Assessment of alternative land management practices using hydrological simulation and a decision support tool: Arborea agricultural region, Sardinia

摘要

Quantifying the impact of land use on water supply and quality is a primaryfocus of environmental management. In this work we apply a semidistributedhydrological model (SWAT) to predict the impact of different land managementpractices on water and agricultural chemical yield over a long period oftime for a study site situated in the Arborea region of central Sardinia,Italy. The physical processes associated with water movement, crop growth,and nutrient cycling are directly modeled by SWAT. The model simulations areused to identify indicators that reflect critical processes related to theintegrity and sustainability of the ecosystem. Specifically we focus onstream quality and quantity indicators associated with anthropogenic andnatural sources of pollution. A multicriteria decision support system isthen used to develop the analysis matrix where water quality and quantityindicators for the rivers, lagoons, and soil are combined withsocio-economic variables. The DSS is used to assess four options involvingalternative watersheds designated for intensive agriculture and dairyfarming and the use or not of treated wastewater for irrigation. Ouranalysis suggests that of the four options, the most widely acceptableconsists in the transfer of intensive agricultural practices to the largerwatershed, which is less vulnerable, in tandem with wastewater reuse, whichrates highly due to water scarcity in this region of the Mediterranean. Moregenerally, the work demonstrates how both qualitative and quantitativemethods and information can assist decision making in complex settings.