Agricultural land use and trophic state of the Lake Vico (Central Italy)

The Lake Vice Basin (Central Italy) has already been a subject for previous studies, mostly aimed to define planning criteria, based on territorial pr ocesses. Results underlined the environmental peculiarities of the place, f irst of all the lake itself, whose trophic state is growing up, due mostly to heavy soil erosion and related non-point sources of nutrients (phosphoru s above all) from agricultural land. It is then a typical case study which highlights how agricultural sustainab ility could be fundamental for environmental safety and, vice versa, how en vironmental processes (trophic evolution of a lake and related nutrients di ffuse sources, in the specific case) could be the focus in the sustainabili ty definition. Being environmental concerns for the Lake Vice rather recent (phosphorus co ncentration is heavily increased in the last fifteen years) the evolution o f land use of last fifty years has been evaluated by the interpretation of aerial photos of 1954, 1971, and 1994. Furthermore, being P mobilisation du e to soil erosion, the respective erosion maps have been built up, applying the USLE model at basin scale. This application has been compared with a n ew approach, based on the integration of GLEAMS (Groundwater Loading Effect s of Agricultural Management Systems) results with a GIS (Geographic Inform ation System). Results highlight that the new map, based on GLEAMS, is very similar to USL E map, but it allows a very simple construction of the risk map and, conseq uently, to immediately plan best management practices (BMP) effectively to control nutrients mobilisation.