Peiyue Li

Building a new and sustainable “Silk Road economic belt”

The building of the Silk Road economic belt is an exciting prospect that may bring immense economic benefits to Eurasian countries. However, intensive human activities to be induced by it may double the water crisis in central Asia, deteriorate the vulnerable environment, and accelerate energy consumption in this area. To build a new and sustainable Silk Road economic belt, advancing scientific research, reinforcing international collaboration and enhancing education are necessary steps. With careful planning, sound research, good data and the support from governments and the people, the Silk Road economic belt can be developed in an environmentally sustainable manner that is a credit to all involved.

Origin and assessment of groundwater pollution and associated health risk: a case study in an industrial park, northwest China

Groundwater quality which relates closely to human health has become as important as its quantity due to the demand for safe water. In the present study, an entropy-weighted fuzzy water quality index (WQI) has been proposed for performing groundwater quality assessment in and around an industrial park, northwest China, where domestic water requirements are solely met by groundwater. The human health risk was assessed with the model recommended by the United States Environmental Protection Agency. In addition, the sources of major ions and main contaminants were also analyzed. The study shows that groundwater in the study area has been contaminated conjunctively by natural processes and industrial and agricultural activities. Nitrate, manganese (Mn), fluoride, total dissolved solids, total hardness and sulfate are major contaminants influencing groundwater quality. Nitrate and heavy metals such as Mn are mainly affected by human agricultural activities and industrial production, while other contaminants are mainly originated from mineral weathering and water–rock interactions. The results of water quality assessment suggest that half of the groundwater samples collected are of medium quality thus require pretreatment before human consumption. The mean health risk caused by the consumption of contaminated groundwater in the area is 8.42 × 10−5 per year which surpasses the maximum acceptable level (5 × 10−5 per year) recommended by the International Commission on Radiologic Protection. The entropy-weighted fuzzy WQI proposed in this study can not only assign proper weights to parameters but also treat uncertainties associated with water quality classification. This study will be of interest to international environmentalists and hydrogeologists. It will also be useful in regional groundwater management and protection.

Major Ion Chemistry of Shallow Groundwater in the Dongsheng Coalfield, Ordos Basin, China

A hydrogeochemical study was conducted in the Dongsheng Coalfield, Ordos Basin, China, to identify the mechanisms responsible for the chemical compositions of the shallow groundwater and to document water quality with respect to agricultural and drinking supply standards, prior to mining. Tri-linear diagrams, principal component analysis, and correlation analysis were used to reveal the hydrogeochemical characteristics of the shallow groundwater, and the potential water–rock interactions. In general, the major cations and anions were present at low concentrations, but were relatively higher around Jiushenggong than elsewhere in the study area. Groundwater around Jiushenggong has a long residence time and is also subject to extensive evapotranspiration. The dominant hydrochemical facies are HCO3-Ca, HCO3-Na, and mixed HCO3-Ca·Na·Mg types. Increases in major ion concentrations along the flow path, including Na, Cl, and SO4, coincide with increases in total dissolved solids. The predominant mechanism controlling groundwater chemistry proved to be the dissolution of carbonates, gypsum, and halite. Cation exchange and mixing with local recharge water are also important factors. The shallow groundwater quality in the study area is suitable for agricultural and drinking purposes.ZusammenfassungEs wurde ein hydrochemische Studie im Kohlefeld Dongsheng (Ordos Becken, China) durchgeführt, um die Mechanismen aufzuklären, die für die chemische Zusammensetzung des flachen Grundwassers verantwortlich sind und um die Grundwasserqualität vor Beginn des Bergbaus zu dokumentieren, gemessen an Standards für die Wassernutzung in der Landwirtschaft und für die Trinkwasserversorgung. Dreiecksdiagramme, Hauptkomponentenanalyse und Korrelationsanalyse wurden benutzt, um die hydrochemische Charakteristik des flachen Grundwassers und die möglichen Wechselwirkungen Wasser-Gestein aufzuklären. Grundsätzlich waren die Konzentrationen der Hauptkationen und –anionen niedrig. Um Jiushenggong waren die Konzentrationen jedoch höher als im restlichen Untersuchungsgebiet. Das Grundwasser um Jiushenggong hat eine lange Aufenthaltszeit und ist außerdem durch hohe Evapotranspiration beeinflusst. Die dominierenden Grundwassertypen sind HCO3-Ca, HCO3-Na und gemischte HCO3-Ca*Na*Mg Typen. Die Zunahme der Konzentrationen der Hauptionen entlang des Fließweges, einschließlich Na, Cl und SO4, treten zusammen mit einem Anstieg der Gesamtkonzentration gelöster Stoffe auf. Die dominierenden Prozesse, die den Grundwasserchemismus bestimmen, sind die Auflösung von Karbonaten, Gips und Halit. Kationenaustausch und die Mischung mit der lokalen Grundwasserneubildung sind ebenfalls wichtige Faktoren. Die Qualität des flachen Grundwassers ist für landwirtschaftliche Nutzung und die Trinkwassergewinnung geeignet.ResumenSe realize un studio hidrogeoquímico en Dongsheng Coalfield, Ordos Basin, China, para identificar los mecanismos responsables de las composiciones químicas del agua subterránea superficial y documentar la calidad de agua con respecto a los estándares de agua potable y de agua para agricultura anteriores a la minería. Diagramas trilineales, análisis de componentes principales y análisis de correlación fueron usados para revelar las características hidrogeoquímicas del agua subterránea superficial y de las interacciones potenciales agua-roca. En general, los principales cationes y aniones estuvieron presentes en bajas concentraciones pero fueron relativamente mayores cerca de Jiushenggong. El agua subterránea cerca de Jiushenggong tiene un largo tiempo de residencia y está sujeto a evapotranspiración extensiva. Las fases hidroquímicas dominantes son HCO3-Ca, HCO3-Na y mezclas tipo HCO3-Ca*Na*Mg. Incrementos en las concentraciones de los iones mayoritarios a lo largo del flujo, incluyendo Na, Cl y SO4, coinciden con el total de sólidos disueltos. La disolución de carbonatos, yeso y halita provó ser el mecanismo que controla la química del agua subterránea. El intercambio de cationes y la mezcla con agua de recarga, son otros factores de importancia. La calidad del agua subterránea superficial en el área de estudio es adecuada para la agricultura y también para el consumo.摘要为了研究鄂尔多斯盆地东胜煤田煤矿开采前浅层地下水的水化学形成机制及其农业用水和饮用水水质状况,采用水文地球化学的理论,通过三线图、主成分分析和相关分析研究了浅层地下水的水文地球化学特征及其潜在的水岩作用。研究表明:总体上研究区地下水主要阴阳离子含量较低,但在九盛宫附近这些主要阴阳离子的含量相对较高。这主要是由于九盛宫附近浅层地下水径流缓慢,滞留时间较长且蒸发强烈。研究区浅层地下水主要以HCO3-Ca, HCO3-Na和HCO3-Ca·Na·Mg为主,主要离子浓度(包括Na+、Cl−和SO42−)沿流向不断增大,引起溶解性总固体也沿流向逐渐增大。碳酸盐、石膏和岩盐的溶解为控制地下水化学成分演化的主要机制。阳离子交换和局部补给水的混合也是影响地下水化学成分变化的重要因素。研究区浅层地下水水质适用于农业灌溉和饮用。

Hydrochemical appraisal of groundwater quality for drinking and irrigation purposes and the major influencing factors: a case study in and around Hua County, China

Groundwater is the major source of water for drinking and irrigation purposes in and around Hua County, China. However, long-term industrial effluents in the upstream of the area have produced contamination to groundwater. To provide a clear and better understanding of the status and extent of groundwater pollution to local decision makers, groundwater quality was assessed for drinking and irrigation purposes in this study using sodium adsorption ratio (SAR), residual sodium carbonate (RSC), soluble sodium percentage (%Na), permeability index (PI), an entropy weighted water quality index (EWQI), and some graphical approaches such as Wilcox and US Salinity Laboratory (USSL) diagrams. Factors that have significant influences on the hydrochemistry and quality of groundwater were also discussed in detail. Finally, some measures for the protection and management of groundwater in the study area were provided to local decision makers. The results show that shallow groundwater in and around the Hua County is mainly slightly alkaline freshwater with the majority of the samples falling in the category of HCO3–Ca and mixed HCO3·SO4–Ca·Mg. Medium quality water is prevalent in the study area for drinking purpose, and the main contaminants in groundwater are total dissolved solid (TDS), total hardness (TH), SO42−, Cl−, NO3−, NO2−, and oil. Groundwater in the study area is suitable for agricultural irrigation with regard to sodium hazard, but mixing of low and high salinity water is recommended before irrigation to reduce the salinity hazard in local areas. Natural processes such as weathering of parent rocks, cation exchange, and groundwater evaporation are the dominant factors influencing groundwater chemistry in the study area. However, river water leakage and human interference are becoming increasingly important in altering natural groundwater chemistry. The recommendations suggest in this study may help to prevent further groundwater pollution in the study area, and the results and recommendations reported here will also be useful for many other regions facing similar problems.

Using correlation and multivariate statistical analysis to identify hydrogeochemical processes affecting the major ion chemistry of waters: a case study in Laoheba phosphorite mine in Sichuan, China

Prior to mining, the water in and around the mine is rarely influenced by human activities, and hydrogeochemical processes are the major factors influencing and controlling water chemistry. To identify these natural hydrogeochemical processes in Laoheba phosphorite mine (Sichuan Province, China), correlation and multivariate statistical techniques were used. Results show that water quality in the area is generally good before the Laoheba phosphorite mine goes into construction and production. The cluster analysis classified water samples into 4 clusters (C1–C4). Samples from C1 and C2 are of HCO3−Ca·Mg and HCO3−Ca type, while those from C3 and C4 are of HCO3−Ca·Mg type. Most parameters except Cl− and pH show an increasing trend in the order of C1 to C4. Three principal components were extracted, and PC1 represents the ion exchange and the weathering of calcite, dolomite, and silicate minerals. PC2 and PC3 indicate the process of water recharge from upstream waters and the process of evaporation, respectively. The hydrochemistry of waters in the area is a result of multiple factors, and natural mineral weathering and ion exchange are the most important ones.

Groundwater quality assessment based on rough sets attribute reduction and TOPSIS method in a semi-arid area, China

In order to enrich and improve the groundwater quality assessment system, a new coupled assessment model based on rough set attribute reduction and the technique for order preference by similarity to ideal solution (TOPSIS) was proposed. The proposed model was applied in the groundwater quality assessment of a semi-arid area, northwest China. The results show that most chemical indices except NH4+, F−, and Mn meet the Standards for Drinking Water of China and the groundwater quality overall is good. All assessed water samples are found to be fit for human consumption according to the comprehensive assessment results. Rough set attribute reduction for groundwater quality assessment is practical. The assessment results after attribute reduction show a good consistency with those before attribute reduction. Rough set attribute reduction and TOPSIS evaluation coupled model is clear in ideas and simple in calculation, and evaluation results are reasonable as well. The coupled model can be applied to solve many multiple criteria decision making problems such as groundwater quality assessment.

Assessment of groundwater vulnerability in the Yinchuan Plain, Northwest China using OREADIC

Groundwater vulnerability assessments provide a measure of the sensitivity of groundwater quality to an imposed contaminant load and are globally recognized as an essential element of all aquifer management and protection plans. In this paper, the vulnerability of groundwaters underlying the Yinchuan Plain of Northwest China is determined using OREADIC, a GIS-based assessment tool that incorporates the key characteristics of the universally popular DRASTIC approach to vulnerability assessment but has been modified to consider important additional hydrogeological factors that are specific to the region. The results show that areas of high vulnerability are distributed mainly around Qingtongxia City, Wuzhong City, Lingwu City, and Yongning County and are associated with high rates of aquifer recharge, shallow depths to the water table, and highly permeable aquifer materials. The presence of elevated NO3− in the high vulnerability areas endorses the OREADIC approach. The vulnerability maps developed in this study have become valuable tools for environmental planning in the region and will be used for predictive management of the groundwater resource.

Progress, opportunities, and key fields for groundwater quality research under the impacts of human activities in China with a special focus on western China

Groundwater quality research is extremely important for supporting the safety of the water supply and human health in arid and semi-arid areas of China. This review article was constructed to report the latest research progress of groundwater quality in western China where groundwater quality is undergoing fast deterioration because of fast economic development and extensive anthropogenic activities. The opportunities brought by increasing public awareness of groundwater quality protection were also highlighted and discussed. To guide and promote further development of groundwater quality research in China, especially in western China, ten key groundwater quality research fields were proposed. The review shows that the intensification of human activities and the associated impacts on groundwater quality in China, especially in western China, has made groundwater quality research increasingly important, and has caught the attention of local, national, and international agencies and scholars. China has achieved some progress in groundwater quality research in terms of national and regional laws, regulations, and financial supports. The future of groundwater quality research in China, especially in western China, is promising reflected by the opportunities highlighted. The key research fields proposed in this article may also inform groundwater quality protection and management at the national and international level.

Groundwater Quality in Western China: Challenges and Paths Forward for Groundwater Quality Research in Western China

Groundwater quality issues are becoming as important as groundwater quantity issues, making groundwater quality research a hot topic worldwide. With human activity intensifying in western China as a result of the West Development Program and the Silk Road economic belt project of China, groundwater quality in western China is deteriorating rapidly. This special issue of Exposure and Health promotes groundwater quality research to respond to these challenges. This introductory article details the challenges faced by contemporary groundwater quality researchers, and proposes ways to advance groundwater quality research in western China. The paper also introduces the articles that follow in this special issue. The key goal of this work is to encourage new and experienced scholars to engage with this field.

Assessment of soil salinization based on a low-cost method and its influencing factors in a semi-arid agricultural area, northwest China

An investigation of soil salinization was carried out in the Nanshantaizi area (Northwest China) with WET Sensor. This device can measure such soil parameters as bulk soil electrical conductivity, water content, and the pore water electrical conductivity that are important for soil salinization assessments. A distribution map of soil salinization was produced, and the factors influencing soil salinization and its processes were discussed in detail. The study shows that moderately salinized to salt soils are mainly observed in the alluvial plain, where groundwater level is high and lateral recharge water contains high salinity. Nanshantaizi is covered by slightly salinized soils. The soil salinization distribution estimated by WET Sensor is generally consistent with the actual levels of salinization. Soil salinity in Nanshantaizi is mostly of natural origin and accumulated salts could leach to deeper soils or aquifers by water percolation during irrigation. Groundwater evaporation, groundwater level depth and quality of recharge water are important factors influencing soil salinization in the alluvial plain.