Prediction method and system for ecological water level variation under coal mining in ecologically fragile areas

Abstract

The present invention belongs to the technical field of green mining, and provides a method and system for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas. The present invention first determines the thickness of the effective aquiclude of overburden after coal seam mining through data related to mine engineering geological conditions, hydrogeological conditions, and coal seam mining conditions in ecologically fragile areas; then, according to the thickness of the effective aquiclude of overburden after coal seam mining, three types of ecological groundwater leakage caused by coal seam mining are proposed, and their leakage states are determined; finally, on the basis of establishing a well flow model under different ecological groundwater leakage states, the ecological water level drawdown in a virtual water injection process is calculated, and the degree of ecological water level variation under different ecological groundwater leakage states is predicted; the method of on-site geological drilling water level monitoring is avoided, and a comprehensive prediction of the degree of ecological water level variation under coal seam mining in ecologically fragile areas is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of green mines, and in particular relates to a method and system for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas. Background Art

[0002] With the rapid increase in coal resource depletion and mining difficulties in economically developed areas, the focus of coal mining has shifted to arid and semi-arid ecologically fragile areas. The annual average evaporation in some ecologically fragile areas can reach 4-8 times the rainfall, the ecological geological environment is fragile, and water resources are scarce; among them, the Quaternary groundwater is an important ecological water resource to maintain the surface vegetation ecology. Due to large-scale coal resource development, the groundwater ecological water level has changed, inducing environmental deterioration problems such as vegetation withering, desertification intensification, and surface water accumulation; therefore, accurately predicting the degree of ecological water level variation under coal seam mining is of great theoretical and practical significance for safe mining and ecological geological environment protection in ecologically fragile mining areas.

[0003] The inventors have found that, at present, the study of ecological water level changes under coal mining is mainly obtained through on-site geological borehole water level monitoring, and the analytical prediction method of ecological groundwater level under coal mining is rarely considered from the perspective of groundwater dynamics; if there is no systematic analytical prediction method of ecological groundwater level under coal mining, the cost of drilling and its water level monitoring will increase sharply only from the perspective of actual measurement. On the other hand, drilling monitoring only monitors from a "point" perspective and it is difficult to form a "surface" monitoring. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a method and system for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas. The present invention can solve the problem of the degree of ecological water level variation under coal seam mining, and provide a theoretical reference basis for safe mining of mines and protection of the ecological and geological environment of mining areas.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas, comprising:

[0007] Obtain data on engineering geological conditions, hydrogeological conditions, and coal mining conditions in ecologically fragile areas;

[0008] Determine the height of the water-conducting fracture zone based on the relevant data of engineering geological conditions, hydrogeological conditions, and coal mining conditions;

[0009] According to the height of the water-conducting fracture zone and the structure of the overlying strata of the coal seam, the thickness of the effective water-blocking layer of the overlying strata after coal seam mining is calculated;

[0010] According to the thickness of the effective aquifer of the overburden after coal mining, the ecological groundwater leakage state is determined by the threshold comparison method;

[0011] Establish well flow models under different ecological phreatic seepage conditions;

[0012] The water level decline process of the well flow model is regarded as a virtual pumping well, and the water level recovery process of the well flow model is regarded as a virtual injection well. The time corresponding to the recovery of the water level drop in the virtual injection process to different degrees is calculated, and the degree of ecological water level variation under different ecological groundwater leakage states is predicted.

[0013] Furthermore, the development height of the water-conducting fracture zone is calculated by the coal seam mining thickness and the coal seam burial depth.

[0014] Furthermore, the distance from the bottom interface of the phreatic aquifer to the coal seam minus the height of the development of the water-conducting fracture zone is equal to the thickness of the effective impermeable layer of the overburden after mining of the coal seam.

[0015] Furthermore, the lithology combination of the effective aquiclude of the overburden rock was determined in combination with the geological columnar diagram of the mining area, including bedrock, loess and laterite;

[0016] When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively greater than the corresponding first preset values, the ecological phreatic leakage state is determined to be a phreatic non-leakage state;

[0017] When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively less than or equal to the corresponding first preset value, and respectively greater than or equal to the preset second preset value, the ecological phreatic leakage state is determined to be a phreatic leakage state; wherein the corresponding first preset value is greater than the corresponding second preset value;

[0018] When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively less than the corresponding second preset values, it is determined that the ecological phreatic leakage state is phreatic complete leakage.

[0019] Furthermore, combined with the virtual pumping time and virtual pumping flow, the recovery time required for the water level to return to different water levels was calculated, and the degree of ecological water level variation under the condition of no leakage in the diving was predicted:

[0020] The drawdown of the virtual water injection process is equal to the product of the first value and the second value; the first value is equal to the ratio of the virtual pumping flow rate to the product of 4π and the water conductivity of the aquifer; the second value is equal to the difference between the third value and the fourth value, the third value is equal to the natural logarithm of the ratio of the sum of the virtual water injection time plus the virtual pumping time to the virtual water injection time, and the fourth value is equal to the ratio of the product of the square of the distance from the calculation point to the virtual water injection well and the water supply degree to the product of 4, the water conductivity of the aquifer and the virtual water injection time.

[0021] Furthermore, the virtual pumping time is equal to the product of the fifth value and the sixth value; the fifth value is equal to the ratio of the product of the preset coefficient and the virtual pumping flow rate to the water conductivity of the aquifer; the sixth value is equal to the ratio of the product of the preset coefficient, the water conductivity of the aquifer and the virtual pumping time to the product of the square of the distance from the calculation point to the virtual pumping well and the water supply degree, and then taking the logarithm with base 10.

[0022] Furthermore, combined with the virtual pumping time and virtual pumping flow, the recovery time required for the water level to return to different water levels was calculated, and the degree of ecological water level variation under the state of seepage in the groundwater was predicted:

[0023] The drawdown during the virtual water injection process is equal to the product of the seventh value and the eighth value; the seventh value is equal to the ratio of the sum of the virtual pumping flow and the leakage volume to the product of 4π and the water conductivity of the aquifer; the eighth value is equal to the difference between the ninth value and the tenth value, the ninth value is equal to the natural logarithm of the ratio of the sum of the virtual water injection time and the virtual pumping time to the virtual water injection time, and the tenth value is equal to the ratio of the product of the square of the distance from the calculation point to the virtual water injection well and the water supply degree to the product of 4π, the water conductivity of the aquifer and the virtual water injection time.

[0024] In a second aspect, the present invention also provides a system for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas, comprising:

[0025] The data acquisition module is configured to: obtain data related to engineering geological conditions, hydrogeological conditions, and coal mining conditions in ecologically fragile areas;

[0026] The first calculation module is configured to: determine the height of the water-conducting fracture zone according to data related to engineering geological conditions, hydrogeological conditions, and coal seam mining conditions;

[0027] The second calculation module is configured to calculate the thickness of the effective waterproof layer of the overburden after the coal seam is mined according to the height of the water-conducting fracture zone and the structure of the overburden strata of the coal seam;

[0028] The state determination module is configured to: determine the ecological groundwater leakage state through a threshold comparison method according to the thickness of the effective aquifer of the overburden after coal mining;

[0029] The well flow model building module is configured to: build well flow models under different ecological phreatic seepage conditions;

[0030] The prediction module is configured to: regard the water level decline process of the well flow model as a virtual pumping well, and the water level recovery process of the well flow model as a virtual injection well, calculate the time corresponding to the water level drop in the virtual injection process to recover to different degrees, and predict the degree of ecological water level variation under different ecological groundwater leakage states.

[0031] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas as described in the first aspect.

[0032] In a fourth aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas described in the first aspect are implemented.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention first determines the height of the water-conducting fracture zone through the engineering geological conditions, hydrogeological conditions, and coal seam mining conditions in the ecologically fragile area, and calculates the thickness of the effective waterproof layer of the overburden after coal seam mining according to the height of the water-conducting fracture zone; then, according to the thickness of the effective waterproof layer of the overburden after coal seam mining, the ecological groundwater leakage state is determined; finally, on the basis of establishing a well flow model under different ecological groundwater leakage states, the depth reduction of the virtual water injection process is calculated to realize the prediction of the degree of variation of the ecological water level under different ecological groundwater leakage states; the method of on-site geological drilling water level monitoring is avoided, and the comprehensive prediction of the degree of variation of the ecological water level under coal seam mining in the ecologically fragile area is realized;

[0035] 2. The method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas in the present invention is simple and easy to implement, reduces drilling costs, realizes the law of ecological groundwater level variation under different coal seam mining conditions, and provides a theoretical reference for safe mining of mines and protection of the ecological and geological environment of mining areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0037] Figure 1 This is a flow chart of Example 1 of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0040] Embodiment 1:

[0041] This embodiment provides a method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas, including:

[0042] S1. Collect relevant data on engineering geological conditions, hydrogeological conditions and coal seam mining conditions of the mining area or working face;

[0043] Engineering geological conditions may include the rock structure of the overlying rock layer, soil layer, phreatic aquifer, etc. of the mining area / working surface, thickness of each rock layer, density, elastic modulus, internal friction angle, cohesion, Poisson's ratio and other main physical and mechanical parameters;

[0044] Hydrogeological conditions may include the depth of ecological water level in the mining area, the location and water level data of water level monitoring wells in the mining area, the permeability coefficient, porosity and water supply degree of the overlying impermeable rock or soil layer, and other hydrogeological parameters;

[0045] Coal seam mining conditions may include coal seam burial depth, coal seam mining thickness, working face inclined length, coal mining method, relative position of water level monitoring well and coal mining working face, etc.

[0046] S2. Three situations of ecological phreatic leakage in coal seam mining are proposed: no phreatic leakage, phreatic leakage and complete phreatic leakage;

[0047] S3. Determine the thickness of the effective aquifer of the overburden after coal seam mining and judge the state of ecological groundwater leakage;

[0048] The non-leakage of groundwater can be understood as: after coal seam mining, there is a sufficiently large effective impermeable layer thickness between the top interface of the water-conducting fracture zone and the bottom interface of the groundwater aquifer, and no leakage occurs in the groundwater; however, due to the influence of coal mining subsidence, the groundwater ecological water level will still fluctuate.

[0049] The occurrence of groundwater leakage can be understood as follows: after coal seam mining, there is an effective impermeable layer of overburden of a certain thickness, and groundwater resources experience a certain degree of leakage, inducing groundwater ecological water level variation.

[0050] Complete leakage of groundwater can be understood as: after coal seam mining, the water-conducting fracture zone is highly developed into the groundwater aquifer, there is no or very little effective aquiclude, and groundwater flows to the goaf in large quantities, which leads to a continuous decline in the ecological water level. In this case, no specific analysis is made below.

[0051] S3.1. Calculate the height of the water-conducting fracture zone caused by coal mining:

[0052] Combined with coal mining conditions and engineering hydrogeological conditions, according to relevant standards and specifications, the maximum height of the coal mining-induced water-conducting fracture zone, referred to as the guide height, is determined; or the maximum height of the water-conducting fracture zone is determined based on the empirical formula (1) fitted with the measured value of the guide height in a certain ecologically fragile mining area:

[0053] y=77.109M c 0.414 +0.075H c -44.759 (1)

[0054] Among them, M c is the mining thickness of coal seam, m; H c is the coal seam burial depth, m.

[0055] S3.2. Determine the thickness of the effective waterproof layer of the overburden after coal mining:

[0056] On the basis of clarifying the maximum height of the water-conducting fracture zone, combined with the stratigraphic structure of the coal seam overlying rock, the thickness of the effective aquifer of the overlying rock after coal seam mining is obtained by subtracting the maximum height of the water-conducting fracture zone from the distance from the bottom interface of the phreatic aquifer to the coal seam; further combined with the geological columnar diagram of the mining area, the lithology combination of the effective aquifer of the overlying rock is clarified, namely: bedrock, loess or laterite.

[0057] S3.3. Determine the state of ecological groundwater leakage:

[0058] The leakage state of ecological groundwater is closely related to the thickness of the effective aquiclude of the overburden. According to the engineering practice experience of ecologically fragile mining areas: when the thickness of the effective aquiclude of the overburden after coal seam mining is greater than 125m, the thickness of loess is greater than 36m, and the thickness of laterite is greater than 22m, groundwater will not leak; when the thickness of the effective aquiclude of the overburden after coal seam mining is between 15-125m, the thickness of loess is between 10-36m, and the thickness of laterite is between 5-22m, groundwater will leak; when the thickness of the effective aquiclude of the overburden after coal seam mining is less than 15m, the thickness of loess is less than 10m, and the thickness of laterite is less than 5m, groundwater will completely leak; it can be understood that 125, 36 and 22 are the corresponding first preset values, and 15, 10 and 5 are the corresponding second preset values.

[0059] S4. Establish a well flow model of ecological water level variation under the condition that no leakage occurs in the submerged water, and analyze the degree of ecological water level variation under the condition that no leakage occurs in the submerged water;

[0060] S4.1. Analysis of the applicability of the ecological water level variation well flow model under the condition that no leakage occurs in the groundwater:

[0061] Under the condition that no leakage occurs in the groundwater, the ecological water level drops due to the impact of coal mining subsidence, and then rises due to the lateral recharge of the groundwater. Based on this, the evolution law of this process is approximately regarded as a well flow mathematical model, that is, the water level drop process is regarded as a virtual pumping well, and the water level recovery process is regarded as a virtual injection well.

[0062] S4.2. Establish a well flow model under the condition that no leakage occurs in diving:

[0063] Combined with the Theis well flow formula, a well flow mathematical model of the relationship between the ecological water level drawdown s and time t is established, as shown in formula (2):

[0064]

[0065] Where Q is the virtual pumping flow, m 3 / s; r is the distance from the calculation point to the virtual pumping well, m; T is the water conductivity of the aquifer, m 2 / d, T = KM, where K is the permeability coefficient, m / d, M is the aquifer thickness, m; μ is the water supply degree.

[0066] S4.3. Calculate virtual pumping flow:

[0067] The ecological water level drop process is approximated as a constant flow Q at time t p The virtual pumping well for internal pumping is combined with the existing monitored water level, ground subsidence, and the positional relationship between the mining working face and the monitoring well, and the Jacob well formula (3) is revised to obtain the virtual pumping constant flow Q.

[0068]

[0069] Among them, s p is the drawdown of the virtual pumping process, m; t p is the virtual pumping time, d; Q is the virtual pumping flow, m 3 / s; r is the distance from the calculation point to the virtual pumping well, m; T is the water conductivity of the aquifer, m 2 / d, T = KM, where K is the permeability coefficient, m / d, M is the aquifer thickness, m; μ is the water supply degree.

[0070] S4.4. Analysis of ecological water level variation:

[0071] The ecological water level recovery process is approximately a virtual water injection stage. The improved Theis well formula (4) is combined with the virtual pumping time t p , virtual pumping flow Q, calculate the recovery time t required for the water level to return to different water levels r , analyze the degree of ecological water level variation.

[0072]

[0073] Among them, s r is the drawdown of the virtual water injection process, m; t r is the virtual water injection time, d; t p is the virtual pumping time, d; Q is the virtual pumping flow, m 3 / s; r is the distance from the calculation point to the virtual injection well, m; T is the water conductivity of the aquifer, m 2 / d, T = KM, where K is the permeability coefficient, m / d, M is the aquifer thickness, m; μ is the water supply degree.

[0074] S5. Analyze the evolution law of submerged leakage under the condition of submerged leakage:

[0075] S5.1. Combine the numerical simulation software COMSOL Multiphysics to simulate the deformation characteristics of the overlying rock strata during coal mining, combine the empirical formula fitting in step S3, and use the Mohr-Coulomb criterion to comprehensively identify and determine the height of the water-conducting fracture zone during coal mining;

[0076] S5.2. Output the damage and deformation of the overlying residual aquiclude after the above-mentioned simulated mining, use the Darcy seepage module to redefine the evolution process of the permeability and porosity of the deformed rock layer of the overlying residual aquiclude, and establish a leakage model of the phreatic aquifer under coal seam mining;

[0077] S5.3. In the above-mentioned phreatic leakage model, the Darcy velocity integration is performed on the vertical section where the water-conducting fracture zone is located, the leakage of the phreatic aquifer through the water-conducting fracture zone is calculated, and the relationship Q'(k, t) between the leakage amount Q' and the permeability k and time t is fitted based on mathematical and statistical analysis.

[0078] S6. Establish a well flow model for ecological water level variation under the condition of phreatic water leakage, and analyze the degree of ecological water level variation under the condition of phreatic water leakage:

[0079] S6.1. Analysis of the applicability of the well flow model under the condition of leakage from diving:

[0080] Under the condition of groundwater leakage, the ecological water level drops due to the influence of coal mining subsidence and groundwater leakage. Later, due to the lateral recharge of groundwater, the ecological water level recovers to varying degrees. Based on this, the process is approximately regarded as a well flow mathematical model, that is, the water level drop process is regarded as a virtual pumping well, and the water level recovery process is regarded as a virtual injection well. Among them, the drop in ecological water level is caused by the depth drop caused by mining subsidence and the depth drop caused by groundwater leakage caused by coal mining.

[0081] S6.2. Establish a well flow model under the condition of leakage from diving:

[0082] Combined with the Theis well flow formula, a well flow mathematical model of the relationship between the ecological water level drawdown s' and time t is established, see formula (5):

[0083]

[0084] Where Q is the virtual pumping flow, m 3 / s; Q' is the leakage, m 3 / s; k is permeability, m 2; r is the distance from the calculation point to the virtual pumping well, m; T is the water conductivity of the aquifer, m 2 / d, T = KM, where K is the permeability coefficient, m / d, M is the aquifer thickness, m; μ is the water supply degree.

[0085] S6.3. Calculate the virtual pumping flow rate under the condition of submerged leakage:

[0086] The ecological water level drop process is approximated as a constant flow Q and leakage Q' at time t p The virtual pumping well for internal pumping is combined with the existing monitored water level, ground subsidence and the position relationship between the mining working face and the monitoring well, and the Jacob well formula (6) is revised to obtain the virtual pumping constant flow Q.

[0087]

[0088] Among them, s p ’ is the water level drop during the decline, m; t p ’ is the time taken for the water level to drop, d; Q is the virtual pumping flow, m 3 / s; Q' is the leakage, m 3 / s;k p ’ is the permeability, m 2 ; r is the distance from the calculation point to the virtual pumping well, m; T is the water conductivity of the aquifer, m 2 / d, T = KM, where K is the permeability coefficient, m / d, M is the aquifer thickness, m; μ is the water supply degree.

[0089] S6.4. Analyze the degree of ecological water level variation under the condition of phreatic water leakage:

[0090] The ecological water level recovery process is approximately a virtual water injection stage. The improved Theis well formula (7) is combined with the virtual pumping time t p , virtual pumping flow Q, calculate the recovery time t' required for the water level to recover to different water levels, and analyze the degree of ecological water level variation under the condition of groundwater leakage.

[0091]

[0092] Among them, s r ’ is the drawdown of the virtual water injection process, m; t r ’ is the virtual water injection time, d; t p ’ is the virtual pumping time, d; Q is the virtual pumping flow, m 3 / s; Q' is the leakage, m 3 / s;k r ’ is the permeability, m 2 ; r is the distance from the calculation point to the virtual injection well, m; T is the water conductivity of the aquifer, m 2 / d, T = KM, where K is the permeability coefficient, m / d; M is the aquifer thickness, m; and μ is the water supply degree.

[0093] S7. Comprehensively consider the variation law of ecological water level under different leakage conditions of diving, and build an analytical prediction system for the degree of ecological water level variation under coal mining.

[0094] Embodiment 2:

[0095] This embodiment provides a system for predicting ecological water level variation under coal mining in ecologically fragile areas, including:

[0096] The data acquisition module is configured to: obtain data related to engineering geological conditions, hydrogeological conditions, and coal mining conditions in ecologically fragile areas;

[0097] The first calculation module is configured to: determine the height of the water-conducting fracture zone according to data related to engineering geological conditions, hydrogeological conditions, and coal seam mining conditions;

[0098] The second calculation module is configured to calculate the thickness of the effective waterproof layer of the overburden after the coal seam is mined according to the height of the water-conducting fracture zone and the structure of the overburden strata of the coal seam;

[0099] The state determination module is configured to: determine the ecological groundwater leakage state through a threshold comparison method according to the thickness of the effective aquifer of the overburden after coal mining;

[0100] The well flow model building module is configured to: build well flow models under different ecological phreatic seepage conditions;

[0101] The prediction module is configured to: regard the water level decline process of the well flow model as a virtual pumping well, and the water level recovery process of the well flow model as a virtual injection well, calculate the depth of the virtual injection process, and predict the degree of ecological water level variation under different ecological phreatic seepage conditions.

[0102] The working method of the system is the same as the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas in Example 1, and will not be repeated here.

[0103] Embodiment 3:

[0104] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas described in Example 1 are implemented.

[0105] Embodiment 4:

[0106] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas described in Example 1 are implemented.

[0107] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A method for predicting the variation of ecological water level under coal mining in ecologically fragile areas, characterized in that: include: Obtain data on engineering geological conditions, hydrogeological conditions, and coal mining conditions in ecologically fragile areas; Determine the height of the water-conducting fracture zone based on the relevant data of engineering geological conditions, hydrogeological conditions, and coal mining conditions; According to the height of the water-conducting fracture zone and the structure of the overlying strata of the coal seam, the thickness of the effective water-blocking layer of the overlying strata after coal seam mining is calculated; According to the thickness of the effective aquifer of the overburden after coal mining, the ecological groundwater leakage state is determined by the threshold comparison method; Establish well flow models under different ecological phreatic seepage conditions; The water level decline process of the well flow model is regarded as a virtual pumping well, and the water level recovery process of the well flow model is regarded as a virtual injection well. The time corresponding to the water level decline in the virtual injection process is calculated to recover to different degrees, and the degree of ecological water level variation under different ecological phreatic seepage states is predicted. Combined with the geological columnar diagram of the mining area, the lithology combination of the effective aquiclude of the overburden rock is determined, including bedrock, loess and laterite; When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively greater than the corresponding first preset values, the ecological phreatic leakage state is determined to be a phreatic non-leakage state; When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively less than or equal to the corresponding first preset value, and respectively greater than or equal to the preset second preset value, the ecological phreatic leakage state is determined to be a phreatic leakage state; wherein the corresponding first preset value is greater than the corresponding second preset value; When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively less than the corresponding second preset values, the ecological phreatic leakage state is determined to be phreatic complete leakage.

2. The method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas according to claim 1, characterized in that: The development height of the water-conducting fracture zone is calculated by the coal seam mining thickness and coal seam burial depth.

3. The method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas according to claim 1, characterized in that: The distance from the bottom interface of the phreatic aquifer to the coal seam minus the development height of the water-conducting fracture zone is equal to the thickness of the effective impermeable layer of the overburden after mining of the coal seam.

4. The method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas according to claim 1, characterized in that: Combined with the virtual pumping time and virtual pumping flow, the recovery time required for the water level to recover to different water levels is calculated, and the degree of ecological water level variation under the condition of no leakage in the diving is predicted: The drawdown of the virtual water injection process is equal to the product of the first value and the second value; the first value is equal to the ratio of the virtual pumping flow rate to the product of 4π and the water conductivity of the aquifer; the second value is equal to the difference between the third value and the fourth value, the third value is equal to the natural logarithm of the ratio of the sum of the virtual water injection time plus the virtual pumping time to the virtual water injection time, and the fourth value is equal to the ratio of the product of the square of the distance from the calculation point to the virtual water injection well and the water supply degree to the product of 4, the water conductivity of the aquifer and the virtual water injection time.

5. The method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas according to claim 4, characterized in that: The virtual pumping drawdown is equal to the product of the fifth value and the sixth value; the fifth value is equal to the ratio of the product of the preset coefficient and the virtual pumping flow rate to the water conductivity of the aquifer; The sixth value is equal to the ratio of the product of the preset coefficient, the water conductivity of the aquifer and the virtual pumping time to the product of the square of the distance from the calculation point to the virtual pumping well and the water supply degree, and then taking the logarithm with base 10.

6. The method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas according to claim 1, characterized in that: Combined with the virtual pumping time and virtual pumping flow, the recovery time required for the water level to recover to different water levels is calculated, and the degree of ecological water level variation under the state of seepage in the groundwater is predicted: The drawdown of the virtual water injection process is equal to the product of the seventh value and the eighth value; the seventh value is equal to the ratio of the sum of the virtual pumping flow and the leakage to the product of 4π and the water conductivity of the aquifer; The eighth value is equal to the difference between the ninth value and the tenth value. The ninth value is equal to the natural logarithm of the ratio of the sum of the virtual injection time and the virtual pumping time to the virtual injection time. The tenth value is equal to the ratio of the product of the square of the distance from the calculation point to the virtual injection well and the water supply degree to the product of 4π, the water conductivity of the aquifer and the virtual injection time.

7. The ecological water level variation prediction system under coal mining in ecologically fragile areas is characterized by: include: The data acquisition module is configured to: obtain data related to engineering geological conditions, hydrogeological conditions, and coal mining conditions in ecologically fragile areas; The first calculation module is configured to: determine the height of the water-conducting fracture zone according to data related to engineering geological conditions, hydrogeological conditions, and coal seam mining conditions; The second calculation module is configured to calculate the thickness of the effective waterproof layer of the overburden after the coal seam is mined according to the height of the water-conducting fracture zone and the structure of the overburden strata of the coal seam; The state determination module is configured to: determine the ecological groundwater leakage state through a threshold comparison method according to the thickness of the effective aquifer of the overburden after coal mining; The well flow model building module is configured to: build well flow models under different ecological phreatic seepage conditions; The prediction module is configured to: regard the water level decline process of the well flow model as a virtual pumping well, and the water level recovery process of the well flow model as a virtual water injection well, calculate the time corresponding to the water level decline in the virtual water injection process to recover to different degrees, and predict the degree of ecological water level variation under different ecological phreatic seepage states; Combined with the geological columnar diagram of the mining area, the lithology combination of the effective aquiclude of the overburden rock is determined, including bedrock, loess and laterite; When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively greater than the corresponding first preset values, the ecological phreatic leakage state is determined to be a phreatic non-leakage state; When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively less than or equal to the corresponding first preset value, and respectively greater than or equal to the preset second preset value, the ecological phreatic leakage state is determined to be a phreatic leakage state; wherein the corresponding first preset value is greater than the corresponding second preset value; When the thickness of the effective waterproof layer of the overburden after coal seam mining, the thickness of loess and the thickness of red soil are respectively less than the corresponding second preset values, the ecological phreatic leakage state is determined to be phreatic complete leakage.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas as described in any one of claims 1 to 6 are implemented.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method for predicting the degree of ecological water level variation under coal seam mining in ecologically fragile areas as described in any one of claims 1-6 are implemented.

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