershed dissolved organic carbon source apportionment device 900 includes:

[0108] The data acquisition module 901 is used to obtain river network data, water flow direction data and grid model parameters of a preset watershed, as well as grid soil organic matter content in a soil pool.

[0109] The hydrological information output module 902 is used to input grid model parameters, river network data and water flow direction data into the variable infiltration capacity model to obtain hydrological information of a preset time scale and grid accuracy in a preset watershed.

[0110] The result output module 903 is used to input the hydrological information and the gridded soil organic matter content in the soil pool into the dissolved organic carbon output and migration model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale.

[0111] In one embodiment of the present application, the gridded model parameters include: gridded soil parameters, gridded vegetation parameters, gridded vegetation library parameters, gridded snow elevation zone parameters and gridded meteorological driving parameters. The preset watershed can be selected as needed, for example, the Yanjin River Basin.

[0112] In one embodiment of the present application, the variable infiltration capacity model is obtained by adjusting parameters in a preset variable infiltration capacity model based on sample grid model parameters of a preset watershed; hydrological information includes: surface runoff, groundwater runoff, soil moisture content in each layer, and water flow direction. The preset variable infiltration capacity model is a large-scale distributed hydrological model based on the concept of SVATS (SoilVegetationAtmosphericTransferSchemes), which is commonly used to simulate hydrological processes at the watershed scale.

[0113] In one embodiment of the present application, the dissolved organic carbon output and transport model is obtained by adjusting parameters in a preset dissolved organic carbon output and transport model based on sample hydrological information and gridded soil organic matter content in a sample soil pool.

[0114] In one embodiment of the present application, by coupling a variable infiltration capacity model and a dissolved organic carbon output and migration model, the entire process of "source-flow-sink" of dissolved organic carbon in a preset watershed water body is simulated, and the gridded dissolved organic carbon output, gridded dissolved organic carbon migration path and gridded dissolved organic carbon contribution ratio of the preset watershed within a preset time scale can be obtained, which significantly improves the spatiotemporal resolution and quantitative accuracy of dissolved organic carbon source analysis, and provides technical support for the precise prevention and control of dissolved organic carbon in the watershed.

[0115] It should be noted that the apparatus for analyzing the source of dissolved organic carbon in a watershed provided in the above embodiment and the method for analyzing the source of dissolved organic carbon in a watershed provided in the above embodiment are of the same concept, wherein the specific manner in which each module and unit performs operations has been described in detail in the method embodiment and will not be repeated here. In actual applications, the apparatus for analyzing the source of dissolved organic carbon in a watershed provided in the above embodiment can allocate the above functions to different functional modules as needed, i.e., divide the internal structure of the apparatus into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0116] An embodiment of the present application also provides an electronic device, comprising: one or more processors; a storage device for storing one or more programs, which, when executed by one or more processors, enables the electronic device to implement the method for analyzing the source of dissolved organic carbon in a watershed provided in the above-mentioned embodiments.

[0117] Figure 10 The following is a schematic diagram showing the structure of a computer system suitable for implementing an electronic device according to an embodiment of the present application. Figure 10 The computer system 1000 of the electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0118] like Figure 10 As shown, the computer system 1000 includes a central processing unit (CPU) 1001, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 1002 or the program loaded from the storage part 1008 into the random access memory (RAM) 1003, such as executing the method in the above embodiment. Various programs and data required for system operation are also stored in the RAM 1003. The CPU 1001, ROM 1002 and RAM 1003 are connected to each other via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0119] The following components are connected to the I / O interface 1005: an input section 1006 including a keyboard, a mouse, and the like; an output section 1007 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 1008 including a hard disk and the like; and a communication section 1009 including a network interface card such as a LAN (Local Area Network) card or a modem. The communication section 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to the I / O interface 1005 as needed. Removable media 1011, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 1010 as needed, so that computer programs read therefrom can be installed into the storage section 1008 as needed.

[0120] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 1009, and / or installed from a removable medium 1011. When the computer program is executed by the central processing unit (CPU) 1001, the various functions defined in the system of the present application are executed.

[0121] It should be noted that the computer-readable medium shown in the embodiments of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable computer program. This propagated data signal can take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0122] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. Among them, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0123] The units involved in the embodiments described in this application may be implemented by software or hardware, and the units described may also be set in a processor. In some cases, the names of these units do not constitute limitations on the units themselves.

[0124] Another aspect of the present application provides a computer-readable storage medium having stored thereon computer-readable instructions. When executed by a computer processor, the computer executes the methods for source elucidation of dissolved organic carbon in a watershed as described in the aforementioned embodiments. The computer-readable storage medium may be included in the electronic device described in the aforementioned embodiments, or may exist independently and not be incorporated into the electronic device.

[0125] It should be noted that, although several modules or units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiment of the application, the features and functions of two or more modules or units described above can be concretized in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.

[0126] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the embodiments of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the embodiments of the present application.

[0127] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed herein.

[0128] It should be understood that the above content is only a preferred exemplary embodiment of the present application and is not intended to limit the implementation scheme of the present application. Ordinary technicians in this field can easily make corresponding changes or modifications based on the main concept and spirit of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection required by the claims.

Claims

1. A method for source analysis of dissolved organic carbon in a watershed, characterized in that: The method comprises: Obtain river network data, water flow direction data, and grid model parameters for a preset watershed, as well as grid soil organic matter content in a soil pool. The grid model parameters include: grid soil parameters, grid vegetation parameters, grid vegetation pool parameters, grid snow elevation zone parameters, and grid meteorological driving parameters. Inputting the grid model parameters, the river network data, and the water flow direction data into a variable infiltration capacity model to obtain hydrological information of a preset time scale and grid accuracy within the preset watershed; the variable infiltration capacity model is obtained by adjusting parameters in a preset variable infiltration capacity model based on the sample grid model parameters of the preset watershed; the hydrological information includes: surface runoff, underground runoff, moisture content of each soil layer, and water flow direction; The hydrological information and the gridded soil organic matter content in the soil pool are input into the dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon transport path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale; the dissolved organic carbon output and transport model is obtained by adjusting the parameters in the preset dissolved organic carbon output and transport model based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool.

2. The method for source analysis of dissolved organic carbon in a watershed according to claim 1, characterized in that: If the preset variable infiltration capacity model includes a land surface process unit and a confluence process unit, the process of adjusting the parameters in the preset variable infiltration capacity model based on the sample grid model parameters of the preset watershed to obtain the variable infiltration capacity model includes: Inputting the sample grid model parameters into the land surface process unit to obtain hydrological information of each grid sample within the preset time scale; Obtaining sample river network data and sample water flow direction data, inputting the hydrological information of each grid sample, the sample river network data and the sample water flow direction data into the confluence process unit to obtain simulated flow data of the preset watershed; Setting a mouth section in the preset watershed as a control node, taking a difference between simulated flow data and measured flow data of the control node as a first difference, and determining a first Nash efficiency coefficient based on the first difference; the first Nash efficiency coefficient is negatively correlated with the first difference; and the measured flow data and the simulated flow data belong to the same time scale; If the first Nash efficiency coefficient is greater than or equal to a preset Nash efficiency coefficient threshold, the preset variable infiltration capacity model is used as the variable infiltration capacity model; If the first Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the parameters in the land surface process unit and the parameters in the confluence process unit are adjusted until the first Nash efficiency coefficient determined by the difference between the adjusted simulated flow data and the flow measurement data is greater than or equal to the preset Nash efficiency coefficient threshold, and the combination of the adjusted land surface process unit and the adjusted confluence process unit is used as the variable infiltration capacity model; the adjusted simulated flow data is the simulated flow data of the control node output by the adjusted confluence process unit.

3. The method for source analysis of dissolved organic carbon in a watershed according to claim 1 or 2, characterized in that: Before obtaining the river network data, water flow direction data and grid model parameters of the preset watershed, the method further includes: Obtaining boundary vector data, fishing net vector data, soil parameters, vegetation parameters, vegetation library parameters, snow elevation zone parameters and meteorological driving parameters of the preset watershed; Using a preset grid size as a division unit, discretizing the boundary vector data and the fishing net vector data to obtain a plurality of grid units, and using each grid unit as a basic calculation unit of the variable infiltration capacity model; Performing spatial interpolation calculation on the soil parameters to obtain soil parameters of each basic calculation unit, and using the soil parameters of all basic calculation units as the gridded soil parameters; Performing spatial interpolation calculation on the vegetation parameters to obtain vegetation parameters of each basic calculation unit, and using the vegetation parameters of all basic calculation units as the gridded vegetation parameters; Performing spatial interpolation calculation on the vegetation library parameters to obtain vegetation library parameters of each basic calculation unit, and using the vegetation library parameters of all basic calculation units as the gridded vegetation library parameters; Performing spatial interpolation calculation on the snow elevation band parameters to obtain the snow elevation band parameters of each basic calculation unit, and using the snow elevation band parameters of all basic calculation units as the gridded snow elevation band parameters; Performing spatial interpolation calculation on the meteorological driving parameters to obtain meteorological driving parameters of each basic calculation unit, and using the meteorological driving parameters of all basic calculation units as the gridded meteorological driving parameters; Furthermore, the river network data and the water flow direction data are extracted from the digital elevation data of a preset resolution.

4. The method for source analysis of dissolved organic carbon in a watershed according to claim 1, wherein: Based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool, the parameters of the preset dissolved organic carbon output and transport model are adjusted to obtain the dissolved organic carbon output and transport model. The process includes: Obtain the gridded dissolved organic carbon concentration, the gridded dissolved organic carbon concentration soil adsorption coefficient, the gridded sample soil heterotrophic respiration, the gridded dissolved organic carbon total amount, and the gridded soil aqueous solution temperature in the sample soil aqueous solution; and obtain the water content of each layer of the sample soil, the sample surface runoff, and the sample underground runoff from the sample hydrological information; the gridded dissolved organic carbon concentration in the sample soil aqueous solution is determined by the preset soil organic carbon ratio in the soil organic matter, the preset dissolved organic carbon ratio in the soil organic carbon, the water content of each layer of the sample soil, the gridded soil organic matter content in the sample soil pool, and the grid area; the gridded dissolved organic carbon concentration soil adsorption coefficient is determined by the gridded dissolved organic carbon concentration in the sample soil, the adsorption affinity of the gridded sample soil and the dissolved organic carbon, and the desorption parameter of the gridded sample soil and the dissolved organic carbon; the gridded sample soil heterotrophic respiration is determined by the preset gridded sample soil heterotrophic respiration rate, the preset gridded sample soil heterotrophic respiration temperature sensitivity, and the gridded soil temperature; Calculating the dissolved organic carbon output driven by surface runoff in each grid based on the sample surface runoff, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration, and the gridded dissolved organic carbon concentration soil adsorption coefficient; Calculating the dissolved organic carbon output driven by underground runoff in each grid based on the sample underground runoff, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration, and the gridded dissolved organic carbon concentration soil adsorption coefficient; Determine the dissolved organic carbon output of each grid based on the dissolved organic carbon output driven by surface runoff and the dissolved organic carbon output driven by subsurface runoff in each grid; Determining an inter-grid dissolved organic carbon attenuation based on the water flow direction, the position of each grid in the water flow direction, a preset gridded dissolved organic carbon degradation rate, a preset gridded decomposition stability sensitivity coefficient of dissolved organic carbon in a preset watershed water body, the gridded soil aqueous solution temperature, and the gridded total dissolved organic carbon amount; Determining the dissolved organic carbon migration amount between grids based on the water flow direction, the position of each grid in the water flow direction, the dissolved organic carbon output, and the dissolved organic carbon attenuation, and determining the gridded dissolved organic carbon migration path according to the dissolved organic carbon migration amount between grids; Determine the simulated flux of the sampling point based on the water flow direction, the dissolved organic carbon attenuation between grids, and the dissolved organic carbon migration between grids; determine the gridded dissolved organic carbon contribution ratio based on the simulated flux and the dissolved organic carbon migration between grids; the simulated flux is used to characterize the dissolved organic carbon accumulation at the sampling point; taking a difference between the simulated flux and a measured amount of dissolved organic carbon at the sampling point as a second difference, and determining a second Nash efficiency coefficient based on the second difference; the second Nash efficiency coefficient is negatively correlated with the second difference; the measured amount of dissolved organic carbon and the simulated flux belong to the same time scale; If the second Nash efficiency coefficient is greater than or equal to the preset Nash efficiency coefficient threshold, the preset dissolved organic carbon output migration model is used as the dissolved organic carbon output migration model; If the second Nash efficiency coefficient is less than the preset Nash efficiency coefficient threshold, the parameters in the preset dissolved organic carbon output transport model are adjusted until the second Nash efficiency coefficient determined by the difference between the adjusted simulated flux and the dissolved organic carbon measurement is greater than or equal to the preset Nash efficiency coefficient threshold, and the adjusted dissolved organic matter output transport model is used as the dissolved organic carbon output transport model; the adjusted simulated flux is the dissolved organic carbon accumulation at the sampling point output by the adjusted dissolved organic matter output transport model.

5. The method for source analysis of dissolved organic carbon in a watershed according to claim 4, characterized in that: The process of calculating the dissolved organic carbon output driven by surface runoff in each grid based on the surface runoff, the gridded dissolved organic carbon concentration in the sample soil aqueous solution, the gridded sample soil heterotrophic respiration, and the gridded dissolved organic carbon concentration soil adsorption coefficient includes: The calculation formula for the output of dissolved organic carbon driven by surface runoff in each grid is as follows: DOC runoff,i =[DOC] i ×K absorb,i ×Q surf,i -SR i , Among them, DOC runoff,i represents the output of dissolved organic carbon driven by surface runoff in the i-th grid, [DOC] i represents the dissolved organic carbon concentration in the i-th grid of the sample soil aqueous solution. The dissolved organic carbon concentrations in all grids of the sample soil aqueous solution constitute the gridded dissolved organic carbon concentration in the sample soil aqueous solution. K absorb,i It represents the soil adsorption coefficient of dissolved organic carbon concentration in the i-th grid. The soil adsorption coefficients of dissolved organic carbon concentration in all grids constitute the gridded soil adsorption coefficient of dissolved organic carbon concentration. Q surf,i represents the sample surface runoff of the i-th grid, SR i It represents the heterotrophic respiration of the sample soil in the i-th grid, and the heterotrophic respiration of the sample soil in all grids constitutes the gridded sample soil heterotrophic respiration.

6. The method for source analysis of dissolved organic carbon in a watershed according to claim 4, characterized in that: The process of determining the amount of dissolved organic carbon attenuation between grids based on the water flow direction, the position of each grid in the water flow direction, a preset grid-based dissolved organic carbon degradation rate, a preset grid-based decomposition stability sensitivity coefficient of dissolved organic carbon in a preset watershed water body, the grid-based soil aqueous solution temperature, and the grid-based total amount of dissolved organic carbon includes: Get the position of the current grid in the direction of the water flow; If the current grid is the starting grid in the water flow direction, the dissolved organic carbon attenuation between the starting grid and the next grid is set as the preset attenuation; If the current grid is an intermediate grid in the water flow direction, then calculating the dissolved organic carbon attenuation between the intermediate grid and the next grid based on the preset gridded dissolved organic carbon degradation rate, the preset gridded decomposition stability sensitivity coefficient, the gridded soil aqueous solution temperature, and the gridded total dissolved organic carbon amount; The calculation formula for the dissolved organic carbon attenuation between the intermediate grid and the next grid includes: Among them, DOC i,j represents the attenuation of dissolved organic carbon between the i-th grid and the j-th grid, SR w,i represents the dissolved organic carbon degradation rate of the i-th grid. The dissolved organic carbon degradation rates of all grids constitute the preset gridded dissolved organic carbon degradation rate. Q 10w,i Represents the decomposed stable sensitivity coefficient of the i-th grid, and the decomposed stable sensitivity coefficients of all grids constitute the preset gridded decomposed stable sensitivity coefficient, T i represents the soil water solution temperature of the ith grid. The soil water solution temperature of all grids constitutes the gridded soil water solution temperature. Tw represents the reference value of soil absorption. SDOC i represents the total dissolved organic carbon of the i-th grid, and the total dissolved organic carbon of all grids constitutes the gridded total dissolved organic carbon.

7. The method for source analysis of dissolved organic carbon in a watershed according to claim 6, characterized in that: The process of determining the amount of dissolved organic carbon migration between grids based on the water flow direction, the position of each grid in the water flow direction, the dissolved organic carbon output, and the dissolved organic carbon attenuation includes: If the current grid is the starting grid in the water flow direction, determining the dissolved organic carbon migration amount between the starting grid and the next grid based on the dissolved organic carbon output of the starting grid, the output ratio of the starting grid, and the preset attenuation; If the current grid is the middle grid in the water flow direction, the dissolved organic carbon migration amount between the middle grid and the next grid is calculated based on the dissolved organic carbon migration amount between the previous grid and the middle grid and the dissolved organic carbon attenuation amount between the middle grid and the next grid.

8. A device for analyzing the source of dissolved organic carbon in a watershed, characterized in that: include: A data acquisition module is used to obtain river network data, water flow direction data, and grid model parameters of a preset watershed, as well as grid soil organic matter content in a soil pool. The grid model parameters include: grid soil parameters, grid vegetation parameters, grid vegetation pool parameters, grid snow elevation zone parameters, and grid meteorological driving parameters. a hydrological information output module, configured to input the gridding model parameters, the river network data, and the water flow direction data into a variable infiltration capacity model to obtain hydrological information of a preset time scale and gridding accuracy within the preset watershed; the variable infiltration capacity model is obtained by adjusting parameters in a preset variable infiltration capacity model based on the sample gridding model parameters of the preset watershed; the hydrological information includes: surface runoff, groundwater runoff, moisture content of each soil layer, and water flow direction; The result output module is used to input the hydrological information and the gridded soil organic matter content in the soil pool into the dissolved organic carbon output and transport model to obtain the gridded dissolved organic carbon output, gridded dissolved organic carbon transport path and gridded dissolved organic carbon contribution ratio of the preset watershed within the preset time scale; the dissolved organic carbon output and transport model is obtained by adjusting the parameters in the preset dissolved organic carbon output and transport model based on the sample hydrological information and the gridded soil organic matter content in the sample soil pool.

9. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the method for analyzing the source of dissolved organic carbon in a watershed as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the method for source analysis of dissolved organic carbon in a watershed provided in any one of claims 1 to 7.

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