The assessment of nitrogen losses from agricultural systems and the degree of related groundwater pollution is fundamental to the standards established by the European Community Framework Directive for water protection (WFD). Intrinsic groundwater vulnerability indices, which can describe nitrogen pollution originating from non-point agricultural sources, are a basic tool for the evaluation of agricultural production as based on environmental policies. Many methods exist to describe intrinsic groundwater vulnerability. In this study, the LOS, SINTACS and GOD indices were used to assess the agricultural lands, located in the Sarigkiol basin, Greece. The first method is based on a deterministic approach and regression analysis; while the other two approaches are parametric methods based on empirical ratings and weights. This study presents the strengths and weaknesses of these different groundwater vulnerability indices and the related opportunities and challenges associated with their wide scale application within Greece. The study found significant differences between the results of the three indices and that this could be attributed to the different approaches and parameters used in the calculations. In contrast with SINTACS and GOD, LOS describes the intrinsic vulnerability of the unsaturated zone to release nitrogen to the groundwater but does not take into account groundwater properties (saturated zone). The SINTACS and GOD methods cannot be applied to highland regions, where an aquifer does not exist; and do not take climatologic conditions into account, which tends to change the nitrogen cycle. In comparison, the LOS index can be adapted to different climatic environments. In the SINTACS and GOD methods, uncertainty is increased in the calibration of weights and ratings because it is based on subjective criteria. In comparison, LOS does not need calibration as it uses more detailed data. The LOS index showed preferred performance because it better described the differences between the lower and higher altitude areas, which have different climatic conditions, and it was applied even on the parts of the study area which were far from the main aquifer.
Application of intrinsic groundwater vulnerability indices for the agricultural land of Sarigkiol basin – Greece in GIS environment
ASCHONITIS, Vasileios;COLOMBANI, Nicolo';SALEMI, Enzo;MASTROCICCO, Micol
2012
Abstract
The assessment of nitrogen losses from agricultural systems and the degree of related groundwater pollution is fundamental to the standards established by the European Community Framework Directive for water protection (WFD). Intrinsic groundwater vulnerability indices, which can describe nitrogen pollution originating from non-point agricultural sources, are a basic tool for the evaluation of agricultural production as based on environmental policies. Many methods exist to describe intrinsic groundwater vulnerability. In this study, the LOS, SINTACS and GOD indices were used to assess the agricultural lands, located in the Sarigkiol basin, Greece. The first method is based on a deterministic approach and regression analysis; while the other two approaches are parametric methods based on empirical ratings and weights. This study presents the strengths and weaknesses of these different groundwater vulnerability indices and the related opportunities and challenges associated with their wide scale application within Greece. The study found significant differences between the results of the three indices and that this could be attributed to the different approaches and parameters used in the calculations. In contrast with SINTACS and GOD, LOS describes the intrinsic vulnerability of the unsaturated zone to release nitrogen to the groundwater but does not take into account groundwater properties (saturated zone). The SINTACS and GOD methods cannot be applied to highland regions, where an aquifer does not exist; and do not take climatologic conditions into account, which tends to change the nitrogen cycle. In comparison, the LOS index can be adapted to different climatic environments. In the SINTACS and GOD methods, uncertainty is increased in the calibration of weights and ratings because it is based on subjective criteria. In comparison, LOS does not need calibration as it uses more detailed data. The LOS index showed preferred performance because it better described the differences between the lower and higher altitude areas, which have different climatic conditions, and it was applied even on the parts of the study area which were far from the main aquifer.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.