Pollution risk assessment based on source apportionment in a groundwater resource area,NE China

Pollution risk assessment of a groundwater resource area is instrumental in contributing to groundwater protection. This study considered the evaluation results of source apportionment by combining a principal component analysis (PCA) with a factor analysis (FA) to identify potential risk sources. The vulnerability was evaluated using a DRASTIC model as the main pollution pathway, and groundwater quality as a pollution receptor, in order to validate the risk of pollution in a typical groundwater resource area of northeastern China. Results showed that four principal potential pollution sources were point source pollution such as water-rock interaction, dissolution of iron and manganese bearing minerals due to geological processes, non-point source pollution of nitrogen such as agriculture fertilizers, and organic pollution resulting from domestic and industrial wastewater. A “high” and “relatively high” pollution risk occurred mainly at the northwestern and southeastern edges of the region, respectively, with a widely distributed “moderate” pollution risk over the majority of the study area, and a “relatively low” and “low” pollution risk located mainly in the central of the Limin Groundwater Resources area, which showed that the potential pollution sources, especially due to human activity, have significantly changed the distribution of pollution risk in groundwater resource areas.     

下辽河平原地下水脆弱性的时空演变

地下水脆弱性受相关因子变化的影响,在时空分布上具有动态变化性,因此分析地下水脆弱性的时空演变及结构变化规律对于地下水有针对性地污染防治具有重要意义。以下辽河平原为研究区,选取1991、2000和2010年的相关人为因子参数,结合DRASTIC模型计算这3个年份的地下水脆弱性综合指数,利用Arc GIS的地理统计工具分析地下水脆弱性的演变状况。在此基础上计算G指数得到地下水脆弱性的空间热冷点分布,结合重心和标准差椭圆对热点的变动情况进行定量分析。研究结果表明:(1)1991年地下水脆弱性以较低脆弱性和高脆弱性区为主,分别占研究区面积的36.5%和31.3%,到2000年以一般脆弱性和较高脆弱性区为主,面积比例分别达到31.6%和25.9%,发展到2010年主要以较高脆弱性为主,面积比例占41.71%;(2)1991—2010年下辽河平原地下水脆弱性总体上呈现先增后减的趋势,沈阳市及周边长期处于高值状况,南部沿海地区逐步演化为高值脆弱性区;(3)1991和2000年的热点集中区主要分布在新民市和辽中县的西部地带,期间变化较小,2010年的滨海地区也发展成热点集中区,各时期内冷点分布面积比较少,且零散;(4)1991年至2000年,热点重心向西南方向位移了2.264km,热点分布格局进一步趋于东—西方向;2000年到2010年,热点重心向西南方向位移了30.787km,标准差椭圆长轴旋转角逆时针转动了32.44°,整体热点分布格局为东北—西南方向。     

Responses of groundwater vulnerability to groundwater extraction reduction in the Hun River Basin,northeastern China

Intensive groundwater extraction causes many environmental problems globally. Reducing groundwater extraction is a primary method for alleviating these problems. However, this reduction may create new pollution issues because of an increase in groundwater vulnerability. A case study was done using the DRAOTIC evaluation method (an improved DRASTIC method for organic pollutant in aquifer vulnerability; soil (S factor) has been updated by organic matter (O factor) in the method) for the Hun River Basin, northeastern China, where groundwater intensive extraction had caused serious environmental and hydrogeological problems. The assessment results show that moderate vulnerability level is the main vulnerability level in the Hun River Basin; high vulnerability level and low vulnerability level categories occupy a smaller area; while very high and very low vulnerability categories occupy the smallest area. By combining the predicted groundwater level distribution and DRAOTIC model, the responses of groundwater vulnerability to different groundwater extraction reductions could be studied. The results show that groundwater vulnerability levels increased as groundwater extraction was reduced; this is because the rising groundwater levels make it easier for pollution coming from the surface to reach the aquifer. The more the reduction in groundwater extraction, the greater the increase in the area with higher vulnerability levels, and the greater the increase in pollution risk.     

Source apportionment of pollution in groundwater source area using factor analysis and positive matrix factorization methods

By means of factor analysis (FA) and positive matrix factorization (PMF) methods, groundwater pollution sources were identified in the Jinji groundwater source area, which is beside the Yellow River and is the only urban water supply source for the city of Wuzhong in Northwestern China. The sources of groundwater were quantified based on 16 samples of shallow groundwater from the source area. The source apportionment with the PMF model identified three dominant groundwater pollution sources. These were anthropogenic activities of agricultural and industrial pollution with a pollution contribution of 53.0%, water–rock interaction of 24.6%, and evaporation and concentration of 22.4%. The source apportionment with the FA model identified four sources which were evaporation and concentration, with the largest contribution (42.6%), followed by anthropogenic activities (29.2%), mineral dissolution and industrial pollution (22.4%), and natural effects (5.8%). Specific attention should be paid to these natural (fluoride, TH, etc.) and anthropogenic sources (NH₄⁺, NO₂^?, turbidity, total bacterial count, etc.), and pertinent measures should be taken to control local groundwater pollution. The most significant trait of the PMF is its scientific interpretation and physical explanation of the results, depending on non-negative restriction of the pollution source profiles and contributions.     

基于ArcGIS的下辽河平原地下水脆弱性评价及空间结构分析

以下辽河平原为研究区,通过选取1991、2000和2010年3个代表年的相关参数,在DRASTIC模型基础上构建评价指标体系进行地下水脆弱性评价,并以地下水中氮元素浓度为响应指标通过显著性检验,在此基础上借助GS+、Arc GIS和Geoda095i等软件的制图功能和空间统计分析功能,对下辽河平原地下水脆弱性的空间分布特征、变异规律以及空间关联格局进行研究分析,结果表明:11991—2010年下辽河平原地下水脆弱性总体上呈先增后减趋势,空间分布上以沈阳市为中心的地下水高脆弱区向南部沿海方向扩散;21991—2010年研究区地下水脆弱性Moran's I表现为较强正相关现象,且关联程度呈略微下降趋势;31991—2010年研究区地下水脆弱性局部空间自相关和显著性水平均发生了明显的变化;4研究区内地下水脆弱性受结构性因素和随机性因素共同作用,且随机性因素在3个时期内有逐步上升趋势。研究成果反映了研究区地下水脆弱性空间结构的变异规律及驱动机制,为决策者在未来地下水污染防治方面提供相关参考依据。     

Statistical and multivariate statistical techniques to trace the sources and affecting factors of groundwater pollution in a rapidly growing city on the Chinese Loess Plateau

Abstract

Groundwater quality is defined by various water quality parameters. The aims of the research are to understand the relationships among different groundwater quality parameters and to trace the sources and affecting factors of groundwater pollution via statistical and multivariate statistical techniques. The 36 shallow groundwater samples collected from shallow pumping wells in Yan’an City were analyzed for various water quality parameters. Correlation analysis, principal component analysis (PCA), hierarchical cluster analysis (HCA), and multivariable linear regressions (MLR) were jointly used in this study to explore the sources and affecting factors of groundwater pollution. The study reveals that the mineral dissolution/precipitation and anthropogenic input are the main sources of the physicochemical indices and trace elements in the groundwater. Groundwater chemistry is predominantly regulated by natural processes such as dissolution of carbonates, silicates, and evaporates and soil leaching, followed by human activities as the second factor. Climatic factors and land use types are also important in affecting groundwater chemistry. Cl^– is the greatest contributor to the overall groundwater quality revealed by the two regression models. The first model which has eight dependent variables is high in model reliability and stability, and is recommended for the overall groundwater quality prediction. The study is helpful for understanding groundwater quality variation in urban areas.     

Study of integrated risk regionalisation method for soil contamination in industrial and mining area

Industrial and mining areas have been included as key governance plots of China’s soil management and protection. In this study, we developed an assessment method for soil integrated risk in industrial and mining areas, with a comprehensive consideration of pollution risk, pollution sources and receptors of soil risk. The method consists of four parts, including soil risk assessment, vulnerability assessment of soil risk receptors, risk level assessment of pollution sources and integrated risk assessment. Using this method, we could produce a complete soil risk regionalisation map that presents the total factor risk level of soil contamination of industrial and mining areas in ArcGIS. This study also took a typical industrial and mining area in China as a case and quantitatively and spatially assessed the integrated soil contamination risk. Results showed: (1) the integrated risk of the study area ranged from moderate level to high level; (2) the risk of pollution sources in the study area ranged from moderate level to high level; (3) vulnerability of soil risk receptors in streets was lower than that in the towns.     

Risk assessment and source identification of coastal groundwater nitrate in northern China using dual nitrate isotopes combined with Bayesian mixing model

Due to the intensive and complicated human activities, the identification of nitrate pollution source of coastal aquifer is usually a challenge. This study firstly adopted stable isotope technique and stable isotope analysis in R (SIAR) model to identify the nitrate sources and contribution proportions of different sources in typical coastal groundwater of northern China. The results showed that about 91.5% of the groundwater samples illustrated significantly high nitrate concentrations exceeding the maximum WHO drinking water standard (50 mg/l), reflecting the high risk of groundwater nitrate pollution in the coastal area. A total of 57 sampling sites were classified into three groups according to hierarchical cluster analysis (HCA). The δ¹⁵N-NO₃^? and δ¹⁸O-NO₃^? values of groundwater samples from Group C (including nine samples) were much higher than those from Group A (including 40 samples) and Group B (including 8 samples). SIAR results showed that NH₄⁺ fertilizer was the dominant nitrate source for groundwater samples of Groups A and B while manure and sewage (M&;S) served as dominant source for Group C. This study provided essential information on the high risk and pollution sources of coastal groundwater nitrate of northern China.     

Development of Relative Risk Model for Regional Groundwater Risk Assessment: A Case Study in the Lower Liaohe River Plain,China

Increasing pressure on water supply worldwide, especially in arid areas, has resulted in groundwater overexploitation and contamination, and subsequent deterioration of the groundwater quality and threats to public health. Environmental risk assessment of regional groundwater is an important tool for groundwater protection. This study presents a new approach for assessing the environmental risk assessment of regional groundwater. It was carried out with a relative risk model (RRM) coupled with a series of indices, such as a groundwater vulnerability index, which includes receptor analysis, risk source analysis, risk exposure and hazard analysis, risk characterization, and management of groundwater. The risk map is a product of the probability of environmental contamination and impact. The reliability of the RRM was verified using Monte Carlo analysis. This approach was applied to the lower Liaohe River Plain (LLRP), northeastern China, which covers 23604 km². A spatial analysis tool within GIS which was used to interpolate and manipulate the data to develop environmental risk maps of regional groundwater, divided the level of risk from high to low into five ranks (V, IV, III, II, I). The results indicate that areas of relative risk rank (RRR) V cover 2324 km², covering 9.8% of the area; RRR IV covers 3986 km², accounting for 16.9% of the area. It is a new and appropriate method for regional groundwater resource management and land use planning, and is a rapid and effective tool for improving strategic decision making to protect groundwater and reduce environmental risk.     

Hydrogeochemical evolution and risk assessment of human health in a riverbank filtration site,northeastern China

Intensive agriculture and industrial activities have resulted in contamination in rivers and groundwater quality, which threatens human health. In this study, we used comprehensive physiochemical indicators to assess the quality of groundwater used for drinking and irrigation in addition to the potential risks to local residents in a riverbank filtration site. Human health risks through drinking water intake and dermal contact were also estimated. Moreover, we analyzed the spatial distribution regularities of health risk values in a riverbank filtration site. The assessment results revealed that NH₄–N, NO₂–N, F^?, Mn, and As are main contaminants affecting groundwater quality and that 62% of the total samples is suitable for a variety of purposes. All groundwater in the study area is suitable for irrigation based on the sodium adsorption ratio (SAR), residual sodium carbonate (RSC), Na percentage (%Na), and U.S. Salinity Laboratory (USSL) and Wilcox diagrams. The health risk assessment suggests that residents in the study area are at high health risk, and women and children face higher risk than men in both non-carcinogenic and carcinogenic risks. The spatial distribution regularities of health risk values suggest that the human health risk value of each groundwater sample is different in the study area and has certain regularity. Therefore, effective measurements must be taken to address the groundwater contamination and to reduce the human health risks.     

基于多风险源胁迫的西南地区生态风险评价

西南地区生态环境复杂、人地矛盾突出,生态系统面临着多种风险胁迫,进行生态风险评价对区域生态风险的预警和防控具有重要的意义。基于西南地区的生态环境特征,将生态风险分为自然灾害风险与人类活动风险,从风险源危险性、生态系统潜在损失度、生态系统易损性3个方面构建单一风险评价模型,将单一风险评价结果进行综合分析得到西南地区综合生态风险结果。研究表明,西南高生态风险区面积为17.02万km2,占研究区总面积7.4%,主要分布在念青唐古拉山、邛崃山、哀牢山、无量山、金沙江、怒江、澜沧江、大渡河流域等地,以及成都、重庆、贵阳等人地作用强烈的大城市周边。这些地区环境复杂,灾害易发,应加强防控与监测,优化产业结构,继续推进生态保护工程,降低生态风险。     

Assessment of shallow groundwater quality and its suitability for drinking purpose near the Béni-Mellal wastewater treatment lagoon (Morocco)

Abstract

The present study aimed to evaluate the suitability for drinking purpose of shallow groundwater near the Béni-Mellal wastewater treatment lagoon based on various physicochemical, heavy metals, and bacteriological parameter analyses. The physicochemical results revealed that some of the samples do not comply with the Moroccan and/or WHO standards for drinking water. Parameters including turbidity, TH, Na⁺, Li⁺, Ba²⁺, Ca²⁺ (～47.1% of samples), Cd (～52.9% of samples), Fe (～82.4% of samples), Pb (～58.8% of samples), T. coliforms, and E. coli exceeded the drinking limits. The statistical analyses revealed that the shallow groundwater chemistry is mainly controlled by geogenic and anthropogenic sources. For quality assessment, using the Moroccan groundwater assessment grid, the values of EC and Cl^–, NO₃^–, NH₄⁺, oxidability, and E. coli, fixed as pollution indicators, showed that most of the wells showed medium-to-poor quality, 14% of them have a very poor water quality, and 20% of them belong to the bad water quality. According to geometric and arithmetic DWQI values, the groundwater quality was frequently fair to good, needing treatment or at least disinfection before public consumption. A sensitivity analysis results indicated that Fe, Cd, Cr, Pb, and E. coli have an important impact on the DWQI computing.     

典型棕地修复前后土壤重金属生态风险变化——以江西贵溪冶炼厂为例

目前,我国对于棕(褐)地周边区域生态风险的研究较少,且主要是针对风险源带来的潜在危害进行评价,没有考虑风险受体能够承受生态风险能力的大小,生态风险评价研究不全面。在棕(褐)地周边区域的生态风险评价中加入风险受体的相关研究,主要从风险源的危害分析和风险受体的生态脆弱性两方面对生态风险进行评价,使评价更加全面,另外,现有研究少有对生态风险在时间上的变化研究,考虑了生态风险时间上的变化,对贵溪冶炼厂周边两个时期的生态风险进行评价并分析其变化,利用GIS软件对评价结果进行空间表达,对研究区域存在的生态风险空间差异进行分析。结果表明:修复前苏门区、九牛岗、水泉区、串山垅等地区存在很强生态风险,沈家-林家区和长塘周家区的生态风险相对较小,处于中等风险水平,修复后研究区的生态风险大大降低,很强风险降为强风险水平,中等风险降为低风险,说明修复方式比较有效,但仍有小范围区域存在较强风险,应加强修复,研究区域中耕地的生态脆弱性最大。对于生态脆弱性较大且生态风险较大的区域应进一步进行修复治理,生态脆弱性大而生态风险较低的地区应加强监测防范,防止再次发生较强风险。     

气候变化对物种脆弱性影响的多组分评估——以中国山杏为例

气候变化威胁着全球生物多样性,评估物种脆弱性是研究气候变化对生物多样性影响的关键所在。目前多数研究主要通过物种适宜区面积变化来判断物种脆弱性,这单一维度会忽略其它因素的影响。采用多组分评估框架,将物种适宜区面积变化、生境破碎程度变化、受保护面积变化和人类干扰程度变化四个组分纳入物种总体脆弱性指数中,以中国具有较高经济和生态价值的山杏(Armeniaca sibirica)作为研究对象,评估未来(2061—2080年)三种共享社会经济路径(ssp)ssp126、ssp245、ssp585下山杏物种脆弱性。研究结果表明：未来山杏生境适宜区有向我国东北和西北方向扩张的趋势,扩张区面积明显大于消失区,这种差异化程度依赖于社会发展路径情景;未来适宜区内的保护区面积将由当前6.50×10⁴km²增加到1.10×10⁵km²(三种气候变化情景下的平均值),未来适宜生境破碎化程度将保持稳定,生境适宜区内的人类干扰强度将下降;各组分的比较中,受保护面积变化对山杏总体脆弱性的贡献将超过山杏适宜生境面积变化和其它组分的贡...     

辽河三角洲湿地区域生态风险评价

生态风险评价区别于生态影响评价的重要特征在于其强调不确定性因素的作用,区域生态风险评价相对于一般生态风险评价而言,其所涉及的风险源以及评价受体等都在区域内具有窨异质性,即具有区域分异现象,因而更具复杂性,以辽河三角洲湿地（盘锦市）为研究范围进行区域生态风险评价理论和方法的探讨,针对辽河三角洲主要生态风险源洪涝、干旱、风暴潮灾害和油田污染事故的概率进行了分级评价;并提出度量生态环境重要性和脆弱性的指标,分析了风险源的危害作用;运用遥感资料和地理信息系统（GIS）技术,完成了区域生态风险综合评价。     

浑河河水及其沿岸地下水污染特征

选择沈阳地区重要河流浑河及其沿岸地下水进行定量分析,研究并探讨了包括无机物和有机物在内的水质综合污染特征。结果表明,浑河河水中氨氮、硝氮、亚硝氮和酚超过了地表水环境质量标准,最大超标倍数分别为15.8、1.5、82.4和1.8倍,检测出的11种卤代烃、氯苯和六六六等有机物均未超标。浑河沿岸地下水中氨氮、硝氮、亚硝氮、化学需氧量、酚和铅超过地下水质量标准,超标率分别为31.6%、10.5%、26.3%、36.8%、47.4%和26.8%,检测出的4种卤代烃和六六六等有机物均未超标。河水及其沿岸地下水中的污染物,尤其是有机污染物种类和浓度高值基本出现在城西的谟家—大祝断面之间。浑河水质主要受城市工业废水、居民生活污水排放的影响,沿岸地下水的污染来源包括工业生产或农村居民生活造成的地表污染物垂直入渗式的点源污染、浑河水侧向渗透补给式的线源污染以及农药化肥使用产生的面源污染,而有机污染物主要通过点源污染地下水。浑河各区段的使用功能、包气带岩性及沿岸水源地开采井布局等因素都为受污染的河水对沿岸几百米范围内的浅层地下水的补给提供了条件,造成浅层地下水的污染,对当地生态系统及人类健康构成潜在威胁。     

Transport of groundwater-borne phosphorus to Lake Bysjön,South Sweden

Lake Bysjön is a hypertrophic seepage lake, with groundwater as a main external source of phosphorus. Twelve groundwater samples from the vicinity of the lake were high in phosphate (0.4 to 11 mg l^–1, mean value 2.57 mg l^–1 PO₄-P), both within the riparian zone and in two shallow wells located upstreams the lake in the nearby village. Phosphorus sorption capacity of four sand samples measured with the Langmuir isotherm method was low (7.3 to 121,1 mg kg^–1 PO₄-P), with the lowest values found within the riparian zone. It is suggested that the phosphorus originates from garden fertilizers and other human sources, and that the low absorption capacity of the soils is caused by the leaching of calcium from the watershed, a process which started some 3000 years ago. Riparian zone itself has almost no retention capacity, and processes within it (e.g., redox-related) have only secondary importance for the transport of phosphorus to the lake.     

高潜水位煤矿区生态风险识别与评价

生态风险评价是生态环境保护与管理的重要研究内容,并广泛运用于流域与较大范围的区域尺度的研究。以区域生态风险评价理论为基础,结合高潜水位煤矿区生态环境以及煤炭开采对生态系统造成的危害的特点,通过分析风险源、风险受体、生态终点以及暴露—响应过程,对高潜水位煤矿区生态风险的识别与评价方法进行了研究,构建了典型高潜水位煤矿区的生态风险识别与评价概念模型与空间分析框架,分析了煤矿区生态风险识别的主要技术手段与方法,并构建了以缓冲为主要手段的综合生态风险评价方法。选择山东东滩煤矿作为研究对象,针对研究区内存在的采煤塌陷、洪涝、污染、景观及社会等生态风险类型,定量评价其空间差异,并提出相应的风险防范措施。案例分析结果表明,研究区综合生态风险重度、中度、一般、轻度分别占到研究区的4.70%,64.00%,24.09%,7.20%。生态风险较高的区域主要位于矿区中西部,为煤矸石山、裸露煤炭堆积与发电厂分布区域;中度风险是研究区主要的风险类型。从降低生态风险保障矿区生态安全角度,在未来矿区规划与生态治理过程中,提出了具体的应对措施,包括:(1)注重源头控制;(2)建立高生态风险区域阻隔带;(3)加强污染的监测与控制;(4)采用边开采边治理技术。建议加强生态风险高区域的阻隔,建立生态缓冲带,减缓对整个矿区的综合影响,构建东滩煤矿生态风险防范的空间结构。     

Geochemical assessment of fluoride enriched groundwater and health implications from a part of Yavtmal District,India

Abstract

A comprehensive study was conducted from a semi-arid part of Yavtmal District, Maharashtra, India through combination approaches of geochemical modeling and its health consequences. The groundwater quality assessment shows that 55% of groundwater samples have the concentration of fluoride above the desirable limit. The high Na⁺/Ca⁺ ratio (>1.0) suggest the occurrence of cation exchange, which is further supported by Scholler’ chloro-alkaline indices. The geochemical modeling reveals that the existence of CaCO₃ precipitation and CaF₂ in groundwater. Simulation analysis indicates the dissolution of calcite, gypsum, and albite and precipitation of dolomite, fluorite, halite, and K-feldspar along with cation exchange as the main water–rock interactions influencing the groundwater chemistry. This is further significantly supported by pollution index of groundwater (PIG). PIG indicates about 18% of total samples fall in very high pollution zone, 3% in high pollution zone, 8% in moderate pollution zone, 24% in low pollution zone, and remaining (47%) express insignificant pollution. The 28% of subject studied have skeletal fluorosis varying from mild to severe type. In different pollution zones, the affected persons by dental fluorosis are varying from 15% to 41%. A proper monitoring and treatment are required for high fluoride water before its use for drinking and cooking.     

沙漠腹地天然绿洲不同林龄胡杨水分利用来源

了解干旱荒漠绿洲区主要植被的水分利用来源,能为该区域植被保护和水资源的合理分配提供科学依据.本研究以达里雅布依天然绿洲胡杨幼龄木(胸径DBH≤10 cm)、成熟木(10 cm＜DBH≤40 cm)和过熟木(DBH＞40 cm)为对象,测定不同林龄胡杨木质部水和潜在水源(地表水、0～3m土层土壤水、地下水)的氧同位素,运...