Niepewność oceny podatności wód podziemnych na zanieczyszczenia dla obszarów miejskich na przykładzie warszawskiej dzielnicy Bielany

. Groundwater vulnerability assessment is an important environment management tool. In this study assessment of groundwater vulnerability to pollution was conducted by DRASTIC method in urban area, represented by the Bielany – district of Warsaw. The results of this study showed that 70% of the study area has medium or moderately high pollution potential and nearly 30% area has low and very low pollution potential. Two sensitivity tests were performed: the map removal sensitivity analysis and the single-parameter sensitivity analysis. Sensitivity analysis is defined as the evaluation of the effect of changes of input values on the output of the model, therefore, in order to reduce subjectivity of groundwater vulnerability assessment sensitivity analysis was performed for DRASTIC procedure. Both tests highlighted the role of the parameter „depth to water” in groundwater vulnerability assessment.