A multicriteria approach for mapping risks of agricultural pollution for water resources: The Venice Lagoon Watershed case study

A multicriteria analysis system was developed for producing risk maps of ag ricultural pollution due to alternative cultivation systems in the Watershe d of the Lagoon of Venice (WLV) in Italy. Results of a field-scale simulati on model for agricultural diffuse pollution were used to compile a matrix o f environmental impacts, in terms of pollution indices. The most widespread combinations of typical environments (as defined by combinations of soil a nd climate variables) and alternative land uses (types of crops and cultiva tion systems) were described in the impact matrix. Land use in terms of cro p distribution was based on census data. Two alternative cultivation system s were defined on the basis of the recent changes to the European Common Ag ricultural Policy: ordinary and eco-compatible. The effects of alternative scenarios were evaluated in terms of pollution risks for water resources. T he evaluation procedure was built into the framework of a geographical info rmation system to take into account the spatial features of pollution pheno mena, vulnerability of the land and risk for water resources. The results d emonstrated the great potential of eco-compatible practices for reducing th e risks for surface and groundwater (-15 and -50%, respectively). (C) 1999 Academic Press.