Method and system for calculating groundwater precipitation recharge amount

Abstract

The application discloses a kind of groundwater precipitation infiltration recharge quantity calculation method and system, belong to groundwater resource quantity measurement technical field, wherein groundwater precipitation infiltration recharge quantity calculation method includes steps: grid research area, obtain the hydrological geographic data information of grid unit, according to the karst degree coefficient of grid unit identified according to hydrological geographic data information, according to hydrological geographic data information, calculate the groundwater recharge of grid unit karst area, according to hydrological geographic data information, calculate the groundwater recharge of grid unit non-karst area, according to the groundwater recharge of grid unit karst area and non-karst area calculated according to the karst degree of grid unit, groundwater recharge.The factor that it introduces karst rock to groundwater precipitation infiltration recharge quantity influence, can be more accurate quantification groundwater recharge in karst area on large spatial scale, provide a kind of reasonable and feasible, convenient operation scientific quantification method for sustainable use management groundwater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of groundwater resource measurement and calculation, and more particularly to a method and system for calculating groundwater recharge infiltration recharge. BACKGROUND

[0002] Groundwater is an important source of human water supply, accounting for one-fourth of the total amount of global freshwater withdrawal. Over-extraction of groundwater can lead to a decline in groundwater level and a decrease in surface runoff, while having a negative impact on freshwater biological systems. Karst areas refer to regions with landforms and geological structures formed due to dissolution, which contain a large number of underground spaces such as karst caves and dissolution cracks, and are very suitable for the storage and flow of groundwater, being an important storage space for groundwater. Accurate quantification of groundwater recharge in karst areas can provide a quantitative basis for the extraction and use of groundwater, and is an important basis for the sustainable management of groundwater.

[0003] There are mainly two ways to solve the above problems in the prior art: large-scale quantification and small-scale quantification. In the large-scale groundwater recharge algorithm, karst topography is generally ignored, while in the small-scale karst hydrological model, the structure is too complex and the parameters are numerous, which cannot be applied to large-scale karst area groundwater recharge estimation. SUMMARY

[0004] The present application provides a method and system for calculating groundwater recharge infiltration recharge, which can more accurately quantify the groundwater recharge in karst areas on a large spatial scale, provide more reliable data basis for the scientific use and management of groundwater, and solve the problem that the existing large-scale groundwater recharge algorithm generally ignores karst topography, while the small-scale karst hydrological model is too complex in structure and difficult to be applied in a large range.

[0005] To solve the above problems, the present application provides the following technical solutions:

[0006] On the one hand, the present application provides a method for calculating groundwater recharge infiltration recharge, comprising the following steps:

[0007] S1: gridding the study area;

[0008] S2: obtaining hydrological geographic data information of the grid unit;

[0009] S3: identifying the karst degree coefficient of the grid unit according to the hydrological geographic data information;

[0010] S4: calculating the groundwater recharge of the karst area of the grid unit according to the hydrological geographic data information;

[0011] S5: calculating the groundwater recharge of the non-karst area of the grid unit according to the hydrological geographic data information;

[0012] S6: calculating the groundwater recharge of the grid unit according to the karstification degree of the grid unit, the groundwater recharge of the karst area and the groundwater recharge of the non-karst area.

[0013] The method for calculating the groundwater precipitation infiltration recharge has the following beneficial effects: the karstification degree coefficient is determined by calculation, the influencing factor of the groundwater recharge of the karst area is introduced, the groundwater recharge of the karst area and the groundwater recharge of the non-karst area are calculated respectively, the groundwater recharge of the area is calculated according to the karstification degree of the space, the specific application method of the influencing factor in the calculation of the groundwater recharge is provided, the groundwater recharge of the karst area can be quantified more accurately on a large space scale based on the surface hydrological process, and a reasonable, feasible and convenient scientific quantification method for the sustainable use and management of groundwater is provided.

[0014] In some embodiments, the S2: obtaining the hydrological geographical data information in the hydrological geographical data information of the grid unit includes a karst aquifer map, a precipitation data set, a land evaporation data set, an urban impervious surface raster map, a soil water storage capacity data set, a runoff coefficient and a large-scale groundwater recharge.

[0015] Therefore, these data information can be obtained by internet search and used for calculating the karstification degree coefficient of the grid unit, the groundwater recharge of the karst area and the groundwater recharge of the non-karst area.

[0016] In some embodiments, the step S3: identifying the karstification degree coefficient of the grid unit according to the hydrological geographical data information includes:

[0017] The grid unit is projected to identify the land area in the grid unit;

[0018] The proportion of the grid occupied by the continuously distributed rock and the discontinuously distributed rock in the grid unit is determined according to the karst aquifer map;

[0019] The total area of the karst rock of the exposed surface in the grid unit is calculated according to the proportion of the grid occupied by the continuously distributed rock and the discontinuously distributed rock.

[0020] The area proportion of the karst rock is calculated according to the total area of the karst rock of the exposed surface in the grid unit and the land area.

[0021] Therefore, the karstification degree of the grid unit is calculated by the ratio of the area of the karst rock of the exposed surface in the grid unit to the land area, which facilitates the quantitative analysis of the influence of the karst area on the groundwater recharge.

[0022] In some embodiments, the step S4: calculating the groundwater recharge of the karst area of the grid unit according to the hydrological geographical data information includes:

[0023] According to the grid cell precipitation data set and the land evaporation data set, the effective precipitation of the grid cell is calculated;

[0024] According to the urban impervious surface grid map, the area proportion of the urban impervious surface of the grid cell is calculated;

[0025] According to the area proportion of the urban impervious surface of the grid cell, the urban runoff of the grid cell is calculated;

[0026] According to the effective precipitation, the urban runoff, the soil water storage capacity data set and the runoff coefficient of the grid cell, the groundwater recharge of the karst area is calculated;

[0027] Among them, the formula for calculating the groundwater recharge of the karst area according to the effective precipitation, the urban runoff, the soil water storage capacity data set and the runoff coefficient of the grid cell is:

[0028]

[0029] R 3，t is the maximum potential groundwater recharge, P eff，t is the effective precipitation in the grid cell, R 1，t is the urban runoff, γ is the runoff coefficient, S s，t-1 is the soil water storage capacity, S s，max is the maximum soil water storage capacity.

[0030] Therefore, according to the effective precipitation, the urban runoff, the soil water storage capacity data set and the runoff coefficient of the grid cell, the groundwater recharge of the karst area can be calculated.

[0031] In some embodiments, the step S4 of calculating the grid cell karst area groundwater recharge according to the hydrological geographic data information further comprises:

[0032] Comparing the karst area groundwater recharge with the ground observation results;

[0033] Adjusting the size of the runoff coefficient according to the comparison result;

[0034] Recalculating the karst area groundwater recharge according to the adjusted runoff coefficient.

[0035] Therefore, according to the comparison of the ground observation data, the preliminary calculated karst area groundwater recharge can be further corrected, and the accuracy of the calculation result is improved.

[0036] In some embodiments, the formula for calculating the grid cell groundwater recharge according to the grid cell karstification degree, the karst area groundwater recharge and the non-karst area groundwater recharge is:

[0037]

[0038] wherein R g_grid is the groundwater recharge amount of the grid unit, f karst is the karstification degree coefficient of the grid unit, is the groundwater recharge amount of the karst area, is the groundwater recharge amount of the non-karst area.

[0039] Thus, according to the karstification degree, the groundwater recharge amount of the karst area and the groundwater recharge amount of the non-karst area of the grid unit, the regional average groundwater recharge amount considering the special geomorphic characteristics of the karst area is obtained.

[0040] On the other hand, the present application also provides a groundwater precipitation infiltration recharge amount calculation system, comprising:

[0041] a gridding module, used for dividing a region to be studied into a plurality of grid units;

[0042] an information acquisition module, used for acquiring hydrographic data information of the grid units;

[0043] a karstification calculation module, connected with the information acquisition module, used for calculating the karstification degree in the grid units;

[0044] a karst area groundwater recharge amount calculation module, connected with the information acquisition module, used for calculating the groundwater recharge amount of the karst area in the grid units;

[0045] a non-karst area groundwater recharge amount calculation module, connected with the information acquisition module, used for calculating the groundwater recharge amount of the non-karst area in the grid units;

[0046] a groundwater recharge amount calculation module, connected with the karstification calculation module, the karst area groundwater recharge amount calculation module and the non-karst area groundwater recharge amount calculation module, used for calculating the groundwater recharge amount of the grid units according to the karstification degree, the groundwater recharge amount of the karst area and the groundwater recharge amount of the non-karst area.

[0047] The groundwater precipitation infiltration recharge amount calculation system of the present application has the following beneficial effects: through the karstification calculation module, the karstification degree is calculated, and the groundwater recharge amount of the karst area and the groundwater recharge amount of the non-karst area can be calculated respectively, the calculation mode of the groundwater recharge is more comprehensive, and more scientific and accurate karst area groundwater recharge amount calculation results can be obtained.

[0048] In some embodiments, the karstification calculation module comprises:

[0049] a land area calculation module, used for calculating the land area in the grid units;

[0050] The karst rock area calculation module is used to calculate the total area of ​​karst rock exposed on the surface of the grid unit based on the karst aquifer map obtained by the information acquisition module.

[0051] The karstification coefficient calculation module is used to calculate the karstification degree coefficient within the grid cell based on the land area and the total area of ​​karst rocks.

[0052] Therefore, by calculating the area ratio of exposed karst rocks on the ground surface, a quantitative coefficient of karstification degree can be obtained.

[0053] In some embodiments, the groundwater recharge calculation module for the karst area includes:

[0054] The effective precipitation calculation module is used to calculate the effective precipitation of the grid cell based on the grid cell precipitation dataset and the land evapotranspiration dataset obtained by the information acquisition module.

[0055] The urban runoff calculation module is used to calculate urban runoff based on the urban impermeable surface grid map obtained by the information acquisition module and the calculation results of the effective precipitation calculation module.

[0056] The maximum potential groundwater recharge calculation module is used to calculate the groundwater recharge in the karst area based on the soil water storage capacity dataset and runoff coefficient obtained by the information acquisition module, as well as the effective precipitation and urban runoff of the grid unit.

[0057] Therefore, by using information such as precipitation datasets, land evapotranspiration datasets, soil water storage capacity datasets, and runoff coefficients, the groundwater recharge in the karst area can be obtained.

[0058] In some embodiments, the karst area groundwater recharge calculation module further includes:

[0059] The correction module is used to correct the groundwater recharge in the karst area.

[0060] Therefore, the calculation results can be corrected using actual measurement data, thereby further improving the accuracy of the calculation results. Attached Figure Description

[0061] Figure 1 This is a flowchart illustrating a method for calculating groundwater precipitation infiltration recharge according to an embodiment of the present invention.

[0062] Figure 2 for Figure 1 The diagram shows a flowchart of step S3 in a method for calculating groundwater precipitation infiltration recharge.

[0063] Figure 3 for Figure 1 The diagram shows a flowchart of step S4 in a method for calculating groundwater precipitation infiltration recharge.

[0064] Figure 4 For Figure 1 A comparison chart of the results of a groundwater precipitation infiltration recharge calculation method and actual observation results is shown in the figure;

[0065] Figure 5 The structure schematic diagram of a groundwater precipitation infiltration recharge calculation system according to another embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0066] The present application will be further described in detail below with reference to the accompanying drawings.

[0067] In one aspect, Figure 1 A groundwater precipitation infiltration recharge calculation method according to the present application is shown schematically. As shown in the figure, Figure 1 The method comprises the following steps:

[0068] S1: gridding the study area;

[0069] S2: obtaining hydrological geographic data information of the grid unit;

[0070] S3: identifying the karstification degree coefficient of the grid unit according to the hydrological geographic data information;

[0071] S4: calculating the groundwater recharge of the karst area of the grid unit according to the hydrological geographic data information;

[0072] S5: calculating the groundwater recharge of the non-karst area of the grid unit according to the hydrological geographic data information;

[0073] S6: calculating the groundwater recharge of the grid unit according to the karstification degree, the groundwater recharge of the karst area and the groundwater recharge of the non-karst area of the grid unit.

[0074] Step S1: gridding the study area, the specific implementation process is as follows: find the area to be studied on the Baidu map, find the longitude and latitude of the uppermost, lowermost, leftmost and rightmost four points of the boundary of the study area on the Baidu map by visual method, and take the integral values as the coordinate control points. Taking the global range as an example, the four points are: (-179.75, 89.75), (-179.75, -89.85), (179.75, 89.75) and (179.75, -89.75). Then select a suitable spatial resolution, for example 5 radians (about 55 km), divide the study area into grids with an interval of 5 radians using ArcGIS software, obtain the gridded surface layer covering the study area, and determine the centroid longitude and latitude coordinates of each grid.

[0075] Step S2: Obtain hydrological geographic data information of the grid cell, wherein the hydrological geographic data information includes but is not limited to karst aquifer map, precipitation data set, land evaporation data set, urban impervious surface raster map, soil water storage capacity data set, runoff coefficient, large-scale groundwater recharge, which can be obtained by searching and downloading on the Internet through public channels.

[0076] In this way, the karstification degree coefficient of the grid cell can be identified according to the karst aquifer map, the karst area groundwater recharge of the grid cell can be calculated according to the precipitation data set, the land evaporation data set, the urban impervious surface raster map, the soil water storage capacity data set and the runoff coefficient, and the non-karst area groundwater recharge can be calculated according to the large-scale groundwater recharge. After obtaining the karstification degree, the karst area groundwater recharge and the non-karst area groundwater recharge of the grid cell, the influence of the karst area groundwater recharge can be determined according to the karstification degree, and then the grid cell groundwater recharge can be calculated by comprehensively considering the proportion of the karst area groundwater recharge and the non-karst area groundwater. The grid cell groundwater recharge is more accurate than the existing large-scale groundwater recharge algorithm which ignores the factors of the karst area, and compared with the existing complex small-scale karst hydrological model, the grid cell groundwater recharge can be expanded to a large research area by means of grid splicing combination, which has stronger practicability.

[0077] In one embodiment, referring to FIG. 3, step S3 includes: Figure 2

[0078] Projecting the grid cell to identify the land area in the grid cell;

[0079] Determining the proportion of the grid occupied by the continuously distributed rocks and the discontinuously distributed rocks in the grid cell according to the karst aquifer map;

[0080] Calculating the total area of the karst rocks on the exposed surface in the grid cell according to the proportion of the grid occupied by the continuously distributed rocks and the discontinuously distributed rocks;

[0081] Calculating the area proportion of the karst rocks according to the total area of the karst rocks on the exposed surface in the grid cell and the land area.

[0082] In the specific implementation process, the normal equidistant azimuth projection is adopted to calculate the area and the water area of each grid cell, and the land area A of the grid cell is obtained by subtracting the water area from the area. land ​From the karst aquifer map WOKAM downloaded from the internet, the karst aquifer raster map of the study area was extracted. The five categories of exposed karst rocks in WOKAM were categorized into two types: spatially continuous rocks and discontinuous rocks. The proportion of each type of karst rock in the grid was then determined. i Set the values ​​to 0.4 and 0.9 respectively, and calculate the total area A of karst rock distribution on the exposed surface within the grid cell. overlay，i Then calculate the area A of exposed carbonate rock-evaporite within the grid cell. overlay，i A% of the total land area land The ratio of this area to the total area is denoted as the karstification degree coefficient f of the grid unit. karst :

[0083]

[0084] In one specific embodiment, such as Figure 3 As shown, step S4: Calculating the groundwater recharge of the karst area in the grid unit based on the hydrogeographic data includes:

[0085] Calculate the effective precipitation of the grid cell based on the grid cell precipitation dataset and the land evapotranspiration dataset;

[0086] Based on the aforementioned urban impermeable surface grid map, calculate the area percentage of the urban impermeable surface in each grid unit.

[0087] The urban runoff within the grid unit is calculated based on the area ratio of the impermeable surface in the urban area of ​​the grid unit.

[0088] The groundwater recharge in the karst area is calculated based on the effective precipitation, urban runoff, soil water storage capacity dataset and runoff coefficient within the grid cell.

[0089] In the specific implementation process, based on the large spatial scale (spatial resolution of more than 5 radians) precipitation dataset obtained from the Internet search, historical long-series daily precipitation data P at the grid scale within the study area were extracted according to the four coordinate control points of the study area. t The total number of years in the sequence should not be less than 30 years, taking 1980-2015 as an example. Next, search for a large-scale land evapotranspiration dataset, which needs to be corrected relative to ground observations (such as a global land evapotranspiration dataset). Extract daily land surface evapotranspiration data E at a grid scale within the study area based on the four coordinate control points of the study area. act，t The difference between rainfall data and actual evapotranspiration is taken as the effective precipitation P reaching the soil. eff，t That is, P eff，t =P t -E act，t .

[0090] Next, high-precision MODIS urban data covering the study area was obtained through internet search. An impermeable surface raster map of the urban area was extracted, and this urban raster map was overlaid with the grid layer of the study area to calculate the area proportion f of the impermeable surface within each grid cell. urban Within the urban area, 50% of effective rainfall is directly converted into urban runoff R. 1，t Then we can obtain:

[0091]

[0092] Then, based on the soil water retention capacity S obtained from internet searches, which is determined by soil texture and crop root depth, s，max The dataset was used to extract a raster map of soil water storage capacity within the study area, and a high-precision soil evapotranspiration data sequence covering the study area was searched and downloaded. soil，t Assuming the initial soil moisture content S s，t =0 represents half of the water storage capacity, and the effective rainfall and soil water storage S during a given period. s，t-1 The sum of these values ​​exceeds the soil's maximum water storage capacity, S. s，mgx Part of it becomes soil overflow R 2，t Soil water storage during specific periods (S) s，t It will also be updated accordingly:

[0093] R 2，t =max(P eff，t -R 1，t +S s，t-1 -S s，max ,0)

[0094]

[0095] The gridded runoff coefficient γ covering the study area was obtained from the WaterGAP global hydrological model. Missing runoff coefficient values ​​were interpolated from adjacent areas. The maximum potential groundwater recharge R was calculated based on soil infiltration. 3，t :

[0096]

[0097] Since surface runoff in karst areas is negligible, we consider all non-urban land surface runoff to be able to replenish the groundwater aquifer through karst topography. Therefore, the groundwater recharge in karst areas... for:

[0098]

[0099] Using days or months as the research step size (t=1 day or t=1 month), long-term simulations were conducted. The first two years were a warm-up period, and the simulated recharge amounts for the remaining years were averaged. For example, the precipitation and evaporation datasets were from 1980 to 2015, representing the average groundwater recharge in the karst region. Should be the daily or monthly average from 1982-2015.

[0100] In one embodiment, as shown in Figure 3 Step S4: calculating karst area groundwater recharge amount according to hydrological geographic data information further comprises:

[0101] Comparing the karst area groundwater recharge amount with ground observation results;

[0102] Adjusting runoff coefficient size according to comparison results;

[0103] Recalculating karst area groundwater recharge amount according to adjusted runoff coefficient.

[0104] In the specific implementation process, mainly in the case of ground observation data in the study area, the observation data is converted into gridded results, and the karst area groundwater average recharge amount is compared, if the karst area groundwater average recharge amount is overestimated, the runoff coefficient γ is reduced by the same proportion, if underestimated, the runoff coefficient γ is enlarged by the same proportion, and the karst area groundwater average recharge amount is recalculated, so that the simulated average recharge amount is close to the actual ground observation data, and the accuracy of the calculation result is improved.

[0105] In one embodiment, step S5: the method for calculating the grid unit non-karst area groundwater recharge amount according to the hydrological geographic data information is that the grid unit corresponding groundwater recharge amount is taken as the non-karst area groundwater recharge amount. In the specific operation, in the specific implementation process, the groundwater recharge amount simulated by the national or global scale hydrological model is searched and downloaded. This recharge amount data does not consider the factors of karst area, so the groundwater recharge amount covering the study area range can be directly taken as the non-karst area groundwater recharge amount, and the multi-year average non-karst area groundwater recharge amount can be obtained by taking the multi-year average value.

[0106] In one embodiment, step S6: the formula for calculating the grid unit groundwater recharge amount according to the grid unit karstification degree, karst area groundwater recharge amount and non-karst area groundwater recharge amount is:

[0107] Wherein, R g_grid is the grid unit groundwater recharge amount, f karst is the grid unit karstification degree coefficient, is the karst area groundwater recharge amount, is the non-karst area groundwater recharge amount. In this way, in the case of knowing the grid unit karstification degree coefficient f karst , karst area groundwater recharge amount non-karst area groundwater recharge The average groundwater recharge R of the grid unit can be obtained by weighting the karst area and the non-karst area. g_grid .

[0108] According to the above steps, the karst area groundwater recharge can be obtained. and the regional average groundwater recharge R considering the special geomorphic characteristics of karst. g_grid As shown in Figure 4 , the average groundwater recharge R of the grid unit is g_grid Compared with the actual observation data, it is in the same range, which fully shows that the groundwater recharge infiltration recharge calculation method provided by the present application is accurate and reliable, can effectively improve the calculation accuracy of the groundwater recharge in the karst area, and can be applied in a large range of research areas, providing a reasonable and feasible scientific quantification method for sustainable use and management of groundwater.

[0109] On the other hand, as shown in Figure 5 , the present application discloses a groundwater recharge infiltration recharge calculation system, comprising:

[0110] The gridding module is used to divide the area to be studied into a plurality of grid units.

[0111] The information acquisition module is used to acquire the hydrological geographic data information of the grid unit.

[0112] The karstification calculation module is connected with the information acquisition module and is used to calculate the karstification degree in the grid unit.

[0113] The karst area groundwater recharge calculation module is connected with the information acquisition module and is used to calculate the karst area groundwater recharge in the grid unit.

[0114] The non-karst area groundwater recharge calculation module is connected with the information acquisition module and is used to calculate the non-karst area groundwater recharge in the grid unit.

[0115] The groundwater recharge calculation module is connected with the karstification calculation module, the karst area groundwater recharge calculation module and the non-karst area groundwater recharge calculation module, and is used to calculate the groundwater recharge of the grid unit according to the karstification degree, the karst area groundwater recharge and the non-karst area groundwater recharge.

[0116] In the implementation process, the gridding module divides the area to be studied into a plurality of grid units, and provides the grid units with basic information such as longitude and latitude for other modules; the information acquisition module acquires hydrographic data of the grid units through Internet search, download and other methods. The data includes but is not limited to karst aquifer map, precipitation data set, land evaporation data set, urban impervious surface raster map, soil water storage capacity data set, runoff coefficient, large-scale groundwater recharge, and the like; the karstification calculation module calculates the degree of karstification in the grid unit according to the karst aquifer map to obtain the area ratio of the karst area in the grid unit; the karst area groundwater recharge calculation module calculates the groundwater recharge of the karst area in the grid unit according to the precipitation data set, the land evaporation data set, the urban impervious surface raster map, the soil water storage capacity data set, the runoff coefficient and the like; the non-karst area groundwater recharge calculation module calculates the groundwater recharge of the non-karst area in the grid unit according to the large-scale groundwater recharge; and the groundwater recharge calculation module calculates the groundwater recharge of the grid unit according to the area ratio of the karst area in the grid unit, the groundwater recharge of the karst area and the groundwater recharge of the non-karst area. The groundwater precipitation infiltration recharge calculation system takes into account the influence factor of the karst area on the groundwater infiltration, and can obtain more scientific and accurate calculation results of the groundwater recharge in the karst area.

[0117] In one embodiment, the karstification calculation module comprises:

[0118] The land area calculation module is configured to calculate the land area in the grid unit.

[0119] The karst rock area calculation module is configured to calculate the total area of the karst rock on the exposed surface of the grid unit according to the karst aquifer map acquired by the information acquisition module.

[0120] The karstification coefficient calculation module is configured to calculate the karstification degree coefficient of the grid unit according to the land area and the total area of the karst rock.

[0121] In the implementation process, the land area calculation module calculates the land area of the grid unit by subtracting the water area from the area of the grid unit; the karst rock area calculation module calculates the total area of the karst rock in the grid unit according to the identification method provided in the above embodiment; and the karstification coefficient calculation module calculates the area ratio of the karst area in the grid unit, i.e. the karstification degree coefficient, by dividing the total area of the karst rock in the grid unit by the land area.

[0122] In one embodiment, the karst area groundwater recharge calculation module comprises:

[0123] The effective precipitation calculation module is configured to calculate the effective precipitation of the grid unit according to the grid unit precipitation data set and the land evaporation data set acquired by the information acquisition module.

[0124] a city runoff calculation module, configured to calculate the city runoff according to the impervious surface raster map of the city obtained by the information acquisition module and the calculation result of the effective precipitation calculation module;

[0125] a maximum potential groundwater recharge calculation module, configured to calculate the groundwater recharge in the karst area according to the soil water storage capacity dataset and the runoff coefficient obtained by the information acquisition module, and the grid unit effective precipitation and the city runoff.

[0126] In one specific embodiment, the groundwater recharge calculation module in the karst area further comprises:

[0127] a correction module, configured to correct the groundwater recharge in the karst area.

[0128] In the specific implementation process, the effective precipitation calculation module, the city runoff calculation module and the maximum potential groundwater recharge calculation module calculate the maximum potential groundwater recharge by using the formula provided in the above embodiment according to the precipitation dataset, the land evapotranspiration dataset, the impervious surface raster map of the city, the soil water storage capacity dataset and the runoff coefficient obtained by the information acquisition module, and take the maximum potential groundwater recharge as the groundwater recharge in the karst area, then the correction module compares the calculated groundwater recharge in the karst area with the actual observation data, adjusts the runoff coefficient according to the comparison result, and recalculates the groundwater recharge in the karst area by using the new runoff coefficient to obtain the corrected groundwater recharge in the karst area.

[0129] In summary, the groundwater recharge calculation method of the present application determines the karstification degree coefficient by the distribution of bare karst rocks, and calculates the groundwater recharge in the karst area and the groundwater recharge in the non-karst area respectively, and calculates the groundwater recharge in the region according to the karstification degree of a certain space, introduces the influencing factor of the groundwater recharge in the karst area, and provides the specific application method of the influencing factor in the calculation of the groundwater recharge, which can more accurately quantify the groundwater recharge in the karst area on a large spatial scale based on the surface hydrological process, and provides a reasonable and feasible scientific quantification method for the sustainable use and management of groundwater.

[0130] The above only describes some embodiments of the present application. For those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, therefore, the present application is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope of the present application.

Claims

1. A method for calculating groundwater precipitation infiltration recharge, characterized in that, Includes the following steps: S1: Gridded research area, divided into several grid units; S2: Obtain hydrological and geographic data information of grid cells, including karst aquifer maps, precipitation datasets, land evapotranspiration datasets, urban impermeable surface raster maps, soil water storage capacity datasets, runoff coefficients, and large-scale groundwater recharge. S3: Identify the karstification degree coefficient of the grid unit based on the aforementioned hydrological and geographical data information, including Project the grid cells to identify the land area within each grid cell; The proportion of continuously distributed rocks and discontinuously distributed rocks in a grid cell is determined based on the karst aquifer map. The total area of ​​exposed karst rock within a grid cell is calculated based on the proportion of continuously distributed rocks and discontinuously distributed rocks in the grid. The area ratio of karst rocks is calculated based on the total area of ​​exposed karst rocks and the land area within the grid cell. S4: Calculate the groundwater recharge of the karst area in the grid unit based on the aforementioned hydrological and geographical data, including... Calculate the effective precipitation of the grid cell based on the grid cell precipitation dataset and the land evapotranspiration dataset; Based on the aforementioned urban impermeable surface grid map, calculate the area percentage of the urban impermeable surface in each grid unit. The urban runoff within the grid unit is calculated based on the area ratio of the impermeable surface in the urban area of ​​the grid unit. Based on the effective precipitation, urban runoff, soil water storage capacity dataset and runoff coefficient within the grid cell, calculate the groundwater recharge in the karst area. The formula for calculating the groundwater recharge in the karst area, based on the effective precipitation, urban runoff, soil water storage capacity dataset, and runoff coefficient within the grid cell, is as follows: For the maximum potential groundwater recharge, For the effective precipitation within the grid cell, For the urban runoff, The runoff coefficient is... This refers to the soil's water storage capacity over a given period. This represents the maximum water storage capacity of the soil. S5: Calculate the groundwater recharge of the non-karst area in the grid unit based on the hydrological and geographical data information, and take the groundwater recharge of the grid unit as the groundwater recharge of the non-karst area. S6: Calculate the groundwater recharge of the grid unit based on the degree of karstification, groundwater recharge in the karst area, and groundwater recharge in the non-karst area. The formula is as follows: in, This represents the groundwater recharge of the grid unit. The karstification degree coefficient of the grid unit. This refers to the groundwater recharge in the karst area. This represents the groundwater recharge in the non-karst area.

2. The method for calculating groundwater precipitation infiltration recharge according to claim 1, characterized in that, Step S4: Calculating the groundwater recharge of the karst area in the grid unit based on the hydrogeographic data information also includes: The groundwater recharge in the karst area was compared with the results of ground observations. Adjust the runoff coefficient based on the comparison results; The groundwater recharge in the karst area is recalculated based on the adjusted runoff coefficient.

3. A groundwater precipitation infiltration recharge calculation system using the groundwater precipitation infiltration recharge calculation method according to any one of claims 1-2, characterized in that, include: The gridding module is used to divide the area to be studied into several grid cells; The information acquisition module is used to acquire hydrological and geographic data information of the grid units; A karstification calculation module, connected to the information acquisition module, is used to identify the karstification degree coefficient within a grid cell based on hydrogeographic data information. A karst area groundwater recharge calculation module is connected to the information acquisition module and is used to calculate the groundwater recharge of the karst area within the grid unit based on hydrogeographic data information. The groundwater recharge calculation module for non-karst areas is connected to the information acquisition module and is used to calculate the groundwater recharge in non-karst areas within the grid unit based on hydrological and geographical data information, and to use the groundwater recharge corresponding to the grid unit as the groundwater recharge in non-karst areas. The groundwater recharge calculation module is connected to the karstification calculation module, the karst area groundwater recharge calculation module, and the non-karst area groundwater recharge calculation module. It is used to calculate the groundwater recharge of the grid unit based on the degree of karstification, the groundwater recharge of the karst area, and the groundwater recharge of the non-karst area.

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