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1.
Rural drinking water safety is a growing concern in China. This study investigated the health risk of pollution of groundwater for the drinking water supply in Mingshan County, Ya'an City, in Sichuan Province, China, using 46 samples from the years 1991 to 2010. Carcinogenic, non-carcinogenic, and total risks were assessed by the model recommended by the United States Environmental Protection Agency (U.S. EPA). Thematic maps of the risks caused by single and multiple factors were generated from inverse distance weighting interpolation (IDW) and the geostatistical analysis functions of ArcGIS. The results show that the carcinogenic risks caused by chemicals in groundwater for drinking water supply are low, within the acceptable interval for risk management. However, non-carcinogenic risks are high and the number of sampling sites with risk values exceeding the standards amounted to 29. Non-carcinogenic risks of Cr6+, nitrate, fluoride, and Fe at sites 43, 46, 50, 64, 67, and 74 were the sources that caused high total health risk. This study reveals the risk level of groundwater quality and orders of treatment of pollutants, and provides a scientific basis for groundwater management in this area.  相似文献   

2.
The main goal of the project was to assess nitrogen pollution of surface waters and groundwater in the Federal State of North Rhine Westphalia (NRW), Germany. For this purpose the hydro(geo-)logical models GROWA-DENUZ/WEKU were coupled to the agro-economic model RAUMIS in order to assess the diffuse nitrogen loads and to approaches to determine the nitrogen loads from point sources. In this way the complex socio-economic interrelations and hydrological/hydrogeological interdependencies were simultaneously. The model network was applied consistently across the whole territory of NRW. At first the actual N inputs into groundwater and surface waters resulting from diffuse sources and point sources were assessed. For the relevant diffuse input pathways (groundwater runoff, drainage runoff and natural interflow) this was done in a spatial resolution of 100 m???100 m. In the case of point source inputs information from municipal waste water treatment plants, industrial effluents, rainwater sewers and combined sewer overflows has been considered. For NRW an actual total N input into surface waters of ca. 117.000 t???a?1?N has been quantified. As the inputs via natural interflow (ca. 30 %), groundwater runoff (ca. 26 %) and drainage systems (ca. 18 %) hold the largest portion, it is evident that measures to control nitrate pollution have to focus on the inputs from diffuse sources. For this purpose, initially the development of the agrarian sector according to the Common Agricultural Policy, CAP until 2015 including supplementary measures and other impact factors has been analysed. The impact of this so-called baseline scenario 2015 was predicted for both, the diffuse N surpluses and the N pollution of groundwater and surface waters. It could be shown that the baseline projections for the agricultural sector through 2015 may lead to decrease of the diffuse N inputs into groundwater by ca. 13.500 t???a?1?N and an overall decrease of the diffuse N inputs into surface waters by ca. 25.000 kg???ha?1???a?1?N. Based on the baseline scenario 2015 the additional N reduction to guarantee nitrate concentrations in groundwater below the EU-threshold value of 50 mg???l?1 NO3 was determined by means of a backward model calculation. This was done using the predicted nitrate concentrations in the leachate 2015 for the individual 100 m???100 m grids as starting points. In this way for the whole territory of NRW an additional N reduction beyond the baseline scenario 2015 of ca. 12.000 t???a?1?N has been assessed. Model results indicate that additional N reduction measures don’t have to be implemented area-covering in order to be efficient, but in certain subareas only. It is suggested that in these subareas the available financial resources for the implementation of N reduction measures shall be used for individual, i.e. regionally adapted nitrate reduction measures.  相似文献   

3.
There are many factors controlling groundwater pollution and vulnerability. However, the factors’ weights are still not reasonably investigated. In order to assess groundwater quality and the controlling factors in semiarid region, 178 groundwater samples were collected and analyzed for salinity and nitrate content. New statistical techniques of prediction profiler and hierarchical cluster combined with geographic information systems (GIS) were used to assess the groundwater quality based on three categorical controlling factors; landuse/ land cover (LULC), soil texture, and aquifer type. It is hypothesized these factors are controlling groundwater quality with various weights. Groundwater salinity across the study area varied from 327.0 to 9110.0 mg/L, while nitrate ranged from 0.2 mg/L to 339.6 mg/L. Both prediction profiler and cluster analyses provided excellent tools for quantifying the pollution magnitudes, weighing the controlling factors, and visualizing the pollution zones. Prediction profiler showed high capability to predict groundwater pollution (P?<?0.0001 and 0.0038 for salinity and nitrate, respectively) where LULC was the most effective factor, followed by aquifer type and soil texture class. According to desirability function analysis, maximum salinity and nitrate pollution was predicted to be associated with irrigated agriculture lands at shallow aquifers with silty clay loam soils. Hierarchical cluster analysis combined with GIS mapping was able to group the controlling factors into six vulnerability zones. The generated groundwater spatial pollution map allowed for potential pollution sources identification (e.g. fertilizer use, treated waste water, overdrafting). This paper also offers detailed mapping for decision makers to allow further ecosystem restoration and rehabilitation planning.  相似文献   

4.
In this study, total coliforms, thermotolerant coliforms, Escherichia coli and groundwater nitrate concentration were monitored at 127 groundwater sampling points (only 62 water points for bacteriological parameters) located in the southern part of Abidjan District. Each water sampling location was sampled in March and July 2007, representing respectively the long dry season and the long wet season. Geostatistical methods were used to analyze the spatial variability of nitrates and the groundwater nitrate pollution risk. The maximum seasonal content of total coliforms and thermotolerant coliforms ranged from 400 to 1000 CFU/100 mL and from 200 to 500 CFU/100 mL respectively. Moreover, 94% of these locations presented traces of bacteriological contamination. This contamination was mainly recorded during the rainy period. The degree of correlation between bacterial abundance and chemical parameters is variable. Nitrites, ammonium and potassium favoured coliform abundance. In the 127 water points, groundwater nitrate concentrations ranged from 4 to 198 mg L?1 and were log-normally distributed in the study area. The groundwater contamination risk map indicated that the strongly urbanized west side of the site presented a high probability of exceeding the WHO drinking water standard (50 mg L?1NO3?).  相似文献   

5.
对宿州市农村地下水重金属含量进行检测,并采用美国环保署(United States Environment Protection Agency,USEPA)推荐的评价模型开展了重金属健康风险评价。检测结果表明部分地下水已不宜被直接饮用,特别是近郊的农村地下水。健康风险评价结果表明,化学致癌物的所致健康风险值远高于化学非致癌物,后者经饮用水途径产生的健康风险均处于可忽略水平。化学致癌物Cr、Cd所致健康风险均值分别为1.24×10-6、1.34×10-5a-1,占总健康风险值的比例分别为89.52%和10.45%,说明宿州市农村地下水中Cr和Cd具有一定的致癌风险,应作为优先污染物予以重视。  相似文献   

6.
盐城滨海平原地下水质量现状及健康风险评价   总被引:3,自引:0,他引:3       下载免费PDF全文
为了查明盐城滨海平原区地下水质量状况,选择具有代表性的267个地下水井,检测了33项化学指标,利用单指标综合评价和影响因素识别相结合的方法研究了本区地下水的质量现状,并同时给出毒理学指标的饮水途径健康风险以供参考。结果表明:一般化学指标对本区地下水质量影响程度最高,原生指标中钠离子、铁、锰、氯化物、溶解性总固体、碘化物,砷化物对超Ⅲ类水单指标贡献率超过20%,污染指标中氨氮贡献率最大,为8%,重金属指标对区域地下水质量影响很小;化学致癌物As、Cd和Cr中,As的健康风险值最大,各含水层所致健康危害风险值数量级在10~(-5)~10~(-3)a~(-1),为研究区首要的环境健康风险管理控制指标;化学非致癌物亚硝酸盐、硝酸盐、氟化物中,氟化物的健康风险最大,其数量级在10~(-8)~10~(-6)a~(-1),深层地下水和浅层地下水样品中超过USEPA(1×10~(-4)a~(-1))最大可接受风险的比例分别为82%和88%;重金属指标汞、锰、铜、锌和铅的健康危害风险值均较小,绝大部分都低于10~(-6)a~(-1),其中锰和铅的健康风险值相对较高。开展地下水质量和毒理指标的健康风险评价,可为本区地下水资源的合理开采利用和保护提供参考。  相似文献   

7.
陈家冲垃圾填埋场地下水环境健康风险评价   总被引:1,自引:0,他引:1       下载免费PDF全文
垃圾填埋是目前国内处理城市生活垃圾的主要方式,由垃圾渗滤液引发地下水环境污染已成为当前主要的水环境问题之一。选择武汉市陈家冲垃圾填埋场为研究对象,通过对该区周边地下水布孔取样和监测,分析了垃圾填埋场对其周围地下水环境的影响。结果表明:研究区地下水的主要污染因子为Pb、Cd和Fe,且各污染物的浓度与采样深度、井距呈负相关关系。垃圾填埋场产生污染的影响范围主要在距离800m以内、深度小于5.5m的地下水。为进一步了解该区地下水对人体健康危害的风险程度,对研究区地下水进行了水环境健康风险评价,结果显示:研究区各采样井地下水的总风险值在2.71×10~(-4)/a~7.12×10~(-3)/a,均超过国际辐射防护委员会(ICRP)推荐的最大可接受值5.0×10~(-5)/a,主要风险因子为基因毒物质Cd和Cr(VI)以及躯体毒物质硝态氮;其中,Cd和硝态氮所致的健康风险值超标率100%,而Cr(VI)的健康风险值超标率为50%,对暴露人群存在健康危害风险。此外,对男性和女性健康风险值的研究显示,研究区地下水环境中污染物的男性健康危害风险值普遍高于女性。  相似文献   

8.
This paper describes the use of the dual isotope method involving δ(15)N and δ(18)O measurements of dissolved nitrates to assess the origin and fate of groundwater nitrate at the Klju? groundwater source, Serbia. A sampling campaign was conducted in September 2007 during flow conditions obtaining groundwater from observation wells and river water fed by a shallow aquifer hosted in alluvial (sandy-gravel) sediments. Nitrate isotope ratios ranged from +5.3 to +16.9‰ and δ(18)O(NO(3)) values varied from -2.3 to +5.0‰. Two major contamination sources were identified with isotopic compositions characteristic for nitrate derived from nitrification of soil organic nitrogen (+5.3 to +7.8‰ for δ(15)N) resulting in nitrate concentrations of 33.6 and 78.8 mg/L and nitrate derived from animal wastes or human sewage, e.g. via septic systems, yielding δ(15)N values of +9.9 to +11.9‰ and elevated nitrate concentrations of 31.2-245.8 mg/L. The occurrence of nitrification and denitrification was also revealed based on concentration and isotope data for dissolved nitrate.  相似文献   

9.
Delineation of groundwater potential zones (GWPZ) has been performed for a coastal groundwater basin of eastern India. The groundwater potential zone index (GWPZI) map is generated by using Analytic Hierarchy Process (AHP) from different influencing features, e.g., Land Use/Land Cover (LU/LC), soil (S), geomorphology (GM), hydrogeology (HG), surface geology (SG), recharge rate (RR), drainage density (DD), rainfall (RF), slope (Sl), surface water bodies (SW), lineament density (LD), and Normalized Difference Vegetative Index (NDVI). Recharge rate values are estimated from hydrological water balance model. Overlay weighted sum method is used to integrate all thematic feature maps to generate GWPZ map of the study area. Four zones have been identified for the coastal groundwater basin [very good: 36.39 % (273.53 km2, good: 43.57 % (327.47 km2), moderate: 18.27 % (137.30 km2), and poor: 1.77 % (13.27 km2)]. Areas in north to south-west and south-east direction show very good GWPZ due to the presence of low drainage density. GWPZ map and well yield values show good agreement. Sensitivity analysis reveals that exclusion/absence of rainfall and lineament density increases the poor groundwater potential zones. Omission of hydrogeology, soils, surface geology, and NDVI show maximum increase in good GWPZ. Obtained GWPZ map can be utilized effectively for planning of sustainable agriculture. This analysis demonstrates the potential applicability of the methodology for a general coastal groundwater basin.  相似文献   

10.
海河平原区是我国政治文化中心和工农业生产基地,也是高氟地下水的重灾区。调查研究该地区高氟地下水的分布规律、影响因素、健康风险对于区域社会经济发展和水生态文明建设具有重要意义。根据2014-2015年海河平原区269眼浅层地下水监测井的氟化物检测数据,研究区地下水中氟化物浓度最高为2.26mg/L。高氟水主要分布在研究区中部,原生地质条件和人类活动是影响高氟水形成的主要因素。采用非致癌物质健康风险评估模型对高氟水地区的健康风险进行了量化评估,该地区氟化物健康风险平均为0.45×10~(-8)。避免高氟水危害应实施水源优选、水质监测、合理开发地下水等多个方面的措施。  相似文献   

11.
松花江傍河水源地地下水污染健康风险评价   总被引:1,自引:0,他引:1  
高亚威  刘派  徐威 《人民长江》2018,49(16):19-23
为研究松花江流域某傍河水源地地下水污染对人体健康产生的危害风险,对该地区地下水水质进行了监测分析,并采用《污染场地风险评估技术导则》(HJ 25.3-2014)推荐的水环境健康风险评价模型,对当地地下水环境健康风险进行评价。结果表明:地下水中F~-、NH_4-N、Mn和As均不同程度地超过了国家饮用水卫生标准(GB 5749-2006)规定的限制;非致癌物质健康风险表现为AsMnF~-NH_4~+ZnCuNO_3~-NO_2~-Cr~(6+),致癌物质健康风险评价表现为AsCr~(6+)。该地区健康风险评价结果表明:研究区地下水污染物会对人体健康造成危害,其中成年女性和儿童相比于成年男性面临更高的健康风险。  相似文献   

12.
Many water resources optimization problems involve conflicting objectives which the main goal is to find a set of optimal solutions on, or near to, Pareto front. In this study a multi-objective water allocation model was developed for optimization of conjunctive use of surface water and groundwater resources to achieve sustainable supply of agricultural water. Here, the water resource allocation model is based on simulation-optimization (SO) modeling approach. Two surrogate models, namely an Artificial Neural Network model for groundwater level simulation and a Genetic Programming model for TDS concentration prediction were coupled with NSGA-II. The objective functions involved: 1) minimizing water shortage relative to the water demand, 2) minimizing the drawdown of groundwater level, and 3) minimizing the groundwater quality changes. According to the MSE and R2 criteria, the results showed that the surrogate models for prediction of groundwater level and TDS concentration performed favorably in comparison to the measured values at the number of observation wells. In Najaf Abad plain case study, the average drawdown was limited to 0.18 m and the average TDS concentration also decreased from 1257 mg/lit to 1229 mg/lit under optimal conditions.  相似文献   

13.
With its important geographical location and status as the largest saltwater body in China, Qinghai Lake plays a vital role in the ecological environment of the northeastern part of the Qinghai-Tibet Plateau. Due to climate change and the subsequent adjustment of Qinghai Lake’s tourism policy, it is necessary to understand groundwater discharges in southeast of Qinghai lake both for ecological protection and risk prevention. This study used radium isotopes 223Ra and 224Ra to trace groundwater discharges and nutrients carried into the lake. The spatial characteristics of Ra isotopes with greater activity in the upper and bottom layers in the lake indicated that they were influenced by inputs of shallow groundwater and diffusion from sediments. The average 224Ra diffusion flux of the sediments in the Lake was 33.54 dpm m?2 d?1. Based on the 224Ra mass balance model, the discharge flux of shallow groundwater in this region was estimated to be 3.49 × 106 ~ 3.68 × 106 m3 d?1. The PO43? and SiO2 fluxes carried into the southeastern of the lake by groundwater were 1.78 × 1011 ~ 1.88 × 1011 mg/y and 2.22 × 1012 ~ 2.34 × 1012 mg/y, respectively. It is thus essential to monitor shallow groundwater discharge into Qinghai Lake for the protection of the water environment and prevention of potential ecological risks.  相似文献   

14.
In this study, a statistical model was established to estimate the groundwater table using precipitation, evaporation, the river stage of the Liangduo River, and the tide level of the Yellow Sea, as well as to predict the groundwater table with easily measurable climate data in a coastal plain in eastern China. To achieve these objectives, groundwater table data from twelve wells in a farmland covering an area of 50 m × 150 m were measured over a 12-month period in 2013 in Dongtai City, Jiangsu Province. Trend analysis and correlation analysis were conducted to study the patterns of changes in the groundwater table. In addition, a linear regression model was established and regression analysis was conducted to understand the relationships between precipitation, evaporation, river stage, tide level, and groundwater table. The results are as follows:(1) The groundwater table was strongly affected by climate factors(e.g., precipitation and evaporation), and river stage was also a significant factor affecting the groundwater table in the study area( p 0.01, where p is the probability value).(2) The groundwater table was especially sensitive to precipitation. The significance of the factors of the groundwater table were ranked in the following descending order:precipitation, evaporation, and river stage.(3) A triple linear regression model of the groundwater table, precipitation, evaporation, and river stage was established. The linear relationship between the groundwater table and the main factors was satisfied by the actual values versus the simulated values of the groundwater table(R~2 = 0.841, where R~2 is the coefficient of determination).  相似文献   

15.
Inappropriate farming techniques and 4 years of drought (1992–1995) produced conditions for high nitrate concentration in an aquifer located in the Province of Seville (Southwest Spain). The objectives of this study were to study groundwater components and to determine the relationship between the cropping system and nitrate concentrations in groundwater. From October 1994 to May 1996, 16 groundwater samples were obtained from a network of 35 sample points. Groundwater concentrations were analysed by multivariate statistical techniques (factor and cluster analysis). Two factors were found: firstly, agricultural pollution and secondly, salinization (from natural mineralization of groundwater and from anthropogenic effects). High levels of NO3 were closely associated with intensive cotton (Gossypium herbaceum L.) and potato production (Solanum tuberosum L.). The salinization factor includes electrical conductivity, Cl, Na+, Ca2 +, Mg2 +, SO42 – and HCO3. Our study permits the impact of crops on groundwater to be determined. In comparison to the other crops, cotton (Gossypium herbaceum L.) and potato (Solanum tuberosum L.) made the greatest contribution to nitrate pollution and salinization. Use of the groundwater for human consumption in drought periods could represent a public health risk. Alternative farming techniques for these crops such as monitored fractional fertilization and controlled irrigation are recommended.  相似文献   

16.
Groundwater nutrient loading to L. Huron was assessed along a 1.7 km section of beach at Grand Bend, ON, Canada, where septic systems are used for wastewater disposal. The artificial sweetener acesulfame (ACE) was detected in all groundwater samples (7–842 ng/L, n = 78), revealing that the entire surficial aquifer was impacted by septic system wastewater. Nitrate concentrations (3.5 ± 1.4 mg/L, n = 78) were correlated with ACE (r2 = 0.54), indicating that septic systems contribute to nitrate loading in the aquifer. Chloride was also elevated (37 ± 11 mg/L, n = 78), but was not correlated with ACE (r2 = 0.008), indicating a non wastewater source was dominant, likely road salt. Soluble reactive phosphorus (SRP) values were low (5.3 ± 9.3 μg/L, n = 77) and were not correlated with ACE (r2 = 0.006). Sediment profiling below two of the septic system drain-fields, showed that the sand grains had distinct secondary coatings containing P, indicating that mineral precipitation reactions played a role in limiting P concentrations present in the aquifer. Groundwater nutrient loading to the lake was estimated at 13,000 kg N/year from NO3? and 1.9 kg P/year from SRP. These amounts are insignificant compared to nutrient loading from a stream that drains an agricultural catchment and discharges to the lake at the north end of the study site (Parkhill Creek). This calls into question, in some cases, the rationale of decommissioning properly functioning septic systems as a mitigation measure for reducing nutrient loading to nearby water courses.  相似文献   

17.
A survey of young adults was conducted at several 3rd level agricultural institutions across Ireland over a 6-month period. The results from the agri-student survey were compared and contrasted with those of an identical survey of private well owners. Students (n?=?246) scored significantly lower than well owners (n?=?245) in two developed metrics, namely “groundwater source awareness” and “groundwater contamination awareness” (p?n?=?476). Clusters comprised four predictors: presence of an elderly householder (predictor importance = 0.91), residence within the household during well design (predictor importance = 0.55), presence of an infant or young child (≤5 years) in the household (predictor importance = 0.48) previous instance of gastrointestinal illness or symptoms within the household (predictor importance = 0.31) The results of this research may be used to inform future risk management, communication and knowledge transfer policies, which are currently required to ensure the safeguarding of private groundwater supplies both in Ireland and further afield.  相似文献   

18.
In Taiwan’s humid climate, proximal fan groundwater (PFG) is mainly sourced from local precipitation (LP), mountain front recharge (MFR), and mountain block recharge (MBR). This study evaluates the relative importance of the above sources’ respective contributions to the PFG of the Langyang alluvial plain (LAP), northeastern Taiwan. To this end, we first identify stable isotopic characteristics of these target waters and evaluate the hydrological relations among them. Further, we employ ternary end member mixing analysis (EMMA) based on δ 18O and electrical conductivity to semi-quantitatively calculate contributing fractions and amounts of water for respective LP, MFR, and MBR end members. EMMA results indicate that the respective contribution fractions of LP, MFR, and MBR to PFG at the LAP are approximately 28, 60, and 12 %, respectively. Further, we employ the obtained contribution fractions to understand the corresponding water amounts of each end-member contributed to PFG. In total, 325 × 106 m3 of water recharges PFG annually; of which, 226 × 106 m3/yr. is from MFR, 76 × 106 m3/yr. from LP, and 23 × 106 m3/yr. from MBR. MFR is clearly the greatest source of water at the LAP and local water resource management and protection authorities should concentrate their energies on this important contributor to groundwater. To keep these results in context, limitations to the EMMA approach are evaluated in the text.  相似文献   

19.
Accelerated soil erosion is a threat for the societies due to the loss of ecosystems services. Soil erosion and sediment delivery have been assessed in a small catchment of Central Spain with a new water body, the Pareja Limno-reservoir, located in its outlet. This limno-reservoir was created in 2006 with environmental and recreational purposes in the riverine zone of a large reservoir. Sedimentation risk is an issue of concern regarding limno-reservoirs environmental feasibility. Thus, the study of the soil erosion in the Pareja Limno-reservoir catchment and its sediment delivery seemed of the utmost importance. In this paper we establish an affordable and simple methodology to address it. A soil erosion and deposition monitoring network was installed in the Ompólveda River basin (≈88 km2), which flows into the Pareja Limno-reservoir. Results obtained were related with those from a sedimentation study previously carried out in the limno-reservoir. Gross hillslope erosion in the catchment was 6.0 Mg ha?1 year?1, which is in agreement with values reported for Mediterranean areas. After subtraction of the deposition measured, a soil loss of 1.2 Mg ha?1 year?1 was found in the catchment. Sediment delivery ratio (SDR) was estimated to be 3.8 %. SDR is low as a result of the low connectivity between the stream network and the limno-reservoir. Some local characteristics may also have a secondary influence in the low SDR value. Results obtained support the environmental feasibility of the Pareja Limno-reservoir from the sedimentation risk perspective. They also demonstrate that the methodology followed allows the assessment of soil loss and sediment delivery at a catchment scale, and the identification of areas where the erosion problems are most severe.  相似文献   

20.
Although an extensive literature emphasizes the disadvantages of intermittent water supply, it remains prevalent in rural areas of developing countries. Understanding the effects of water supply time restrictions on domestic water use activities and patterns, especially for hygienic purposes, is important for the elaboration of the water supply. We studied the influence of intermittent and continuous water supply on water consumption and related activities in villages in the central region of the Wei River basin, China. Data were collected from a survey of 225 households in the sampled villages. Compared with a continuous water supply of 24 h d?1 (hours per day), adopting an intermittent water supply can reduce domestic water consumption. However, it presents risks in terms of hygiene behavior, particularly the frequency of face, hands, and feet washing, as well as water sharing among family members. Outdoor water consumption is more affected than indoor water consumption under slight supply restriction (≥6 and?<?24 h d?1), whereas indoor water use is most affected under moderate supply restriction (>1.5 and?<?6 h d?1). Villages with high supply restriction (≤1.5 h d?1) meet only the minimum basic requirements for domestic use, 33.6–34.7 L c?1 d?1 (liters per capita per day). We conclude that the determination of the daily water delivery duration for intermittent water supply in rural communities of developing countries should give greater consideration to differences in water use activities and patterns under the water supply time restrictions.  相似文献   

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