A method and system for calculating liquid water content of frozen soil on the Qinghai-Tibet Plateau

Abstract

The present invention provides a method and system for calculating the liquid moisture content of frozen soil on the Qinghai-Tibet Plateau, relating to the field of cryosphere hydrology. The method comprises: obtaining a soil temperature and humidity observation network dataset for the central Qinghai-Tibet Plateau; performing soil texture classification to obtain soil texture classification results; combining the soil texture classification results with the soil temperature and humidity observation network dataset to fit the relationship between the solid moisture content and soil temperature of soils of different textures; determining a formula for calculating the liquid moisture content of the soil based on the relationship between the solid moisture content and soil temperature; improving the VIC model based on the liquid moisture content calculation formula; and calculating the liquid moisture content of frozen soil on the Qinghai-Tibet Plateau using the improved VIC model. The present invention optimizes the VIC model's unfrozen water content algorithm, improves the accuracy of the unfrozen water content calculation results, and effectively improves the VIC model's hydrological simulation results.

Description

Technical Field

[0001] The present invention relates to the field of cryosphere hydrological science and technology, and in particular to a method and system for calculating the liquid water content of frozen soil on the Qinghai-Tibet Plateau. Background Art

[0002] The calculation method for the liquid water content of permafrost on the Qinghai-Tibet Plateau refers to a specific method of measuring the liquid water content in the permafrost layer of the Qinghai-Tibet Plateau. It usually takes into account the multi-layer structure of the soil and the moisture dynamics of different soil types, combines meteorological data, surface characteristics and other factors, simulates precipitation, evaporation, melting and water movement in the permafrost layer, and then calculates the liquid water content in the permafrost.

[0003] The southwestern river source region is a high-altitude, cold region with widespread seasonal and permafrost. In the context of climate warming, in addition to glacier melt runoff replenishing river runoff, the freeze-thaw process of permafrost will affect river flow generation. Calculation of soil solid and liquid moisture is a key step in the runoff generation and runoff calculation of hydrological models. To analyze the permafrost melt-replenishing runoff process in high-altitude, cold regions, the variable infiltration capacity (VIC) hydrological model has become the preferred model.

[0004] However, the existing VIC model relies on multiple parameters with high uncertainty (such as saturated moisture content and latent heat flux) when calculating soil liquid moisture content. The physical meaning of these parameters is not clear, the solid-liquid moisture state conversion in the soil is complex and changeable, and the model has the phenomenon of different parameters with the same effect, which increases the uncertainty of the calculation. The calculation process of the permafrost temperature field is cumbersome and time-consuming, resulting in low model efficiency and difficulty in achieving efficient and accurate liquid moisture content calculation in the complex permafrost environment of the Qinghai-Tibet Plateau. Summary of the Invention

[0005] In order to solve the technical problems that the existing VIC model relies on multiple parameters with high uncertainty (such as saturated moisture content, latent heat flux, etc.) when calculating soil liquid moisture content, the physical meaning of these parameters is not clear, the solid-liquid moisture state conversion of soil is complex and changeable, the model has the phenomenon of different parameters with the same effect, which increases the uncertainty of the calculation, and the calculation process of the frozen soil temperature field is cumbersome and time-consuming, resulting in low model efficiency and difficulty in achieving efficient and accurate liquid moisture content calculation in the complex frozen soil environment of the Qinghai-Tibet Plateau, the present invention provides a method and system for calculating the liquid moisture content of frozen soil on the Qinghai-Tibet Plateau.

[0006] The technical solutions provided by the embodiments of the present invention are as follows:

[0007] First aspect:

[0008] An embodiment of the present invention provides a method for calculating the liquid water content of frozen soil on the Qinghai-Tibet Plateau, comprising:

[0009] S1: Obtain the soil temperature and humidity observation network dataset for the central Tibetan Plateau;

[0010] S2: classify the soil texture and obtain the soil texture classification results;

[0011] S3: Combine the soil texture classification results and the soil temperature and humidity observation network dataset to fit the relationship between the solid water content and soil temperature of different soil textures;

[0012] S4: Based on the relationship between solid water content and soil temperature, determine the calculation formula for the liquid water content of the soil;

[0013] S5: Improve the VIC model based on the liquid water content calculation formula;

[0014] S6: Calculate the liquid water content of permafrost on the Qinghai-Tibet Plateau using the improved VIC model.

[0015] Second aspect:

[0016] An embodiment of the present invention provides a system for calculating liquid water content of frozen soil on the Qinghai-Tibet Plateau, comprising:

[0017] processor;

[0018] A memory storing computer-readable instructions, wherein when the computer-readable instructions are executed by the processor, the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau according to the first aspect is implemented.

[0019] The third aspect:

[0020] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau according to the first aspect is implemented.

[0021] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0022] In the present invention, actual soil temperature and humidity observation data of the central Qinghai-Tibet Plateau are used in combination with soil texture classification results to closely integrate regional characteristics with model calculations, significantly improving the calculation accuracy of liquid water content. Based on the fitting formula of the relationship between solid moisture content and temperature, the calculation of liquid moisture content is made more scientific and rigorous. The liquid moisture content calculation formula is introduced to replace the unfrozen water content formula in the traditional VIC model, reducing the number of uncertainty parameters on which the unfrozen water content calculation formula of the VIC model depends, optimizing the unfrozen water content algorithm, improving the accuracy of the unfrozen water content calculation results, and effectively improving the hydrological simulation results of the VIC model. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A schematic flow chart of a method for calculating liquid water content of frozen soil on the Qinghai-Tibet Plateau provided by an embodiment of the present invention;

[0025] Figure 2 A graph showing the relationship between soil solid moisture content and soil temperature provided by an embodiment of the present invention;

[0026] Figure 3 A schematic diagram of the structure of a system for calculating liquid water content of frozen soil on the Qinghai-Tibet Plateau provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0028] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.

[0029] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are the same. The terms "of," "corresponding," and "corresponding" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are the same.

[0030] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0031] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Manual Figure 1 , which shows a flow chart of a method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau provided by an embodiment of the present invention.

[0033] An embodiment of the present invention provides a method for calculating the liquid water content of frozen soil on the Qinghai-Tibet Plateau, the method comprising:

[0034] S1: Obtain the soil temperature and humidity observation network dataset for the central Tibetan Plateau.

[0035] It should be noted that by obtaining the soil temperature and humidity observation network dataset in the central Qinghai-Tibet Plateau, high-resolution spatiotemporal data are provided, which accurately reflects the regional soil temperature and humidity dynamics, supports comparative studies of different geological and climatic conditions, provides a reliable measured basis for improving models and verifying calculation results, and improves calculation accuracy.

[0036] S2: Classify the soil texture and obtain the soil texture classification results.

[0037] In a possible implementation, S2 is specifically:

[0038] The soil texture classification of the central Qinghai-Tibet Plateau was carried out using the international soil texture classification standard, combining clay, silt, sand and porosity, and the soil texture classification results were obtained.

[0039] It should be noted that by using international standards, the comparability of soil classification results in different regions can be ensured, and it has universal applicability. The ratio of clay, silt and sand can accurately describe the soil's physical properties such as hydrology and nutrient retention capacity, providing a scientific basis for land use, agricultural production and other fields. The consideration of porosity helps to evaluate the permeability and water holding capacity of the soil, which is particularly important for hydrological research in permafrost areas. Through fine soil texture division, the changes in soil moisture under different climatic conditions can be better simulated and predicted.

[0040] Reference Manual Figure 2 , shows a relationship diagram between soil solid moisture content and soil temperature provided by an embodiment of the present invention.

[0041] like Figure 2 , shows the relationship between the solid moisture content and soil temperature of two soil types (Ali loam and Maqu loam), where the horizontal axis is soil temperature (℃) and the vertical axis is soil solid moisture content. It can be seen from the figure that with the increase of soil temperature, the solid moisture content of both soils shows a downward trend, which indicates that the ice in the soil gradually melts into liquid water. The solid moisture content range of Ali loam is relatively wide and varies greatly with temperature. The solid moisture content of Maqu loam changes relatively smoothly and is relatively less affected by temperature, reflecting the differences in moisture status of different soil textures during freeze-thaw processes.

[0042] In actual operation, the coefficient of influence of temperature change on solid moisture content is -0.01536 for Ali loam and -0.01547 for Maqu loam, with little difference between the two, indicating that the effects of temperature change on the two soils are similar. For the regression constant, it is 0.3573 for Ali loam and 0.3371 for Maqu loam, showing a small difference. For the goodness of fit of the regression model, both are 0.8607, indicating that the model fitting effect is good. The root mean square error, used to evaluate the prediction accuracy of the model, is 0.02799 for Ali loam and 0.01289 for Maqu loam, indicating that the prediction accuracy of Maqu loam is higher.

[0043] S3: Combining the soil texture classification results with the soil temperature and humidity observation network dataset, the relationship between the solid water content and soil temperature of soils with different textures is fitted.

[0044] It should be noted that by combining soil texture and actual temperature and humidity data, the relationship between solid moisture content and soil temperature can be accurately fitted for different soil types, thereby improving the accuracy of hydrological models in permafrost areas. Combined with temperature and humidity observation network data, changes in soil temperature and humidity can be analyzed at a finer spatial scale, providing more targeted environmental change assessments. This can effectively help analyze the changing patterns of permafrost moisture and provide important support for assessing the impact of climate change on permafrost areas.

[0045] S4: Based on the relationship between solid moisture content and soil temperature, determine the calculation formula for the liquid moisture content of the soil.

[0046] Among them, solid moisture content refers to the content of solid water (ice) in the soil, and liquid moisture content refers to the content of liquid water in the soil.

[0047] In a possible implementation, S4 specifically includes:

[0048] S401: Based on the universal gas state equation, fit the relationship between the sum of soil solid and liquid moisture and soil temperature.

[0049] Among them, the universal gas state equation is a formula that describes the relationship between gas pressure, volume, temperature and gas quantity.

[0050] It should be noted that fitting the relationship between moisture and temperature through physical formulas has a strong scientific basis and universality. It can quantify the change law of the total amount of solid and liquid moisture in the soil, provide a reliable theoretical basis for the calculation of liquid water content, enhance the dynamic adaptability of the model, and facilitate the analysis of changes in frozen soil moisture under different climatic conditions.

[0051] S402: Based on the sum of the solid and liquid moisture in the soil and the relationship between the solid moisture content and the soil temperature, a solid moisture content sequence of the soil in different soil layers is calculated.

[0052] Among them, the sum of solid and liquid soil moisture refers to the sum of solid water and liquid water in the soil, the solid moisture content refers to the ratio of the mass of solid water in the soil to the mass of the soil, and the solid moisture content series is a data series that describes the changes in the moisture content of a substance, reflecting the changing trend over time or other variables (such as temperature, pressure or environmental conditions).

[0053] It should be noted that by integrating the relationship between solid and liquid moisture and temperature, the solid moisture content of different soil layers can be accurately calculated, providing quantitative data for in-depth analysis of the moisture distribution and dynamic changes in the permafrost layer, and enhancing the accuracy of the soil moisture model.

[0054] S403: Fit the relationship between soil ice content and soil temperature based on the solid water content series.

[0055] S404: Determine a calculation formula for the liquid moisture content of the soil based on the relationship between the sum of the solid and liquid moisture in the soil and the soil temperature, and the relationship between the soil ice content and the soil temperature.

[0056] It should be noted that combining the relationship between soil moisture and temperature can more accurately describe the dynamic changes of liquid water in frozen soil and provide an accurate liquid moisture calculation method, which is suitable for hydrological analysis under different soil layers and temperature conditions.

[0057] In a possible implementation, the universal gas state equation is specifically:

[0058] PV a =nRT

[0059] Where P represents the gas pressure in the soil, V a represents the volume of gas in the soil, n represents the amount of substance in the gas in the soil, R represents the Avogadro constant, and T represents the soil temperature at the corresponding depth.

[0060] In one possible implementation, the relationship between the sum of soil solid and liquid moisture and soil temperature is specifically:

[0061] V a =VV s -V w -V i =[(SR) / (gM)]T

[0062] V i +V w =VV s -[(SR) / (gM)]T

[0063] Among them, V a represents the volume of gas in the soil, V represents the total volume of the soil, and V s represents the volume of soil particles, Vw represents the volume of soil liquid water, V i represents the volume of solid water in the soil, S represents the cross-sectional area of ​​the soil, T represents the soil temperature at the corresponding depth, and M represents the molar mass of the air.

[0064] In one possible implementation, the relationship between soil ice content and soil temperature is specifically:

[0065] V i_sim =kT+b

[0066] Among them, V i_sim represents the soil ice content, k represents the slope of the relationship between soil ice content and soil temperature, and b represents the intercept of the relationship between soil ice content and soil temperature.

[0067] In a possible implementation, the calculation formula for the liquid moisture content of the soil is specifically:

[0068] V w =VV s -[(S×R) / (g×M)]×TV i_sim

[0069] V w =VV s -[(S×R) / (g×M)]×T-(k T sim +b)

[0070] Where V represents the total volume of soil, V s represents the volume of soil particles, V w represents the volume of soil liquid water, V i_sim represents the soil ice content, S represents the soil cross-sectional area, R represents the Avogadro constant, T represents the soil temperature at the corresponding depth, and T sim Indicates, g represents the acceleration due to gravity, and M represents the molar mass of air.

[0071] It should be noted that deriving the calculation formula for liquid moisture content through the relationship between solid moisture content and soil temperature can accurately simulate the moisture state of soil at different temperatures and enhance the adaptability and accuracy of hydrological models in permafrost areas.

[0072] S5: Improve the VIC model based on the liquid water content calculation formula.

[0073] In a possible implementation, S5 specifically includes:

[0074] The VIC model is improved by replacing the unfrozen water content calculation formula in the VIC model with the soil liquid moisture content calculation formula.

[0075] It should be noted that by introducing an accurate liquid moisture content calculation formula into the VIC model, the accuracy and efficiency of the model in simulating the hydrological dynamics of permafrost areas can be significantly improved, enabling the VIC model to more accurately capture the soil moisture state transition caused by temperature changes.

[0076] S6: Calculate the liquid water content of permafrost on the Qinghai-Tibet Plateau using the improved VIC model.

[0077] It should be noted that by calculating the liquid moisture content of permafrost on the Qinghai-Tibet Plateau through the improved VIC model, the moisture dynamics of permafrost areas can be simulated more accurately, the changes in liquid moisture during soil freezing and thawing can be effectively predicted, and the accuracy and reliability of regional hydrological models can be improved.

[0078] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0079] In the present invention, actual soil temperature and humidity observation data of the central Qinghai-Tibet Plateau are used in combination with soil texture classification results to closely integrate regional characteristics with model calculations, significantly improving the calculation accuracy of liquid water content. Based on the fitting formula of the relationship between solid moisture content and temperature, the calculation of liquid moisture content is made more scientific and rigorous. The liquid moisture content calculation formula is introduced to replace the unfrozen water content formula in the traditional VIC model, reducing the number of uncertainty parameters on which the unfrozen water content calculation formula of the VIC model depends, optimizing the unfrozen water content algorithm, improving the accuracy of the unfrozen water content calculation results, and effectively improving the hydrological simulation results of the VIC model.

[0080] Reference Manual Figure 3 , which shows a structural schematic diagram of a system for calculating liquid water content of frozen soil on the Qinghai-Tibet Plateau provided by the present invention.

[0081] The present invention further provides a Qinghai-Tibet Plateau frozen soil liquid water content calculation system 20, which is applied to the above-mentioned Qinghai-Tibet Plateau frozen soil liquid water content calculation method, comprising:

[0082] Processor 201.

[0083] The memory 202 stores computer-readable instructions. When the computer-readable instructions are executed by the processor 201, the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau according to the method embodiment is implemented.

[0084] The Qinghai-Tibet Plateau frozen soil liquid water content calculation system 20 provided by the present invention can execute the above-mentioned Qinghai-Tibet Plateau frozen soil liquid water content calculation method and achieve the same or similar technical effects. To avoid repetition, the present invention will not elaborate on it again.

[0085] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0086] In the present invention, actual soil temperature and humidity observation data of the central Qinghai-Tibet Plateau are used in combination with soil texture classification results to closely integrate regional characteristics with model calculations, significantly improving the calculation accuracy of liquid water content. Based on the fitting formula of the relationship between solid moisture content and temperature, the calculation of liquid moisture content is made more scientific and rigorous. The liquid moisture content calculation formula is introduced to replace the unfrozen water content formula in the traditional VIC model, reducing the number of uncertainty parameters on which the unfrozen water content calculation formula of the VIC model depends, optimizing the unfrozen water content algorithm, improving the accuracy of the unfrozen water content calculation results, and effectively improving the hydrological simulation results of the VIC model.

[0087] It should be understood that the processor in the embodiments of the present invention may be a central processing unit (CPU), but may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0088] It should also be understood that the memory in the embodiments of the present invention may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory may be random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0089] The above embodiments can be implemented in whole or in part via software, hardware (e.g., circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. A computer program product comprises one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the processes or functions according to the embodiments of the present invention are fully or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired means (e.g., infrared, wireless, microwave, etc.). A computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or data center that contains a collection of one or more available media. Available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media. Semiconductor media can be solid-state drives.

[0090] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. A and B can be singular or plural. Furthermore, the character " / " as used herein generally indicates an "or" relationship between the associated objects, but it may also indicate an "and / or" relationship. For specific understanding, please refer to the context.

[0091] In this disclosure, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.

[0092] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0093] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0094] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0095] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, and can be electrical, mechanical, or other forms.

[0096] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0097] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0098] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or the portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0099] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau as described in the method embodiment is implemented.

[0100] The computer-readable storage medium provided by the present invention can implement the steps and effects of the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau in the above-mentioned method embodiment. To avoid repetition, the present invention will not go into details.

[0101] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0102] In the present invention, actual soil temperature and humidity observation data of the central Qinghai-Tibet Plateau are used in combination with soil texture classification results to closely integrate regional characteristics with model calculations, significantly improving the calculation accuracy of liquid water content. Based on the fitting formula of the relationship between solid moisture content and temperature, the calculation of liquid moisture content is made more scientific and rigorous. The liquid moisture content calculation formula is introduced to replace the unfrozen water content formula in the traditional VIC model, reducing the number of uncertainty parameters on which the unfrozen water content calculation formula of the VIC model depends, optimizing the unfrozen water content algorithm, improving the accuracy of the unfrozen water content calculation results, and effectively improving the hydrological simulation results of the VIC model.

[0103] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

[0104] There are a few points to note:

[0105] (1) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention. Other structures may refer to conventional designs.

[0106] (2) For the sake of clarity, the thickness of layers or regions in the drawings used to describe the embodiments of the present invention are exaggerated or reduced, that is, these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, the element may be "directly on" or "under" the other element or intervening elements may be present.

[0107] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to form new embodiments.

[0108] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau, characterized in that: include: S1: Obtain the soil temperature and humidity observation network dataset for the central Tibetan Plateau; S2: classify the soil texture and obtain the soil texture classification results; S3: combining the soil texture classification result and the soil temperature and humidity observation network dataset, fitting the relationship between the solid water content and soil temperature of soils with different textures; S4: determining a calculation formula for the liquid moisture content of the soil based on the relationship between the solid moisture content and the soil temperature; S5: improving the VIC model according to the liquid water content calculation formula; S6: Calculate the liquid water content of permafrost on the Qinghai-Tibet Plateau using the improved VIC model; Wherein, the S4 specifically includes: S401: fitting the relationship between the sum of soil solid and liquid moisture and the soil temperature according to the universal gas state equation; S402: Calculating a solid moisture content sequence of the soil in different soil layers based on the sum of the solid and liquid moisture in the soil and the relationship between the solid moisture content and the soil temperature; S403: fitting the relationship between soil ice content and the soil temperature according to the solid water content sequence; S404: Determine a calculation formula for the liquid moisture content of the soil based on the relationship between the sum of the soil solid and liquid moisture and the soil temperature and the relationship between the soil ice content and the soil temperature; Wherein, the S5 is specifically: The VIC model is improved by replacing the unfrozen water content calculation formula in the VIC model with the soil liquid moisture content calculation formula.

2. The method for calculating liquid water content of frozen soil in the Qinghai-Tibet Plateau according to claim 1, characterized in that: The S2 is specifically: The soil texture classification results of the central Qinghai-Tibet Plateau were obtained by adopting the international soil texture classification standard and combining clay, silt, sand and porosity.

3. The method for calculating liquid water content of frozen soil in the Qinghai-Tibet Plateau according to claim 1, characterized in that: The universal gas state equation is specifically: PV a = nRT; in, P represents the gas pressure in the soil. V a represents the volume of gas in the soil, n The amount of gas in the soil. R represents the Avogadro constant, T Indicates the soil temperature at the corresponding depth.

4. The method for calculating liquid water content of frozen soil in the Qinghai-Tibet Plateau according to claim 1, characterized in that: The relationship between the sum of the soil solid and liquid moisture and the soil temperature is specifically: V a =VV s -V w -V i =[(SR) / (gM)]T; V i +V w =VV s -[(SR) / (gM)]T; in, V a represents the volume of gas in the soil, V represents the total volume of soil, V s represents the volume of soil particles, V w represents the volume of soil liquid water, V i represents the volume of soil solid water, S represents the cross-sectional area of ​​soil, T represents the soil temperature at the corresponding depth, M represents the molar mass of air, R represents the Avogadro constant, g represents the acceleration due to gravity, M Indicates the molar mass of air.

5. The method for calculating liquid water content of frozen soil in the Qinghai-Tibet Plateau according to claim 1, characterized in that: The relationship between the soil ice content and the soil temperature is specifically: V i_sim =kT+b; in, V i_sim represents the soil ice content, k represents the slope of the relationship between soil ice content and soil temperature, b represents the intercept of the relationship between soil ice content and soil temperature, T Indicates the soil temperature at the corresponding depth.

6. The method for calculating liquid water content of frozen soil in the Qinghai-Tibet Plateau according to claim 1, characterized in that: The calculation formula of the liquid moisture content of the soil is specifically: V w =VV s -[(S×R) / (g×M)]×TV i_sim； V w =VV s -[(S×R) / (g×M)]×T-(k T+b); in, V represents the total volume of soil, V s represents the volume of soil particles, V w represents the volume of soil liquid water, V i_sim represents the soil ice content, S represents the cross-sectional area of ​​soil, R represents the Avogadro constant, T represents the soil temperature at the corresponding depth, g represents the acceleration due to gravity, M represents the molar mass of air, k represents the slope of the relationship between soil ice content and soil temperature, b The intercept of the relationship between soil ice content and soil temperature.

7. A system for calculating liquid water content of frozen soil in the Qinghai-Tibet Plateau, characterized in that: include: processor; A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau according to any one of claims 1 to 6 is implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for calculating the liquid water content of frozen soil in the Qinghai-Tibet Plateau according to any one of claims 1 to 6 is implemented.

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