Method for evaluating influence of flow field control of strip mine area on underground water

Abstract

The invention discloses a method for evaluating influence of flow field control of a strip mine area on underground water. The method comprises the following steps: collecting geological data of a research area; hydrogeological research data are collected; collecting research hydrological data; establishing a research area conceptual model; establishing a research area numerical model; performing parameter assignment on the numerical model of the research area; calculating the numerical model of the research area; performing model feasibility analysis; and simulating an underground water flow field under mine area underground water control. According to the invention, the overall change condition of the underground water system can be comprehensively and dynamically known. The effectiveness of underground water control measures and the potential influence on the surrounding environment can be evaluated, and a scientific basis is provided for water resource management and environmental protection of a mining area.

Description

Technical Field

[0001] The present invention relates to the field of open-pit mining, and particularly to a method for evaluating the influence of flow field control in an open-pit mining area on groundwater. Background Art

[0002] With the continuous expansion of the scale of open-pit mining, its interference with the groundwater system has attracted increasing attention. During the open-pit mining process, in order to ensure the dryness and safety of the mining working face, various flow field control measures are often required, such as the dewatering method, the curtain grouting method, etc. Artificial flow field control measures will have an impact on aspects such as the groundwater level and the water flow direction. Traditional research methods based on on-site observations and physical tests are difficult to comprehensively and dynamically understand the overall changes in the groundwater system. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for evaluating the influence of flow field control in an open-pit mining area on groundwater to solve the technical problems mentioned in the background art.

[0004] A method for evaluating the influence of flow field control in an open-pit mining area on groundwater, the method comprising the following steps:

[0005] Step 1, collect geological data of the study area;

[0006] Step 2, collect hydrogeological data of the study;

[0007] Step 3, collect hydrological data of the study;

[0008] Step 4, establish a conceptual model of the study area;

[0009] Step 5, establish a numerical model of the study area;

[0010] Step 6, assign parameters to the numerical model of the study area;

[0011] Step 7, perform arithmetic calculations on the numerical model of the study area;

[0012] Step 8, analyze the feasibility of the numerical model;

[0013] Step 9, simulate the groundwater flow field under the control of the groundwater in the mining area.

[0014] As a further technical solution of the present invention, collecting the geological data of the study area includes:

[0015] Step 1.1, collect stratigraphic lithology classification information, including the distribution range, thickness variation and mutual combination relationship of various rocks in different strata;

[0016] Step 1.2: Collect geological structure features, including the exact location, strike, dip angle, and throw of faults, the shape, dip direction and dip angle of the axial plane, and the undulation of the hinge of folds, as well as the occurrence, density, and filling conditions of joints, etc.;

[0017] Step 1.3: Classify, record, and store geological data of various research areas.

[0018] As a further technical solution of the present invention, in Step 2, the steps of collecting hydrogeological data of the research area include:

[0019] Step 2.1: Collect the types, number of layers, thickness, and spatial distribution of aquifers;

[0020] Step 2.2: Collect the variation of hydrogeological parameters such as permeability coefficient, specific yield, and storage coefficient in different regions;

[0021] Step 2.3: Collect the dynamic change data of groundwater levels;

[0022] Step 2.4: Collect the recharge sources and discharge pathways of groundwater, including the quantified data of precipitation infiltration, river leakage, and lateral runoff recharge, as well as the flow information of evapotranspiration, river discharge, and artificial extraction;

[0023] Step 2.5: Classify, record, and store hydrogeological data of various research areas.

[0024] As a further technical solution of the present invention, in Step 3, the steps of collecting hydrological data of the research area include:

[0025] Step 3.1: Collect meteorological data of the research area;

[0026] Step 3.2: Collect hydrological data of hydrological stations in the research area;

[0027] Step 3.3: Collect precipitation data of the research area;

[0028] Step 3.4: Classify, record, and store hydrological data of various research areas.

[0029] As a further technical solution of the present invention, in Step 4, the steps of establishing a conceptual model of the research area include:

[0030] Step 4.1: According to the research purpose and actual geographical conditions, delimit the boundary of the groundwater system and clarify the research area;

[0031] Step 4.2: Simplify the geological structure in the research area and generalize the strata with different lithologies and hydraulic characteristics into representative aquifers and aquitards;

[0032] Step 4.3: Analyze the distribution law of hydrogeological parameters of the aquifer;

[0033] Step 4.4: Determine the recharge and discharge methods of groundwater and generalize its boundary conditions;

[0034] Step 4.5: Identify the source-sink terms in the system, quantify the intensity and distribution of the source-sink terms, and determine the artificial extraction sink term based on the distribution and extraction volume of the production wells.

[0035] As a further technical solution of the present invention, in Step 5, the steps of establishing a numerical model of the study area include:

[0036] Step 5.1: Use the Grid module in GMS to establish a grid structure;

[0037] Open the GMS software, enter the Grid module, and set the grid size and grid division method according to the scope and accuracy requirements of the study area; when dividing the grid, ensure that the grid boundary matches the boundary of the study area, and perform special processing on important geological structures (such as obvious folds, faults, etc.) and the locations of production wells so that they are located at the grid nodes or the centers of grid cells;

[0038] Step 5.2: Use geological information from multiple sources (such as formation lithology data, geological structure mapping data, borehole exploration data, etc.) to construct a geological model;

[0039] Import geological information from multiple sources into the GMS software, and use the geological modeling tools in the software to construct a geological model; according to the formation lithology and geological structure information, set different formation units and geological structure surfaces in the model and assign their corresponding physical properties; through interpolation and extrapolation of borehole data, construct a three-dimensional geological model to accurately reflect the geological structure of the study area;

[0040] Step 5.3: Use spatial interpolation methods to calculate the surface elevation, the elevation of the top and bottom plates of the unconfined aquifer and the confined aquifer in the study area, and establish a three-dimensional geological model;

[0041] Utilize the existing topographic data points and borehole data, and set appropriate interpolation parameters (such as the power exponent when selecting the inverse distance weighted interpolation method, the smoothing factor in the spline interpolation method, etc.); combine the elevation data (referring to the elevation data of the surface, the top plate of the unconfined aquifer, the bottom plate of the unconfined aquifer, the top plate of the confined aquifer, the bottom plate of the confined aquifer, etc. relative to a certain reference plane obtained through measurement or calculation) with the three-dimensional geological model to further improve the three-dimensional geological model and ensure the accurate spatial position and shape of the aquifer.

[0042] As a further technical solution of the present invention, in Step 6, the steps of parameter assignment for the numerical model of the study area include:

[0043] Step 6.1: Parameter zoning of the numerical model;

[0044] According to the differences in geological and hydrogeological conditions, the numerical model is zoned. Areas with similar hydrogeological parameters (such as similar hydraulic conductivity, specific yield, storage coefficient, etc. fluctuating within a preset range) are divided into the same parameter zone. In the GMS software, use polygon or irregular grid tools to draw the parameter zone boundaries and assign a unique identifier to each zone; based on the previously obtained hydrogeological parameter data, assign hydrogeological parameters to each parameter zone;

[0045] Step 6.2: Assignment of hydrogeological parameters;

[0046] In the parameter editing interface of the GMS software, input the hydraulic conductivity, specific yield, and storage coefficient into the model zone by zone; for some areas lacking measured data, refer to the parameter values of surrounding areas with similar geological conditions and combine geostatistical methods for estimation and assignment. For the source-sink terms in the model, accurate assignment is carried out;

[0047] Step 6.3: Assignment of source-sink terms;

[0048] For the precipitation infiltration recharge source, calculate the recharge amount for each time step according to the precipitation data and infiltration coefficient of the study area and distribute it to the corresponding grid cells or nodes. For the river leakage recharge source, determine the magnitude and distribution of the recharge amount according to the river water level, flow rate, and leakage coefficient; for the artificial extraction sink term, set sink points at the corresponding positions according to the extraction amount data of the production wells and assign the correct extraction intensity value.

[0049] As a further technical solution of the present invention, in step 7, the steps of calculating the numerical model of the study area include:

[0050] Step 7.1: Import the constructed numerical model and the assigned parameter information into the MODFLOW operation module built in the GMS software;

[0051] Step 7.2: Open the "MODFLOW Global / Basic Package" module and set factors according to the research requirements and actual situations;

[0052] Step 7.3: Check the operation model; use the "check simulation" function to comprehensively check the model. The inspection content includes whether there are problems in aspects such as the boundary conditions, parameter assignment, and grid structure of the model. If problems are found, conduct one-by-one investigation and correction according to the error information prompted by the software to ensure the integrity and correctness of the model;

[0053] Step 7.4. Use the "run simulation" function to start the calculation. During the calculation process, pay close attention to the calculation progress and the use of computer resources.

[0054] Step 7.5, read the calculation results;

[0055] Use the "read budget" function to read the calculation results, organize and analyze the calculated groundwater level, flow rate and flow, and generate data reports and charts.

[0056] As a further technical solution of the present invention, in step 8, the step of model feasibility analysis includes:

[0057] Step 8.1, model calibration;

[0058] Model calibration first collects long-term and high-frequency water levels, flow rates and water quality at multiple observation points in the study area, selects key parameters for preliminary adjustment and runs the model, uses the "Plot Wizard" module to draw a comparison curve between simulation and observation values and calculates the fitting index, adjusts key parameters in a targeted manner based on the results, iterates multiple times and records the calibration log, analyzes the adjustment rules and sensitivity of key parameters, until the fitting index meets the preset standards, completes the calibration and enables the model to accurately simulate the behavior of the groundwater system;

[0059] Step 8.2: Model verification;

[0060] Prepare a validation set of key indicators that are independent of the calibration data, input the calibrated model operation, use visualization tools to draw a comparison curve between simulation and observation values, and calculate indicators. If the results match and the indicators meet the standards, the model is reliable. Otherwise, analyze the reasons and re-examine the calibration process and improve and optimize it until it passes the verification to ensure that it can reflect the characteristics of the groundwater system.

[0061] As a further technical solution of the present invention, in step 9, the step of simulating the groundwater flow field under the control of groundwater in the mining area includes:

[0062] Step 9.1, generalize the groundwater control measures, generalize the groundwater control measures in the study area into: source control, runoff control and discharge control;

[0063] Step 9.2, achieving the simulation effect of groundwater control in the mining area by adjusting parameters;

[0064] By adjusting the relevant parameters in the model, the simulation effect of groundwater control in the mining area can be achieved; in the GMS software, different parameter combinations are set for different control measures and simulation scenarios, and the model is run for simulation calculation to observe the changes in the groundwater flow field and analyze the impact of different parameter changes on the groundwater flow field;

[0065] Step 9.3: Simulate the groundwater flow field under the control of the mine area groundwater, and analyze the influence of the mine area groundwater control on the groundwater flow field;

[0066] Simulate the groundwater flow field under the control of the mine area groundwater. Using the visualization function of the GMS software, draw the contour map of the groundwater level and the velocity vector map, etc.; Analyze the influence of the mine area groundwater control on the groundwater flow field. By comparing the changes in the flow field before and after the control, evaluate the effectiveness of the groundwater control measures and the potential impact on the surrounding environment, and provide a scientific basis for the water resource management and environmental protection of the mine area.

[0067] Beneficial effects achieved by the present invention:

[0068] The present invention provides a method for evaluating the influence of the flow field control in an open-pit mine area on groundwater. The present invention can comprehensively and dynamically understand the overall changes in the groundwater system. The present invention can evaluate the effectiveness of the groundwater control measures and the potential impact on the surrounding environment, and provide a scientific basis for the water resource management and environmental protection of the mine area. Description of the drawings

[0069] Figure 1 It is a flowchart of a method for evaluating the influence of the flow field control in an open-pit mine area on groundwater. Detailed implementation manners

[0070] The following will describe in detail the technical solutions of the present invention with reference to specific drawings.

[0071] Please refer to Figure 1 , this embodiment provides a method for evaluating the influence of the flow field control in an open-pit mine area on groundwater, and the method includes the following steps:

[0072] Step 1: Collect the geological data of the study area;

[0073] Step 2: Collect the hydrogeological data of the study;

[0074] Step 3: Collect the hydrological data of the study;

[0075] Step 4: Establish a conceptual model of the study area;

[0076] Step 5: Establish a numerical model of the study area;

[0077] Step 6: Assign parameters to the numerical model of the study area;

[0078] Step 7: Perform arithmetic calculations on the numerical model of the study area;

[0079] Step 8: Analyze the feasibility of the numerical model;

[0080] Step 9: Simulate the groundwater flow field under the control of the mine area groundwater.

[0081] In this embodiment, the geological data collection of the study area includes:

[0082] Step 1.1: Collect the stratigraphic lithology classification information, including the distribution range, thickness variation, and mutual combination relationship of various rocks in different strata;

[0083] Step 1.2: Collect the geological structure characteristics, including the precise location, strike, dip angle, and fault throw of faults, the shape, axial plane dip and dip angle, and hinge undulation of folds, the occurrence, density, and filling conditions of joints, etc.;

[0084] Step 1.3: Classify, record, and store various geological data of the study area for convenient subsequent query and call.

[0085] In this embodiment, in Step 2, the steps for collecting hydrogeological data of the study area include:

[0086] Step 2.1: Collect the types, number of layers, thickness, and spatial distribution of aquifers, such as the specific locations and ranges of unconfined aquifers and confined aquifers, and the hydraulic connection between each aquifer;

[0087] Step 2.2: Collect the variation of hydrogeological parameters such as permeability coefficient, specific yield, and storage coefficient in different regions;

[0088] Step 2.3: Collect the dynamic change data of groundwater levels;

[0089] Step 2.4: Collect the recharge sources and discharge pathways of groundwater, including the quantitative data of recharge methods such as precipitation infiltration, river leakage, and lateral runoff recharge, as well as the flow information of discharge pathways such as evapotranspiration, discharge to rivers, and artificial extraction;

[0090] Step 2.5: Classify, record, and store various hydrogeological data of the study area for convenient subsequent query and call.

[0091] In this embodiment, in Step 3, the steps for collecting hydrological data of the study area include:

[0092] Step 3.1: Collect the meteorological data of the study area;

[0093] Step 3.2: Collect the hydrological data of hydrological stations in the study area, such as surface runoff flow;

[0094] Step 3.3: Collect the precipitation data of the study area;

[0095] Step 3.4: Classify, record, and store various hydrological data of the study area for convenient subsequent query and call.

[0096] In this embodiment, in Step 4, the steps for establishing a conceptual model of the study area include:

[0097] Step 4.1: Define the boundary of the groundwater system and clarify the scope of the study area according to the research purpose and actual geographical conditions.

[0098] When determining the constant head boundary, through long-term monitoring of the water levels of surface water bodies and combined with hydrological analysis, considering the seasonal and inter-annual variations of the water levels, determine a reasonable water head value. For the impermeable boundary, based on geological exploration data, accurately judge the impermeable properties of faults and the distribution range of impermeable rock layers to ensure the accurate setting of the boundary. When setting the flow boundary, through on-site flow monitoring and water balance analysis, considering the lateral inflow and outflow of groundwater and its hydraulic connection with the surrounding aquifers, determine the boundary flow value.

[0099] Step 4.2: Simplify the geological structure within the study area and generalize the strata with different lithologies and hydraulic characteristics into representative aquifers, aquitards, etc.

[0100] According to the lithology and hydraulic characteristics of the strata, re-divide different stratigraphic units into aquifers and aquitards and assign corresponding attribute parameters. For example, mark the previously determined sandstone aquifer as an aquifer unit with a certain permeability coefficient and storage coefficient in the model, and mark the shale aquitard as an aquitard unit with extremely low permeability. During the generalization process, continuously compare the original geological data with the generalization results and make necessary adjustments and verifications to ensure the accuracy of the generalization.

[0101] Step 4.3: Analyze the distribution laws of hydrogeological parameters such as the permeability coefficient, porosity, and storage rate of the aquifer.

[0102] Step 4.4: Determine the recharge and discharge methods of groundwater, such as recharge by precipitation infiltration, recharge by river leakage, discharge by evaporation, discharge by artificial extraction, etc., and generalize their boundary conditions.

[0103] When setting the recharge and discharge conditions, for recharge by precipitation infiltration, set infiltration parameters by region according to different soil types and vegetation-covered areas; for discharge by evaporation, consider the evaporation differences under different seasons and different surface cover conditions and use a layered calculation method to determine the evaporation discharge amount; for river leakage, adjust the leakage parameters in real time according to the permeability changes of riverbed sediments and the dynamic changes of the hydraulic gradient between the river and groundwater.

[0104] Step 4.5: Identify the source-sink terms in the system, quantify the intensity and distribution of the source-sink terms, and determine the artificial extraction sink term according to the distribution and extraction volume of production wells.

[0105] In this embodiment, in Step 5, the steps for establishing the numerical model of the study area include:

[0106] Step 5.1: Use the Grid module in GMS to establish a grid structure.

[0107] Open the GMS software, enter the Grid module, and set the appropriate grid size and grid division method according to the scope and accuracy requirements of the research area; for areas with complex terrain and large variations in hydrogeological conditions, use a smaller grid size to improve the accuracy of the model; for relatively uniform areas, the grid size can be appropriately increased to reduce the amount of calculation; when dividing the grid, ensure that the grid boundary matches the boundary of the research area, and perform special processing on important geological structures (such as obvious folds, faults, etc.) and the locations of production wells so that they are located at the grid nodes or the centers of grid cells;

[0108] Step 5.2: Use geological information from multiple sources such as previous borehole data (such as formation lithology data, geological structure mapping data, borehole exploration data, etc.) to construct a geological model;

[0109] Import geological information from multiple sources such as previous borehole data and geological exploration reports into the GMS software, and use the geological modeling tools in the software to construct a geological model; according to the formation lithology and geological structure information, set different formation units and geological structure surfaces in the model and assign them corresponding physical properties, such as rock type, permeability, porosity, etc.; through interpolation and extrapolation of borehole data, construct a three-dimensional geological model to accurately reflect the geological structure of the research area;

[0110] Step 5.3: Use spatial interpolation methods to calculate the surface elevation, the elevation of the top and bottom plates of the unconfined aquifer and the confined aquifer in the research area, and establish a three-dimensional geological model;

[0111] Use the existing topographic data points and borehole data to set appropriate interpolation parameters (such as the power exponent when selecting the inverse distance weighted interpolation method, the smoothing factor in the spline interpolation method, etc.), such as the variogram model and the search radius, to generate a high-precision elevation surface; combine the elevation data (referring to the elevation data of the surface, the top plate of the unconfined aquifer, the bottom plate of the unconfined aquifer, the top plate of the confined aquifer, the bottom plate of the confined aquifer, etc. relative to a certain reference plane obtained through measurement or calculation) with the three-dimensional geological model to further improve the three-dimensional geological model and ensure the accurate spatial position and shape of the aquifer.

[0112] In this embodiment, in step 6, the steps of assigning parameters to the numerical model in the research area include:

[0113] Step 6.1: Division of parameter zones for the numerical model;

[0114] According to the differences in geological and hydrogeological conditions (such as lithology, permeability, porosity, etc.), the numerical model is divided into zones. Areas with similar hydrogeological parameters (such as similar hydraulic conductivity, specific yield, storage coefficient, etc. fluctuating within a preset range) are divided into the same parameter zone. For example, strata with similar hydraulic conductivity are divided into one zone. In the GMS software, using polygon or irregular grid tools, draw the parameter zone boundaries and assign a unique identifier to each zone; based on the previously obtained hydrogeological parameter data, assign hydrogeological parameters to each parameter zone;

[0115] Step 6.2: Assign hydrogeological parameters;

[0116] In the parameter editing interface of the GMS software, input parameters such as hydraulic conductivity, specific yield, and storage coefficient into the model zone by zone; for some areas lacking measured data, refer to the parameter values of surrounding areas with similar geological conditions and combine geostatistical methods for estimation and assignment. For the source-sink terms in the model, make accurate assignments;

[0117] Step 6.3: Assign source-sink terms;

[0118] For the precipitation infiltration recharge source, calculate the recharge amount for each time step according to the precipitation data and infiltration coefficient of the study area, and distribute it to the corresponding grid cells or nodes. For the river leakage recharge source, determine the magnitude and distribution of the recharge amount according to the river water level, flow rate, and leakage coefficient; for the artificial extraction sink term, set sink points at the corresponding positions according to the extraction amount data of the production wells and assign the correct extraction intensity value.

[0119] In this embodiment, in step 7, the steps of calculating the numerical model of the study area include:

[0120] Step 7.1: Import the constructed numerical model and the parameter information after assignment into the MODFLOW operation module built in the GMS software. In the software interface, select appropriate import options to ensure that the data is transferred to the operation module completely and accurately;

[0121] Step 7.2: Open the "MODFLOW Global / Basic Package" module and set factors such as operation methods and simulation time according to the research requirements and actual situations; for the operation method, select a numerical solution method suitable for the geological and hydrogeological conditions of the study area, and set the corresponding iteration parameters and convergence criteria. Determine the start time and end time according to the research time span and set an appropriate time step to ensure the accuracy and stability of the simulation results;

[0122] Step 7.3, check the operation model; use the "check simulation" function to conduct a comprehensive check on the model, including whether there are any problems (errors or unreasonableness) in the model's boundary conditions, parameter assignments, grid structure, etc. If problems are found, check and correct them one by one according to the error messages prompted by the software to ensure the integrity and correctness of the model;

[0123] Step 7.4, use the "run simulation" function to start the calculation; during the calculation process, pay close attention to the calculation progress and the use of computer resources. If the calculation process is abnormally interrupted or the calculation time is too long, analyze the cause and take corresponding measures, such as adjusting the calculation parameters, optimizing computer performance, etc., to ensure the smooth completion of the calculation;

[0124] Step 7.5, read the calculation results;

[0125] Use the "read budget" function to read the calculation results, organize and analyze the calculated groundwater level, flow rate, flow rate and other data, and generate data reports and charts for subsequent result analysis and discussion.

[0126] In this embodiment, in step 8, the steps of model feasibility analysis include:

[0127] Step 8.1, model calibration;

[0128] Model calibration first collects long-term and high-frequency data on water level, flow rate, water quality, etc. from multiple observation points in the study area, selects key parameters such as permeability coefficient, makes preliminary adjustments, and then runs the model. Use the "Plot Wizard" module to draw a comparison curve between simulation and observation values and calculate fitting indicators such as RMSE and NSE. According to the results, adjust key parameters in a targeted manner, iterate multiple times and record calibration logs, analyze the adjustment rules and sensitivity of key parameters, until the fitting indicators meet the preset standards (i.e., RMSE is within an acceptable range and NSE is high), and complete the calibration so that the model can accurately simulate the behavior of the groundwater system.

[0129] Step 8.2: Model verification;

[0130] Prepare a validation set that is independent of the calibration data and contains key indicators such as groundwater level, input the calibrated model operation, use visualization tools to draw a comparison curve between simulation and observation values, and calculate indicators such as root mean square error and determination coefficient. If the results match and the indicators meet the standards, the model is reliable. Otherwise, analyze the reasons, which may be problems with the model structure. It is necessary to re-examine the calibration process and improve and optimize it, such as adjusting parameters, until it passes the verification to ensure that it can reflect the characteristics of the groundwater system.

[0131] In this embodiment, in step 9, the step of simulating the groundwater flow field under the control of the mining area groundwater includes:

[0132] Step 9.1: Generalize the groundwater control measures, and generalize the groundwater control measures in the study area as: source control, runoff control, and discharge control;

[0133] Step 9.2: Achieve the simulation effect of groundwater control in the mining area by adjusting parameters;

[0134] By adjusting the relevant parameters in the model, such as the permeability coefficient of the aquifer, specific yield, mining intensity, etc., achieve the simulation effect of groundwater control in the mining area; In the GMS software, for different control measures and simulation scenarios, set different parameter combinations, and run the model for simulation calculation, observe the changes in the groundwater flow field, and analyze the influence degree of different parameter changes on the groundwater flow field;

[0135] Step 9.3: Simulate the groundwater flow field under the groundwater control in the mining area, and analyze the influence of the groundwater control in the mining area on the groundwater flow field;

[0136] Simulate the groundwater flow field under the groundwater control in the mining area, use the visualization function of the GMS software to draw the contour map of the groundwater level and the velocity vector map, etc.; Analyze the influence of the groundwater control in the mining area on the groundwater flow field, such as the shape of the drawdown funnel of the groundwater level, the change trend of the velocity, the change of the hydraulic gradient, etc. By comparing the changes in the flow field before and after the control, evaluate the effectiveness of the groundwater control measures and the potential impact on the surrounding environment, and provide a scientific basis for the water resource management and environmental protection in the mining area.

[0137] It should be noted that in this article, the term "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article, or device including that element.

[0138] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for evaluating the impact of flow field control in open-pit mining areas on groundwater, characterized in that, The method includes the following steps: Step 1: Collect geological data of the study area; Step 2: Collect hydrogeological data of the study area; Step 3: Collect hydrological data of the study area; Step 4: Establish a conceptual model of the study area; Step 5: Establish a numerical model of the study area; Step 6: Assign parameters to the numerical model of the study area; Step 7: Perform calculations on the numerical model of the study area; Step 8: Conduct a feasibility analysis of the numerical model; Step 9: Simulate the groundwater flow field under the control of the mine groundwater.

2. The method for evaluating the influence of open-pit mining area flow field control on groundwater according to claim 1, characterized in that, Collecting geological data of the study area includes: Step 1.1: Collect classification information of formation lithology, including the distribution range, thickness variation, and mutual combination relationship of various rocks in different strata; Step 1.2: Collect geological structure characteristics, including the precise location, strike, dip angle, and throw of faults, the shape, axial plane dip and dip angle, and hinge undulation of folds, and the occurrence, density, and filling conditions of joints; Step 1.3: Classify, record, and store data of various geological data of the study area.

3. A method for evaluating the impact of flow field control in open-pit mining areas on groundwater according to claim 1, characterized in that In Step 2, the steps of collecting hydrogeological data of the study area include: Step 2.1: Collect the type, number of layers, thickness, and spatial distribution of aquifers; Step 2.2: Collect the variation of hydrogeological parameters in different regions; Step 2.3: Collect data on the dynamic changes of groundwater levels; Step 2.4: Collect the recharge sources and discharge pathways of groundwater, including quantitative data on precipitation infiltration, river leakage, and lateral runoff recharge, as well as flow information on evapotranspiration, discharge to rivers, and artificial extraction; Step 2.5: Classify, record, and store data of various hydrogeological data of the study area.

4. A method for evaluating the impact of flow field control in an open-pit mining area on groundwater according to claim 1, characterized in that, In Step 3, the steps of collecting hydrological data of the study area include: Step 3.1: Collect meteorological data of the study area; Step 3.2: Collect hydrological data of hydrological stations in the study area; Step 3.3: Collect precipitation data of the study area; Step 3.4: Classify, record, and store data of various hydrological data of the study area.

5. The method for evaluating the influence of flow field control in open-pit mining areas on groundwater according to claim 1, characterized in that, In Step 4, the steps of establishing a conceptual model of the study area include: Step 4.1: According to the research purpose and actual geographical situation, delimit the boundary of the groundwater system and clarify the scope of the area under study; Step 4.2: Simplify the geological structure within the study area and generalize strata with different lithologies and hydraulic characteristics into representative aquifers and aquitards; Step 4.3: Analyze the distribution law of hydrogeological parameters of the aquifer; Step 4.4: Determine the recharge and discharge methods of groundwater and generalize their boundary conditions; Step 4.5: Identify the source-sink terms in the system, quantify the intensity and distribution of the source-sink terms, and determine the artificial extraction sink term based on the distribution of production wells and extraction volume.

6. The method for evaluating the influence of flow field control in open-pit mining areas on groundwater according to claim 5, wherein In Step 5, the steps of establishing a numerical model of the study area include: Step 5.1: Use the Grid module in GMS to establish a grid structure; Open the GMS software, enter the Grid module, and set the grid size and grid division method according to the scope and accuracy requirements of the study area; when dividing the grid, ensure that the grid boundary matches the boundary of the study area, and perform special processing on important geological structures and production well locations so that they are located at the grid nodes or the center of the grid cells. Important geological structures include obvious fold and fault geological structures; Step 5.2: Construct a geological model using geological information from multiple sources. Import geological information from multiple sources into the GMS software, and use the geological modeling tools in the software to construct a geological model. According to the formation lithology and geological structure information, set different formation units and geological structure planes in the model and assign corresponding physical properties to them. By interpolating and extrapolating borehole data, construct a three-dimensional geological model to accurately reflect the geological structure of the study area. Step 5.3: Use spatial interpolation methods to calculate the surface elevation, the elevation of the roof and floor of the unconfined aquifer and the confined aquifer in the study area, and establish a three-dimensional geological model. Use the existing topographic data points and borehole data to set appropriate interpolation parameters. Combine the elevation data with the three-dimensional geological model to further improve the three-dimensional geological model and ensure the accurate spatial position and shape of the aquifer.

7. A method for evaluating the influence of flow field control in an open-pit mining area on groundwater according to claim 5, characterized in that, In Step 6, the steps for assigning parameters to the numerical model in the study area include: Step 6.1: Division of parameter zones for the numerical model. According to the differences in geological and hydrogeological conditions, conduct a division of zones for the numerical model. Divide the areas with similar hydrogeological parameters into the same parameter zone. In the GMS software, use polygon or irregular grid tools to draw the boundaries of the parameter zones and assign a unique identifier to each zone. Based on the hydrogeological parameter data obtained previously, assign hydrogeological parameters to each parameter zone. Step 6.2: Assignment of hydrogeological parameters. In the parameter editing interface of the GMS software, input the permeability coefficient, specific yield, and storage coefficient into the model zone by zone. For some areas lacking measured data, refer to the parameter values of surrounding areas with similar geological conditions and estimate and assign values by combining geostatistical methods. For the source-sink terms in the model, make accurate assignments. Step 6.3: Assignment of source-sink terms. For the precipitation infiltration recharge source, calculate the recharge amount for each time step according to the precipitation data and infiltration coefficient in the study area, and distribute it to the corresponding grid cells or nodes. For the river leakage recharge source, determine the magnitude and distribution of the recharge amount based on the river water level, flow rate, and leakage coefficient. For the artificial extraction sink term, set sink points at the corresponding locations according to the extraction amount data of the production wells and assign the correct extraction intensity values to them.

8. A method for evaluating the impact of flow field control in open-pit mining areas on groundwater according to claim 1, characterized in that, In Step 7, the steps for calculating the numerical model in the study area include: Step 7.1: Import the constructed numerical model and the parameter information after assignment into the MODFLOW operation module built into the GMS software. Step 7.2: Open the "MODFLOW Global / Basic Package" module and set factors according to the research requirements and actual situation. Step 7.3: Check the operation model. Use the "check simulation" function to comprehensively check the model. The inspection content includes whether there are problems in aspects such as the boundary conditions, parameter assignment, and grid structure of the model. If problems are found, conduct a one-by-one investigation and correction according to the error information prompted by the software to ensure the integrity and correctness of the model. Step 7.

4. Use the "run simulation" function to start the calculation. During the calculation process, pay close attention to the calculation progress and the use of computer resources. Step 7.5, read the calculation results; Use the "read budget" function to read the calculation results, organize and analyze the calculated groundwater level, flow rate and flow, and generate data reports and charts.

9. A method for evaluating the impact of flow field control in open-pit mining areas on groundwater according to claim 1, characterized in that In step 8, the steps of model feasibility analysis include: Step 8.1, model calibration; Model calibration first collects long-term and high-frequency water levels, flow rates and water quality at multiple observation points in the study area, selects key parameters for preliminary adjustment and runs the model, uses the "Plot Wizard" module to draw a comparison curve between simulation and observation values and calculates the fitting index, adjusts key parameters in a targeted manner based on the results, iterates multiple times and records the calibration log, analyzes the adjustment rules and sensitivity of key parameters, until the fitting index meets the preset standards, and completes the calibration so that the model can accurately simulate the behavior of the groundwater system; Step 8.2: Model verification; Prepare a validation set of key indicators that are independent of the calibration data, input the calibrated model operation, use visualization tools to draw a comparison curve between simulation and observation values, and calculate indicators. If the results match and the indicators meet the standards, the model is reliable. Otherwise, analyze the reasons and re-examine the calibration process and improve and optimize it until it passes the verification to ensure that it can reflect the characteristics of the groundwater system.

10. The method for evaluating the influence of flow field control in open-pit mining areas on groundwater according to claim 1, characterized in that, In step 9, the steps of simulating the groundwater flow field under the control of groundwater in the mining area include: Step 9.1: Generalize the groundwater control measures. Generalize the groundwater control measures in the study area into: source control, runoff control and discharge control; Step 9.2, achieving the simulation effect of groundwater control in the mining area by adjusting parameters; By adjusting the relevant parameters in the model, the simulation effect of groundwater control in the mining area can be achieved; in the GMS software, different parameter combinations are set for different control measures and simulation scenarios, and the model is run for simulation calculation to observe the changes in the groundwater flow field and analyze the impact of different parameter changes on the groundwater flow field; Step 9.3, simulate the groundwater flow field under the groundwater control in the mining area, and analyze the impact of the groundwater control in the mining area on the groundwater flow field; Simulate the groundwater flow field under groundwater control in the mining area, and use the visualization function of GMS software to draw groundwater level contour maps and flow velocity vector maps; analyze the impact of groundwater control in the mining area on the groundwater flow field, and evaluate the effectiveness of groundwater control measures and their potential impact on the surrounding environment by comparing the flow field changes before and after control, so as to provide a scientific basis for water resource management and environmental protection in the mining area.

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