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1.
地下水是水资源的重要组成部份,地下水污染危害人的健康,影响人们的生产和生活,查明某一地区地下水容易受污染的可能性即地下水脆弱性,能为管理决策部门提供合理开发地下水资源,防治地下水污染的科学规划和管理依据。在脆弱性评价工作中,应用GIS技术完成地下水系统脆弱性编图,并进行地下水环境保护功能分区,是查明某一示范区地下水脆弱性的可靠手段和科学依据。本文以河北省沧州地区为例,以DRASTIC模型的七项评价因子为脆弱性评价指标,利用MAPGIS为平台实现地下水脆弱性编图,方便从事地下水工作的管理人员及时掌握地下水污染动态、空间分布及演化趋势。  相似文献   

2.
地下水脆弱性评价是地下水保护工作的核心内容之一,针对泰安市的特点和区域特色,利用DRASTIC方法,选取地下水位埋深、净补给量、含水层介质类型、土壤介质类型、地形坡度、包气带介质类型以及含水层渗透系数7个参数为评价指标,对该地区的地下水脆弱性进行了定量评价,将泰安市地下水的脆弱性分为脆弱性高、较高、中等和低4个等级,并绘制了地下水脆弱性分区图,对该地区今后制订地下水资源管理、土地利用、环境保护及城市规划等政策措施具有较重要的参考指导作用。  相似文献   

3.
Groundwater drought is a specific type of hydrological drought that concerns groundwater bodies. It may have a significant adverse effect on the socio-economic, agricultural, and environmental conditions. Investigating the effect of different climatic and anthropogenic factors on groundwater drought provides essential information for sustainable planning and management of (ground) water resources. The aim of this study is to identify the influencing factors on groundwater drought in north-western Bangladesh, to understand the forcing mechanisms. A multi-step methodology is proposed to achieve this objective. The standardised precipitation index (SPI) and reconnaissance drought index (RDI) have been used to quantify the aggregated deficit between precipitation and the evaporative demand of the atmosphere, i.e. meteorological drought. The influence of land-cover patterns on the groundwater drought has been identified by calculating spatially distributed groundwater recharge as a function of land cover. Groundwater drought is defined by a threshold method. The results show that the evapotranspiration and rainfall deficits are determining meteorological drought, which shows a direct relation with groundwater recharge deficits. Land-cover change has a small effect on groundwater recharge but does not seem to be the main cause of groundwater-level decline (depletion) in the study area. The groundwater depth and groundwater-level deficit (drought) is continuously increasing with little correlation to meteorological drought or recharge anomalies. Overexploitation of groundwater for irrigation seems to be the main cause of groundwater-level decline in the study area. Efficient irrigation management is essential to reduce the growing pressure on groundwater resources and ensure sustainable water management.  相似文献   

4.
Assessment of groundwater vulnerability to pollution is an effective tool for the delineation of groundwater protection zones. DRASTIC approach was used to determine vulnerability zones in Dire Dawa groundwater basin, a semiarid region of Ethiopia. Maps of the seven DRASTIC parameters were prepared. GIS-ArcView was used for mapping and performing weighted-overlay analysis. The result of the analysis indicated that eastern part of the study area, in which Dire Dawa town is located, is highly vulnerable. A low aquifer vulnerability class was determined for the western portion of the study area as a result of greater groundwater depths, higher relative soil-clay content, and relatively low recharge rates for this area. The area between the two zones is of medium vulnerability. Observed nitrate concentrations in boreholes are in accordance with the vulnerability map. Some of the boreholes in the Sabian well field (Dire Dawa area) already deliver groundwater with nitrate levels significantly exceeding health standards set by the World Health Organization, while boreholes in the western part (low vulnerability zone) contain almost no nitrate. The result of this study is useful for risk assessments and for the development of effective groundwater management strategies for this region and others like it.  相似文献   

5.
The aim of this study is to elaborate a synthetic document for the assessment of groundwater vulnerability to pollution in the Hajeb-Jelma aquifer. The specific object is to incorporate the Geographical Information System (GIS) to generate groundwater vulnerability and risk maps with DRASTIC model. Indeed, GIS could help to make the results of a complicated model more clear through visual representation, providing an applicable tool for decision makers. The vulnerability map of Hajeb-Jelma watershed shows three classes: moderate, high and very high depending on the intrinsic properties. The risk map shows a very high risk dependant on hydrogeological characteristics, land use and human impacts in major part of the Hajeb-Jelma region. These maps could serve as a scientific basis for sustainable land use planning and groundwater management in the Hajeb-Jelma region.  相似文献   

6.
Groundwater vulnerability and risk mapping is a relatively new scientific approach for facilitating planning and decision making processes in order to protect this valuable resource. Pan European methodology for aquifers vulnerability has recently been developed by assessing all the existing relevant techniques and emphasizing on karstic environments. In the particular study, state-of-the-art methods and tools have been implemented such as remote sensing, isotopic investigations and GIS to map the groundwater vulnerability and pollution risk in a geologically complex area of W. Greece. The updated land use map has been developed from a Landsat 7+TM image elaborated with image analysis software, while the detailed hydrogeologic properties of the area have been recorded with an intensive isotopic study. The local groundwater vulnerability map has been produced following the aforementioned Pan European method, in a GIS environment while the risk map, which was the final product of the study, has been developed after combining the vulnerability and the land use maps. The results indicated that the areas comprised of highly tectonized calcareous formations represented high vulnerability and risk zones while forested areas away from the karstic aquifer illustrated moderate to low vulnerability. Moreover, human activities increase the pollution risk in lowland areas consisting of sedimentary deposits that have been classified as moderate vulnerability. The particular methodology operated efficiently in this study and due to its accuracy and relatively easy implementation can be used as a decision support tool for local authorities.  相似文献   

7.
基于GIS的农业面源硝酸盐地下水污染动态风险评价   总被引:1,自引:0,他引:1  
地下水中的硝酸盐污染具有全球性,这不仅是一个环境问题,也是一个经济和人类健康问题。DRASTIC方法可以进行地下水污染的脆弱性评价,但是却没有涵盖风险的概念,也忽视了污染物随地表水流运动的动态特性。因此,所得结果可能有碍于“欧洲水管理框架指南”在地下水水质管理中的执行。笔者基于DRASTIC方法开发了一个动态风险评价方法,并将其运用于英国北爱尔兰Upper Bann流域中的一个小流域。研究区地下水硝酸盐污染风险评价结果表明,此方法将有效地帮助决策者在流域范围内开展农业面源地下水污染预防措施。“非常高风险”和“高风险”区分别占研究区面积的5.1%和10.5%。此结果可帮助当地政府针对流域内这些“非常高风险”和“高风险”区的特点制订地下水质保护政策。此方法同样适用于任何面源可溶性污染物的地下水污染动态风险评价。  相似文献   

8.
Groundwater, the most vital water resource being used for irrigation, domestic and industrial purposes is nowadays under severe threat of contamination. Groundwater contamination risk assessment is an effective tool for groundwater management. In the study, a DRASTIC model which is based on the seven hydrogeological parameters viz: depth of water, net-recharge, aquifer media, soil media, topography, impact of vadose zone and hydraulic conductivity was used to evaluate the groundwater pollution potentiality of upper Betwa watershed. ArcGIS was used to create the ground water vulnerability map by overlaying the seven layers. Based on groundwater vulnerability map, the watershed has been divided in three vulnerable zones viz; low vulnerability zone with 42.83 km2 of area, moderate with 369.21 km2 area and high having 270.96 km2 of area. Furthermore, the DRASTIC model has been validated by nitrate concentration over the area. Results of validation have shown that in low vulnerable zone, no nitrate contamination has been recorded. While in the moderate zone nitrate has been found in the range of 1.6-10ppm. However, in high vulnerable zone 11-40ppm of nitrate concentration in groundwater has been recorded, which proves that the DRASTIC model is applicable for the prediction of groundwater vulnerability in the watershed and in similar areas too.  相似文献   

9.
Groundwater resources have become more vulnerable to contamination due to rapid population growth and economic development. This study aimed to assess the groundwater contamination risk in the Weining Plain, China. Based on the specific conditions of the Weining Plain, a new model DRTSWI with a weighting scheme determined by analytic hierarchy process was developed to evaluate the intrinsic groundwater vulnerability for the study area. An integrated approach, combining the toxicity, the release possibility, and the potential release quantity of the pollutants, was used to estimate the pollution loading. The groundwater contamination risk results were obtained by overlaying the intrinsic vulnerability and pollution loading maps. These indicated that two industrial parks pose the main threat to groundwater quality, due to their unfavorable hydrogeological setting and potential pollution sources on the surface. Some areas in and around the industrial parks exhibit groundwater pollution, which was identified on the contamination risk map using buffer analysis. High risk areas are industries with high or medium vulnerability. The vulnerability and contamination risk maps developed for this study are valuable tools for environmental planning and can be used for predictive management of groundwater resources.  相似文献   

10.
Groundwater vulnerability is a cornerstone in evaluating the risk of groundwater contamination and developing management options to preserve the quality of groundwater. Based on the professional model (DRASTIC model) and geographical information system (GIS) techniques, this paper carries out the shallow groundwater vulnerability assessment in the Zhangye Basin. The DRASTIC model uses seven environmental parameters (depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone, and hydraulic conductivity) to characterize the hydrogeological setting and evaluate aquifer vulnerability. According to the results of the shallow groundwater vulnerability assessment, the Zhangye Basin can be divided into three zones: low groundwater vulnerability risk zone (risk index <120); middle groundwater vulnerability risk zone (risk indexes 120–140) and high risk zone (risk index >140). Under the natural conditions, the middle and high groundwater vulnerability risk zones of the Zhangye Basin are mainly located in the groundwater recharge zones and the important cities. The high, middle and low groundwater vulnerability risk zones of the Zhangye Basin cover around 17, 21 and 62% of study area, respectively.  相似文献   

11.
Increasing pressure on water resources worldwide has resulted in groundwater contamination, and thus the deterioration of the groundwater resources and a threat to the public health. Risk mapping of groundwater contamination is an important tool for groundwater protection, land use management, and public health. This study presents a new approach for groundwater contamination risk mapping, based on hydrogeological setting, land use, contamination load, and groundwater modelling. The risk map is a product of probability of contamination and impact. This approach was applied on the Gaza Strip area in Palestine as a case study. A spatial analyst tool within Geographical Information System (GIS) was used to interpolate and manipulate data to develop GIS maps of vulnerability, land use, and contamination impact. A groundwater flow model for the area of study was also used to track the flow and to delineate the capture zones of public wells. The results show that areas of highest contamination risk occur in the southern cities of Khan Yunis and Rafah. The majority of public wells are located in an intermediate risk zone and four wells are in a high risk zone.  相似文献   

12.
地下水水质监测与评价   总被引:16,自引:5,他引:11  
地下水由于分布广、水质好且开发费用低而成为全世界重要的供水水源。中国北方生活供水的一半来自地下水,地下水也是干旱期重要的农业灌溉水源。然而,地下水水质日益面临来自农业、工业和城市污染源的威胁。地下水水质监测是评价水质状况最可靠的方法,并可作为供水水源保护的早期预警系统。它为水管理部门和水用户提供可靠的科学数据以便更好地管理和保护地下水资源。世界上正在执行两个巨大的地下水质监测和评价项目:一个是欧盟的水框架计划;另一个是美国的国家水质评价计划。文章评述了地下水水质监测的现状,介绍了地下水易污性评价、地下水污染源分级和地下水污染风险评价的方法。地下水易污性分区图是土地利用规划和供水水源保护的基础。地下水污染源分级结果为污染源治理提供了优先顺序。地下水污染风险分区图圈划出地下水污染的高风险区,为地下水资源保护和地下水污染监测提供重要的依据。  相似文献   

13.
A shallow unconfined low-lying coastal aquifer in southern Finland surrounded by the Baltic Sea is vulnerable to changes in groundwater recharge, sea-level rise and human activities. Assessment of the intrinsic vulnerability of groundwater under climate scenarios was performed for the aquifer area by utilising the results of a published study on the impacts of climate change on groundwater recharge and sea-level rise on groundwater–seawater interaction. Three intrinsic vulnerability mapping methods, the aquifer vulnerability index (AVI), a modified SINTACS and GALDIT, were applied and compared. According to the results, the degree of groundwater vulnerability is greatly impacted by seasonal variations in groundwater recharge during the year, and also varies depending on the climate-change variability in the long term. The groundwater is potentially highly vulnerable to contamination from sources on the ground surface during high groundwater recharge rates after snowmelt, while a high vulnerability to seawater intrusion could exist when there is a low groundwater recharge rate in dry season. The AVI results suggest that a change in the sea level will have an insignificant impact on groundwater vulnerability compared with the results from the modified SINTACS and GALDIT. The modified SINTACS method could be used as a guideline for the groundwater vulnerability assessment of glacial and deglacial deposits in inland aquifers, and in combination with GALDIT, it could provide a useful tool for assessing groundwater vulnerability to both contamination from sources on the ground surface and to seawater intrusion for shallow unconfined low-lying coastal aquifers under future climate-change conditions.  相似文献   

14.
基于熵权与GIS耦合的DRASTIC地下水脆弱性模糊优选评价   总被引:3,自引:1,他引:2  
张保祥  万力  余成  孟凡海 《现代地质》2009,23(1):150-156
地下水脆弱性评价与编图是保护地下水环境工作的基础,DRASTIC模型是目前国际上最普遍应用的地下水脆弱性评价方法。在利用GIS进行地下水脆弱性评价的基础上,引进基于熵权的模糊优选评价方法,构建了基于熵权与GIS耦合的DRASTIC地下水脆弱性模糊优选评价模型。将该模型应用于黄水河流域,计算出了各评价参数的熵权和各叠加分区基于熵权的隶属度,据此将地下水脆弱性划分为高、中、低3个等级。结果表明,评价过程中避免了人为因素的干扰,更能真实地反映客观情况,为地下水脆弱性的评价提供新的思路和方法。  相似文献   

15.
When used in a comprehensive risk assessment framework, aquifer vulnerability maps are a tool to identify the relative susceptibility of the groundwater from sources of contamination at the land surface. The DRASTIC method was designed for use over large areas with a wide variety of geological and hydrogeologic settings as a screening tool in groundwater protection and management. In this study, a series of vulnerability maps were made for the Greater Oliver area, in south central Okanagan, British Columbia, Canada, to test the sensitivity of the methodology to changes in input data type, interpretation, and mapping approaches. The study also illustrates how DRASTIC can be modified for use in areas of limited geological variability, where it may be important for smaller-scale changes in vulnerability to be recognized. Maps were produced using the original DRASTIC rating tables, a set of expanded tables using the original properties but modified ranges to accommodate the variability of data in the valley bottom region, and alternate tables, with modified properties and ranges. Differences in vulnerability rating for the maps using selected combinations and data interpretations are compared to the map using original DRASTIC rating tables using visual and statistical methods. One map was generated using expert hydrological knowledge. The modified tables allowed a greater amount of variability to be expressed in the valley bottom area compared to using the original tables and methods, and could provide a reasonable approach for assessing local scale variability for source water protection planning.  相似文献   

16.
一种新的水文地质图件:地下水易污染性图简介   总被引:2,自引:0,他引:2  
蒋益平 《世界地质》1996,15(3):71-73
地下水易污染性图是一种新编制的水文地质图件,简要介绍了地下水易污染性图的编制目的与意义,发展史,内容与编制方法和评价方法。  相似文献   

17.
This study outlines an improved method, MLPI (modified leaching potential index) model, for delineating and mapping groundwater vulnerability and assessing groundwater vulnerability to contaminants, including degradable contaminants, radioactive elements and nondegradable pollutants. The primary objective is to produce specific sensitivity maps at city or county scale that can be used for recognition of aquifer sensitivity and for protection of groundwater quality. Groundwater vulnerability assessment using the MLPI method is applied to Datong city, Shanxi Province, with the following conclusions: (1) specific vulnerability was differentiated and ; (2) groundwater vulnerability is of temporal variation.  相似文献   

18.
地下水的防污性能评价是地下水环保工作的基础,其结果能为地下水环境保护、饮水安全保障体系建设等提供科学依据。针对传统DRASTIC评价模型存在的不足,结合江苏省浅层孔隙含水层的水文地质条件。提出基于层次分析法(AHP)的DRAVT防污性能评价模型,利用GIS空间分析功能进行地下水防污性能评价.该模型的评价结果客观科学,能有效的为规划部门及地下水资源管理部门服务。  相似文献   

19.
Kim  Ji Eun  Yu  Jisoo  Ryu  Jae-Hee  Lee  Joo-Heon  Kim  Tae-Woong 《Natural Hazards》2021,109(1):707-724

Due to the complex characteristics of drought, drought risk needs to be quantified by combining drought vulnerability and drought hazard. Recently, the major focus in drought vulnerability has been on how to calculate the weights of indicators to comprehensively quantify drought risk. In this study, principal component analysis (PCA), a Gaussian mixture model (GMM), and the equal-weighting method (EWM) were applied to objectively determine the weights for drought vulnerability assessment in Chungcheong Province, located in the west-central part of South Korea. The PCA provided larger weights for agricultural and industrial factors, whereas the GMM computed larger weights for agricultural factors than did the EWM. The drought risk was assessed by combining the drought vulnerability index (DVI) and the drought hazard index (DHI). Based on the DVI, the most vulnerable region was CCN9 in the northwestern part of the province, whereas the most drought-prone region based on the DHI was CCN12 in the southwest. Considering both DVI and DHI, the regions with the highest risk were CCN12 and CCN10 in the southern part of the province. Using the proposed PCA and GMM, we validated drought vulnerability using objective weighting methods and assessed comprehensive drought risk considering both meteorological hazard and socioeconomic vulnerability.

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20.
Groundwater vulnerability assessments calculate the sensitivity of quality of groundwater to an imposed contaminant load which is essential element of the aquifer management plans. Seventy five groundwater samples have been analyzed for different chemical parameters to understand the groundwater quality of the lower Varuna river basin, Uttar Pradesh, India. The intrinsic groundwater vulnerability map of the lower Varuna catchment area in the north of the city of Varanasi (India) shows a high dependency on the depth to groundwater. The topmost layer of alluvial silty clay, protects the groundwater against contamination in this urban area, but the retention time in the unsaturated zone can be estimated to several months only. The input dataset is very sparse i.e. groundwater levels were measured twice (pre- and post-monsoon 2009) and the geological map shows only alluvium as the outcrop. Several boreholes in this area show, that the alluvium has a thickness of about 4 m and below that are fine grained sands. The surface information does not allow the development of a risk map since land use changes very fast and contamination areas can not be identified accurately. The vulnerability maps developed in this study have become important tools for environmental planning and predictive management of the groundwater resources in the fast urbanizing region in the Varanasi area.  相似文献   

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