A method for optimizing and controlling exploitation of a river-side water source based on a deposition environment

Abstract

A kind of optimization and control mining technology method of river-adjacent water source based on sedimentary environment includes seven steps of multi-source data integration and preliminary three-dimensional hydrogeological model construction, sedimentary environment fine description and pollution mechanism identification, river-adjacent water source optimization layout, water level-water quality linkage mining, water quality safety early warning system construction, optimization of mining amount, dynamic closed-loop management and the like.The method is especially suitable for high-arsenic groundwater areas such as the Yellow River and the Yellow River old channel, and a "water-ecology-economy" trinity demonstration mode is constructed, which not only guarantees water supply safety and improves water resource utilization efficiency, but also protects ecological environment and promotes regional industrial and agricultural sustainable development.

Description

Technical Field

[0001] This application pertains to the field of groundwater resource development, specifically relating to an optimized management and extraction method for riverside water sources based on sedimentary environments. This method is particularly suitable for high-arsenic groundwater areas such as the Yellow River and its former course, and is especially well-suited to riverside water sources in the lower reaches of the Yellow River characterized by suspended river topography, widespread Quaternary sediments, and a high risk of arsenic contamination in groundwater. Background Technology

[0002] The Yellow River basin and its former course are important industrial and agricultural production bases in my country, containing dozens of large riverside water sources that play a core role in ensuring regional water supply. Due to the unique sedimentary environment of this region, Quaternary sediments are enriched in arsenic, and the complex hydrogeological conditions and volatile redox environment result in widespread arsenic contamination in groundwater, with exceedance rates reaching 30%-50%, seriously threatening drinking water safety.

[0003] In recent years, influenced by climate warming and humidification, the average annual rainfall in the Yellow River Basin has increased by 15%-20% compared to normal years. Coupled with the implementation of groundwater extraction reduction policies in the North China Plain and the South-to-North Water Diversion Project, the groundwater level in the lower reaches of the Yellow River has generally risen by 0.5-3 meters. This change alters the redox conditions at the sediment-water interface, accelerates the release of arsenic from sediments, and exacerbates the risk of groundwater quality deterioration.

[0004] Currently, the centralized extraction model has long been used in riverside water source areas, with water quantity assurance as the core objective, lacking a holistic consideration of water quality safety and ecological protection. Existing technologies mostly focus on macroscopic analysis of hydrogeological conditions, lacking a detailed characterization of the heterogeneity within the Quaternary sedimentary environment, failing to clearly define the quantitative relationship between sedimentary characteristics and pollutant release, and thus making it difficult to accurately predict water quality evolution trends, resulting in extraction schemes lacking specificity.

[0005] Currently, traditional mining methods typically only set a single water level control threshold, without establishing a linkage mechanism between water level fluctuations and water quality changes. When the water level exceeds the control range, it easily triggers the release of large amounts of pollutants such as arsenic from sediments, causing deterioration of the extracted water quality. Some water sources have been forced to reduce production or shut down due to substandard water quality. In addition, the mining layout lacks ecological guidance. The drawdown cones formed by concentrated mining have led to a significant drop in groundwater levels, causing ecological and geological problems such as land subsidence, wetland shrinkage, and insufficient ecological flow in rivers, thus disrupting the regional hydrological cycle balance.

[0006] More notably, the utilization rate of the back-river depressions and along-river depressions inside and outside the dikes in the lower reaches of the Yellow River is less than 10%. Their natural hydrological regulation potential has not been brought into play, and the pressure of water level decline caused by mining has not been alleviated through natural replenishment. Instead, the idle terrain has led to a waste of water resources.

[0007] Current research on this technical problem mainly focuses on single aspects such as water quality remediation and optimized water allocation, such as using chemical oxidation to remove arsenic from groundwater or calculating exploitable quantities through numerical models. However, none of these methods have solved the problem of coordinated management among water quantity, water quality, and ecology. Therefore, this application provides an optimized management and extraction method based on precise characterization of the sedimentary environment, integrated water level-water quality linkage control, and consideration of ecological protection, which can achieve safe, efficient, and sustainable development of riverside water source areas. Summary of the Invention

[0008] This application provides a method for optimized management and exploitation of riverside water sources based on sedimentary environment. By integrating multi-source data to construct a refined hydrogeological model, it accurately depicts the sedimentary environment and pollutant release mechanism, establishes a water level-water quality linkage control system, couples multiple models to construct a safety early warning system, optimizes the exploitation layout and intensity, and ultimately achieves the three-in-one goal of water quantity guarantee, water quality safety and ecological protection, thus resolving the contradiction between exploitation and ecological protection in high-arsenic riverside water sources.

[0009] Overall, this method constructs a refined hydrogeological model by integrating multi-source data, accurately depicts the sedimentary environment and pollutant release mechanism, establishes a water level-water quality linkage control system, couples multiple models to construct a safety early warning system, optimizes mining layout and intensity, and ultimately achieves the three-in-one goal of water quantity guarantee, water quality safety and ecological protection, so as to achieve the purpose of "mining based on replenishment, ecological priority and coordinated development".

[0010] Firstly, the core improvement of this application lies in overcoming the limitations of existing technologies that "emphasize water quantity, neglect water quality, and weaken ecology," and constructing a four-in-one management system of "sedimentation-water level-water quality-ecology," forming an optimized mining model that combines safety, economy, and ecology. The technical solution of this application will be described in detail below.

[0011] An optimized management and exploitation method for riverside water sources based on sedimentary environment, the specific implementation steps of which are as follows:

[0012] Step 1: Multi-source data integration and preliminary 3D hydrogeological model construction. The purpose is to integrate multi-type and multi-scale data to achieve preliminary accurate construction of the hydrogeological model, providing a reliable framework for subsequent sedimentary environment characterization.

[0013] In contrast, existing technologies for constructing hydrogeological models often rely on a single type of data, such as hydrogeological survey data or water level monitoring data. This results in narrow data coverage and low accuracy, making it impossible for the model to accurately reflect the true hydrogeological conditions of the study area. Consequently, the design of mining schemes based on the model lacks scientific rigor.

[0014] The integration of multi-source data and the construction of a preliminary three-dimensional hydrogeological model involve the comprehensive collection of multi-type and multi-scale data, including basic geology, hydrogeology, geochemistry, geomorphology, and meteorology. High-precision standardized maps are selected, and the results of nearly 10 years of exploration and monitoring data over many years are combined. A parameter assignment method that combines field measurements and experience is adopted to strictly control the model calibration and verification errors.

[0015] The preliminary three-dimensional hydrogeological structure model constructed by comprehensively collecting data has higher accuracy (correction error ≤ 0.5 meters), which can accurately reflect the structure of the aquifer system and the state of water flow. This provides a basic framework for the subsequent detailed characterization of the sedimentary environment and the optimization of mining schemes, avoiding problems such as insufficient targeting of mining schemes and failure of water quality control due to model deviations.

[0016] Specifically, a comprehensive collection of historical data and field survey data for the study area was conducted, encompassing basic geological maps, regional hydrogeological survey data, hydrogeological parameter data, groundwater dynamic characteristics data, solute transport and geochemical data, regional geomorphological features, and meteorological data. The basic geological maps used were standardized maps at a scale of 1:50,000 to ensure data accuracy. The hydrogeological survey data included investigation reports from the past 10 years, as well as sufficient drilling and geophysical exploration results, ensuring the authenticity of the model construction. Based on the collected data, the aquifer system structure, boundary properties, recharge-drainage relationships, and flow conditions of the study area were comprehensively assessed. A hydrogeological conceptual model was established, and mature numerical models such as MODFLOW were selected for mathematical model construction. Parameter assignment was performed using a combination of measured and empirical methods, and scientific boundary conditions were set. The model was calibrated using water level monitoring data from the past 3 years, with the calibration error controlled to ≤0.5 meters. Finally, independent monitoring data from the past year were used for verification, ultimately constructing a preliminary three-dimensional hydrogeological structure model.

[0017] Step 2: Detailed characterization of the sedimentary environment and identification of pollution mechanisms. This step aims to overcome the limitations of existing technologies that only perform macroscopic analysis of the sedimentary environment, to achieve precise quantification of the heterogeneity and key chemical properties within the sedimentary environment, and to identify the core control factors for pollutant release.

[0018] In comparison, existing technologies for analyzing sedimentary environments typically only focus on macroscopic stratigraphic division, without paying attention to the heterogeneity within aquifers (such as mud interlayers and paleochannel distribution), nor quantifying the key attributes in sediments that control pollutant release. Therefore, it is impossible to clearly define the quantitative relationship between sedimentary characteristics and arsenic release. Under these conditions, it is easy to mistakenly extract high-arsenic layers during mining, leading to water quality exceeding standards.

[0019] The steps for detailed characterization of sedimentary environment and identification of pollution mechanisms are based on a preliminary hydrogeological model. Through methods such as typical exploration boreholes, detailed core imaging, and multi-dimensional sediment analysis, the heterogeneity of the aquifer is accurately characterized, key attributes such as grain size composition and clay mineral content are quantified, and optimized to obtain a three-dimensional attributed hydrogeological model. This is a key condition for identifying and further controlling arsenic release.

[0020] By accurately locating the distribution range of high-arsenic and high-organic-matter layers, the core control factors of arsenic release can be identified, effectively avoiding the risks of mining high-arsenic layers and solving the problem of water quality exceeding standards due to insufficient understanding of the sedimentary environment in existing technologies.

[0021] Furthermore, based on the macro framework established in the first step, typical exploration boreholes are deployed in areas lacking data or water-sensitive areas. Through a combination of detailed core imaging, high-resolution geophysical data analysis, and modern sedimentary analogy analysis, the heterogeneous characteristics within the aquifer are accurately characterized, identifying the spatial distribution and connectivity of high-permeability or flow-blocking units such as mudstone interlayers, sand lenses, and paleochannels. Simultaneously, core samples are taken at standardized intervals for comprehensive sediment analysis, including grain size analysis, X-ray diffraction analysis, total organic carbon analysis, and BCR sequential extraction experiments. This quantifies the key attributes controlling pollutant adsorption and reaction, and clarifies the distribution range of high-arsenic and high-organic-matter layers. The above data are then integrated to optimize the preliminary three-dimensional hydrogeological structure model, supplementing key morphological surface information to form a three-dimensional attributed hydrogeological structure model. Kriging geostatistics methods are used to achieve accurate three-dimensional spatial interpolation of attribute parameters, ultimately identifying key sedimentary environmental factors controlling pollutant release and providing accurate data for subsequent water quality management.

[0022] The third step: Optimizing the layout of water sources along the river. This step involves fully utilizing the natural hydrological regulation potential of the depressions inside and outside the Yellow River dike to construct a spatial layout of "peripheral replenishment - core extraction - ecological protection." Existing technologies typically employ a centralized extraction layout without ecological protection.

[0023] Compared to existing technologies, traditional methods often employ a centralized mining layout with evenly distributed wells, failing to utilize the natural hydrological regulation potential of depressions inside and outside the dikes. This typically leads to significant drops in groundwater levels, land subsidence, and wetland shrinkage caused by the resulting drawdown cones. This new approach uses the Yellow River as the core water source, utilizing depressions to construct artificial infiltration recharge zones, forming a "peripheral recharge - core mining" pattern. It is complemented by a purification and pretreatment system and a complete ecological protection system, including effective ecological buffer zones, wetland buffer zones, and drainage channels.

[0024] By optimizing the layout of water sources along rivers, the natural hydrological regulation potential of depressions can be fully utilized, the intensity of groundwater recharge can be strengthened, and a balance between extraction and recharge can be achieved. At the same time, the ecological protection system can reduce the interference of mining activities on the ecological environment and maintain the ecological flow of the river.

[0025] Specifically, taking the Yellow River main stream as the core water source, and considering the distribution characteristics of back-river depressions and along-river depressions inside and outside the Yellow River dike, a water diversion hub and purification pretreatment system are set up. The water intake is kept at a reasonable horizontal distance from the Yellow River dike to avoid affecting the stability of the dike. The pretreatment system includes screens, sedimentation tanks, and biological purification ponds, purifying the water layer by layer to ensure that the quality of the replenished water meets the standards. The Yellow River water is transported to the depressions through an ecological replenishment canal network to construct an artificial infiltration replenishment zone and enhance the intensity of groundwater replenishment. A group of extraction wells is deployed in the core layer of the replenishment zone in a quincunx pattern, with reasonable control over the spacing and depth of the wells to ensure that the replenished water flow fully infiltrates and forms a stable hydrological cycle. At the same time, ecological isolation zones and wetland buffer zones are set up, along with drainage canals, to construct a complete ecological protection system to prevent mining activities from disturbing the wetland ecosystem and maintain the ecological flow of the river.

[0026] Step 4: Water level-water quality linkage extraction. By establishing a dynamic linkage mechanism between water level and water quality, synchronous control of water level and water quality can be achieved during the extraction process.

[0027] In existing technologies, only a single water level control threshold is typically set, and water level or water quality is monitored only periodically. Therefore, simultaneous control of water level and water quality is impossible. When water level fluctuations trigger arsenic release, it cannot be detected and addressed in a timely manner, leading to deterioration of the extracted water quality. By optimizing the extraction well structure and constructing a comprehensive dynamic monitoring system (e.g., real-time water level monitoring, periodic monitoring of water quality and hydrochemical isotopes), and combining this with a three-dimensional attributed model to simulate different water level fluctuation scenarios, the control effect of sedimentary configuration on water flow and solute transport can be verified, and model parameters can be optimized.

[0028] The coordinated mining method can monitor water level and water quality dynamics in real time, accurately capture the impact of water level fluctuations on water quality, optimize mining parameters in a timely manner, achieve coordinated control of water level and water quality, avoid water quality exceeding standards due to single water level control in existing technologies, and ensure stable water quality during mining.

[0029] In addition, the well structure was optimized, with different pipe materials designed for lacustrine sedimentary layers and aquifers. The bottom of the filter pipe consisted of a stainless steel mesh wrapped with gauze, and the bottom of the mesh was a stainless steel impermeable plate to prevent sediment from entering. A comprehensive dynamic monitoring system was constructed, with high-precision automatic water level and temperature monitoring probes installed in each well to monitor water level dynamics in real time. Sufficient water quality monitoring points were deployed in the well cluster area to regularly monitor key water quality indicators such as arsenic concentration and redox potential. Simultaneously, hydrochemical isotope analysis was conducted to identify groundwater recharge sources. In the second step, a three-dimensional attributed hydrogeological structure model was constructed, setting different water level fluctuation scenarios to simulate water flow and solute transport processes, quantifying the dynamic response of water quality indicators, verifying the control effect of sedimentary configuration on water flow and solute transport, and further optimizing model parameters.

[0030] Step 5: Construction of Water Quality Safety Early Warning Model and Determination of Warning Water Level. A water level-water quality coupled model is constructed by coupling two models to establish a three-level early warning system, which can realize early prevention and control of water quality safety.

[0031] Currently, there is no comprehensive water quality safety early warning system, either domestically or internationally. Simply relying on periodic water quality testing cannot predict water quality evolution trends in advance, nor are there clear tiered control measures. When water quality exceeds standards, extraction can only be passively halted, leading to water supply interruptions. For example, by coupling a three-dimensional attributed hydrogeological model with the PHREEQC hydrogeochemical model, the water quality evolution process under different extraction scenarios can be simulated. Sensitivity analysis can determine the head threshold, establishing a three-tiered early warning system that clarifies the water level range and control requirements for different warning levels.

[0032] The construction of water quality safety early warning models and the determination of warning water levels can predict water quality evolution trends in advance, accurately identify critical water level conditions, and achieve early prevention and control of water quality safety through graded early warning, avoiding water supply interruptions caused by water quality exceeding standards. At the same time, it can achieve precise linkage between early warning and control, and improve the initiative and scientific nature of water quality management.

[0033] A three-dimensional attributed hydrogeological structure model is coupled with the PHREEQC hydrogeochemical model to simulate the water quality evolution process under different mining scenarios. The model focuses on changes in redox conditions, sediment-water interface reactions, the dilution effect of river lateral seepage, and the impact of mining layout on the regional flow field, comprehensively covering key influencing factors of water quality evolution. Critical water level conditions are identified through model calculations, and sensitivity analysis is used to determine the geochemical processes most sensitive to water level changes and their corresponding head thresholds. Combined with water quality standards for different mining purposes, key water quality safety indicators are defined, and a three-tiered early warning system (green, yellow, and red) is established. The water level ranges and control requirements for different warning levels are clearly defined, enabling early prevention and precise control of water quality safety.

[0034] Step 6: Optimization calculation of extraction volume based on water quality and ecological safety. By establishing an extraction volume optimization model under multiple constraints, a balance is achieved between maximizing the extraction volume of high-quality groundwater and ensuring ecological safety.

[0035] Existing technologies, when calculating the exploitable amount of groundwater, only consider water quantity constraints, neglecting water quality safety, ecological flow, and geological disaster prevention. This results in either excessive extraction leading to water quality exceeding standards and ecological damage, or insufficient extraction causing water resource waste. Furthermore, they fail to develop differentiated allocation strategies for different hydrological years, making it impossible to achieve a balance between extraction and replenishment throughout the year. This application, by dividing different water quality sensitive areas and setting multi-dimensional constraints such as water level, water quality, ecological flow, and geological disasters, establishes an optimization model aimed at maximizing the extraction of high-quality groundwater, and develops differentiated extraction allocation strategies based on different hydrological years.

[0036] This improvement will enable the maximization of high-quality groundwater extraction while ensuring water quality and ecological safety (annual ground subsidence ≤3 mm, ecological flow meeting standards). At the same time, a differentiated allocation strategy will ensure a balance between extraction and replenishment throughout the year, avoiding problems such as water quality exceeding standards and ecological damage caused by unreasonable extraction volumes due to existing technologies.

[0037] Based on clearly defined key control indicators and corresponding warning water levels, different water quality sensitive areas are delineated. For each area, multi-dimensional constraints are set, including water level, water quality, ecological flow, and geological hazards. Specifically, the geological hazard constraint specifies an annual land subsidence of ≤3 mm, and the ecological flow constraint ensures that the ecological flow of the Yellow River main stream is not less than 30% of the multi-year average flow. An optimization model is established with the goal of maximizing the extraction of high-quality groundwater. An optimization method combining numerical simulation and genetic algorithms is used to calculate the exploitable groundwater volume under safe water quality conditions. Furthermore, differentiated extraction allocation strategies are formulated for different hydrological conditions in wet, normal, and dry years to ensure a balance between extraction and replenishment throughout the year.

[0038] Step 7: Dynamic Control and Closed-Loop Management. Establish a closed-loop management system of "monitoring-evaluation-early warning-adjustment" to overcome the limitations of existing technology mining schemes that are fixed and lack dynamic adjustment.

[0039] Traditional mining plans, once determined, remain fixed for a long period and cannot establish dynamic monitoring and iterative update mechanisms. When sedimentary environments and hydrological conditions change, the mining plan cannot be adjusted in a timely manner. With a closed-loop management system, monitoring data can be collected in real time, and regular assessments and early warnings can be issued. The mining plan can be adjusted based on the warning level, and model parameters can be updated iteratively every quarter.

[0040] Dynamic regulation and closed-loop management can adapt to changes in sedimentation environment and hydrological conditions in a timely manner, continuously optimize mining plans, ensure the adaptability and long-term effectiveness of technical solutions, avoid the control failure caused by fixed mining plans, and maintain the balance of water quantity and quality in the long term.

[0041] The water level-water quality dynamic monitoring system constructed in the fourth step collects monitoring data in real time, conducts a comprehensive evaluation of the monitoring data monthly, and analyzes whether the water level and water quality are within a safe range. Targeted control measures are taken according to the warning level. When a yellow warning is triggered, the mining intensity is reduced in time. When a red warning is triggered, mining in the corresponding area is stopped immediately and an emergency replenishment plan is initiated. The optimization model is iterated and updated every quarter. Based on the latest monitoring data and changes in the sedimentary environment, the warning water level and mining plan are adjusted to achieve dynamic optimization of the mining process and ensure the adaptability and long-term effectiveness of the technical solution.

[0042] The specific operation method and steps of the technical solution of this application will be explained in detail below.

[0043] A method for optimized management and exploitation of riverside water sources based on sedimentary environment, specifically including the following steps:

[0044] The first step is to integrate multi-source data and construct a preliminary three-dimensional hydrogeological model: collect multi-type and multi-scale relevant data of the study area, establish a hydrogeological conceptual model and construct a numerical model, and form a preliminary three-dimensional hydrogeological structure model after calibration and verification.

[0045] The second step is to refine the sedimentary environment and identify the pollution mechanism: Based on the preliminary model, exploratory boreholes are laid out and sediment analysis is carried out to characterize the heterogeneity of the aquifer, optimize and obtain a three-dimensional attributed hydrogeological model, and identify the key sedimentary environmental factors for pollutant release.

[0046] The third step is to optimize the layout of riverside water sources: taking the river as the core water source, constructing artificial infiltration and replenishment areas in the depressions inside and outside the dike, and setting up a group of mining wells and supporting an ecological protection system.

[0047] The fourth step is water level-water quality linked mining: optimize the mining well structure, build a dynamic monitoring system, and optimize parameters by combining model simulation;

[0048] The fifth step is to construct a water quality safety early warning system: couple two models to simulate water quality evolution, determine critical water levels, and establish a three-level graded early warning system;

[0049] Step 6: Optimize extraction volume: Divide water quality sensitive areas, set multi-dimensional constraints, calculate the extractable volume, and formulate a differentiated allocation strategy based on hydrological year.

[0050] Step 7, Dynamic Closed-Loop Management: Real-time monitoring and evaluation, adjustment of mining plans based on early warnings, and regular iterative updates to the model.

[0051] As a further preferred option, the multi-source data mentioned in the first step includes basic geological, hydrogeological, geochemical, geomorphological, meteorological, groundwater dynamic characteristics, solute transport, paleochannel distribution and depression ditch distribution data, etc. Among them, the basic geological map is a standard map with a scale of 1:50000, the hydrogeological exploration data includes survey reports and drilling and geophysical exploration results from the past 10 years; the numerical model is the MODFLOW model, and the parameter assignment method is a combination of measured and empirical methods, the model correction error is ≤0.5 meters, and it is verified with independent monitoring data from the past year.

[0052] As a further preferred option, the drilling spacing in the second step is 700-800 meters, the depth is 90-220 meters, and the core sampling interval is 2.5-3 meters. The heterogeneity of the aquifer is characterized by fine core imaging and geophysical analysis. Grain size analysis, X-ray diffraction and other sediment analyses are carried out. Kriging geostatistics method is used to realize three-dimensional interpolation of attribute parameters, and the permeability coefficient estimation error is ≤8%.

[0053] As a further preferred option, the purification pretreatment system described in the third step includes a bar screen, a sedimentation tank, and a biological purification pond. The bar screen spacing is 3.5-4mm, the effective volume of the sedimentation tank is 1100-1200m³, the retention time is 2.3-2.5 hours, the area of ​​the biological purification pond is 5500-6000m², and the water depth is 1.1-1.2 meters. The artificial infiltration recharge area has an infiltration pond with a water depth of 0.7-0.8 meters, a vegetation buffer zone width of 55-60 meters, and the extraction well group is arranged in a quincunx pattern. The water intake is kept at a reasonable horizontal distance from the Yellow River dike, not less than 200 meters.

[0054] As a further preferred option, in the fourth step, the lacustrine sedimentary section of the extraction well uses a φ180mm solid PVC pipe, and the aquifer section uses a φ180mm filter pipe with a filter pore diameter of 5.5-6mm and a porosity of 24-25%. The bottom of the filter pipe is a stainless steel filter screen wrapped with gauze, and the bottom of the filter screen is a stainless steel impermeable base plate. The automatic water level and temperature monitoring probe has an accuracy of ±0.01 meters and monitors once per hour. Water quality indicators such as arsenic concentration are sampled regularly and water chemical isotope analysis is carried out. The parameters are optimized by simulating different water level fluctuation scenarios through model simulation.

[0055] As a further preferred option, the dual models mentioned in the fifth step are a three-dimensional attributed hydrogeological structure model and a PHREEQC hydrogeochemical model, which focus on simulating water quality evolution influencing factors such as changes in redox conditions; the three-level early warning system uses arsenic concentration ≤10μg / L as the key indicator, clarifies the water level range of each early warning level in different areas of the upper and lower reaches of the Yellow River, and determines the head threshold through sensitivity analysis.

[0056] As a further preferred option, the water quality sensitive areas mentioned in step six are divided into three levels: high, medium, and low. The constraints include annual land subsidence ≤ 3 mm and the ecological flow of the Yellow River main stream not less than 30% of the multi-year average flow. The exploitable amount is calculated by combining numerical simulation and genetic algorithm. The exploitable amount in a wet year is about 10% higher than that in a normal year, and 10-15% lower in a dry year.

[0057] As a further preferred option, the dynamic control measures described in step seven are as follows: reduce mining intensity by 23-25% when a yellow alert is issued, and stop mining in the corresponding area and initiate emergency replenishment when a red alert is issued; the model is iterated and updated every quarter, and the monitoring data is comprehensively evaluated every month to ensure continuous optimization of the mining process.

[0058] As a further preferred option, the method is applicable to high-arsenic groundwater areas such as the Yellow River and its former course, and is particularly suitable for riverside water sources with the characteristics of suspended river landforms in the lower reaches of the Yellow River, widespread distribution of Quaternary sediments, and high risk of arsenic exceeding the standard in groundwater, with the arsenic content in groundwater controlled at 3-8 μg / L.

[0059] Data shows that after adopting this method, the extraction volume of high-quality groundwater increases by 33-35% compared with the traditional method, the engineering construction cost decreases by 27-28% compared with the traditional scheme, the cost of water treatment per ton decreases by 0.38-0.4 yuan, the annual ground subsidence is ≤3 mm, and the wetland area increases by 1.4-1.5% annually.

[0060] The technical effects of this application will be explained in more detail below.

[0061] Compared with traditional technologies, this application has achieved a comprehensive upgrade of the technology for mining water sources along rivers, and has made significant progress in water quality safety, water resource utilization, ecological protection, engineering economy and comprehensive benefits. Through the integration and collection of multiple data, it can be seen that after stable operation, the data and effects in all aspects have been greatly improved.

[0062] Comparison Projects Existing technology This application proposal Effect Water quality compliance rate 58%-65% 100% (arsenic concentration 3-8 μg / L) Completely resolve water supply safety hazards in high arsenic areas High-quality groundwater extraction volume 39,000-50,000 m³ / d (unstable) 46,000-50,000 m³ / d (stable, 50,000 m³ / d in Example 1) Increase production by 33%-35% to achieve a balance between production and replenishment. Annual ground subsidence 8-9.5 mm ≤3 mm (Example 1: 2.2 mm) Effectively prevent and control geological disasters and reduce economic losses Construction costs Conventional costs This reduces costs by 27%-28% compared to traditional methods (28% in Example 1). Improve the economic efficiency of the project and facilitate its promotion. Cost per ton of water treated Conventional costs Price reduced by 0.38-0.4 yuan (0.4 yuan in Example 1). Reduce subsequent water treatment investment and save costs. Annual change in wetland area Continued shrinkage Average annual growth rate of 1.4%-1.5% (1.5% in Example 1) Restoring the ecological environment and achieving a win-win situation for mining and ecology.

[0063] First, relying on the detailed characterization of sedimentary environment and the identification of pollution mechanisms, it is possible to accurately avoid the risks of mining high-arsenic layers, identify the key control factors for pollutant release, and combine water quality safety early warning models and a three-level graded early warning system to achieve early prevention and precise control of pollutants such as arsenic, effectively avoiding water quality exceeding standards due to insufficient understanding of sedimentary environment and lack of accurate early warning in existing technologies.

[0064] In practical applications, the compliance rate of extracted water quality has increased from 58%-65% with existing technologies to 100%, with arsenic concentration stably controlled at 3-8 μg / L, fully complying with the drinking water standards of the "Groundwater Quality Standard" (GB / T 14848-2017). This completely resolves the safety hazards of water supply from riverside water sources in high-arsenic areas, ensuring the health of residents' drinking water, and preventing water source production reduction or closure due to substandard water quality, thus improving the stability of water supply. As verified in Example 1, the extracted water quality using this application achieves 100% compliance with standards, with arsenic concentration stably controlled at 3-8 μg / L, while the compliance rate of existing technologies in the same area is only 58%-65%, highlighting the universality and superiority of this application.

[0065] Secondly, water resource utilization efficiency has been significantly improved, enabling the efficient development of high-quality groundwater. By integrating multi-source data to construct accurate hydrogeological models and optimizing the layout of application sites in a "peripheral recharge-core extraction" pattern, the natural hydrological regulation potential of the depressions inside and outside the Yellow River dike has been fully utilized to construct artificial infiltration recharge zones, strengthen groundwater recharge intensity, and, combined with an optimized strategy of prioritizing the extraction of high-quality groundwater, the extraction volume of high-quality groundwater has been significantly increased.

[0066] Compared to traditional methods, this approach increases the extraction rate of high-quality groundwater by 33%-35%, raising the exploitable volume to 46,000-50,000 m³ / d. It also achieves a balance between extraction and replenishment, effectively alleviating regional water shortage pressures and enhancing water supply capacity. This differs from existing technologies that rely solely on natural recharge, suffer from low extraction efficiency, and waste high-quality water resources. Existing technologies, in the corresponding areas of this example, only extract 39,000-50,000 m³ / d of high-quality groundwater and cannot achieve a stable balance between extraction and replenishment, leading to water shortages during dry years.

[0067] Furthermore, ecological and geological disasters have been effectively prevented and controlled. Improvements to water level-water quality linkage mining, ecological protection layout, and closed-loop management, by controlling mining depth and optimizing mining intensity, avoid disturbance from deep high-arsenic water, effectively reducing the risk of geological disasters such as land subsidence and ground fissures. Annual land subsidence has been reduced from 8-9.5 mm in existing technologies to ≤3 mm, and in Example 1 to 2.2 mm, significantly reducing economic losses caused by geological disasters.

[0068] Simultaneously, by rationally controlling groundwater levels, establishing ecological isolation zones and wetland buffer zones, and maintaining river ecological flow, the stability of the wetland ecosystem is ensured, achieving an average annual increase in wetland area of ​​1.4%-1.5%. This effectively curbs ecological problems such as wetland shrinkage and insufficient river ecological flow caused by existing technology-based mining activities, restores the regional hydrological cycle balance, achieves a "win-win situation for mining and ecology," and resolves the contradiction between existing technology-based mining activities and ecological protection. In the corresponding area of ​​the example, the existing technology resulted in an annual land subsidence of 8 mm, continuous wetland shrinkage, and continuous deterioration of the ecological environment.

[0069] Furthermore, the project boasts outstanding economic efficiency and applicability, facilitating widespread application and reducing mining costs. By optimizing the layout and fully integrating the characteristics of the Yellow River as a suspended river and the distribution of depressions on both banks, it maximizes the use of natural topography to achieve water diversion and replenishment, eliminating the need for large-scale artificial structures and significantly reducing construction costs. The project cost is 27%-28% lower than traditional mining schemes.

[0070] In addition, the technical solution of this application is universal and can be flexibly adjusted according to the different sedimentary environment and hydrogeological conditions of different regions. It does not require complicated equipment and processes and is applicable to various high-arsenic river water sources across the country, especially suitable for areas with a wide distribution of high-arsenic and Quaternary sediments, such as the Yellow River and the old course of the Yellow River.

[0071] Finally, since the extracted water quality fully meets the standards, there is no need to add an additional arsenic removal treatment process, which greatly reduces water treatment costs. The cost of treating each ton of water is reduced by 0.38-0.4 yuan, resulting in significant annual savings in water treatment expenses. At the same time, through scientific management and protection, the lifespan of the water source is extended, enhancing its long-term utilization value.

[0072] From a sustainability perspective, this application constructs a demonstration model that integrates "water, ecology, and economy," which not only ensures water supply security and improves water resource utilization efficiency, but also protects the ecological environment and promotes the sustainable development of regional industry and agriculture. Attached Figure Description

[0073] Figure 1 This is a flowchart of the technical method of this application.

[0074] Figure 2 This is a schematic diagram illustrating the water level-sedimentation environment-water quality response relationship in this application.

[0075] Figure 3 This is a schematic diagram of the water quality safety early warning system of this application.

[0076] Figure 4 This is a plan view of the riverside water source area for this application.

[0077] Figure 5 This is a schematic diagram of the Yellow River water pretreatment facility for the replenishment canal in this application.

[0078] Figure 6 This is a schematic cross-section diagram of the riverside water source area in this application.

[0079] Attached reference numerals: 1. Yellow River; 2. Yellow River floodplain; 3. Depression; 4. Yellow River dike; 5. Water diversion canal; 6. Yellow River water pretreatment facilities; 6-1. Water level control gate and screen; 6-2. Sedimentation tank; 6-3. Biological purification pond; 7. Water supply direction during extraction process; 8. Water flow direction in the supply canal; 9. Permeable layer; 10. Vegetated buffer zone; 11. Ecological bank protection; 12. Drainage canal; 13. Ecological transition zone. Detailed Implementation

[0080] The present application will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present application and are not intended to limit the scope of protection of the present application. The equipment and materials used in this application are all commercially available conventional products, and the monitoring methods all adopt existing national standard methods.

[0081] Example 1: Application case of a riverside water source in Henan Province, lower reaches of the Yellow River

[0082] The riverside water source is located in a region of Henan Province in the lower reaches of the Yellow River, covering an area of ​​about 50 km². It belongs to the high-arsenic groundwater area of ​​the old course of the Yellow River, with a Quaternary sediment thickness of 120-180 meters. The arsenic content of the groundwater is generally 15-80 μg / L. The water quality compliance rate of traditional extraction methods is only 65%, and there is a risk of land subsidence, with an annual subsidence of about 8 mm.

[0083] The study area contains several river-side and back-side depressions, with a total area of ​​approximately 8 km². Previously, the utilization rate was less than 8%, and the natural hydrological regulation potential was not fully realized. At the same time, there are problems such as water waste and fragile ecological environment. To meet the application scenario of this application, the technical methods of this application are adopted for optimized management and mining.

[0084] The implementation process strictly followed the technical solution of this application. First, multi-source data integration and preliminary three-dimensional hydrogeological model construction were carried out. Basic maps such as 1:50,000 regional geological maps and hydrogeological maps of the study area, as well as multiple geological-hydrological profile maps, hydrogeological survey reports of the past 10 years, 30 sets of drilling data, 25 sets of pumping test data, groundwater level monitoring data of the past 5 years, Yellow River main stream flow data, water quality monitoring data of the past 3 years, topographic vector data, ancient river channel distribution map, and meteorological data of the past 10 years were collected.

[0085] Based on the above data, a hydrogeological conceptual model was established. A preliminary three-dimensional hydrogeological structure model was constructed using MODFLOW, with a correction error of 0.3 meters and a verification error of 0.4 meters to ensure the accuracy of the model.

[0086] Subsequently, a detailed characterization of the sedimentary environment and identification of pollution mechanisms were conducted. Typical exploration boreholes were laid out in water-sensitive areas at intervals of 800 meters and depths of 100-220 meters. Through core imaging and high-resolution seismic reflection profile analysis, multiple layers of mudstone interlayers and multiple paleochannels were identified. Core samples were taken at 3-meter intervals for comprehensive sediment analysis. The particle size distribution was determined by laser particle size analyzer, and the permeability coefficient was estimated with an error of 8%. X-ray diffraction analysis showed that the montmorillonite content was 15%-22%, the iron oxide content was 3%-5%, the TOC analysis showed that the organic matter content was 0.8%-1.5%, and the BCR sequential extraction experiment showed that the arsenic in the iron-manganese oxide bound state accounted for 45%-60%, clearly indicating that the high arsenic layer was distributed in the depth range of 10-30 meters.

[0087] By integrating and optimizing the data, a three-dimensional attributed hydrogeological structure model was obtained, which identified organic matter content and iron oxide content as key sedimentary environmental factors controlling arsenic release, providing a scientific basis for subsequent management.

[0088] Next, we will construct an optimized layout model for riverside water sources, such as... Figure 4 As shown, the water intake extends into the main stream of the Yellow River, 220 meters from the levee, to avoid affecting the stability of the levee; purification and pretreatment facilities will be constructed, such as... Figure 5 As shown, the system includes a water level control gate and a screen, a sedimentation tank and a biological purification pond. The screen spacing is 4mm, the effective volume of the sedimentation tank is 1200m³, the retention time is 2.5 hours, and the biological purification pond has an area of ​​6000m² and a water depth of 1.2 meters to ensure that the replenishment water quality meets the standards.

[0089] The recharge canal is 4 meters wide with a bottom slope of 1.5‰ and adopts an ecological bank protection design to prevent water erosion. An artificial infiltration recharge area is constructed using the river depression in the study area, with an infiltration pool depth of 0.8 meters and a vegetation buffer zone width of 60 meters to enhance the intensity of groundwater recharge. A group of extraction wells is arranged in a quincunx pattern in the core layer of the recharge area, with a spacing of 100 meters and a well depth of 70-100 meters to ensure sufficient infiltration of the recharge water flow. A 1200-meter-wide ecological isolation belt is set up and planted with native trees such as poplar and willow. A drainage canal is also provided to return excess water to the Yellow River, constructing a complete ecological protection system.

[0090] Employing a water level-water quality linked extraction method, such as... Figure 6 As shown, the structure of the extraction wells was optimized. The lacustrine sedimentary section of the extraction well used a φ180mm solid PVC pipe, while the aquifer section used a φ180mm filter pipe with a filter hole diameter of 6mm and a porosity of 25%. The bottom was wrapped with a 40-mesh stainless steel filter screen to prevent sediment from entering. Each extraction well was equipped with an automatic water level probe with an accuracy of ±0.01 meters, which monitored once per hour. Twelve water quality monitoring points were set up in the extraction well area. Initially, samples were collected and monitored weekly, and after stabilization, monthly monitoring was conducted. At the same time, groundwater samples were collected for hydrochemical isotope analysis to determine that the main sources of recharge were lateral seepage from the Yellow River and precipitation infiltration.

[0091] Multiple water level fluctuation scenarios were set in the three-dimensional attributed hydrogeological structure model to verify the control effect of sedimentary configuration on solute transport and further optimize the model parameters.

[0092] Construct a water quality safety early warning model and determine the warning water level, such as Figure 3 As shown, a three-dimensional attributed hydrogeological model and a PHREEQC model were coupled to simulate the water quality evolution process under different mining scenarios. Sensitivity analysis showed that the reduction and dissolution of iron and manganese oxides was the most sensitive geochemical process to water level changes. Drinking water standards were defined as arsenic ≤10μg / L. The green water level was defined as >35m below the ground, the yellow water level as 20-35m below the ground, and the red water level as ≥20m below the ground. A three-level early warning system was established.

[0093] Optimization calculations for extraction volume based on water quality and ecological safety were conducted, dividing the area into high-sensitivity, medium-sensitivity, and low-sensitivity zones. The high-sensitivity zone covers an area of ​​15 km², the medium-sensitivity zone 25 km², and the low-sensitivity zone 10 km². Constraints were set, including groundwater level control within the range of 8-14 meters, arsenic concentration ≤10 μg / L, Yellow River ecological flow ≥30% of the multi-year average flow, and annual subsidence ≤3 mm. A combination of numerical simulation and genetic algorithm was used to calculate the exploitable volume of high-quality groundwater to be 50,000 m³ / d. Different annual extraction volume allocation strategies were formulated for different hydrological years: 55,000 m³ / d in wet years, 50,000 m³ / d in normal years, and 42,000 m³ / d in dry years, ensuring a balance between extraction and replenishment.

[0094] Establish a dynamic control and closed-loop management system, such as Figure 1 As shown, water level and water quality data are monitored in real time, and a comprehensive assessment is conducted monthly. No red alerts were triggered during operation, but two yellow alerts were triggered, and the mining intensity was reduced by 25% in a timely manner. The model is updated every quarter, and the warning water level and mining plan are adjusted according to the latest monitoring data and changes in the sedimentary environment to ensure continuous optimization of the mining process.

[0095] After one year of operation, the water source has shown remarkable results, fully verifying the feasibility and beneficial effects of this application. The water quality compliance rate is 100%, the arsenic concentration is stable at 3-8 μg / L, the extraction volume of high-quality groundwater is increased by 35% compared with traditional methods, the land subsidence is reduced to 2.2 mm, the wetland area increases by 1.5%, the cost of water treatment per ton is reduced by 0.4 yuan, and the engineering cost is reduced by 28% compared with traditional solutions. It has achieved synergistic optimization of water quantity, water quality and ecology, and completely solved many problems existing in traditional extraction methods in this area.

Claims

1. A method for optimized management and exploitation of riverside water sources based on sedimentary environment, comprising the following steps: The first step is to integrate multi-source data and construct a preliminary three-dimensional hydrogeological model: collect multi-type and multi-scale relevant data of the study area, establish a hydrogeological conceptual model and construct a numerical model, and form a preliminary three-dimensional hydrogeological structure model after calibration and verification. The second step is to refine the sedimentary environment and identify the pollution mechanism: Based on the preliminary model, exploratory boreholes are laid out and sediment analysis is carried out to characterize the heterogeneity of the aquifer, optimize and obtain a three-dimensional attributed hydrogeological model, and identify the key sedimentary environmental factors for pollutant release. The third step is to optimize the layout of riverside water sources: taking the river as the core water source, constructing artificial infiltration and replenishment areas in the depressions inside and outside the dike, and setting up a group of mining wells and supporting an ecological protection system. The fourth step is water level-water quality linked mining: optimize the mining well structure, build a dynamic monitoring system, and optimize parameters by combining model simulation; The fifth step is to construct a water quality safety early warning system: couple two models to simulate water quality evolution, determine critical water levels, and establish a three-level graded early warning system; Step 6: Optimize extraction volume: Divide water quality sensitive areas, set multi-dimensional constraints, calculate the extractable volume, and formulate a differentiated allocation strategy based on hydrological year. Step 7, Dynamic Closed-Loop Management: Real-time monitoring and evaluation, adjustment of mining plans based on early warnings, and regular iterative updates to the model.

2. The method according to claim 1, characterized in that, The multi-source data mentioned in the first step includes basic geology, hydrogeology, geochemistry, geomorphology, meteorology, groundwater dynamics, solute transport and paleochannel distribution data.

3. The method according to claim 1, characterized in that, The second step includes setting the spacing and depth of exploration boreholes and core sampling; characterizing the heterogeneity of the aquifer through fine core imaging and geophysical analysis; and conducting grain size analysis and X-ray diffraction sediment analysis.

4. The method according to claim 1, characterized in that, The purification pretreatment system described in the third step includes a bar screen, sedimentation tank, biological purification pond, artificial infiltration recharge area, and vegetation buffer zone.

5. The method according to claim 1, characterized in that, In the fourth step, the lacustrine sedimentary section of the mining well uses solid PVC pipes, while the aquifer section uses filter pipes with a filter screen wrapped around the bottom. An automatic water level monitoring probe monitors the water quality once per hour, regularly monitors arsenic concentration and water chemical isotope analysis, and optimizes parameters by simulating different water level fluctuation scenarios using a model.

6. The method according to claim 1, characterized in that, The dual models mentioned in the fifth step are a three-dimensional attributed hydrogeological structure model and a hydrogeochemical model. The three-level early warning system uses an arsenic concentration of ≤10μg / L as an indicator and determines the head threshold through sensitivity analysis.

7. The method according to claim 1, characterized in that, The water quality sensitive areas mentioned in step six are divided into three levels: high, medium, and low. The constraints include annual land subsidence ≤ 3 mm and ecological flow of the Yellow River main stream not less than 30% of the multi-year average flow. The exploitable amount is calculated by combining numerical simulation and genetic algorithm. The exploitable amount in a wet year can be increased by up to 10% compared with that in a normal year, while it can be reduced by 10-15% in a dry year.

8. The method according to claim 1, characterized in that, The dynamic control measures described in step seven are as follows: reduce mining intensity by 23-25% when a yellow alert is issued, and stop mining in the corresponding area and start emergency replenishment when a red alert is issued; the model is iterated and updated every quarter, and the monitoring data is comprehensively evaluated every month.

9. The method according to claim 1, characterized in that, This method is applicable to riverside water sources where Quaternary sediments are widely distributed and the risk of arsenic exceeding the standard in groundwater is high.

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