Evaluation method and system for the impact of water-to-dry land conversion on groundwater level in groundwater overexploitation areas

Abstract

The present invention provides an evaluation method and system for the impact of water-to-dry land conversion on groundwater level in groundwater over-exploitation areas, which solves the technical problems of the complex evaluation process and limited data quality of existing evaluation technologies. The method includes: obtaining relevant basic data of water resources in groundwater over-exploitation areas; forming a measurement method and irrigation statistical data for water resource utilization in the process of crop water-to-dry land conversion; and then forming water saving data of groundwater resources in the process of crop water-to-dry land conversion; forming groundwater resource utilization type data based on relevant basic data; and forming evaluation data of the impact of water-to-dry land conversion on groundwater level through the impact of irrigation well groups on groundwater level observation wells based on water saving and utilization type. It has the advantages of short cycle, low cost and quantitative calculation. It can calculate the water saving based on the irrigation water use process and water volume statistics of the surrounding areas of water-to-dry land conversion with effective precipitation, and can form an accurate calculation of the water level benefit of water saving. It provides a scientific basis for groundwater resource management and decision-making.

Description

Technical Field

[0001] The present invention relates to the technical field of groundwater utilization, and in particular to a method and system for evaluating the impact of water-to-dry land conversion on groundwater levels in a groundwater over-exploitation area. Background Art

[0002] With population growth and economic development, the demand for water resources is increasing, of which agricultural water accounts for more than 50% of the total water consumption. In many arid and semi-arid areas, groundwater has become an important source of irrigation water. Due to long-term excessive extraction, groundwater over-exploitation has led to widespread environmental problems, which not only threatens the sustainability of water resources, but also may lead to a series of environmental problems such as ground subsidence, water quality deterioration, and ecological environment damage. In the face of the continuous decline in groundwater levels in groundwater over-exploitation areas and the increasing depletion of groundwater resources, adjusting the agricultural water use structure and implementing water resource management measures such as "converting water to dry land" have become important means to alleviate the situation of groundwater over-exploitation. As a farmland water resource management measure, "converting water to dry land" reduces groundwater extraction by converting irrigated land that relies on groundwater irrigation to dry land that relies on precipitation. This measure not only helps to improve the utilization efficiency of water resources, but also promotes water balance and reduces the excessive decline of groundwater levels, thereby alleviating the adverse effects of groundwater over-exploitation.

[0003] However, the quantitative evaluation of the impact of the implementation of the "water-to-dryland" measures on the recovery of groundwater levels is a complex issue, which involves multiple fields such as hydrogeology and farmland management. An effective evaluation method needs to consider the impact of factors such as changes in groundwater extraction and precipitation. Therefore, proposing a scientific and reasonable evaluation method is of great practical significance for guiding the specific implementation measures of "water-to-dryland", optimizing crop types, evaluating economic benefits, and providing an objective basis for policy making. In the prior art, the evaluation of water level changes in groundwater over-exploitation areas usually adopts the groundwater numerical simulation method of models such as Modflow and Feflow, that is, a numerical model is established for the region according to the actual situation to simulate the impact of changes in surface water on groundwater levels. However, many parameters are required, including hydrogeological parameters, regional groundwater development and utilization data, and groundwater level series observation data, resulting in high data collection costs. At the same time, for groundwater over-exploitation areas, due to the high intensity of groundwater development and utilization, there are many groundwater users, the model is difficult to generalize, the establishment of numerical models is time-consuming, the model parameter adjustment is complex, and there are many uncertainties. Summary of the invention

[0004] In view of the above problems, an embodiment of the present invention provides a method and system for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater over-exploitation areas, which solves the technical problems of the existing evaluation technology, such as the complex evaluation process and the limited evaluation accuracy due to the quality of collected data.

[0005] The method for evaluating the impact of water-to-drying in a groundwater over-exploitation area on groundwater level in an embodiment of the present invention includes:

[0006] Obtain relevant basic data on water resources in groundwater over-exploitation areas;

[0007] Based on the relevant basic data, the measurement method of water resource utilization and the corresponding irrigation statistics in the process of crop water-to-dryland conversion are formed;

[0008] Based on the measurement method and the corresponding irrigation statistical data, the water saving data of groundwater resources in the process of crop water-to-dry land conversion is formed;

[0009] Based on the relevant basic data, the utilization type data of groundwater resources in the process of crop water-to-dry land conversion is formed;

[0010] Based on the amount of water saved and the type of water utilization, the impact of irrigation wells in the groundwater over-exploitation area on the groundwater level of related water level observation wells is used to form assessment data on the impact of water-to-dry land conversion on the groundwater level.

[0011] In one embodiment of the present invention, the relevant basic data include time-series statistical data in the fields of geography, meteorology, hydrology, and agriculture.

[0012] In one embodiment of the present invention, the metering method includes a direct metering method, which forms an actual irrigation quota for water-converted dry crops based on the irrigation water consumption of irrigation wells around water-converted dry crops; and then, based on the area of ​​water-converted dry crops, the quota method is used to calculate the actual irrigation water consumption in the irrigation water use process of water-converted dry crops in the groundwater over-exploitation area.

[0013] In one embodiment of the present invention, the measurement method includes an indirect measurement method, which measures the effective precipitation and crop water demand actually supplemented to the plant root layer soil, determines the annual irrigation water demand, and combines the water-to-dry land conversion implementation area to calculate the estimated irrigation water volume of the crop irrigation water use process in the groundwater over-exploitation area.

[0014] In one embodiment of the present invention, the amount of water saved in groundwater resources during the process of converting crops from water to dry land includes:

[0015] Determine the difference in irrigation water volume before and after the crop water-to-dry farming conversion based on direct or indirect measurement methods, and determine the amount of water saved in each irrigation well by groundwater resources after the implementation of the water-to-dry farming conversion based on the difference in irrigation water volume.

[0016] In one embodiment of the present invention, the irrigation wells also include closed wells, and the actual irrigation water volume or the measured irrigation water volume of the irrigation wells surrounding the closed wells is allocated to the closed wells according to the irrigation coverage and coverage weights in the groundwater over-exploitation area, and the water saved by the irrigation wells surrounding the closed wells is allocated to the closed wells according to the irrigation coverage and coverage weights, so as to obtain the water saved by each closed well to cope with the irrigation water volume after crop water is converted to drought.

[0017] In one embodiment of the present invention, the groundwater storage type is divided into submersible or pressurized water utilization types.

[0018] In one embodiment of the present invention, the formation of the evaluation data includes:

[0019] Calculate the water level drawdown of a single irrigation well based on the type of groundwater resource utilization and water conservation of the single irrigation well;

[0020] Determine the water level drawdown in the observation well based on the water level drawdown in each single irrigation well;

[0021] The impact assessment of groundwater levels before and after crop water conversion to drought conditions was determined based on the water level drop in the observation wells.

[0022] The evaluation system of the impact of water-to-drying in groundwater over-exploitation areas on groundwater levels in the embodiment of the present invention comprises:

[0023] A memory for storing program codes in the process of the above-mentioned evaluation method;

[0024] A processor is used to execute the program code.

[0025] The evaluation system of the impact of water-to-drying in groundwater over-exploitation areas on groundwater levels in the embodiment of the present invention comprises:

[0026] An information acquisition device for acquiring relevant basic data on water resources in groundwater over-exploitation areas;

[0027] Irrigation statistics device, used to form the measurement method of water resource utilization and corresponding irrigation statistics in the process of crop water-to-dry conversion based on relevant basic data;

[0028] A water-saving statistical device for forming water-saving data of groundwater resources in the process of crop water-to-drying conversion according to the metering method and the corresponding irrigation statistical data;

[0029] A type classification device for forming utilization type data of groundwater resources in the process of crop water-to-dry land conversion based on relevant basic data;

[0030] The evaluation and processing device is used to form evaluation data on the impact of water-to-dry land conversion on the groundwater level through the impact of irrigation well groups on the groundwater level of relevant water level observation wells in the groundwater over-exploitation area according to the amount of water saved and the type of utilization.

[0031] The method and system for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater over-exploitation areas according to the embodiment of the present invention provide an improved method for quantitatively evaluating the benefits of water levels during the implementation of water-to-dry land conversion in groundwater over-exploitation areas, where the intensity of groundwater development and utilization is high and water use is complex. It has the advantages of short cycle, low cost and quantitative calculation, and can calculate the amount of water saved based on the irrigation water use process and water volume statistics of the surrounding areas of water-to-dry land conversion based on effective precipitation, and can form an accurate calculation of the benefits of water level for water saving. It can accurately evaluate the impact of "water-to-dry land conversion" measures on groundwater level changes, and provide a scientific basis for groundwater resource management and decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure is a flow chart of a method for evaluating the impact of water-to-drying conversion on groundwater levels in a groundwater over-exploitation area according to an embodiment of the present invention.

[0033] Figure 2 It is a schematic diagram showing the arrangement of irrigation wells and observation wells in a method for evaluating the impact of water-to-dry land conversion on groundwater levels in a groundwater over-exploitation area according to an embodiment of the present invention.

[0034] Figure 3 It is a schematic diagram of the architecture of a system for evaluating the impact of water-to-drying conversion on groundwater levels in groundwater over-exploitation areas according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer and more understandable, the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The method for evaluating the impact of water conversion to dry land on groundwater level in a groundwater overexploitation area according to an embodiment of the present invention is as follows: Figure 1 As shown. Figure 1 In this embodiment, the present invention includes:

[0037] Step 100: Obtain relevant basic data on water resources in groundwater overexploitation areas.

[0038] Those skilled in the art can understand that the statistical quantification of the water resource utilization process in groundwater over-exploitation areas needs to be carried out comprehensively through time-series statistical data in related fields such as geography, meteorology, hydrology, and agriculture. In the quantification process, geographical data include but are not limited to altitude, surface geological structure, underground geological structure, etc., meteorological data include but are not limited to climate, rainy season cycle and rainfall, temperature cycle and degree of change, etc., hydrological data include but are not limited to flood season cycle and flow, river direction and flow, runoff direction and flow, etc., and agricultural data include but are not limited to the distribution of natural vegetation in the region, crop types, distribution structure and distribution changes, etc. The relevant basic data composed of statistical data of geography, meteorology, hydrology, agriculture and other stages can be obtained through periodic statistical data from various professional departments or functional departments.

[0039] Step 200: Form a measurement method for water resource utilization and corresponding irrigation statistics in the process of converting crops from water to dry land based on relevant basic data.

[0040] The measurement methods include direct measurement and indirect measurement. In the direct measurement method, water metering equipment is first used to form the actual irrigation quota of water-to-dry crops based on the irrigation water consumption of irrigation wells around water-to-dry crops; then, based on the area of ​​water-to-dry crops, the quota method is used to calculate the actual irrigation water volume of water-to-dry crops in the groundwater over-exploitation area. In the indirect measurement method, the effective precipitation and crop water demand actually added to the root layer of the plant are calculated based on precipitation and hydrological statistics, the area of ​​water-to-dry crops implemented, and the planting types and structures, to determine the annual irrigation water demand, and combined with the area of ​​water-to-dry crops implemented, the estimated irrigation water volume of the crop irrigation water process in the groundwater over-exploitation area is calculated.

[0041] In the crop water-to-dryland project, existing irrigation wells that are used to save and protect groundwater are sealed. The actual irrigation water volume or the estimated irrigation water volume of the irrigation wells around the sealed wells is allocated to the sealed wells according to the irrigation coverage and coverage weight in the groundwater over-exploitation area. This ensures that the number of wells corresponding to the irrigation water volume has the same measurement basis before and after the implementation of the water-to-dryland project, avoiding large local deviations.

[0042] Step 300: Generate groundwater resource water saving data in the process of converting crops from water-based crops to dry crops based on the metering method and corresponding irrigation statistical data.

[0043] Determine the difference in irrigation water volume before and after the crop water-to-dry farming conversion based on direct or indirect measurement methods, and determine the amount of water saved in each irrigation well by groundwater resources after the implementation of the water-to-dry farming conversion based on the difference in irrigation water volume.

[0044] For closed wells, the water saved in the irrigation wells around the closed wells is allocated to the closed wells according to the irrigation coverage and coverage weight, so as to obtain the water saved in each closed well (location) to cope with the irrigation water after the crop water is converted to drought.

[0045] Step 400: Generate groundwater resource utilization type data in the process of converting crops from water to dry land based on relevant basic data.

[0046] The type of groundwater storage in the groundwater overexploitation area is determined based on the basic data such as groundwater storage and burial conditions and hydrogeological parameters, and is divided into the type of utilization of phreatic water or confined water. The type of utilization in the same groundwater overexploitation area or in a part of the overexploitation area can be determined separately.

[0047] Step 500: Based on the amount of water saved and the type of water used, the impact of the irrigation well group in the groundwater over-exploitation area on the groundwater level of the relevant water level observation wells is used to generate evaluation data on the impact of water-to-dry land conversion on the groundwater level.

[0048] Considering that crop irrigation mostly uses water from wells, the amount of water drawn from irrigation wells can be used to equal the amount of irrigation water in groundwater overexploitation areas or local areas of overexploitation areas. According to the principle of water level superposition of interference well groups, the observation benchmark of groundwater level is formed by setting water level observation wells, and the water saving of related irrigation wells is marked to form a stable quantification of the change of water saving for the observation benchmark water level, and the groundwater level drop after crop water-to-dry conversion is determined as the evaluation data of the impact of water-to-dry conversion on groundwater level.

[0049] The setting of irrigation wells and observation wells is as follows: Figure 2 As shown. Figure 2 In the process, the water-to-drought area in the groundwater over-exploitation area or the local water-to-drought area is determined, and the location of irrigation wells in the water-to-drought area is determined, and appropriate water level observation wells are set according to the location of irrigation wells based on the principle of superposition of water levels of interference well groups.

[0050] The method for evaluating the impact of water-to-drought conversion on groundwater levels in groundwater over-exploitation areas according to the embodiment of the present invention provides an improved method for quantitatively evaluating water level benefits during the implementation of water-to-drought conversion in groundwater over-exploitation areas where the intensity of groundwater development and utilization is high and water use is complex. It has the advantages of short cycle, low cost and quantitative calculation, and can calculate the amount of water saved based on the irrigation water use process and water volume statistics of the surrounding areas of water-to-drought conversion based on effective precipitation, and can form an accurate calculation of the water level benefits of the water saved. The evaluation data obtained by this evaluation method can be used as a water level benefit evaluation before and after the implementation of "water-to-drought conversion" for crops, and can accurately evaluate the impact of "water-to-drought conversion" measures on groundwater level changes, providing a scientific basis for groundwater resource management and decision-making.

[0051] like Figure 1 As shown, in one embodiment of the present invention, in step 500, forming the evaluation data of the impact of water-to-drought conversion on the groundwater level includes:

[0052] Step 510: Calculate the water level drawdown of a single irrigation well based on the type of groundwater resource utilization and the amount of water saved by the single irrigation well.

[0053] The flow rate of each irrigation well after the water-to-dry land conversion can be calculated based on the amount of water saved in each irrigation well (including sealed wells) after the water-to-dry land conversion.

[0054] When the utilization type of groundwater resources is confined water, the following model is used to calculate the water level drawdown:

[0055]

[0056] Where: s is the water level drop, Q is the irrigation well flow rate, K is the soil permeability coefficient under the irrigation well, M is the thickness of the aquifer under the irrigation well, u is the parameter, r is the distance between the observation well and the irrigation well, μ * is the water storage coefficient of the aquifer under the irrigation well, t is the time from the start of irrigation well pumping to the calculation time, W(u) is the constant flow well function of the aquifer without leakage, e is a natural constant, and y is the integral variable.

[0057] When the type of groundwater resource utilization is diving, the following model is used to calculate the water level drawdown:

[0058]

[0059] Among them: s′ is the corrected water level drawdown, H0 is the initial water head, and u is the soil water supply degree in the irrigation well.

[0060] Step 520: Determine the water level drop in the observation well according to the water level drop in each single irrigation well.

[0061] The water level drawdown in the observation well is the algebraic sum of the water level drawdowns in the individual irrigation wells. s is the water level drawdown and n is the number of irrigation wells.

[0062] Step 530: Determine the impact assessment of groundwater level before and after crop water conversion to drought according to the water level drop in the observation well.

[0063] The water level drop in the observation wells reflects the groundwater level change data in the groundwater overexploitation area or in the part of the overexploitation area after the crop water conversion to drought. It reflects the impact of the crop water conversion on the groundwater level below.

[0064] The method for evaluating the impact of water-to-drying in groundwater over-exploitation areas on groundwater levels in the embodiment of the present invention uses the objectively distributed irrigation volume changes and water conservation changes of irrigation wells to reflect the objective state of groundwater changes in crop planting areas, effectively simplifying the collection process of complex groundwater parameters.

[0065] The evaluation system of the impact of water-to-drying in groundwater over-exploitation areas on groundwater levels in the embodiment of the present invention comprises:

[0066] A memory, used to store program codes in the process of the evaluation method of the above embodiment;

[0067] The processor is used to execute the program code in the processing of the evaluation method of the above embodiment.

[0068] The processor may be a DSP (Digital Signal Processor) digital signal processor, an FPGA (Field-Programmable Gate Array) field programmable gate array, an MCU (Microcontroller Unit) system board, a SoC (system on a chip) system board, a PLC (Programmable Logic Controller) minimum system including I / O, or remote computing resources.

[0069] An evaluation system for the impact of water conversion to drought on groundwater level in a groundwater overexploitation area according to an embodiment of the present invention is as follows Figure 3 As shown. Figure 3 In this embodiment, the present invention includes:

[0070] Information acquisition device 10, used to acquire relevant basic data of water resources in groundwater over-exploitation areas;

[0071] Irrigation statistics device 20, used to form a measurement method of water resource utilization in the process of crop water-to-dry conversion and corresponding irrigation statistics data according to relevant basic data;

[0072] The water-saving statistical device 30 is used to form the water-saving data of groundwater resources in the process of crop water-to-drying conversion according to the metering method and the corresponding irrigation statistical data;

[0073] Type classification means 40, for forming utilization type data of groundwater resources in the process of crop water-to-dryland conversion according to relevant basic data;

[0074] The evaluation and processing device 50 is used to form evaluation data on the impact of water-to-dry land conversion on the groundwater level through the impact of the irrigation well group in the groundwater over-exploitation area on the groundwater level of the relevant water level observation wells according to the water saving amount and utilization type.

[0075] like Figure 3 As shown, in one embodiment of the present invention, the evaluation processing device 50 further includes:

[0076] A local calculation module 51 is used to calculate the water level drawdown of a single irrigation well according to the type of groundwater resource utilization and water conservation of the single irrigation well;

[0077] A regional calculation module 52, for determining the water level drop of the observation well according to the water level drop of each single irrigation well;

[0078] The data utilization module 53 is used to determine the impact assessment of groundwater level before and after crop water conversion to drought according to the water level drop in the observation well.

[0079] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention 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 by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for evaluating the impact of water-to-drying conversion on groundwater levels in groundwater overexploitation areas, characterized in that: include: Obtain relevant basic data on water resources in groundwater over-exploitation areas; Based on the relevant basic data, the measurement method of water resource utilization and the corresponding irrigation statistics in the process of crop water-to-dryland conversion are formed; Based on the measurement method and the corresponding irrigation statistical data, the water saving data of groundwater resources in the process of crop water-to-dry land conversion is formed; Based on the relevant basic data, the utilization type data of groundwater resources in the process of crop water-to-dry land conversion is formed; Based on the amount of water saved and the type of water used, the impact of irrigation wells in the groundwater overexploitation area on the groundwater level of related water level observation wells is used to generate assessment data on the impact of water-to-dry land conversion on the groundwater level; The measurement method includes a direct measurement method, which forms an actual irrigation quota for water-to-dry crops based on the irrigation water volume of irrigation wells around water-to-dry crops; and then uses a quota method to calculate the actual irrigation water volume of water-to-dry crops in the groundwater over-exploitation area based on the area of ​​water-to-dry crops. The measurement method also includes an indirect measurement method, which measures the effective precipitation and crop water demand actually added to the plant root layer soil, determines the annual irrigation water demand, and combines the water-to-dry land conversion implementation area to calculate the estimated irrigation water volume of the crop irrigation water use process in the groundwater over-exploitation area.

2. The method for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater overexploitation areas according to claim 1, characterized in that: The relevant basic data include time-series statistical data in the fields of geography, meteorology, hydrology and agriculture.

3. The method for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater overexploitation areas according to claim 1, characterized in that: The amount of water saved in groundwater resources during the process of converting crops from water to dry land includes: Determine the difference in irrigation water volume before and after the crop water-to-dry farming conversion based on direct or indirect measurement methods, and determine the amount of water saved in each irrigation well by groundwater resources after the implementation of the water-to-dry farming conversion based on the difference in irrigation water volume.

4. The method for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater overexploitation areas according to claim 1, characterized in that: The irrigation wells also include closed wells, which are allocated to the closed wells according to the irrigation coverage and coverage weights in the groundwater over-exploitation area by distributing the actual irrigation water volume or the estimated irrigation water volume of the irrigation wells around the closed wells, and the water saved in the irrigation wells around the closed wells is distributed to the closed wells according to the irrigation coverage and coverage weights, so as to obtain the water saved by each closed well to cope with the irrigation water volume after crop water conversion to drought conditions.

5. The method for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater overexploitation areas according to claim 1, characterized in that: The groundwater storage types are classified as either phreatic or confined water utilization types.

6. The method for evaluating the impact of water-to-dry land conversion on groundwater levels in groundwater overexploitation areas according to claim 1, characterized in that: The formation of the evaluation data includes: Calculate the water level drawdown of a single irrigation well based on the type of groundwater resource utilization and water conservation of the single irrigation well; Determine the water level drawdown in the observation well based on the water level drawdown in each single irrigation well; The impact assessment of groundwater levels before and after crop water conversion to drought conditions was determined based on the water level drop in the observation wells.

7. An assessment system for the impact of water conversion to dry land on groundwater levels in groundwater overexploitation areas, characterized in that: include: A memory for storing program codes in the process of the evaluation method according to any one of claims 1 to 6; A processor is used to execute the program code.

8. An assessment system for the impact of water-to-drying conversion on groundwater levels in groundwater overexploitation areas, characterized in that: include: An information acquisition device for acquiring relevant basic data on water resources in groundwater over-exploitation areas; Irrigation statistics device, used to form the measurement method of water resource utilization and corresponding irrigation statistics in the process of crop water-to-dry conversion based on relevant basic data; A water-saving statistical device is used to form groundwater resource saving data in the process of converting crops from water to dry land according to a metering method and corresponding irrigation statistical data; the metering method includes a direct metering method, which forms an actual irrigation quota for water-converted crops according to the irrigation water consumption of irrigation wells around water-converted crops; then, according to the area of ​​water-converted crops, the quota method is used to calculate the actual irrigation water consumption in the process of water-converted crops in the groundwater over-exploitation area; the metering method also includes an indirect metering method, which measures the effective precipitation actually supplemented to the root layer soil of the plants and the crop water demand, determines the annual irrigation water demand, and calculates the measured irrigation water consumption in the process of crop irrigation water in the groundwater over-exploitation area in combination with the implementation area of ​​water-converted crops; A type classification device for forming utilization type data of groundwater resources in the process of crop water-to-dry land conversion based on relevant basic data; The evaluation and processing device is used to form evaluation data on the impact of water-to-dry land conversion on the groundwater level through the impact of irrigation well groups on the groundwater level of relevant water level observation wells in the groundwater over-exploitation area according to the amount of water saved and the type of utilization.

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