A method and system for constructing permeability coefficient of soil aquifer system

Abstract

The present application belongs to the field of groundwater science and engineering technology, and specifically relates to a method and system for constructing the permeability coefficient of a soil aquifer system. The method includes the following steps: obtaining basic data; setting spatial resolution, unifying the basic data to the spatial resolution; dividing the underground part of the soil aquifer system in the selected area into soil layers and aquifers from top to bottom; calculating the slope of each surface grid in the longitudinal and latitudinal directions, and obtaining the initial aquifer permeability coefficient; calculating the final soil layer permeability coefficient; calculating the final aquifer permeability coefficient; forming a data set of spatial heterogeneity of the permeability coefficient of the soil aquifer system in the selected area. The method and system for constructing the permeability coefficient of a soil aquifer system of the present application have relatively low data requirements and can be applied to areas with little / no observation data. In addition, the permeability coefficient adjustment and optimization part is simple to calculate, which reduces errors and uncertainties in numerical calculations.

Description

Technical Field

[0001] The present application belongs to the field of hydrogeophysical technology, and specifically relates to a method and system for constructing a permeability coefficient of a soil aquifer system. Background Art

[0002] Permeability is an important parameter to describe the heterogeneity of the soil-aquifer system (or soil aquifer system). The heterogeneity of permeability in the soil-aquifer system has a significant impact on the groundwater flow system and is one of the most important parameters in the simulation of groundwater flow and solute transport. At the regional and basin scales, the heterogeneity of permeability in the soil-aquifer system not only directly controls the groundwater level and shallow soil moisture distribution, but also indirectly affects the surface radiation budget and energy conversion between the ground and the atmosphere. The interaction and feedback between the ground and the atmosphere can affect or even change the climate change response mechanism, causing extreme drought and flood events. In addition, human agricultural activities have made the regional hydrological cycle more complex, which may further amplify the impact of spatial heterogeneity of permeability on surface water heat flux and temperature. Therefore, characterizing the information of three-dimensional hydraulic parameters such as permeability through prior information is of great importance in the simulation and prediction of groundwater flow and solute transport; quantitatively obtaining the influence of permeability heterogeneity of soil-aquifer system on the momentum, moisture and heat exchange between the surface and the atmosphere is particularly important. Understanding and accurately describing the influence of permeability heterogeneity on the law of water and heat exchange between the ground and the atmosphere and its role in the transmission process has important practical significance for disciplines such as agriculture, forestry, hydrology, water resources management, and climate change.

[0003] However, the characterization of the spatial heterogeneity of the permeability coefficient of the soil-aquifer system requires a large amount of hydrogeological data. Due to economic and technical reasons, the observation data of permeability coefficient is severely scarce, so the spatial distribution law of aquifer permeability coefficient is difficult to be quantified quickly and accurately. Although traditional monitoring methods and pumping experiments can provide hydraulic characteristics of shallow aquifers, they are very expensive and can only obtain limited point data. In contrast, geophysical detection methods such as electromagnetic and resistivity methods and seismic tomography have a high coverage density, can quickly obtain hydraulic parameters in local space, and are relatively low in cost, but such methods are difficult to obtain the spatial distribution of permeability coefficient of the soil-aquifer system in the entire basin.

[0004] At present, the impact of soil and aquifer spatial heterogeneity on groundwater-surface water interaction is mainly limited to theoretical research under conceptual models, and most of them are based on the premise that spatial heterogeneity has structural characteristics, that is, it is assumed that the permeability coefficient has a regular and definite functional distribution in space. Therefore, it is of great practical significance to invent a low-cost and easy-to-operate parameterization scheme for the spatial heterogeneity of permeability coefficients in soil-aquifer systems. Summary of the invention

[0005] In order to solve at least one technical problem existing in the prior art, the present application provides a method and system for constructing a soil aquifer system permeability coefficient.

[0006] In a first aspect, the present application discloses a method for constructing a soil aquifer system permeability coefficient, comprising the following steps:

[0007] Step S101, acquiring basic data, wherein the basic data at least includes digital elevation model data, vector river data, soil hydraulic parameter data set, and aquifer hydraulic parameter data set, wherein the digital elevation model data includes the altitude, slope, and aspect data of the surface grid;

[0008] Step S102, setting the spatial resolution, and using a bilinear interpolation resampling method to unify the basic data to the spatial resolution;

[0009] Step S103: Divide the underground part of the soil aquifer system in the selected area into a soil layer and an aquifer from top to bottom according to the characteristics of the selected area;

[0010] Step S104, calculating the slope of each surface grid in the longitudinal and latitudinal directions based on the digital elevation model data, and obtaining the initial aquifer permeability coefficient;

[0011] Step S105, calculating the final soil layer permeability coefficient according to the soil hydraulic parameter data set;

[0012] Step S106, calculating the final aquifer permeability coefficient according to the aquifer hydraulic parameter data set;

[0013] Step S107: forming a data set of spatial heterogeneity of soil aquifer system permeability coefficient in the selected area according to the final soil layer permeability coefficient and the final aquifer permeability coefficient.

[0014] Optionally, in step S102, the step of unifying the vector river data in the basic data to the spatial resolution includes:

[0015] The vector river data is rasterized, and then the river network data obtained after rasterization is unified to the spatial resolution.

[0016] Optionally, in step S103, the soil layer and the aquifer may be divided into multiple layers.

[0017] Optionally, in step S104, the PriorityFlow hydrological algorithm tool is used to process the resampled digital elevation model data and the river network data obtained after rasterization and resampling.

[0018] Optionally, in step S106, the final aquifer permeability coefficient is calculated by the following formula:

[0019]

[0020] Among them, parameters a and b are constants, e is the base of the natural logarithm function, f is called the folding function, Sx and Sy are the slopes in the longitudinal and latitudinal directions calculated in step S104, respectively. K 0 is the initial aquifer permeability coefficient obtained in S104, z is the vertical height, K is the final aquifer permeability.

[0021] Optionally, in step S107, the final soil layer permeability coefficient is merged with the final aquifer permeability coefficient to form a data set of spatial heterogeneity of permeability coefficient of soil aquifer system in the selected area.

[0022] In a second aspect, the present application also discloses a soil aquifer system permeability coefficient construction system, comprising:

[0023] A data acquisition module, used to acquire basic data, the basic data at least including digital elevation model data, vector river data, soil hydraulic parameter data set, aquifer hydraulic parameter data set, wherein the digital elevation model data includes the altitude, slope, and aspect data of the surface grid;

[0024] A data processing module, used for setting the spatial resolution and unifying the basic data to the spatial resolution by using a bilinear interpolation resampling method;

[0025] A structural division module, used for dividing the underground part of the soil aquifer system of the selected area into soil layers and aquifers from top to bottom according to the characteristics of the selected area;

[0026] A slope calculation module, used to calculate the slope of each surface grid in the longitudinal and latitudinal directions based on the digital elevation model data, and obtain the initial aquifer permeability coefficient;

[0027] A soil layer permeability calculation module, used to calculate the final soil layer permeability according to the soil hydraulic parameter data set;

[0028] an aquifer permeability calculation module, used for calculating a final aquifer permeability according to the aquifer hydraulic parameter data set;

[0029] The data set aggregation module is used to form a data set of spatial heterogeneity of soil aquifer system permeability coefficient in the selected area according to the final soil layer permeability coefficient and the final aquifer permeability coefficient.

[0030] Optionally, the data processing module unifies the vector river data in the basic data to the spatial resolution, specifically comprising:

[0031] The vector river data is rasterized, and then the river network data obtained after rasterization is unified to the spatial resolution.

[0032] Optionally, the soil layer and aquifer divided by the structural division module may be divided into multiple layers; and

[0033] The aquifer permeability calculation module calculates the final aquifer permeability by the following formula:

[0034]

[0035] Among them, parameters a and b are constants, e is the base of the natural logarithm function, f is called the folding function, Sx and Sy are the slopes in the longitudinal and latitudinal directions calculated in step S104, respectively. K 0 is the initial aquifer permeability coefficient obtained in S104, z is the vertical height, K is the final aquifer permeability.

[0036] Optionally, the data set aggregation module merges the final soil layer permeability coefficient with the final aquifer permeability coefficient to form a data set of spatial heterogeneity of permeability coefficient of soil aquifer system in the selected area.

[0037] This application has at least the following beneficial technical effects:

[0038] (1) The soil aquifer system permeability coefficient construction method and construction system of this application have relatively low data requirements and can be applied to areas with little or no observation data, and have a certain degree of universality;

[0039] (2) In the soil aquifer system permeability coefficient construction method and construction system of the present application, the permeability coefficient adjustment optimization part is simple to calculate, which reduces the error and uncertainty in the numerical calculation;

[0040] (3) The soil aquifer system permeability construction method and construction system of this application are universal and applicable to most basins / regions in the world, and can be used as a parameterization scheme for a variety of hydrological integrated models;

[0041] (4) In the soil aquifer system permeability coefficient construction method and construction system of the present application, the obtained two-dimensional permeability coefficient spatial distribution can provide more detailed permeability coefficient parameterization scheme support for refined surface water-groundwater integrated modeling or groundwater-land surface process integrated modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of a method for constructing a permeability coefficient of a soil aquifer system of the present application;

[0043] Figure 2 It is a composition diagram of the system for constructing the permeability coefficient of the soil aquifer system of the present application;

[0044] Figure 3 It is a spatial distribution scheme of the permeability coefficient of a soil aquifer system constructed in a specific embodiment of the method and system for constructing the permeability coefficient of a soil aquifer system of the present application;

[0045] In the figure:

[0046] a is the spatial distribution of the unified permeability of the first soil layer (0 ~ 0.05 m); b is the spatial distribution of the unified permeability of the second soil layer (0.05m ~ 0.15 m); c is the spatial distribution of the unified permeability of the third soil layer (0.15 m ~ 0.30 m); d is the spatial distribution of the unified permeability of the fourth soil layer (0.30 m ~ 0.60 m); e is the spatial distribution of the unified permeability of the fifth soil layer (0.60 m ~ 1.00 m); f is the spatial distribution of the unified permeability of the sixth soil layer (1.00 m ~ 2.00 m); g is the spatial distribution of the unified permeability of the aquifer before correction; h is the spatial distribution of the unified permeability of the aquifer after correction. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0048] First, as Figure 1 As shown, the present application discloses a method for constructing a soil aquifer system permeability coefficient, comprising the following steps:

[0049] Step S101, obtaining basic data, which is the original basic data required for constructing a solution for the spatial heterogeneity of permeability coefficient of a soil aquifer system, and includes at least digital elevation model data, vector river data, soil hydraulic parameter data set, and aquifer hydraulic parameter data set.

[0050] Among them, the digital elevation model is a physical ground model that represents the ground elevation in the form of a set of ordered numerical arrays. Its data includes the altitude, slope, and aspect data of the surface grid. The acquisition methods are: photogrammetry, ground measurement, digitization of existing topographic maps, and extraction from existing DEM libraries.

[0051] Vector river data is a physical river model that uses a set of ordered numerical arrays to represent the river's morphology and characteristics, including river flow direction and river slope change rate data; it is obtained through remote sensing image interpretation, GPS measurement, ground survey, digitization of existing water system maps, and algorithm extraction from existing DEM libraries.

[0052] Soil hydraulic parameters refer to a set of key parameters that describe the characteristics of soil water movement, mainly including soil permeability coefficient, porosity, soil bulk density, soil texture, soil moisture content, water layer thickness, field water holding capacity, saturated water holding capacity, wilting coefficient, etc.; they are obtained by: sampling experiment method, in-situ instrument observation method, model method, digitization of existing hydraulic parameter maps, and extraction from existing soil hydraulic parameter database.

[0053] Aquifer hydraulic parameters refer to a set of key parameters that describe the water movement characteristics in aquifers, mainly including permeability coefficient, porosity, water supply degree, water storage coefficient, and water storage rate; they are obtained through sampling experiments, in-situ instrument observations, modeling, digitization of existing hydraulic parameter maps, and extraction from existing aquifer hydraulic parameter libraries.

[0054] Step S102, setting the spatial resolution, using a bilinear interpolation resampling method to unify the digital elevation model data, vector river data, soil hydraulic parameter data set, and aquifer hydraulic parameter data set to the spatial resolution.

[0055] Among them, spatial resolution refers to the minimum ground area that can be identified in the model or on the remote sensing image, which reflects the ability of the model or remote sensing method to capture surface details. The higher the spatial resolution, the clearer the surface details displayed on the remote sensing image, and vice versa. For example, in the fields of environmental monitoring and assessment, disaster monitoring and emergency response, it is necessary to build a model with a kilometer resolution level to achieve relevant application goals.

[0056] In addition, for the vector river data, the vector river data is first rasterized, and then the river network data obtained after rasterization is unified to the spatial resolution.

[0057] Step S103: According to the characteristics of the selected area, the underground part of the soil aquifer system in the selected area is divided into soil layers and aquifers from top to bottom, wherein the soil layers and aquifers can be divided into multiple layers as needed.

[0058] Among them, the selected regional characteristics may include the regional terrain change trend, water resource self-production capacity change trend, evaporation potential change trend, groundwater recharge and storage conditions change trend and other characteristics. In addition, for example, as is well known to those skilled in the art, in arid areas, the vertical stratification of inland river soil aquifer systems is obvious.

[0059] Step S104: Based on the digital elevation model data obtained in step S101, the slope of each surface grid in the digital elevation model in the longitudinal and latitudinal directions is calculated, and the initial aquifer permeability coefficient is obtained.

[0060] Among them, in order to ensure the complete connectivity of the surface river network, hydrological algorithm tools such as PriorityFlow (PriorityFlow is a toolkit for hydrological model terrain processing, jointly developed by Princeton University and Colorado School of Mines in the United States) can be considered to process the resampled digital elevation model data and the river network data obtained after rasterization and resampling.

[0061] Step S105: Calculate the final soil layer permeability coefficient according to the soil hydraulic parameter data set and Darcy's law.

[0062] Step S106: Calculate the final aquifer permeability coefficient based on the aquifer hydraulic parameter data set.

[0063] Specifically, in this step, the final aquifer permeability coefficient is calculated by the following formula:

[0064]

[0065] Among them, parameters a and b are constants; e is the base of the natural logarithm function, and its value is approximately 2.718; Sx and Sy are the slopes in the longitudinal and latitudinal directions calculated in step S104, respectively. K 0 is the initial aquifer permeability coefficient obtained in S104, z is the vertical height, K This is the calculation result of the final aquifer permeability coefficient.

[0066] Step S107: Based on the final soil layer permeability coefficient and the final aquifer permeability coefficient, a data set of spatial heterogeneity of permeability coefficient of the soil aquifer system in the selected area is formed.

[0067] Specifically, in this step, the final soil layer permeability coefficient and the final aquifer permeability coefficient are merged to form a data set of spatial heterogeneity of permeability coefficient of soil aquifer system in the selected area.

[0068] Second, as Figure 2 As shown, the present application also discloses a soil aquifer system permeability coefficient construction system, which may include a data acquisition module 201, a data processing module 202, a structure division module 203, a slope calculation module 204, a soil layer permeability coefficient calculation module 205, an aquifer permeability coefficient calculation module 206 and a data set aggregation module 207.

[0069] Among them, the data acquisition module 201 is used to obtain basic data, which is the original basic data required for the construction scheme of the spatial heterogeneity of the permeability coefficient of the soil aquifer system. For details, please refer to the basic data in step 101 of the construction method of the first aspect above.

[0070] The data processing module 202 is used to set the spatial resolution and unify the digital elevation model data, vector river data, soil hydraulic parameter data set, and aquifer hydraulic parameter data set to the spatial resolution. Similar to step 102 in the construction method of the first aspect, the data processing module 202 here first rasterizes the vector river data, and then unifies the river network data obtained after rasterization to the spatial resolution.

[0071] The structural division module 203 is used to divide the underground part of the soil aquifer system of the selected area into soil layers and aquifers from top to bottom according to the characteristics of the selected area. Similarly, the divided soil layers and aquifers can be divided into multiple layers.

[0072] The slope calculation module 204 is used to calculate the slope of each surface grid in the longitudinal and latitudinal directions based on the digital elevation model data, and obtain the initial aquifer permeability coefficient; similarly, in order to ensure the complete connectivity of the surface river network, hydrological algorithm tools such as PriorityFlow can be considered to process the terrain data (i.e., the resampled digital elevation model data) and river network data.

[0073] The soil layer permeability calculation module 205 is used to calculate the final soil layer permeability according to the soil hydraulic parameter data set.

[0074] The aquifer permeability calculation module 206 is used to calculate the final aquifer permeability according to the aquifer hydraulic parameter data set, and the specific calculation method is the same as the calculation method in step 106 in the construction method of the first aspect mentioned above.

[0075] The data set summary module 207 is used to form a data set of spatial heterogeneity of soil aquifer system permeability coefficient in the selected area based on the final soil layer permeability coefficient and the final aquifer permeability coefficient; specifically, the data set summary module 207 merges the final soil layer permeability coefficient with the final aquifer permeability coefficient to form a data set of spatial heterogeneity of soil aquifer system permeability coefficient in the selected area.

[0076] The soil aquifer system permeability coefficient construction method and construction system of the present application will be further described below through a specific example:

[0077] Example 1

[0078] The selected area in this embodiment is the Heihe River Basin in China. Among them, the calculation area of ​​the ParFlow-CLM model in the Heihe River Basin ranges from 97° to 102°E, 37.7° to 42.7°N. In terms of landform types, the mountainous area in the calculation area accounts for about 30%, the oasis area accounts for about 10%, and the desert area accounts for about 60%. In general, the terrain gradually decreases from south to north, the self-production capacity of water resources decreases from large to small, the evaporation potential increases from small to large, and the groundwater recharge and storage conditions gradually weaken, resulting in significant zoning of water resources, environmental ecology and socio-economic functions.

[0079] The southern boundary is the Qilian Mountains. Due to the existence of the Mesozoic and Cenozoic fold belt at the foot of the Qilian Mountains and the water-blocking effect of the highly mylonitic fault on the northern edge, the lateral runoff recharge of groundwater in the Qilian Mountains on the southern boundary is small; the western boundary is the Daxue Mountain-Mazong Mountain (Northern Mountain), where the bottom impermeable bedrock provides hydrogeological isolation. In most areas, the isowater level line intersects the mountain body approximately vertically, indicating that the number of lateral recharge corridor plains in the western border mountainous area is also very limited; the eastern boundary runs through the Badain Jaran Desert, and the northern boundary is the China-Mongolia border desert area, where the lateral groundwater flow can be ignored. Therefore, the proportion of lateral recharge and discharge (excluding valley underflow) on the boundary of the calculation area is very small and can be ignored.

[0080] The temporal and spatial distribution of surface water in the Heihe River Basin mainly depends on the temporal and spatial distribution of atmospheric precipitation and snowmelt in the Qilian Mountains, as well as the vertical zonation of hydrological meteorology, slope and aspect, and underlying surface conditions in the Qilian Mountains. The upper mountainous area is a surface runoff formation area. The river runoff is affected by precipitation, snowmelt, and surface vegetation coverage. The runoff is unevenly distributed throughout the year, with large interannual variations, but the amplitude is smaller than that of a single precipitation recharge type. The middle corridor plain area is a runoff utilization area, with the altitude gradually decreasing from south to north. The downstream tail lake section is a runoff dissipation area. In general, the annual distribution of surface runoff in the calculation area is basically the same as the precipitation process and high temperature season. The runoff and precipitation are concentrated in the warm season. The spring is mainly recharged by snowmelt and groundwater, and the summer and autumn are mainly recharged by precipitation. It has the characteristics of spring flood, summer flood, autumn flat, and winter dry.

[0081] In addition, the groundwater system in the Heihe River Basin presents certain water circulation characteristics due to the influence of altitude gradient and landform type. The main rivers in the upper reaches generally cut deep into the mountains. Before leaving the mountain mouth, the groundwater, except for the valley underflow, is almost all discharged into the main river and becomes the base flow of the river. The basin in the middle reaches of the oasis area is a typical piedmont groundwater flow system, with a distribution range from the piedmont to the overflow zone at the front edge of the alluvial fan skirt. The aquifer distribution is first dominated by a single thick phreatic aquifer, and the sediment lithology is mainly pebbles and gravels, with extremely strong water conductivity and good conditions for receiving river infiltration recharge. It is the main recharge area for groundwater in the basin.

[0082] The groundwater basin in the downstream desert area has a small topographic gradient, and Quaternary pore water is widely distributed in the area. From south to north, the aquifer particles gradually become finer, the groundwater level gradually becomes shallower, and the aquifer gradually transitions from a phreatic aquifer to a double-layer or multi-layer structured confined aquifer.

[0083] Therefore, in this example, the specific steps of the method for constructing the permeability coefficient of the soil aquifer system in the Heihe River Basin are described as follows:

[0084] In step S101, the digital elevation model data of the Heihe River Basin is the "30m ASTER-GDEM Dataset (2018) in the Qilian Mountains" provided by the National Tibetan Plateau Data Center. This data is based on the ASTER-GDEM data. By downloading, preprocessing, splicing and optimizing the original data, a 30m×30m digital elevation model dataset in the Qilian Mountains is generated. The accuracy and completeness are better than the original data.

[0085] The vector river data is the "MERIT Hydrological Dataset" provided by the MERIT Hydro Hydrological Group of the Industrial Science Research Institute of the University of Tokyo, Japan. Based on the MERIT DEM elevation data and the G1WBM surface water dataset, an algorithm for automatically extracting river networks, MERIT Hydro, was developed to obtain global river vector data maps. Satellite images have verified that the accuracy is very high (90% of the basin errors are within 0.05), especially the accuracy of the river channel positions in the inland river basins of this dataset is high, which is suitable for integrated hydrological modeling of various inland rivers.

[0086] The soil hydraulic parameter dataset is the “Chinese soil dataset for land surface simulation” provided by Sun Yat-sen University, which is constructed based on 8595 soil profiles in the “1:1 million national soil map of the second national soil census”; the aquifer hydraulic parameter dataset is the “Global Aquifer Permeability and Porosity Dataset” GLHYMPS (GLobal HYdrogeology MaPS of permeability and porosity) provided by the Department of Civil Engineering of the University of Victoria, Canada, which can be obtained in the Canadian Borealis shared database.

[0087] In step S102, the spatial resolution is set to 1 km, and the basic data are unified to the spatial resolution using a bilinear interpolation resampling method.

[0088] In step S103, based on the above analysis of the regional characteristics of the Heihe River Basin, the entire soil aquifer system can be generalized into a continuous soil aquifer system with horizontal heterogeneity.

[0089] Thus, we can obtain Figure 3As shown, the total thickness of soil and aquifer is 102 m, divided into 7 layers. The soil layer is divided into 6 layers, which is consistent with the SoilGrids vertical stratification scheme in GSDE, that is, the parameterization scheme of SoilGrids depth distribution is used vertically (0 ~ 0.05 m, 0.05 m ~ 0.15 m, 0.15 m ~ 0.30 m, 0.30 m ~ 0.60 m, 0.60 m ~1.00 m, 1.00 m ~ 2.00 m). The aquifer is 1 layer (i.e. 100 m).

[0090] In step S104, the slope of each surface grid in the longitudinal direction (slopex) and the latitudinal direction (slopey) is calculated based on the digital elevation model data; in addition, after the soil hydraulic parameter data set in the above step S101 is digitized and quality controlled, the initial aquifer permeability coefficient can be obtained.

[0091] In step S105, the final soil layer permeability coefficient is calculated according to the soil hydraulic parameter data set and Darcy's law.

[0092] Specifically, this step can be calculated in a variety of currently mature software, such as MATLAB software. The core processing code of the MATLAB calculation method is: .

[0093] In step S106, the final aquifer permeability coefficient is calculated based on the aquifer hydraulic parameter data set. Similarly, this step can be performed in MATLAB software, and according to the parameterization scheme of the Heihe River Basin, α=20 and b=125 are set.

[0094] Among them, the MATLAB calculation core processing code is:

[0095]

[0096] In step S107, a data set of spatial heterogeneity of permeability coefficient of soil aquifer system in the Heihe River Basin is formed according to the final soil layer permeability coefficient and the final aquifer permeability coefficient, with a total thickness of 102 m, including 6 soil layers and 1 aquifer layer, for a total of 7 layers.

[0097] The geological data set is limited by the resolution, refinement, authenticity of the data source, lack of verification data, and some political boundaries and human factors. Therefore, due to the lack of hydraulic parameters with spatial distribution in the underground, this is the best parameterization scheme at present.

[0098] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for constructing a soil aquifer system permeability coefficient, characterized in that: The steps include: Step S101, acquiring basic data, wherein the basic data at least includes digital elevation model data, vector river data, soil hydraulic parameter data set, and aquifer hydraulic parameter data set, wherein the digital elevation model data includes the altitude, slope, and aspect data of the surface grid; Step S102, setting the spatial resolution, and using a bilinear interpolation resampling method to unify the basic data to the spatial resolution; Step S103, dividing the underground part of the soil aquifer system in the selected area into a soil layer and an aquifer from top to bottom according to the characteristics of the selected area; Step S104, calculating the slope of each surface grid in the longitudinal and latitudinal directions based on the digital elevation model data, and obtaining the initial aquifer permeability coefficient; Step S105, calculating the final soil layer permeability coefficient according to the soil hydraulic parameter data set; Step S106: Calculate the final aquifer permeability coefficient based on the aquifer hydraulic parameter data set. Specifically, the final aquifer permeability coefficient is calculated using the following formula: Wherein, parameters a and b are constants, e is the base of the natural logarithm function, f is called the folding function, Sx and Sy are the slopes in the longitudinal and latitudinal directions calculated in step S104, K0 is the initial aquifer permeability coefficient obtained in step S104, z is the vertical height, and K is the final aquifer permeability coefficient; Step S107: forming a data set of spatial heterogeneity of soil aquifer system permeability coefficient in the selected area according to the final soil layer permeability coefficient and the final aquifer permeability coefficient.

2. The construction method according to claim 1, characterized in that: In step S102, the step of unifying the vector river data in the basic data to the spatial resolution includes: The vector river data is rasterized, and then the river network data obtained after rasterization is unified to the spatial resolution.

3. The construction method according to claim 1, characterized in that: In the step S103, the soil layer and the aquifer may be divided into multiple layers.

4. The construction method according to claim 2, characterized in that: In step S104, the PriorityFlow hydrological algorithm tool is used to process the resampled digital elevation model data and the river network data obtained after rasterization and resampling.

5. The construction method according to claim 1, characterized in that: In step S107, the final soil layer permeability coefficient and the final aquifer permeability coefficient are merged to form a data set of spatial heterogeneity of permeability coefficient of soil aquifer system in the selected area.

6. A soil aquifer system permeability coefficient construction system, characterized in that: include: A data acquisition module (201) is used to acquire basic data, wherein the basic data at least includes digital elevation model data, vector river data, soil hydraulic parameter data set, and aquifer hydraulic parameter data set, wherein the digital elevation model data includes the altitude, slope, and aspect data of the surface grid; A data processing module (202) is used to set a spatial resolution and unify the basic data to the spatial resolution using a bilinear interpolation resampling method; A structure division module (203) is used to divide the underground part of the soil aquifer system of the selected area into soil layers and aquifers from top to bottom according to the characteristics of the selected area; A slope calculation module (204) is used to calculate the slope of each surface grid in the longitudinal and latitudinal directions based on the digital elevation model data, and obtain the initial aquifer permeability coefficient; A soil layer permeability calculation module (205), used to calculate a final soil layer permeability according to the soil hydraulic parameter data set; The aquifer permeability calculation module (206) is used to calculate the final aquifer permeability according to the aquifer hydraulic parameter data set. Specifically, the final aquifer permeability is calculated by the following formula: Wherein, parameters a and b are constants, e is the base of the natural logarithm function, f is called the folding function, Sx and Sy are the slopes in the longitudinal and latitudinal directions calculated in step S104, K0 is the initial aquifer permeability coefficient obtained in step S104, z is the vertical height, and K is the final aquifer permeability coefficient; The data set aggregation module (207) is used to form a data set of spatial heterogeneity of soil aquifer system permeability coefficient in the selected area based on the final soil layer permeability coefficient and the final aquifer permeability coefficient.

7. The construction system according to claim 6, characterized in that: The data processing module (202) unifies the vector river data in the basic data to the spatial resolution, specifically comprising: The vector river data is rasterized, and then the river network data obtained after rasterization is unified to the spatial resolution.

8. The construction system according to claim 6, characterized in that: The soil layer and aquifer divided by the structure division module (203) can be divided into multiple layers.

9. The construction system according to claim 6, characterized in that: The data set aggregation module (207) merges the final soil layer permeability coefficient with the final aquifer permeability coefficient to form a data set of spatial heterogeneity of permeability coefficient of soil aquifer system in the selected area.

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