The effects of alternative agricultural land use scenarios in terms of environmental impact assessment on surface and ground water were simulated by means of combined socio-economic and environmental models. The economic model produced and evaluated alternative farming systems, defined in terms of land use (in farm crop allocations and regional statistics of crop distributions) and cultivation practices as influenced by different macro-economic scenarios of agricultural policies. These scenarios were defined on the basis of the present Common Agricultural Policy of the European Union and possible future measures for reducing the impact of current agricultural systems on the environment. The farmers' decisional process has been simulated with multi-objective functions aimed at maximising profits and minimising risk. The methodology for the environmental impact assessment of farming systems is based on a simulation model for non-point source agricultural pollution which determines the impact of agriculture on a single field basis as influenced by environmental variables (soil and climate) and farmers' decisions (crop, soil management, fertilisation, etc.). The results obtained from this model were used to calculate a series of comparative indices capable of describing the effects of the use of fertilisers and pesticides on surface and ground waters. A geographical information system supported the spatial data management in particular for: a) the definition of simulation environments; b) the integration of physical and statistical geographical information; c) the cartographic presentation of results and the comparison of alternative scenarios. The model has been applied in the area of the Watershed of the Lagoon of Venice (WLV), located in northern Italy and has demonstrated how alternative policy scenarios determine not only significant variations in the overall environmental impacts in the study area, but also remarkable differences in their spatial distribution.
Environmental Impact Assessment of Land Use Planning Based on Ecosystem Services Valuation in Xingguo County