Status quo and change characteristics of groundwater resources pollution in the Hami region based on sustainable development strategies

In order to reasonably develop the groundwater resources in Hami and alleviate the geological environment problems caused by groundwater exploitation, with the reduction of groundwater resources, people began to study the methods to prevent groundwater depletion and pollution (Tabatabaei et al. 2010; Liu et al. 2020; Qi et al. 2023). The scholars collected basic geological data, and meteorological/hydrogeological data and used them as hydrogeological data for studying groundwater dynamics theory (Tao et al. 2022; Wang et al. 2022a). The purpose of Dogan (2019) was to develop a model that can measure the impact of perception on cultural heritage assessment by analyzing the exterior walls of buildings to achieve adaptive reuse and sustainable development strategies. By analyzing the intangible social background that influences the formulation of adaptive reuse strategies, he focuses on the correlation between adaptive reuse and the sustainability of cultural heritage. Romsted (2018) believed that the world is becoming more and more urbanized. Cities have accounted for more than 70% of global energy consumption and 40–50% of global greenhouse gas emissions. More than ever, human beings need sustainable energy infrastructure to provide these services while reducing the impact on the environment (Zhang et al. 2021; Wang et al. 2022b). Ahmed et al. (2017) investigated the problems of the floodplain in the western part of the Ganges and propose some important strategies to map out a development roadmap. The coastal areas of Bangladesh are very diverse in nature and have great potential to create opportunities of national importance and contribute to gross domestic product (GDP). Unfortunately, the coastal areas of the country are vulnerable to disasters. Therefore, human beings need sustainable intervention measures. Best et al. (2019) showed that groundwater can enhance and remove 2,4,6-trinitrotoluene (TNB). Through analysis of groundwater and plant tissues, he believed that the most effective plants to purify groundwater are reeds and fox sedges.

At the same time, scholars have established a water environmental health risk assessment model for water pollution prevention and control (Lalehzari et al. 2013; Miao et al. 2018; Liu et al. 2022). Anuprienko (2021) used a series of intermediate problems to gradually approximate the solution of the nonlinear continuation method applied to groundwater detection problems. He considered other solving methods, combined with slightly modified search methods, and used advanced finite volume discretization to conduct numerical experiments for the model and real-life problems. Qu et al. (2021) adopted defective carbon black material instead of metal matrix composite material, and measures the iron dissolved in groundwater by electroanalysis on the modified electrode. He studied the influence of solid load and electrolyte on electrochemical performance, and verified the measurement accuracy of BP defect modified electrode by measuring Fe(III) standard reference material. Luo et al. (2021) believed that filamentous fungi can enter the drinking water supply system in a variety of ways and exist in a suspended or fixed state, threatening personal health by posing a high risk of invasive infection. His research evaluated the effectiveness of low-concentration chlorine-based disinfectants in controlling the formation of fungal biofilms. Due to the development of modern agriculture and the complexity of hydrochemical environment, the current groundwater pollution risk assessment methods and relevant technical specifications cannot be applied to groundwater pollution risk assessment. It is very difficult to protect and manage the groundwater resources in Hami.

This paper starts with the study of the evolution law of groundwater environment in the Hami area, defines and classifies the evolution of groundwater environment, and uses qualitative and quantitative methods to analyze and study. Groundwater pollution in arid areas is becoming increasingly serious, and water supply safety has brought a series of hidden dangers. Therefore, this paper monitors and evaluates the risk of groundwater pollution in arid areas, which is of great significance to the formulation and implementation of effective safe disposal and water environmental protection measures in the Hami region.

Based on the characteristics of the evaluation system of agricultural land water resources carrying capacity in the Hami area, the distribution index formula optimized by particle swarms is used to analyze it to diagnose the current situation of agricultural land carrying capacity under the current development scale (Wang & Shang 2021; Zhu et al. 2021). Combining the CAS theory with the research on the optimal allocation of water resources for agricultural land in Hami, an optimal allocation model was constructed. In addition to enriching and perfecting CAS theory, water resources optimal allocation theory and its application research system, it provides a new solution for the sustainable exploitation and use of water resources in Hami.

According to the different objectives of groundwater damage assessment, the evaluation objects are also different, that is, the risk recipients are different. The three types of risk assessments of groundwater function all belong to the category of environmental risk assessment.

Here, I represents intake, that is, the content of chemical substances at the exchange boundary, and the unit is mg/(kg·d). p represents the mass concentration of pollutants, that is, the mass concentration of water pollutants evaluated during the entire exposure period, in mg/L. CR stands for the pollution rate, that is, the number of contaminated media per unit time or unit time, unit d⁻¹. FD is the abbreviation of exposure frequency and persistence, and is a physical quantity that characterizes the length and frequency of contact between pollutants and the human body (Rodriguez-Domenech et al. 2019). W is the body weight, that is, the evaluated mass of the human body during the entire exposure period, in kg. AT stands for average time or average contact length, with d as the unit.

Here, SR represents the probability of specific cancer, and the dimension is 1. CDI represents the average daily intake under long-term exposure conditions, and the unit is mg/(kg·d). SF stands for gradient coefficient, the unit is mg/(kg·d).

Here, D represents the biodiversity index. Z represents the number of aquatic species. N represents the abundance of aquatic organisms. Ecological vulnerability is the sensitive response and self-recovery ability of the ecosystem in a specific time and space scale relative to external interference, and is the inherent attribute of the ecosystem.

Here, EI stands for ecological vulnerability index. represents the toxicity response factor of the ith pollutant. represents the actual measured value of the ith pollutant. represents the standard value of the ith pollutant. n represents the number of pollutants.

Here, R is a comprehensive index for groundwater pollution risk assessment. is the score of the ith pollution source risk assessment index. is the weight corresponding to the risk assessment of the ith pollution source. is the score of the jth pollution channel risk assessment index. is the weight corresponding to the risk assessment of the jth pollution channel. is the score of the risk assessment index of the kth pollutant receptor. is the weight corresponding to the risk assessment of the kth pollutant receptor (Avery 2018).

Here, CCPS is the pressure of R resources, expressed by population, is the actual number of R resources, is the standard R resource occupation, and is the carry saturation. P is the population coefficient of the area. If P = 0, then R resource carrying pressure is balanced, indicating that the population is medium (Li & Zhe 2017). A positive number of P indicates that the population pressure is less than the resource capacity, otherwise, it is greater than the resource capacity. The smaller the value of P, the lower the pressure.

At present, many scholars at home and abroad have begun to study comprehensive evaluation methods and models in sustainable development evaluation. Because the choice of evaluation methods and models directly affects the objective scientific validity of the evaluation results (Nadjla et al. 2021).

The standardization of indicators is very important. The standardization method is a standard measurement method based on the environmental state, which can better measure the environment accurately and ensure the correct assessment of the environmental state. Choosing different standardization methods will lead to different data and different indicator final evaluation results. Commonly used standardization methods include linear standardization methods. When converting the actual value of the index into the standardized value of the index, it is assumed that there is a linear relationship between the two to avoid the influence of the dimension value and change the actual value of the index. This method calculates the corresponding change in index valuation proportionally. The linear dimensionless method mainly includes the standard weight method, the standard deviation method, and the threshold method (critical value method) (Chen et al. 2018).

At present, there are problems in the research of sustainable development evaluation of water environment. The theoretical framework for the establishment of the sustainable development indicator system of the water environment is still in the exploratory stage. The development indicators of water environment are mainly social rationality, economic rationality, ecological rationality, efficiency rationality and system rationality, and their homes restrict and influence each other. The theory of sustainable development of water environment basically evolved from the theoretical framework of sustainable development. Therefore, the principles, methods and evaluations of the establishment of the sustainable development index system of water environment have not yet been unified. The existing indicator system is basically a collection of individual indicators, and the scope of indicators is limited to reflecting the characteristics of the water environment itself. These indicators have certain limitations in reflecting the relationship between the environment, nature, and socio-economic subsystems in the composite system. At present, there is a lack of unified water environment index evaluation standards and evaluation methods (Beiyuan et al. 2017).

The sustainable development system of water environment includes the relationship between water environment and society, the relationship between water environment and economy, the relationship between water environment and nature, the relationship between society and nature, the relationship between economy and nature, and the relationship between society and economy (Huang et al. 2019; Huo et al. 2019; Zhang et al. 2019; Bai et al. 2022). The coordinated development of nature, society, and economy is the essence of sustainable development of the water environment, and social development and economic development are inseparable. In fact, people often regard ‘social economics’ as a closely related discipline (Agliardi et al. 2017). Therefore, this article combines the social and economic subsystems. The three subsystems of nature, water environment and social economy constitute a sustainable water environment system. The main considerations between the subsystems are the water environment–society–economic relationship, the water environment–natural relationship, and the social–economic–natural relationship. Groundwater damage assessment objects mainly include per capita water consumption, annual runoff depth, groundwater resource modulus, water resource development rate, and sewage reuse rate.

The scoring standards of this article are determined according to the lowest, low, medium, high, and highest five-level standards. Table 1 shows the scoring standards for the direction indicators of the water environment sustainable development system.

In this article, takes the most unfavorable value, that is, ⁠.

represents the development index value of the ith subsystem at time t. represents the weight of the jth directional index of the ith subsystem. represents the index value of the jth type direction index of the ith subsystem at time t. i, respectively, represents the three subsystems of water environment, social economy, and nature, and t represents the number of cycles.

The ground magnetic resonance spectroscopy (MRS) system uses array coils to directly detect underground complex water-bearing structures (Jin et al. 2022). This article focuses on the resolution analysis of three-dimensional (3D) groundwater detection and the multi-parameter inversion method. This method is used to detect groundwater coil design and imaging.

This measurement mode covers the entire detection range, and the lateral resolution of the edge-to-edge type is low, and the boundary of the 3D target cannot be accurately distinguished. The half-covered measurement mode can effectively improve the lateral resolution, but if the entire detection range is covered, the required measurement times are up to 49, which is too much work. Considering that the center area of the detection range is the focus of detection, laying the coil only on the diagonal can reduce a large number of detection times (13 times, see Figure 3(b)), while ensuring the lateral resolution of the detection center area. If the detection result is displayed on the edge of a certain detection range, consider appropriately increasing the measurement to improve the resolution of this area.

3D groundwater imaging is similar to two-dimensional (2D) and one-dimensional (1D) methods, both include the imaging of water content and relaxation time. It only needs to represent the underground space as a 3D grid, which can be adapted to the water content inversion, QT inversion and the cell inversion algorithm of the water-bearing unit. This article only takes the water content inversion method as an example to realize the imaging of underground 3D water bodies.

At the same time, considering that the vertical resolution is much higher than the horizontal resolution, the ratio of the horizontal size to the vertical size of the grid is set to 20:1, and the specific parameters are shown in Table 2.

Area C is the peripheral area of the detection range, with a large resolution radius, and gradually increases with depth and lateral distance, so the design grid size is also relatively large. It is finally determined that the number of units in the entire area is 130,740, which is only 15% of the uniform division.

In order to apply 3D ground MRS to the imaging effect of complex groundwater, this section establishes a 3D groundwater simulation model in the Hami area. The initial amplitude of the MRS signal in the measurement mode of the diagonal movement of the array coil is calculated, and the simulation data and the measured data are used to perform 3D inversion imaging respectively. The Hami Basin is one of the regions with the least water resources in Xinjiang. The imaging results of water content in this paper reflect the ability of complex groundwater models and the ability to estimate the total amount of groundwater.

According to the analysis of the model resolution matrix, the inversion result is the weighted value of the water content of each position in the model, so the average water content inside the 3D water body must be less than the model setting value. For the quantitative estimation of the 3D water body, the total water volume (the product of the unit water content and the unit volume) or the total water content (the product of the total water volume and the density of water) should be considered. Table 3 shows the distribution results of the total water content and the cumulative total water content in different water content intervals.

According to model assumptions, the total amount of 3D water content is 5.14 × 10^4t. It can be seen from Table 3 that the total water content of the unit with a water content greater than 50% is only 8.19 × 10^3t, which is much smaller than the model water content, while after accumulating the total water content of all units with a water content greater than 5%, it is equal to the model total. For units with water content less than 5%, it is determined by the 1% water content outside the 3D water body and the restriction that the variable constraint cannot be equal to 0 in the inversion algorithm. Although the total water content is large, it should be discarded.

It can be seen from Figure 6 that the bottom boundary calculated by the GPR measurement data is basically consistent with the project construction data. Using the proposed array coil mobile measurement mode, the Hami area was measured on the spot, and 3D groundwater imaging and total water content were estimated. The imaging results are consistent with known geological data and GPR detection results, and the estimated error of the total water content is only 5.75%, which proves the effectiveness of the 3D MRS detection method and the accuracy of the imaging results.

The Hami area is located in an inland area and has concentrated settlements. Therefore, the development of water resources in this area is highly concentrated, but the utilization rate of water resources is low. From the data point of view, the primary industry uses too much water. At the same time, the sewage purification/reuse rate is low, and the water structure is unreasonable. The waste caused by improper use of water resources is also very serious. The comprehensive agricultural water quota is close to 900 cubic meters/mu, and in some mountainous areas it reaches 1,350 cubic meters/mu. In Hami, the popularity of water-saving equipment is low, and the main reason for the serious over exploitation of groundwater is the high investment cost of the reservoir, which is difficult for farmers to bear. The cost of karez is relatively low, and it has become a general water diversion method for agricultural land irrigation.

In this paper, the DRASTIC method is used to evaluate the anti-pollution performance of the Hami area. In areas with poor anti-pollution performance, the groundwater depth is very shallow, the groundwater replenishment intensity is very high, and pollutants are easy to seep into the groundwater body and pollute the groundwater. The areas with better anti-pollution performance are mainly mountainous areas or alluvial plains. The underground water in alluvial plains is several hundred meters deep, and pollutants cannot easily enter the aquifer.

In this paper, groundwater pollution prevention performance and pollution source hazards are selected for groundwater pollution risk assessment. The evaluation results can reflect the risk of groundwater pollution in the Hami area. Areas with higher pollution risks are mainly in industrial production areas and around lakes; the areas with lower pollution risk are mainly in the main high-altitude plains and mountainous areas, these underground waters are buried deep, and the vadose zone is mainly bedrock, the anti-pollution performance is relatively good. Although there are some metal deposits in the area, these pollutants are not easy to enter the aquifer, which is a low pollution risk area.

Changes in the groundwater level of the Hami Basin during the year are mainly affected by artificial mining activities, especially agricultural irrigation and other activities. The groundwater level mainly explains the following.

From January to March, agricultural irrigation water consumption was relatively low, and the groundwater level gradually rose to the highest in March. April to August is the peak season for agricultural water use, and mining volume tends to increase significantly, while groundwater levels tend to drop. And as the amount of crop irrigation continues to increase, the rate of decline is gradually increasing. From September to October, the amount of crop irrigation decreased, but the groundwater level still showed a downward trend. From October to December, the use of groundwater was suspended, and the groundwater level rose slowly. After October, although the mining volume has decreased, the replenishment volume still cannot make up for the loss of groundwater in summer and autumn, making the groundwater level at the end of the year always greater than that at the beginning of the year, and it has been declining year after year. This also shows that the dynamic changes in groundwater in the Hami Basin are closely related to human activities.

Analyzing the cumulative changes of groundwater in the Hami Basin in the past ten years, it can be found that in the five years from 2015 to 2020, the groundwater level has generally declined, and the maximum cumulative decline depth has reached 14 m or more. The decline is greater than the eight years from 2000 to 2020. The cumulative decline of the plain irrigation area south of the Lanxin Highway in the Hami Basin is basically greater than 4 m, and the area is basically located within the severe over-exploitation area. However, according to the field survey in October 2010, the water output of wells in the central irrigation area is relatively large, with a single well output of 200 m³ /h. This is mainly because the huge alluvial fan plain in front of the mountain reserves a large amount of groundwater, which ensures the needs of the central irrigation area.

This study comprehensively used spatial analysis methods, technologies and numerical simulation methods to analyze the natural geographical conditions, regional geology, and hydrogeological conditions in the Hami area, and studied the surface runoff in Hami, constructed a hydrogeological conceptual model and numerical model with Hami as the main body, used this model to predict the changing trend of groundwater level caused by different groundwater exploitation schemes, and analyzed the geological environmental problems caused by different groundwater exploitation schemes.

As the Hami region has been severely over-exploited for groundwater for a long time, the current amount of natural groundwater should not be reduced when determining the number of recoverable resources. The recoverable resources of the two groundwater subsystems in the Barkol Mountain Plain Area (a) and the Karlik Mountain Plain Area (b) are shown in Table 4.

According to the calculation results, if the two groundwater subsystems of the Barkun Mountain Plain and the Karlik Mountain Plain are used as the oasis belt in the Hami region, the recoverable resources are only 333 million cubic meters per year.

As the groundwater in the study area is over-exploited at this stage, the groundwater level in Hami, the over-exploited area, will drop to varying degrees in 2030. In some areas, severe mining will cause the water level to drop, the largest drop by more than 10 m. The main groundwater decline area is the oasis zone, where groundwater is intensively mined, and the groundwater level declines at a faster rate.

The analysis of water resources carrying capacity is a complex study that integrates many influencing factors and is restricted by many factors. At the same time, due to the limited level of personal scientific research ability, this research is only a preliminary exploration of the water resources in the Hami area, and further research is needed in the future. Due to the limited data collected in this paper, the surface runoff data are less, and the data are unevenly distributed in various regions. In particular, there are basically no data on climate change and human activities before the 1980s. This has led to insufficient analysis of the relationship between climate change and human activities and the evolution of groundwater environment. Due to the lack of long-term monitoring data such as reservoirs and lakes, it is difficult to determine the groundwater replenishment part of the ecological water consumption of reservoirs, lakes and rivers in this paper.

Taking the Hami area as the research area, this paper expounds on three aspects of the spatial and temporal evolution characteristics of groundwater dynamic field and groundwater chemical field in the Hami area, and the evolution model of groundwater environment in the Hami area. Aiming at the inconsistency between the exploitation and use of water resources in the Hami area, this research follows the basic guiding ideology of the sustainable development theory and makes a scientific analysis and evaluation of the agricultural land water resources in the Hami area. Aiming at the problems existing in the utilization of water resources in the Hami area, referring to the existing results, this paper selects multiple effective evaluation indicators such as the unit GDP and water resource utilization rate of agricultural land in the Hami area. Based on objective data, the entropy method is used to calculate the index weight coefficient. The four pillars of sustainable development are economy, society, environment and culture. Only through coordinated development of the four aspects can sustainable development be achieved. Adhering to sustainable development can better improve the ecological environment, optimize the ecosystem, and benefit people's long-term development.

No funding was used to support this study.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.