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.
Mapy podatności naturalnej wód podziemnych na zanieczyszczenia stanowią wizualizację oceny podatności wód podziemnych na zanieczyszczenia. Są one jednym z najważniejszych elementów uwzględnianych przy podejmowaniu decyzji odnośnie zagospodarowania terenu i obiektów potencjalnie uciążliwych dla środowiska. Badania podatności wód podziemnych na zanieczyszczenia zostały przeprowadzone na obszarze Kampinoskiego Parku Narodowego (skala regionalna) oraz na wytypowanym poligonie w pobliżu Wiktorowa w Kampinoskim Parku Narodowym (około 30 km2) w skali lokalnej. Ocenę podatności naturalnej przeprowadzono przy zastosowaniu zmodyfikowanej metody DRASTIC oraz na podstawie szacunku czasu przesączania się zanieczyszczeń konserwatywnych. Uzyskane rezultaty wskazują, że rezultat oceny zależy od wykorzystanej metody, stopnia rozpoznania warunków hydrogeologicznych, zastosowanych uproszczeń oraz wyznaczonego celu badań.
EN
Maps of natural groundwater vulnerability to contamination illustrate the assessment of natural groundwater vulnerability. They are also one of the important components that are taken into consideration while making a decision as regards the site management and objects potentially troublesome for the environment. The researches of natural vulnerability were conducted for the area of the Kampinoski National Park (on a regional scale) and for the area (about 30 km2) near Wiktorów (part of the Kampinos National Park) on a local scale. The assessment of vulnerability has been performed with the use of the modified DRASTIC method and calculations of the time migration method of a contaminant through the unsaturated zone. The results of the study indicate that the evaluation of natural groundwater vulnerability to contamination depends on the following factors: research methodology, degree of area recognition, applied simplifications and the purpose of research.
The marsh zone areas include about 2,440 km2 in Kampinos National Park, which amount nearly 30% of park and its buffer’s surface. The specific characteristic of the KNP marsh zones is presence of shallow groundwater; mean depth to groundwater table is formed from 0.16 do 2.30 m. Range and tendencies of groundwater level changes in marsh zones are related to the influence of geogenic and anthropogenic factors. Among geogenic factors, the most important sense have distribution and seasonality of precipitation, which determine the value of infiltration recharge, evapotranspiration and watercourse drainage of shallow groundwater system. The basis of the researches on defining the role of factors determining range and tendencies of groundwater level changes in KNP, has been regular monitoring observations conducted in the park since 1999. The results of correlation indicate on high diversification of relation: atmospheric precipitation – depth to groundwater level. Determination of trend on the different significance levels provides detaching areas where relation between groundwater levels and precipitation is so high that influence of other environmental factors indicating on depth to groundwater table could be skipped and areas where the relation is so low, which indicates on influence of various factors. Groundwater level in marsh areas are characterized by large dynamic of changes. Since 1999, the beginning of the observations, downward trend of groundwater table has been observed, after 2003 the character of trend has been conversed. Another decreasing trend has started in 2007 and with assumption of previous tendencies, its inversion will occur after 2011 (after extremely dry year). Geostatistical analysis of spatial difference of mean year amplitude of depth to groundwater level enabled the assessment of surface water influence on groundwater level changes. The areas of highest value of amplitudes are localized in southern part of northern marsh belt and central part of southern marsh belt. Anthropogenic factors such as: water withdrawal and improper draining system, have not changed in recent years, so their influence can be called as “steady” and acceptably to eliminate in case of elaborating of programs of wetland areas renaturalisation.