Economic evaluation of soil conservation practices, case study: Mian ‎Bisheh Sub-basin in ‎Taleghan Watershed

Soil erosion is one of the critical issues in Iranian watersheds. There are fewer quantitative economic analysis of soil conservation practices effects in Iran. Economic evaluation of soil conservation activities is difficult due to the effect of combined indices and lack of market economic value. In this research، the effects of soil conservation practices are analyzed using Net Present Value (NPV) method in Mian Bishe Sub-basin of Taleghan Watershed in Alborz Province، Iran. This sub-basin was selected due to acceptable period of soil conservation practices for analysis and its technical evaluation experiences. First، basic data were updated using GIS، field survey and identification and measurement of benefit and cost indices. Then، economic value of three main cost indices and six combined benefit indices were identified and computed. Economic indices، including NPV and benefit-cost ratio were estimated by integrating available data. Evaluations show that rehabilitation of Main Bishe Sub-basin in a 30 years period with a discount rate of 15 percent has economic justification in lands with comparative productivity، including mountainous rangelands and hilly badlands with high rate of soil erosion and positive NPV. Also، 25 percent of the total benefits comes through onsite، 55 percent through down streams and 20 percent through neighboring sub-basins and due to reduced flooding risk.