A benefit-cost model for the evaluation of on-site benefits of soil conservation projects in Mexico

Abstract

Soil and water conservation measures can comprise a wide range of activities, both structural and non-structural. Their potential benefits range from protection and productivity increases of the directly affected lands to widely dispersed downstream benefits. While in most situations it is rather difficult to evaluate the latter, it can be shown that in many cases the direct upstream benefits are sufficiently large to justify soil and water conservation programs regardless of potential additional downstream benefits. A benefit-cost model was developed that compares program costs per unit of directly protected agricultural land with the net benefits resulting from two on-site consequences, land productivity enhancement from improved water conservation and elimination of productivity losses from gradual soil destruction. This model was applied to ongoing governmental programs in two Mexican states. The results show that benefits from the prevention of soil destruction are substantially larger than those from immediate productivity increases, although the latter were considered by Mexican authorities to represent the major program benefits.