Assessment of groundwater vulnerability to pollution: a combination of GIS, fuzzy logic and decision making techniques

摘要: The assessment of groundwater vulnerability to pollution aims at highlighting areas a high risk being polluted. This study presents methodology, estimate the an aquifer be polluted from concentrated and/or dispersed sources, which applies overlay and index method involving several parameters. parameters are categorized into three factor groups: group 1 includes relevant internal system’s properties, thus determining intrinsic pollution; 2 comprises external stresses system, such as human activities rainfall effects; 3 incorporates specific geological settings, presence geothermal fields or salt intrusion zones, computation process. Geographical information systems have been used for data acquisition processing, coupled with multicriteria evaluation technique enhanced fuzzy standardization. Moreover, besides assigning weights factors, second set weights, i.e., order has applied factors on pixel by basis, allowing control level in determination enhancement local site characteristics. Individual analysis each resulted intermediate maps, were combined produce final composite map area. region Eastern Macedonia Thrace (Northern Greece), area approximately 14,000 km2. methodology tested calibrated against measured nitrate concentration wells, northwest part area, providing results related aggregation weighting procedure.