Evaluation of Watershed Management Projects in Blockabad-e-Maragheh Catchment's.

Based on estimations, milliards cubic meter / ton water and soil via erosion process were lose annually in Iran and to control this problem ,notable cost and watershed operations are dedicated every year there fore evaluation on conducted watershed management operations is necessary to find the suitable watershed management operations to improve and reclamation of similar watersheds . In this research, watershed management operations done on blockadab watershed located in the south foothill of sahand mountain were evaluated. Comparing predicted and executed operation showed .that there is significant difference between them. As 47.2% of gabion dams, 48.6% of masonary dams ,86.5% of concrete dams have been implemented in comparison to predicted program . in this regard, loose rock dams were executed 85.7% more them predicted value . Regarding biological parameters there was no difference between executed and predicted values.Regarding vegetation coverage from viewpoint of capacity and cover status, previous capacity namely 1.65 reached 1.83 animal units, forge yield reached form 99.5Kg/ha to 110 Kg/ha and cover status showed no difference and had left poor . Vegetation coverage tendency was negative already and at the percent time was evalovated negative . There was no difference in vegetation cover composition and density of cover had reached form44.1 to 46.5 .comparative comparison of executed and predictal factors from viewpoint of technical and engineering it was found that determined goal of project was 93.3% useful life 91.7% , efficiency 91.7% and outcome of structures were evaluated positive. These ratios for biological parameters were 83.3% for project goal useful life , efficiency 70% and outcome was positive. Also, the results and percent of success of mechanical and biological structures were as: gabion dams 52.8%, masonary dams 51.4% , concrete dams13.5% , soiled detention dam 100% , terracing 100% ,seedling 100% , plantation 100% and seeding 100% . based on experiments obtained, conducting mechanical and biological operations on watersheds executed by watershed management office, in province brought out possiblty to control erosion and flood .It was also observed that executed operations ,caused a decerase of sediment value from 6.7 to 5.1 Ton/hec in the study area.