A method for calculating groundwater resource recharge in arid inland basin

Abstract

The present application relates to a kind of calculation methods of arid inland basin groundwater resource recharge, in preselected area setting multiple exploration points, obtain the geological structure composition and hydrogeological condition of area;Geological structure model of area is constructed;Based on the geological structure model of area, plain area space aquifer permeability coefficient, aquifer water supply degree is divided into area;With the help of in-situ monitoring test mode, surface water runoff of monitoring point is collected, based on runoff, obtain groundwater recharge;With the help of statistical method, the function curve of recharge and runoff is established, and the prediction formula of recharge is obtained;Based on the prediction formula of recharge and hydrogeological condition, the annual recharge of groundwater recharge of area is predicted.This method solves the problem that the calculation of arid inland basin groundwater resource recharge is not accurate, difficult to calculate, difficult to manage groundwater resources, difficult to configure.

Description

Technical Field

[0001] This invention relates to the field of groundwater recharge calculation technology, and in particular to a method for calculating groundwater recharge in arid inland basins. Background Technology

[0002] Groundwater is an extremely valuable resource, and the amount of groundwater replenished year by year through surface infiltration is intended to supply human use within a certain period.

[0003] In arid regions, annual rainfall is low, river runoff is small, precipitation variability is high, sunshine is strong, and evaporation is vigorous. Groundwater resources are the most critical factor restricting all human activities.

[0004] As an essential resource for ensuring production and daily life, determining the carrying capacity of groundwater resources and their rational development and utilization are crucial foundations for guaranteeing sustainable economic development and a healthy ecological cycle. To ensure the rational and long-term use of groundwater resources and avoid environmental harm and ecological degradation, extraction should be lower than infiltration recharge. Therefore, a reasonable and appropriate assessment of groundwater recharge should be conducted before development begins.

[0005] Furthermore, due to the inability to accurately determine groundwater content, groundwater levels rise rapidly after replenishment during the flood season, leading to disasters and losses of water and productive resources. Existing technologies suffer from inaccurate and difficult calculations of groundwater recharge, resulting in difficulties in groundwater resource management and allocation, and hindering its rational and effective utilization. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a method for calculating the groundwater recharge in arid inland basins, which solves the technical problems of inaccurate calculation, difficulty in calculation, difficulty in groundwater resource management, and difficulty in allocation of groundwater recharge in arid inland basins.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0010] S10 sets up multiple exploration points in the pre-selected area to obtain the geological structure composition and hydrogeological conditions of the area; based on the geological structure composition and hydrogeological conditions, a geological structure model of the area is constructed by using the Quaternary three-dimensional geological structure modeling method.

[0011] S20. Based on the geological structure model of the region, the permeability coefficient and aquifer yield of the plain area of ​​the region are determined in the model, and the region is divided into zones based on the permeability coefficient and aquifer yield of the plain area.

[0012] S30. Based on the area after the partitioning, select multiple monitoring points, collect the surface water runoff at the monitoring points by means of in-situ monitoring test, and obtain the groundwater infiltration recharge based on the runoff.

[0013] S40. Using statistical methods, the infiltration recharge and surface water runoff are statistically analyzed to establish a function curve of the infiltration recharge and runoff, and a prediction formula for the infiltration recharge is obtained.

[0014] S50. Based on the prediction formula for infiltration recharge and hydrogeological conditions, the annual infiltration recharge of groundwater in the region is predicted.

[0015] Optionally, in step S30;

[0016] The monitoring points include the outlet monitoring point and the overflow zone monitoring point;

[0017] The in-situ monitoring test specifically includes:

[0018] By using a combination of manual cross-sectional measurement and automatic water level observation, surface water level data at each outlet monitoring point are collected, and the cross-sectional runoff at each outlet monitoring point is calculated.

[0019] By using a combination of manual cross-sectional measurement and automatic water level observation, surface water level data at each overflow zone monitoring point are collected, and the cross-sectional runoff at each overflow zone monitoring point is calculated.

[0020] Based on the runoff volume at any of the aforementioned outlet sections and the runoff volume at the overflow zone sections adjacent to the outlet, the infiltration recharge of the river section is calculated.

[0021] Optionally, step S40 specifically includes:

[0022] Based on the infiltration recharge of the river section, a statistical analysis is performed on the infiltration recharge and the runoff at the outlet section to obtain a function curve of the infiltration recharge with respect to the runoff at the outlet section. The function curve represents the relationship between the infiltration recharge and the runoff at the outlet section.

[0023] Optionally, the sampling frequency is 1 hour / time.

[0024] Optionally, based on the function curve of the infiltration recharge amount with respect to the runoff at the outlet section, the prediction formula is as follows:

[0025]

[0026] Wherein, Q0 is the discharge outlet cross-sectional runoff; Q L This refers to the amount of infiltration replenishment.

[0027] Optionally, it also includes:

[0028] Based on the geological structure model of the region, a mathematical model of groundwater flow in the region is constructed;

[0029] The effectiveness of the obtained prediction formula is verified using the groundwater flow mathematical model.

[0030] Optionally, it also includes:

[0031] Based on the geological structure model of the region, surface water and groundwater are sampled using sampling methods to obtain the transformation relationship between surface water and groundwater in the region;

[0032] The effectiveness of the obtained prediction formula is verified based on the aforementioned surface water and groundwater transformation relationship.

[0033] Secondly, embodiments of the present invention also provide an electronic device, comprising: a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program stored in the memory to implement the steps of the method for calculating the groundwater recharge of arid inland basins as described above.

[0034] (III) Beneficial Effects

[0035] This invention provides a method for calculating groundwater recharge in arid inland basins. It involves setting up exploration points for surface surveys and employing techniques such as hydrogeological geophysical exploration, hydrogeological drilling and testing, hydrological monitoring, groundwater level monitoring, in-situ monitoring experiments, remote sensing, and isotope dating to analyze and obtain the region's hydrogeological structure, surface water and groundwater recharge, runoff, and discharge patterns. Based on statistical methods, it calculates the infiltration recharge of groundwater and the runoff of surface water, establishing a function curve for groundwater infiltration recharge versus surface water runoff, and summarizing the conversion relationship function between surface water and groundwater. This method achieves the goal of accurately and simply calculating groundwater recharge in arid inland basins, enabling optimized allocation, simplified management, and effective management of groundwater resources.

[0036] Meanwhile, the calculation method provided by this invention also enables the monitoring and prediction of groundwater levels, effectively predicting the rise in groundwater levels and accurately avoiding disasters caused by rising groundwater levels. Attached Figure Description

[0037] Figure 1This is a schematic flowchart of a method for calculating groundwater recharge in an arid inland basin according to an embodiment of the present invention;

[0038] Figure 2 A river system map of the Bayin River basin provided in an embodiment of the present invention;

[0039] Figure 3 A boundary generalization diagram provided in an embodiment of the present invention;

[0040] Figure 4 This is a three-dimensional geological structure model of the Quaternary system from the Bayinhe alluvial fan to the lacustrine plain, provided in an embodiment of the present invention.

[0041] Figure 5 A spatial aquifer permeability coefficient zoning map of the Bayinhe Plain area provided in an embodiment of the present invention;

[0042] Figure 6 This is a spatial aquifer yield zoning map of the Bayinhe Plain area provided in an embodiment of the present invention;

[0043] Figure 7 This is a graph showing the relationship between the discharge outlet cross-section runoff and the infiltration recharge rate, provided in an embodiment of the present invention.

[0044] Figure 8 A conceptual model of the hydrogeology of the Bayinhe alluvial fan and a simplified schematic diagram of the aquifer provided in an embodiment of the present invention;

[0045] Figure 9 This is a graph showing the variation of groundwater TDS and ions along the path in the Bayinhe River outlet-Keluke Lake profile, provided in an embodiment of the present invention.

[0046] Figure 10 This is a comparison chart of water level and surface water runoff curves at a monitoring point on the Bayin River alluvial fan, provided in an embodiment of the present invention.

[0047] Figure 11 δD-δ of various water bodies in the Bayinhe Plain provided as an embodiment of the present invention 18 O-relationship diagram;

[0048] Figure 12 A zoning map showing the magnitude of water level rise in Delingha in November 2018 compared to June 2018, provided as an embodiment of the present invention;

[0049] Figure 13 This is a diagram showing the relationship between vegetation index and groundwater depth in a typical plain of the Qaidam Basin, provided in an embodiment of the present invention.

[0050] Figure 14 A comparison chart of dynamic curves of flow rate and groundwater monitoring points at monitoring sections in the Bayinhe Plain, provided as an embodiment of the present invention. Detailed Implementation

[0051] To better explain and facilitate understanding of the present invention, it is described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described below are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other; for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0052] like Figure 1 As shown, Figure 1 This invention illustrates a method for calculating groundwater recharge in arid inland basins, comprising the following steps:

[0053] S10 sets up multiple exploration points in the pre-selected area to obtain the geological structure composition and hydrogeological conditions of the area; based on the geological structure composition and hydrogeological conditions, a geological structure model of the area is constructed by means of Quaternary three-dimensional geological structure modeling method.

[0054] For example, in some embodiments, a surface survey is conducted at the exploration site to analyze and obtain the geological structure and hydrogeological conditions of the area. The surface survey methods may include hydrogeological geophysical exploration, hydrogeological drilling and in-situ testing, hydrological monitoring, groundwater level monitoring, remote sensing, and isotope dating.

[0055] In practical applications, the geological structure composition of the acquired area can specifically include stratigraphic structure and stratigraphic lithology, etc.

[0056] S20. Based on the geological structure model of the region, the permeability coefficient and water yield of the aquifer in the plain area of ​​the region are determined in the model, and the region is divided into zones based on the permeability coefficient and water yield of the aquifer in the plain area.

[0057] S30. Based on the area after the partitioning, select multiple monitoring points, and collect the surface water runoff at the monitoring points by means of in-situ monitoring test, and obtain the groundwater infiltration recharge based on the runoff.

[0058] In one embodiment, the surface water runoff at the monitoring point is collected, which may specifically include the riverbed lithology distribution, riverbed infiltration conditions, and the surface water runoff at the beginning and end of the test river section.

[0059] S40. Using statistical methods, the infiltration recharge and surface water runoff are statistically analyzed to establish a function curve of the infiltration recharge and runoff, and a prediction formula for the infiltration recharge is obtained.

[0060] S50. Based on the prediction formula for infiltration recharge and hydrogeological conditions, the annual infiltration recharge of groundwater in the region is predicted.

[0061] In practical applications, the infiltration recharge can also be determined based on the prediction formula, hydrogeological conditions, and stratigraphic structure, according to actual needs. No restrictions are imposed here.

[0062] Furthermore, in practical applications, to ensure the effectiveness of the prediction model, the prediction formula can be validated after it is obtained. For example, in some other embodiments, the specific steps for validation are as follows:

[0063] Based on the geological structure model of the region, a mathematical model of groundwater flow in the region is constructed;

[0064] The effectiveness of the obtained prediction formula is verified using the groundwater flow mathematical model.

[0065] Of course, in other embodiments, other methods that can achieve the same purpose can be used to verify the effectiveness, and no restrictions are placed here.

[0066] For example, based on the geological structure model of the region, the surface water and groundwater can be sampled using a sampling method to obtain the transformation relationship between surface water and groundwater in the region; based on the transformation relationship between surface water and groundwater, the effectiveness of the obtained prediction formula can be verified.

[0067] This embodiment provides a method for calculating groundwater recharge in arid inland basins. Through ground surveys, including but not limited to advanced technologies such as hydrogeological exploration, hydrogeological drilling and testing, hydrological monitoring, groundwater level monitoring, in-situ testing, remote sensing, and isotope dating, the method analyzes and studies the Quaternary hydrogeological structure, groundwater recharge, runoff, and distribution patterns of two watersheds. It grasps the intrinsic relationship between surface water runoff, groundwater level dynamics, and hydrogeological structure, and studies and summarizes the transformation relationship function between surface water and groundwater in the watershed. This method enables simple and targeted calculation of groundwater recharge in arid inland basins, improves prediction accuracy, and can accurately calculate groundwater infiltration recharge, thereby achieving prediction of groundwater resources and optimizing resource allocation.

[0068] In one embodiment, step S30 is specifically implemented as follows: setting up monitoring points at the outlet and overflow zone to conduct in-situ monitoring tests. Specifically, by means of manual cross-sectional measurement and automatic water level observation, surface water level data of each outlet monitoring point are collected, and the cross-sectional runoff of each outlet monitoring point is calculated.

[0069] By using methods such as manual cross-sectional measurement and automatic water level observation, surface water level data of each overflow zone monitoring point are collected, and the cross-sectional runoff of each overflow zone monitoring point is calculated.

[0070] Based on the runoff volume at any of the aforementioned outlet sections and the runoff volume at the overflow zone sections adjacent to the outlet, the infiltration recharge of the river section is calculated.

[0071] In this implementation, the data collection frequency is once per hour. However, in actual applications, the frequency should be determined according to actual needs, and no restriction is imposed here.

[0072] For step S40, the obtained discharge flow rate at the outlet section, discharge flow rate at the overflow zone section, and infiltration recharge are statistically analyzed. Based on the infiltration recharge of the river section, the infiltration recharge and the discharge flow rate at the outlet section are statistically analyzed to obtain a function curve of the infiltration recharge with respect to the discharge flow rate at the outlet section. The function curve represents the relationship between the infiltration recharge and the discharge flow rate at the outlet section.

[0073] To better illustrate the method for calculating groundwater recharge in arid inland basins provided by this invention, a specific embodiment is used here for illustration.

[0074] In this embodiment, for step S10, the pre-selected area is the Qaidam Basin, and multiple exploration points are set up. Through ground surveys, the geological structure and hydrogeological conditions of the Qaidam Basin are obtained.

[0075] The Qaidam Basin is located in northwestern Qinghai Province, and the Bayin River is situated in the northeastern corner of the Qaidam Basin. Figure 2 , Figure 3 As shown, Figure 2 A watershed map of the Bayin River is shown. Figure 3 This embodiment shows a simplified boundary map of the Bayin River. The Bayin River Plain extends from Zongwulong Mountain in the north to the Denan Hills in the south, from Huaitoutala in the west to the Buhet Mountain piedmont in the east. Administratively, it encompasses Delingha City, Gahai Town, and Keluke Town. Its geographical coordinates lie between 96°45′1″ and 97°34′13″ east longitude and 37°8′8″ and 37°30′1″ north latitude, with a total area of ​​approximately 2630 km². 2 The terrain is high on all sides and low in the center, with the highest point being Zongwulong Mountain in the north. Groundwater flows out through the southeast and southwest boundaries towards Gahai Lake and Keluke Lake respectively. The area is 920 km². 2 .

[0076] The landforms can be broadly divided into medium-high mountains, medium-low mountains, low hills, alluvial plains, alluvial-diluvial plains, alluvial plains, and alluvial-lacustrine plains. The alluvial sloping plain is located in the piedmont area, covering an area of ​​870 km². 2Composed of alluvial fans with slopes ranging from 10‰ to 35‰, this area forms a strong runoff zone for groundwater in the basin and also serves as a seasonal surface flood recharge zone. The alluvial-diluvial plain is located in the central part of the plain area. Alluvial plains are distributed along the middle and lower reaches of the Bayin River, while lacustrine plains are distributed in the lower reaches of the Bayin River, including areas such as Gahai Lake and Keluke Lake, with a low, flat terrain sloping slightly towards the lake areas.

[0077] The Bayinhe Plain has a typical arid continental climate. Field surveys were conducted at observation points along the Bayinhe River basin. Based on actual observations and historical exploration data, the region's geomorphological and geological characteristics were determined. The average annual precipitation of 195.3 mm from 1960 to 2020 was obtained from local meteorological stations, with the main precipitation period from May to September, accounting for 85% of the annual precipitation. The average annual flow of the Bayinhe River from 1960 to 2020 was obtained from local hydrological stations, at 11.38 m³ / h. 3 / s, and also obtained information that the area where a large amount of surface water seepage occurred was in the Gobi Desert in the plain area after the Black Stone Mountain Reservoir.

[0078] Of course, in other embodiments, the above data can be obtained entirely from the set exploration points or entirely from the records of historical exploration data, and there is no limitation here.

[0079] Specifically, field surveys at exploration points revealed that the recharge of groundwater by the Bayin River in the plain mainly occurs in the section from the river's exit from the mountain pass to the overflow zone, a recharge section approximately 22 km long. After entering the natural river channel at the exit of the Bayin River, the river water seeps into the ground in a linear fashion, effectively replenishing the groundwater. The amount of seepage is related to factors such as the river surface area, the water level in the riverbed, the riverbed lithology, and the water flow velocity.

[0080] After surface water infiltrates the ground, it scatters and flows downstream towards lakes. During the flood season, it receives strong replenishment from the river, and areas near the Bayin River valley show runoff flowing to both sides. During the dry season, the scattered runoff characteristics are basically restored, with a hydraulic gradient of 0.8–1.5‰. Groundwater flows to the oasis area in the overflow zone and is discharged through springs, evaporation, and transpiration.

[0081] Quaternary strata are widely distributed in the region, with lithology mainly consisting of sand and gravel. From the northern piedmont to the southern Denan Uplift, the Quaternary strata become finer. Controlled by the morphology, structure, and topographic conditions of the sedimentary basement, the strata thickness in the sedimentary center of Gahai Town is 350–500 m, while the thickness near the piedmont is less than 350 m.

[0082] Based on the geological structure composition and hydrogeological conditions information obtained above, and using the Quaternary three-dimensional geological structure modeling method, a geological structure model of the region is constructed, such as... Figure 4 As shown, Figure 4This embodiment shows a three-dimensional geological structure model of the Quaternary system from the Bayinhe alluvial fan to the alluvial-lacustrine plain.

[0083] Regarding step S20, in this embodiment, based on the aforementioned regional geological structure model, the permeability coefficient and aquifer specific yield of the plain area in the region are determined within the model. Based on the permeability coefficient and aquifer specific yield of the plain area, the region is divided into zones, such as... Figure 5 , Figure 6 As shown, Figure 5 This embodiment provides a spatial aquifer permeability coefficient zoning map of the Bayinhe Plain area. Figure 6 A spatial aquifer water yield zoning map of the Bayinhe Plain area is provided.

[0084] For step S30, based on the partitioned Bayinhe Plain area, multiple monitoring points are selected for in-situ monitoring tests. The selected monitoring points include outlet monitoring points and overflow zone monitoring points. With the help of manual cross-section measurement and automatic water level observation, surface water level data of each outlet monitoring point are collected, and the cross-sectional runoff of each outlet monitoring point is calculated.

[0085] By using manual cross-section measurement and automatic water level observation, surface water level data of each overflow zone monitoring point are collected, and the cross-sectional runoff of each overflow zone monitoring point is calculated.

[0086] Based on the runoff volume at any of the aforementioned outlet sections and the runoff volume at the overflow zone sections adjacent to the outlet, the infiltration recharge of the river section is calculated.

[0087] In this embodiment, the Bayin River flows out of the mountains from the Heishishan Reservoir and enters the plain area. The plain area is mainly divided into three stages. First, there is a 3.7-kilometer-long artificially hardened river channel. During this stage, the hardened riverbed acts as a barrier, preventing water infiltration loss and eliminating hydraulic interaction between the river water and groundwater. Second, the Bayin River's hardened channel ends at the railway bridge in Delingha City, where the river flows into a natural channel of 14.8 kilometers. This natural channel's bed is primarily composed of sand, pebbles, and gravel, with groundwater levels ranging from 0 to 100 meters. A significant hydraulic gradient exists between the groundwater and river water, indicating a strong hydraulic connection. A large amount of river water infiltrates into the aquifer during this section. Third, the river then enters the downstream groundwater discharge section. Here, the groundwater level is influenced by strata lithology and topography, resulting in a higher level than the surface. Groundwater discharge (in the form of springs) replenishes the surface river, reversing the hydraulic relationship between the river water and groundwater. Surface water no longer infiltrates to replenish the groundwater. Therefore, based on the experimental objectives, site conditions, and the hydrogeological, geological, and topographical characteristics of the alluvial fan, a 14.8-kilometer natural river section from the railway bridge in Delingha City to the downstream overflow zone was selected as the site for the large-scale in-situ infiltration test. This section has a river width of 50-150 meters, is a natural riverbed of sand, pebbles, and gravel, and the surface water level is higher than the groundwater level. The replenishment relationship between the two is that surface water infiltrates to replenish groundwater. This river section has no water diversion and no lateral surface water replenishment; therefore, we consider the amount of river water infiltrating to replenish groundwater to be the cross-sectional flow difference.

[0088] In this embodiment, temporary hydrological observation sections were set up at five cross-sections: upstream of the Bayinhe Heishishan Reservoir, the urban railway bridge, under the Taoha Bridge, under the Malantan Bridge, and under the downstream Gobi Railway Station. Water level data were collected by a combination of manual cross-section measurement and automatic water level observation devices, with a collection frequency of 1 hour / time.

[0089] In consultation with the Heishishan Reservoir Management Station, water was released at different flow rates, including 20, 25, 30, 50, 70, 100, and 150 cubic meters per second. Simultaneously, field measurements were conducted at the end of the hardened river channel (the beginning of the natural river channel) to obtain surface water level data, and the discharge flow at the outlet section was calculated. In a 14.8-kilometer section downstream of the overflow zone, on-site flow measurements were performed to obtain the overflow zone section runoff. The flow difference was calculated; that is, based on the runoff at any given outlet section and the runoff at the adjacent overflow zone section, the infiltration recharge for that river section was calculated.

[0090] In another embodiment, in order to monitor the response of groundwater to surface water recharge and leakage, cross-sectional and longitudinal monitoring profiles were deployed at different distances along different sections of the Bayin River on both sides, with a total of 22 groundwater dynamic monitoring points deployed to help determine the amount of river infiltration and recharge.

[0091] For step S40, the in-situ monitoring tests were conducted from June to September 2016, June to September 2017, and June to September 2018. Using statistical methods, the runoff at all collected outlet sections and overflow zone sections was statistically analyzed to confirm the corresponding infiltration recharge. The infiltration recharge and outlet section runoff were then statistically analyzed to obtain a function curve of the infiltration recharge as a function of the outlet section runoff.

[0092] In one embodiment, a total of 5210 sets of measured data were acquired, as shown in the table below, which represents a portion of the data from the in-situ monitoring experiment:

[0093]

[0094] like Figure 7 As shown, Figure 7 This is a graph showing the relationship between the discharge outlet cross-section runoff and the infiltration recharge in this embodiment.

[0095] In this embodiment, the annual infiltration volume of the Bayin River from 2016 to 2020 was quantitatively calculated using real-time cross-sectional monitoring data. The results showed that 50.2% of the runoff directly infiltrated and replenished the groundwater. Meanwhile, when the river runoff was less than 25 m³ / h... 3 At a rate of 1 / s, 100% of the river water seeps into groundwater. However, as the river's flow increases, the seepage rate begins to decrease, and when it reaches its limit, the seepage rate no longer increases.

[0096] Based on the above calculations, a function curve between the runoff and the infiltration rate is established to obtain a prediction formula for the infiltration recharge. In some embodiments, this prediction formula may also be referred to as an empirical formula, an approximate formula, etc.

[0097] The formula is:

[0098]

[0099] In the formula, Q0 is the runoff at the river outlet section (m³). 3 / s); Q L Infiltration recharge (m 3 / s).

[0100] Using the relationship, the multi-year average river seepage recharge from 2000 to 2020 was systematically calculated, and the seepage rate was found to be 62.53 × 10⁻⁶. 4 m 3 / d.

[0101] Of course, in other embodiments, the monitoring points and monitoring time set above can be selected according to actual needs, and there are no restrictions here.

[0102] In another embodiment, long-term measurements of infiltration per unit area in a river tributary were conducted. A typical tributary of the Bayin River (with representative riverbed lithology, etc.) was selected, with a total channel length of 162 meters, a channel width of 1.5 meters, a flow velocity of 0.3-0.45 m / s, and a water depth of 0.1-0.25 meters. Infiltration tests were conducted at different flow rates, and the flow loss was calculated using the measured data, which was considered to be the amount of water infiltrating into the aquifer. Simultaneously, the width and length of the river were calculated segment by segment, resulting in an infiltration area of ​​285 square meters. Using the infiltration area and infiltration rate, the infiltration per unit area was calculated. The amount of water replenishing the aquifer through the entire 14.8 km river channel was then calculated using the infiltration per unit area.

[0103] Furthermore, to ensure the effectiveness of the prediction formula, its effectiveness is verified after it is obtained.

[0104] The validity verification process can be specifically implemented using the following steps:

[0105] Based on the geological structure model of the region, a mathematical model of groundwater flow in the region is constructed;

[0106] The effectiveness of the obtained prediction formula is verified using the groundwater flow mathematical model.

[0107] For example, in one embodiment, the middle to the top of the Bayinhe alluvial fan was selected as the verification area. A surface survey was conducted in this area, revealing that the middle to the top of the Bayinhe alluvial fan is a single-structure unconfined aquifer with lithology of sand, gravel, and cobble. The aquifer in the fine-grained plain area of ​​the alluvial fan has a two-layer structure: the upper layer is an unconfined aquifer, mainly composed of sand, gravel, medium-coarse sand, and fine sand; the lower layer is a confined aquifer, mainly composed of sand, gravel, fine sand, and silt. The Lower Pleistocene and its underlying bedrock, due to their poor water-bearing capacity, can be considered relatively impermeable layers and vertically generalized as the bottom boundary of the model, establishing a geological structure model for this area. Figure 8 As shown, Figure 8 This invention illustrates a hydrogeological conceptual model of the Bayinhe alluvial fan and a simplified schematic diagram of the aquifer, provided by an embodiment of the present invention.

[0108] In this model, the replenishment factors include: river seepage, infiltration from floods in front of mountains, lateral runoff, and irrigation seepage; the discharge factors include: spring overflow, groundwater evaporation, runoff discharge towards Keluke Lake and Gahai Lake, and artificial mining.

[0109] Based on the geological structure model, a mathematical model of groundwater flow in the Bayin River Basin is constructed:

[0110]

[0111] Where: Ω—the seepage zone; h—groundwater level (m); kx, ky, kz—permeability coefficients in the x, y, z directions (m / d); kn—permeability coefficient in the normal direction of the boundary surface (m / d); S—storage coefficient of the aquifer below the free surface; μ—gravitational specific yield of the unconfined aquifer; Γ0—upper boundary of the seepage zone, i.e., the free water surface of groundwater; q—the flow rate per unit area of ​​the defined aquifer second-class boundary, positive for inflow and negative for outflow, and zero for impermeable boundaries (m). 3 / s).

[0112] After being regulated by the Heishishan Reservoir, most of the Bayin River, except for a portion diverted for agricultural irrigation, leaks into the river channel, replenishing groundwater. This recharge can be calculated using the previously mentioned approximate formula for river water seepage (i.e., the infiltration recharge formula). After equilibrium verification of the model, the multi-year average river seepage recharge from 2000 to 2020 was determined to be 63.48 × 10⁻⁶. 4 m 3 / d. The leakage rate calculated using the formula is 62.53 × 10⁻⁶. 4 m 3 The error was 1.52%, which is small and verifies the effectiveness of the method.

[0113] Of course, in other embodiments, other methods that can achieve the same purpose can be used to verify the effectiveness, and no restrictions are placed here.

[0114] For example, based on the geological structure model of the region, the surface water and groundwater can be sampled using a sampling method to obtain the transformation relationship between surface water and groundwater in the region; based on the transformation relationship between surface water and groundwater, the effectiveness of the obtained prediction formula can be verified.

[0115] Specifically, in one embodiment, surface water was sampled and its composition was analyzed. This analysis specifically involved detecting changes in solutes and ions in the solution. The selected river section was along the route from the mountain pass to Keluke Lake, i.e., the main recharge section. The analysis revealed a 13.2-fold increase in TDS and a decrease in Ca. 2+ It increased by 33.3 times, the largest increase, Na + Increased by 11.9 times, Mg 2+ Increased by 6 times, SO4 2- Increased by 23.3 times, Cl - The HCO3 content increased by 12.6 times. - It increased by 3.3 times, the smallest increase. For example... Figure 9 As shown, Figure 9 The graph shows the variation of TDS (total dissolved solids) and ions along the path in the Bayinhe River outlet-Keluke Lake profile in this embodiment.

[0116] This indicates that the particles in the Gobi Desert area of ​​alluvial fans and alluvial plains are large, and the surface water flows rapidly in this area, with water receiving replenishment along the way.

[0117] Furthermore, sampling is conducted on different sections of groundwater in the area to obtain water samples. Isotope analysis is performed on the water samples to obtain the evolution of the groundwater recharge source and the transformation relationship between groundwater and surface water.

[0118] Surface water serves as the primary source of groundwater recharge in the Bayinhe Plain area, and its runoff changes directly influence the dynamic characteristics of groundwater. The aquifer near the riverbed is primarily composed of sand, gravel, and pebbles, exhibiting strong vertical permeability and good horizontal water conduction. The groundwater level responds actively and rapidly to changes in river runoff, with fluctuations mirroring the characteristics of river runoff magnitude changes, exhibiting hydrological and hydro-runoff patterns. Figure 10 As shown, Figure 10 A comparison diagram of water level and surface water runoff curves at a monitoring point on the Bayinhe alluvial fan provided in an embodiment of the present invention is shown.

[0119] The isotope detection specifically includes the detection of hydrogen (D, ) in groundwater samples. 3 H), oxygen ( 18 O), carbon ( 14 C) Isotope detection, through detection 14 C 3 H content, by means of 14 C 3 The H method is used to calculate the age of groundwater and analyze the age distribution characteristics of different groundwater flow sections, with the help of... 3 The H content is used to calculate the groundwater recharge rate and estimate the groundwater recharge intensity and amount.

[0120] In this embodiment, the 14C age results show that the age of groundwater gradually increases from the northern mountainous area to Keluke Lake. Since the groundwater in the alluvial fan mainly comes from river water seepage recharge, the shallow groundwater in the Bayin River valley and on both sides, as well as in the north and east, is recharged by seasonal river infiltration from the mountainous area. The groundwater age is generally 0 to 5 ka BP. Far away from the edge of the recharge area, the groundwater age gradually increases, with an age range of 5 to 10 ka BP.

[0121] In this embodiment, isotope analysis was also performed on water bodies such as the Bayin River, spring water, and lake water. Figure 11 As shown, Figure 11 The δD-δ values ​​of various water bodies in the Bayinhe Plain in this embodiment are shown. 18 O-relationship diagram, where δD and δ of water sample are shown. 18The O data showed that the δD of the river water ranged from -59.4‰ to -53.31‰, with an average value of -58.00‰; δ 18 O ranged from -9.18‰ to -8.13‰, with an average of -8.87‰; δD in groundwater ranged from -68.45‰ to -47.41‰, with an average of -59.34‰. 18 The oxygen content ranges from -10.55‰ to -8.45‰, with an average of -9.24‰.

[0122] Furthermore, in some other embodiments, water chemistry and isotope mass balance methods can be applied to quantitatively estimate the conversion amount between river water and groundwater, using the following mass conservation equation:

[0123] Q s ·C s =Q u ·C u +(Q s -Q u )·C V

[0124] In the formula: Q s Q represents the flow rate of the mixed water body. u C represents the flow rate of the water body before mixing. s C represents the concentration of the tracer in the mixed water. u and C v Given the tracer concentration in the water body before mixing, the runoff before and after mixing satisfies the following relationship:

[0125] or

[0126] Therefore, the mixing amount of surface water and groundwater can be calculated.

[0127] In this embodiment, δ 18 Using O as a tracer, the calculation results show that the surface water to groundwater conversion rate in the Bayinhe Plain area is 65.00%.

[0128] Of course, in practical applications, the tracer can also be Cl. - Electrical conductivity, stable isotope δD, etc., are not limited to δ here. 18 O.

[0129] In addition, the method for calculating groundwater recharge in arid inland basins provided by this invention improves the accuracy of groundwater recharge calculation and thus has a good preventive effect on disasters caused by rising groundwater levels.

[0130] In other embodiments, the method provided by this invention can also be used to prevent disasters caused by rising groundwater levels. For example, in the Qaidam Basin, in 2002, 2005, 2012, 2017, 2018, and 2019, the groundwater level rose significantly in the fine soil zone at the edge of the alluvial fan south of Dongsheng Village-Fuyuan Village-Quanshui Village-Guolimu Village in Gahai Town, Delingha County, and in the area around the former site of Wulangangou-Xinxiu Village-Jinyuan Village in Keluke Town on the north side of the Delingha Uplift, leading to serious disasters such as flooding of villages, cracking of houses, and collapse of walls and houses. The groundwater level rose significantly in 2017, and was even more severe in 2018, with Gahai Town almost completely submerged. Looking at the water level monitoring data from 2017 to 2020, the water level in Guolimu New Village in Gahai Town rose by 7-8 meters, and the water level north of the Zhejiang Aid-Qinghai Project Department rose by 9.5 meters, showing a continuous upward trend. Specifically: After the 2017 flood season, water levels in the area rose by 8-15 meters. Water levels in the river valleys rose by more than 8 meters, with some areas experiencing rises exceeding 15 meters. In 2018, water levels in the river valleys rose by 10-15 meters. Figure 12 As shown, Figure 12 This embodiment shows a zoning map of the water level rise in Delingha in November 2018 compared to June 2018.

[0131] By conducting eco-hydrological geological surveys and quantitative remote sensing interpretation, and using correlation analysis of water level depth, TDS content data, survey samples of suitable water levels for vegetation, and vegetation index data, the groundwater TDS threshold of the main plain area of ​​the Qaidam Basin can be determined.

[0132] The maximum water level depth and maximum salinity of dominant ecological vegetation dependent on groundwater level for growth, i.e., the groundwater level threshold. Specifically, in Golmud, the NDVI (NDV threshold) distribution is mainly within the range of 0.3–3.5 m, with some distribution in the range of 3.5–8.2 m and very little distribution in the range of 8.2–10 m; in Delingha, the NDVI distribution is mainly within the range of 0.3–2.6 m, with a significant distribution in the range of 2.6–10 m and many high-value points; in Ulan, the NDVI distribution is densely distributed in the ranges of 0.3–2.6 m and 4.3–8 m, with a relatively dense distribution in the range of 2.3–4.3 m; in the Nuomuhong-Zongjia Plain, the NDVI distribution is densely distributed in the range of 0.3–2.6 m, with high-value points concentrated in the range of 0.6–2.3 m; and in Wutumeiren, the NDVI distribution is densely distributed in the range of 0.5–2.6 m. Figure 13 As shown, Figure 13 The diagram shows the relationship between vegetation index and groundwater depth in a typical plain of the Qaidam Basin.

[0133] Figure 14The diagram shows a comparison of the flow rate at the monitoring section of the Bayinhe Plain and the dynamic curves of groundwater monitoring points. The water levels at groundwater monitoring points at different distances from the river all showed different increases after the river water replenishment. Overall, the groundwater level responded rapidly and the increase was relatively large.

[0134] Statistical calculations of the annual runoff of the Bayin River were performed using formulas. In 2005, when Delingha suffered a disaster, the annual runoff of the Bayin River that year was 4.41 × 10⁻⁶. 8 m 3 The annual runoff of the Bayin River in 2006 was 3.54 × 10⁻⁶. 8 m 3 No disaster occurred; the annual runoff of the Bayin River increased to 4.58 × 10⁻⁶ in 2007. 8 m 3 No disaster occurred; in 2008, the annual runoff of the Bayin River dropped to 3.77 × 10⁻⁶. 8 m 3 However, the annual runoff of the Bayin River in 2009 was 4.41 × 10⁻⁶. 8 m 3 In that year, Delingha experienced a relatively minor groundwater level rise disaster. Looking at the disaster situation, the runoff in 2007 was greater than that in 2009, but no disaster occurred in 2007. This indicates that the disaster primarily occurred when the seepage from the Bayin River, after compensating for the previous year's water level drop, still had a significant surplus, leading to a disaster. To illustrate this, we can compare the average runoff for 2006 and 2007, and 2008 and 2009, obtaining an average runoff of 4.06 × 10⁻⁶. 8 m 3 and 4.09×10 8 m 3 Therefore, it can be seen that the runoff of the Bayin River in the year of the disaster falls between two average values. Thus, by calculating the relationship between its replenishment resources and water level using the formula, 4.07 × 10⁻⁶ can be determined. 8 m 3 This refers to the critical flow rate at which water levels in the Bayinhe Plain cause disasters.

[0135] This invention provides a method for calculating groundwater recharge in arid inland basins. Through ground surveys, hydrogeological exploration, hydrogeological drilling and experiments, hydrological monitoring, groundwater level monitoring, in-situ monitoring experiments, remote sensing, and isotope dating, it analyzes the hydrogeological structure, surface water and groundwater recharge, runoff, and discharge patterns in the region. Based on statistical methods, it calculates the infiltration recharge of groundwater and the runoff of surface water, establishing a function curve of groundwater infiltration recharge versus surface water runoff, and summarizing the transformation relationship function between surface water and groundwater. This method achieves the goal of accurately and simply calculating groundwater recharge in arid inland basins, enabling optimized allocation, simplified management, and effective management of groundwater resources. The method provided by this invention enhances the understanding of the quantitative study of surface water-groundwater transformation relationships, clarifies the evolutionary laws of surface water-groundwater cycles, and the relationship between water and ecology, lakes, and wetlands. It provides fundamental hydrogeological data and scientific basis for improving water resource utilization and security, and for setting groundwater resource red lines to protect the ecological environment.

[0136] Meanwhile, the calculation method provided by this invention also enables the monitoring and prediction of groundwater levels, effectively predicting the rise in groundwater levels and accurately avoiding disasters caused by rising groundwater levels.

[0137] This embodiment also provides an electronic device, including: a memory and a processor; the processor is used to execute a computer program stored in the memory to implement the steps of the method for calculating the groundwater recharge of arid inland basins as described in any of the above embodiments.

[0138] On the other hand, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program, which, when executed by a processor, implements the steps of the method for calculating the groundwater recharge of arid inland basins in any of the above embodiments.

[0139] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions.

[0140] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples, without contradiction.

[0141] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the claims should be interpreted to include both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0142] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, then this invention should also include these modifications and variations.

Claims

1. A method for calculating groundwater recharge in arid inland basins, characterized in that, include: S10. Set up multiple exploration points in the pre-selected area to obtain the geological structure and hydrogeological conditions of the area; Based on the geological structure composition and hydrogeological conditions, a geological structure model of the region is constructed using the Quaternary three-dimensional geological structure modeling method. S20. Based on the geological structure model of the region, the permeability coefficient and aquifer yield of the plain area of ​​the region are determined in the model, and the region is divided into zones based on the permeability coefficient and aquifer yield of the plain area. S30. Based on the partitioned area, select multiple monitoring points, including outlet monitoring points and overflow zone monitoring points; The surface water runoff at the monitoring point was collected using an in-situ monitoring test method, which included: At a sampling frequency of 1 hour / time, surface water level data of each outlet monitoring point are collected by means of manual cross-section measurement and automatic water level observation, and the cross-sectional runoff of each outlet monitoring point is calculated. At a sampling frequency of 1 hour / time, surface water level data of each overflow zone monitoring point are collected by means of manual cross-section measurement and automatic water level observation, and the cross-sectional runoff of each overflow zone monitoring point is calculated. Based on the runoff volume of any of the aforementioned outlet sections and the runoff volume of the overflow zone sections adjacent to the outlet, the infiltration recharge of the river section from the outlet to the adjacent overflow zone is calculated. S40. Using statistical methods, the infiltration recharge and surface water runoff are statistically analyzed to establish a function curve of the infiltration recharge and runoff, and a prediction formula for the infiltration recharge is obtained. S50. Based on the prediction formula for infiltration recharge and hydrogeological conditions, the annual infiltration recharge of groundwater in the region is predicted.

2. The calculation method according to claim 1, characterized in that, Step S40 specifically includes: Based on the infiltration recharge of the river section, a statistical analysis is performed on the infiltration recharge and the runoff at the outlet section to obtain a function curve of the infiltration recharge with respect to the runoff at the outlet section. The function curve represents the relationship between the infiltration recharge and the runoff at the outlet section.

3. The calculation method according to claim 2, characterized in that, Based on the function curve of the infiltration recharge amount with respect to the runoff at the outlet section, the prediction formula is obtained as follows: ； Wherein, Q0 is the discharge outlet cross-sectional runoff; Q L This refers to the amount of infiltration replenishment.

4. The calculation method according to claim 1, characterized in that, Also includes: Based on the geological structure model of the region, a mathematical model of groundwater flow in the region is constructed; The effectiveness of the obtained prediction formula is verified using the groundwater flow mathematical model.

5. The calculation method according to claim 1, characterized in that, Also includes: Based on the geological structure model of the region, surface water and groundwater are sampled using sampling methods to obtain the transformation relationship between surface water and groundwater in the region; The effectiveness of the obtained prediction formula is verified based on the aforementioned surface water and groundwater transformation relationship.

6. An electronic device, characterized in that, The device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program stored in the memory to implement the steps of the method for calculating the groundwater recharge of arid inland basins as described in any one of claims 1 to 5.

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