Liquid swine manure has been recognized as potential fertilizer for agriculture, but excessive and/or prolonged applications of high doses in agricultural systems may cause soil and water pollution. The present paper presents the proposition of a multicriteria model that aims to identify and classify agricultural areas that receive liquid swine manure as soil fertilizers, according to the degree of potential risk of contamination of surface waters. The proposal was based on the knowledge of experts, use of Geographic Information Systems (GIS) and the modelling of a decision support system. The determination of environmental risk criteria was performed based on a literature review and its weighting was defined through consultation with specialists from various institutions, research, extension, educational and environmental of the State of Santa Catarina, Brazil. The model, called SMRISK (Swine Manure Risk), was applied within a watershed with intensive pig farming located in Southern Brazil and proved to be more restrictive compared to the legal regulations used for the environmental licensing of pig farming in the State of Santa Catarina.

Keywords: animal waste, geographic information systems, pig farming