Evaluating the Effectiveness of Biological and Engineering Measures Affecting the Hydrological Services of the Efin Watershed

Today, watershed measures are used as a managerial and executive approach by managers and policymakers to deal with incidents affected by the destruction and improvement of watershed performance. Therefore, in this research, an attempt has been made to evaluate the effectiveness of engineering and biological measures planned in the Efin watershed located in Zirkuh county and south Khorasan province, Iran on hydrological variables and services. To do this, relevant information was obtained and used from relevant organizations. In this research, the changes of Curve Number (CN), Normalized Difference Vegetation Index (NDVI) and the slope of the main river were investigated and their effect on time of concentration, runoff depth and volume were determined. The research results indicate that after the implementation of watershed measures, CN decreases from 1.38% to 29.92% and NDVI increases from 42.44% to 87.50% and the slope of the main river decreases by 66.67%. The runoff depth and volume also decrease from 7.51% to 76.66%. The implementation of watershed management measures has played a different role in different sub-watersheds, and its effectiveness has varied according to the conditions and status of the sub-watersheds. Therefore, it is suggested that in order to achieve better management and more efficient implementation measures, the comprehensive watershed management with a health-oriented approach should be taken into account by officials and managers.