Determination of Ecological Capacity of Applications Based on Hydrological Response Units and Vulnerability Assessment for Sustainable Utilization of Forest Watersheds(Case Study: Zailakirood Basin in Guilan Province)

The aim of this study was to provide a multi-factor ecological power model based on the ecological factors of hydrological response units in order to assessing the ecological potential of different uses in the Zailakirood Basin, northern Iran. First, by employing ArcSWAT 608 units of hydrologic response in 39197 independent polygons were found in the study area. Then, by measuring the hydrological response units by using special ecological capability models, the yield of the studied lands was measured in terms of production, quality of vulnerability and management requirements. In the next step, the final vulnerability of the hydrological response units was assessed against the degradation caused by forest utilization by employing hydrological indicators. In order to evaluate hydrologic indexes, by applying the SWAT model, calibration and sensitivity analysis, the effective parameters in runoff and sediment simulation have been obtained and in each of hydrological response unit, the numerical value of the hydrologic indexes estimated then the hydrological response units which were capable of producing sediments more than the determined limit of the index was changed to protective and supportive usage. So, the usage of potential of utilization 1 of forestry and centralized ecotourism capacity 1 remained without changing the area, potential of utilization 2,3 and 4 of forestry and centralized ecotourism capacity 2 reduced in area. And finally protection and supportive function with an area of 14083 hectares increased. Since slope, soil and land use have the highest variation in the region and cause the most limitation.