A control method for optimizing groundwater extraction

Abstract

The present invention discloses a method for optimizing groundwater exploitation, including: obtaining water level data of a phreatic aquifer, rainfall monitoring data of a phreatic aquifer, water storage coefficient and administrative area of ​​a confined aquifer; obtaining groundwater exploitation of a phreatic aquifer based on the water level data, rainfall monitoring data and administrative area; optimizing and controlling the groundwater exploitation of a phreatic aquifer; optimizing and controlling the groundwater exploitation of a confined aquifer based on the water storage coefficient and administrative area of ​​a confined aquifer. The present invention aims to optimize and balance groundwater exploitation among regions under the premise of the strictest groundwater withdrawal and water consumption, and to avoid imbalance between regional extraction and replenishment as much as possible, and can also provide technical support for trading indicators and water volume trading for subsequent groundwater water rights trading.

Description

Technical Field

[0001] The present invention belongs to the technical field of groundwater resources, and in particular relates to a management and control method for optimizing groundwater exploitation. Background Art

[0002] The protection and management of groundwater resources play a vital role in maintaining ecological balance and ensuring national water security. In most areas, there are unreasonable and unfair indicators in groundwater control, such as ① artificially setting groundwater extraction management values ​​without considering rainfall and groundwater level fluctuation factors; ② the extraction volume and water level fluctuation indicators of large administrative regions are evenly distributed to the small administrative regions under them, without considering the hydrogeological conditions (aquifer water supply and storage coefficient) and administrative area of ​​the small administrative regions; ③ the phreatic aquifer (shallow water) and the confined aquifer (deep water) are uniformly controlled without considering the recharge and discharge relationship of the aquifer itself. The existence of these factors will lead to unreasonable and unfair formulation of groundwater control indicators. In grassroots groundwater management departments, it is often the case that a lot of work has been done but the assessment has not been passed, which makes the control work prone to inactivity. Therefore, it is urgent to introduce a control method to optimize groundwater extraction, guide the management department to formulate reasonable and fair control indicators, and form a virtuous circle for groundwater control work. Summary of the invention

[0003] In order to solve the above technical problems, the present invention proposes a management and control method for optimizing groundwater exploitation, which aims to optimize and balance groundwater exploitation among different regions under the premise of the strictest groundwater withdrawal and use volume, and to avoid the imbalance of extraction and replenishment among regions as much as possible. It can also provide technical support for trading indicators and water volume trading for the subsequent groundwater water rights trading.

[0004] To achieve the above object, the present invention provides a method for optimizing groundwater exploitation, comprising:

[0005] Obtaining data on water levels in unconfined aquifers, monitoring data on rainfall in unconfined aquifers, storage coefficients of confined aquifers and administrative areas;

[0006] Obtaining the groundwater extraction from the phreatic aquifer based on the water level data, rainfall monitoring data and administrative area;

[0007] Optimizing and controlling the amount of groundwater extraction from the phreatic aquifer;

[0008] Based on the water storage coefficient and administrative area of ​​the confined aquifer, the groundwater extraction of the confined aquifer is optimized and controlled.

[0009] Optionally, obtaining the groundwater extraction amount of the phreatic aquifer based on the water level data and rainfall monitoring data includes:

[0010] Based on the water level data and rainfall monitoring data, obtaining a comprehensive groundwater recharge coefficient;

[0011] Based on the comprehensive groundwater recharge coefficient and the administrative area, the groundwater extraction volume of the phreatic aquifer is obtained.

[0012] Optionally, optimizing and controlling the groundwater extraction from the phreatic aquifer includes:

[0013] Dividing the administrative area to obtain a preset number of administrative regions;

[0014] Determine whether the controlled groundwater extraction volume in the administrative area is related to the groundwater level variation value, and obtain the controlled groundwater extraction volume.

[0015] Optionally, determining whether the controlled groundwater extraction volume in the administrative area is related to the groundwater level variation value, and obtaining the controlled groundwater extraction volume includes:

[0016] If the controlled groundwater extraction volume of the administrative area is related to the groundwater level fluctuation value, obtaining the first controlled groundwater extraction volume according to the groundwater level fluctuation value of the administrative area;

[0017] If the controlled groundwater extraction volume of the administrative area is independent of the groundwater level variation value, it is determined whether the groundwater level variation of the administrative area is consistent, and the second controlled groundwater extraction volume is determined.

[0018] Optionally, the method for obtaining the first controlled groundwater extraction volume is:

[0019] Q 开采 =α·P·F+μ·ΔH·F

[0020] Among them, α is the comprehensive groundwater recharge coefficient, P is the precipitation in the year, F is the administrative area, μ is the water supply degree of the aquifer, and ΔH is the annual water level variation of the aquifer.

[0021] Optionally, judging whether the groundwater level variation in the administrative area is consistent and determining the second controlled groundwater extraction volume includes:

[0022] If the groundwater level changes in the administrative areas are consistent, the second controlled groundwater extraction volume is directly determined;

[0023] If the groundwater level variation of the administrative area is inconsistent, it is determined whether the water level variation of the administrative area is a fixed value, and the second controlled groundwater extraction volume is determined.

[0024] Optionally, judging whether the water level variation of the administrative area is a fixed value and determining the second controlled groundwater extraction amount includes:

[0025] If the water level variation of the administrative area is not a fixed value, it is necessary to perform weighted averaging on the administrative area to obtain the second controlled groundwater extraction volume;

[0026] If the water level variation of the administrative area is a fixed value, the second controlled groundwater extraction volume is directly obtained.

[0027] Optionally, the method for obtaining the second controlled groundwater extraction volume is:

[0028]

[0029] Among them, Q k is the groundwater extraction in area k, is the total groundwater extraction in the area, μ k is the water supply degree of the unconfined aquifer in area k, F k is the area of ​​region k.

[0030] Compared with the prior art, the present invention has the following advantages and technical effects:

[0031] At the theoretical level, the present invention derives through a formula in the groundwater resource water quantity-water level control that the groundwater control quantity of phreatic and confined water aquifers is positively correlated with the regional aquifer parameters and area; at the technical level, it discusses how to scientifically and reasonably regulate the groundwater control quantity under different circumstances, which is completely consistent with the theoretical formula level; it can provide theoretical and technical support for groundwater management departments in groundwater quantity-water level control work, and implement the strictest groundwater resource management system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0033] Figure 1 is a flow chart of a method for optimizing groundwater exploitation according to an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of water balance of a submerged aquifer according to an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of administrative district divisions according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of water balance in a confined aquifer according to an embodiment of the present invention;

[0037] Figure 5 This is a relationship diagram between the amount of pressurized water produced and the water level fluctuation in a certain area according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0040] The present invention proposes a control method for optimizing groundwater extraction, such as Figure 1 As shown, the specific steps include:

[0041] Obtaining water level data of unconfined aquifers, rainfall monitoring data of unconfined aquifers, water storage coefficient of confined aquifers and administrative area;

[0042] Obtain groundwater extraction from unconfined aquifers based on water level data, rainfall monitoring data and administrative area;

[0043] Optimize the management and control of groundwater extraction from phreatic aquifers;

[0044] Based on the water storage coefficient of the confined aquifer and the administrative area, the extraction of groundwater from the confined aquifer is optimized and controlled.

[0045] Specifically, among the water balance recharge and discharge items of the groundwater aquifer, the recharge items are precipitation infiltration, field flooding infiltration, surface water infiltration, etc. Nowadays, agricultural water-saving measures are widely implemented, such as shallow buried drip irrigation, sprinkler drip irrigation, etc., and the irrigation infiltration aquifer is almost negligible; long-term over-exploitation of groundwater has caused most rivers and lakes to shrink and dry up, and the water levels of rivers and lakes are out of touch with the groundwater level. Except for some rivers and lakes that carry out ecological water replenishment, their infiltration is also local, and the proportion of surface water infiltration recharge to the aquifer is very small. At present, precipitation infiltration is generally the main source of recharge in plain areas; the discharge item is mainly artificial exploitation. Since the groundwater in plain areas is buried at a large depth, there is basically no base flow discharge of groundwater, groundwater evaporation and other discharges. In addition, at the regional scale, the proportion of groundwater lateral runoff in plain areas to groundwater recharge and discharge flux is relatively small. Without considering the influence of groundwater base flow discharge, groundwater evaporation, lateral runoff, etc., according to the annual water balance principle of groundwater aquifers in the region (townships, counties, and municipal administrative areas), such as Figure 2 As shown, there are:

[0046] α·P·FQ 农业 -Q 其他 =Q 蓄变 = -μ·ΔH·F (1)

[0047] Where: α is the comprehensive recharge coefficient of the aquifer (-), including precipitation infiltration, field irrigation infiltration, surface infiltration, etc. Since precipitation infiltration is generally the main source of recharge in plain areas, for the sake of simplification, it is assumed that the comprehensive recharge coefficient is directly related to the precipitation of the year; P is the precipitation of the year (m); F is the administrative area (m 2 );Q 农业 is the annual agricultural groundwater extraction volume of the aquifer (m3); Q 其他 The annual industrial, domestic and other groundwater extraction volume of the aquifer (m 3 ), μ is the water supply degree of the aquifer (-), ΔH is the annual water level fluctuation of the aquifer (m), which is calculated as the groundwater depth (or water level) at the end of the year minus the groundwater depth (or water level) at the beginning of the year, with an increase in depth being positive and a decrease in depth being negative.

[0048] Dividing both ends of the above equation by F, it can be organized into the form of flux intensity per unit area:

[0049]

[0050] The annual water level variation of the aquifer reflects the balance of recharge and discharge of the aquifer in that year. If the water level variation of the year is positive (increased burial depth), it means that the discharge of the aquifer is greater than the recharge, vice versa.

[0051] Furthermore, based on the water level data and rainfall monitoring data, the groundwater extraction amount of the phreatic aquifer is obtained, including:

[0052] Based on water level data and rainfall monitoring data, obtain the comprehensive groundwater recharge coefficient;

[0053] Based on the comprehensive groundwater recharge coefficient and administrative area, the groundwater extraction volume of the unconfined aquifer is obtained.

[0054] Specifically, considering that rainfall decreases in dry years, groundwater recharge will decrease accordingly, while groundwater extraction will increase accordingly. If extraction and recharge have basically reached a balance in normal years, groundwater recharge in dry years will definitely be less than groundwater extraction. Compared with the beginning of the year, the groundwater depth at the end of the year will increase, and the groundwater level fluctuation will be positive. On the contrary, rainfall in wet years increases relative to normal years, groundwater recharge will increase accordingly, while extraction will decrease. Groundwater recharge will definitely be greater than groundwater extraction. Therefore, the groundwater depth at the end of the year will decrease relative to the beginning of the year, and the groundwater level fluctuation will be negative.

[0055] Collect the monitoring data of the water level and rainfall of the regional phreatic aquifer in the historical period. According to the water balance of the phreatic aquifer (Formula 1), for different precipitation years, we have:

[0056]

[0057] Where: W 农,i is the actual amount of agricultural extraction in the administrative area in year i (m3); W 其他 is the actual mining volume of other mining in the administrative area in year i (m 3 );W 农,j is the actual agricultural extraction volume in the administrative region in year j (m 3 );ΔH i is the groundwater level variation in the i-th year (m), ΔH j is the groundwater level variation in the jth year (m). In the above formula (3), the implicit assumption is that agricultural exploitation is affected by the change of rainfall, so the exploitation volume in different precipitation years is different; while the exploitation volume of industry and daily life is less affected by the change of rainfall, and the exploitation volume in different precipitation years is basically the same.

[0058] Then introduce the following relationship:

[0059] W 农,i =W 农,j +(P j -P i )·F' (4)

[0060] Where F' is the agricultural planting area of ​​the administrative area (m 2 ). Formula (4) means that since agricultural water demand depends on both precipitation and irrigation, the reduction in rainfall in dry years relative to normal years will be compensated by increasing groundwater extraction in agriculture.

[0061] Assuming that the land use and other groundwater consumption in the administrative area remain unchanged in recent years, the comprehensive groundwater recharge coefficient α does not change, and α can be calculated through the relationship between aquifer water balance and actual extraction.

[0062] Combining formula (3) and formula (4), we get:

[0063]

[0064] Furthermore, optimizing the control of groundwater extraction from the phreatic aquifer includes:

[0065] Divide the administrative area to obtain a preset number of administrative regions;

[0066] Determine whether the controlled groundwater extraction volume in the administrative area is related to the groundwater level variation value, and obtain the controlled groundwater extraction volume.

[0067] Furthermore, it is determined whether the controlled groundwater extraction volume in the administrative area is related to the groundwater level fluctuation value. The controlled groundwater extraction volume is obtained by:

[0068] If the controlled groundwater extraction volume of the administrative region is related to the groundwater level fluctuation value, the first controlled groundwater extraction volume is obtained according to the groundwater level fluctuation value of the administrative region;

[0069] If the controlled groundwater extraction volume in the administrative region is not related to the groundwater level variation, then it is determined whether the groundwater level variation in the administrative region is consistent to determine the second controlled groundwater extraction volume.

[0070] Specifically, in the dual control of groundwater "quantity-level", the relationship between groundwater extraction volume and groundwater level fluctuation can be expressed as follows:

[0071] Q 开采 =α·P·F+μ·ΔH·F (6)

[0072] Among them, α is the comprehensive groundwater recharge coefficient, P is the precipitation in the year, F is the administrative area, μ is the water supply degree of the aquifer, and ΔH is the annual water level variation of the aquifer.

[0073] From formula (6), it can be seen that the comprehensive infiltration recharge coefficient can be calculated by formula (5), which is basically unchanged, and the water supply degree of the aquifer is basically unchanged, so the groundwater extraction is directly related to the groundwater level fluctuation and rainfall. In normal water years, the groundwater level fluctuation is 0, and the groundwater extraction and replenishment are balanced, that is, the groundwater extraction is the extractable amount of the aquifer. Similarly, in dry years, if the groundwater level is allowed to drop, the groundwater extraction will increase.

[0074] as follows Figure 3 As shown in the figure, if a certain administrative district needs to carry out more detailed zoning control in groundwater control, the administrative district can be divided into four small administrative districts (A, B, C and D). For example, the city-level administrative district can be subdivided into county-level administrative districts, the county-level administrative districts can be subdivided into townships, and each township can be subdivided into villages.

[0075] Then the groundwater extraction of the entire large administrative region is equal to the sum of the extraction of the four small administrative regions, as follows: Q 开采 =∑Q k开采 , where k represents each small administrative district.

[0076] In optimizing groundwater extraction control, the following situations can be divided into:

[0077] (1) The groundwater control extraction volume of the large administrative area is based on the groundwater level fluctuation value and is calculated using formula (6). In the optimization control, it only needs to be calculated according to the water level fluctuation value of the small administrative area.

[0078] (2) The controlled groundwater extraction volume in a large administrative region is the groundwater red line water consumption or a certain management value, which has nothing to do with the water level fluctuation.

[0079] Furthermore, judging whether the groundwater level fluctuations in the administrative regions are consistent and determining the second controlled groundwater extraction volume include:

[0080] If the groundwater level changes in the administrative area are consistent, the second controlled groundwater extraction volume will be directly determined;

[0081] If the groundwater level fluctuations in the administrative area are inconsistent, determine whether the water level fluctuations in the administrative area are fixed values, and determine the second controlled groundwater extraction volume.

[0082] Further, judging whether the water level variation of the administrative area is a fixed value and determining the second controlled groundwater extraction volume include:

[0083] If the water level variation in the administrative area is not a fixed value, it is necessary to take a weighted average of the administrative areas to obtain the second controlled groundwater extraction volume;

[0084] If the water level variation in the administrative area is a fixed value, the second controlled groundwater extraction volume can be directly obtained.

[0085] Specifically, the groundwater control extraction volume of a large administrative area is the groundwater red line water consumption or a certain management value, which has nothing to do with the water level fluctuation. That is, the total extraction volume of the administrative area is a fixed value. How to optimize the subdivision into smaller administrative areas is as shown in the following formula:

[0086]

[0087] As shown in formula (7), the optimal groundwater extraction volume of a small administrative area is related to the comprehensive infiltration coefficient, precipitation, groundwater level fluctuation under precipitation, aquifer water supply and administrative area of ​​the region. However, for a small administrative area, the comprehensive infiltration coefficient, aquifer water supply and administrative area are fixed and are inherent attributes of the administrative area, so the groundwater extraction volume Q of the small administrative area under precipitation and groundwater level fluctuation under precipitation should be considered. k .

[0088] Substituting formula (5) into formula (6), we can get Q k The relationship is as follows:

[0089]

[0090] ① When the groundwater level fluctuations in each small administrative area are consistent, groundwater extraction is positively correlated with the water supply degree multiplied by the administrative area, so the groundwater extraction volume can be expressed as:

[0091]

[0092] ② When the groundwater level fluctuations in each small administrative area are inconsistent, there are two situations. The first is that the water level fluctuations in the small administrative area are set according to their own conditions. Then the water level fluctuations in the large administrative area can be weighted averaged by the area of ​​the small administrative area, as shown in the following formula:

[0093]

[0094] In this case, the groundwater extraction volume Q k Formula (9) still applies.

[0095] The second case is that the water level fluctuation range of the large administrative area is a fixed value, and is allocated to each small administrative area on this basis. From formula (10), we can see that when When ΔH and F are constant, k =a×F k , where a is a constant, that is, the water level fluctuation of the small administrative area is proportional to the area, which will lead to the groundwater extraction volume Q k With F k Excessive correlation will lead to different small administrative areas Q k The difference is too large. Here, from formula (1), we can see that when the aquifer Q 蓄变 When the water level of the aquifer is constant, the amplitude of the water level change is inversely proportional to the area multiplied by the water supply degree, that is, ΔH k =b / μ k F k , where a is a constant, then formula (8) can be transformed into the following formula:

[0096]

[0097] In this case, the groundwater extraction volume Q k Formula (9) still applies.

[0098] Based on the water storage coefficient of the confined aquifer and the area of ​​the administrative area, the optimization and control of groundwater extraction from the confined aquifer includes:

[0099] Unlike unconfined aquifers, the water balance of confined aquifers includes recharge from lateral inflow and phreatic overflow, and discharge from artificial mining, lateral outflow and overflow. Figure 4 ),have:

[0100] -μ * ×F×ΔH=(Q 侧入 +Q 越入 )-(Q 开采 +Q 侧出 +Q 越出 ) (12)

[0101] Where: F is the administrative area (m 2 );Q 侧入 is the annual lateral runoff recharge of the aquifer (m 3 );Q 侧出is the annual lateral runoff discharge of the aquifer (m 3 );Q 越入 is the annual phreatic recharge of the aquifer (m 3 );Q 越出 is the annual overflow discharge of the aquifer (m 3 );Q 开采 is the annual groundwater extraction from the aquifer, including agriculture, industry, life, etc. (m 3 ); μ * is the water storage coefficient of the aquifer (-); ΔH is the annual water level variation of the aquifer (m). The calculated value is the groundwater depth (or water level) at the end of the year minus the groundwater depth (or water level) at the beginning of the year. An increase in the depth is positive, and a decrease in the depth is negative.

[0102] as follows Figure 5 As shown in the figure, there is an obvious linear positive correlation between the amount of confined water extraction in a certain area and the water level fluctuation. It can be seen that in most deep water over-exploitation areas, groundwater extraction directly affects the water level fluctuation, that is, in formula (12), the lateral runoff and overflow of confined water are not considered, and the proportion of groundwater extraction is relatively small.

[0103] Formula (12) can be simplified as:

[0104] -μ * ×F×ΔH=Q 开采 (13)

[0105] Similarly, the optimized groundwater exploitation technology for the phreatic aquifer introduced in the embodiment and the optimized groundwater exploitation technology for the confined aquifer are not affected by surface infiltration such as rainfall, and their groundwater exploitation is only related to the aquifer water storage coefficient and the administrative area, and is linearly positively correlated. In various situations introduced in the embodiment, the optimized groundwater exploitation technology for confined water can be summarized as follows:

[0106]

[0107] Among them, Q k is the groundwater extraction in area k, is the total groundwater extraction in the area, μ k is the water supply degree of the unconfined aquifer in area k, F k is the area of ​​region k.

[0108] The above are only preferred specific implementations of the present application, but the protection scope of the present application 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 in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for optimizing groundwater extraction, characterized in that: include: Obtaining data on water levels in unconfined aquifers, monitoring data on rainfall in unconfined aquifers, storage coefficients of confined aquifers and administrative areas; Obtaining the groundwater extraction from the phreatic aquifer based on the water level data, rainfall monitoring data and administrative area; Optimizing and controlling the amount of groundwater extraction from the phreatic aquifer; Optimizing the control of groundwater extraction from the phreatic aquifer includes: Dividing the administrative area to obtain a preset number of administrative regions; Determine whether the controlled groundwater extraction volume in the administrative area is related to the groundwater level variation value, and obtain the controlled groundwater extraction volume; Determine whether the controlled groundwater extraction volume of the administrative area is related to the groundwater level fluctuation value, and obtain the controlled groundwater extraction volume including: If the controlled groundwater extraction volume of the administrative area is related to the groundwater level fluctuation value, obtaining the first controlled groundwater extraction volume according to the groundwater level fluctuation value of the administrative area; If the groundwater control extraction volume of the administrative area is independent of the groundwater level fluctuation value, then determine whether the groundwater level fluctuation value of the administrative area is consistent, and determine the second control groundwater extraction volume; The method for obtaining the first controlled groundwater extraction volume is: Q 开采 =α·P·F+μ·ΔH·F Among them, α is the comprehensive groundwater recharge coefficient, P is the precipitation in the year, F is the administrative area, μ is the water supply degree of the aquifer, and ΔH is the annual water level fluctuation of the aquifer; Determining whether the groundwater level variation in the administrative area is consistent and determining the second controlled groundwater extraction volume includes: If the groundwater level changes in the administrative areas are consistent, the second controlled groundwater extraction volume is directly determined; If the groundwater level variation of the administrative area is inconsistent, determining whether the groundwater level variation of the administrative area is a fixed value, and determining the second controlled groundwater extraction amount; Determining whether the water level variation of the administrative area is a fixed value and determining the second controlled groundwater extraction volume includes: If the water level variation of the administrative area is not a fixed value, it is necessary to perform weighted averaging on the administrative area to obtain the second controlled groundwater extraction volume; If the water level variation of the administrative area is a fixed value, the second controlled groundwater extraction volume is directly obtained; The method for obtaining the second controlled groundwater extraction volume is: Among them, Q k is the groundwater extraction in area k, is the total groundwater extraction in the area, μ k is the water supply degree of the unconfined aquifer in area k, F k is the area of ​​region k; Based on the water storage coefficient and administrative area of ​​the confined aquifer, the groundwater extraction of the confined aquifer is optimized and controlled.

2. A method for optimizing groundwater extraction according to claim 1, characterized in that: Based on the water level data and rainfall monitoring data, obtaining the groundwater extraction amount of the phreatic aquifer includes: Based on the water level data and rainfall monitoring data, obtaining a comprehensive groundwater recharge coefficient; Based on the comprehensive groundwater recharge coefficient and the administrative area, the groundwater extraction volume of the phreatic aquifer is obtained.

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