Integrating economic, environmental and GIS modeling to target cost effective land retirement in multiple watersheds

An integrated framework of economic, environmental and GIS modeling is developed to study cost-effective retirement of cropland within and across multiple watersheds to achieve environmental goals. This framework is applied to 12 contiguous agricultural watersheds in the Illinois Conservation Reserve Enhancement Program region of the United States. A key goal of this program is to reduce sediment loadings in the Illinois River by 20% by retiring land from crop production. The characteristics of land parcels to be targeted for retirement within each watershed and the criteria for cost-effective allocation of abatement responsibility across watersheds are analyzed. Our analysis suggests that program costs are minimized when the abatement standard is set for the region rather than uniformly for each watershed. For both policy scenarios, the land parcels targeted for retirement should be those that are highly sloping and adjacent to a water body.