عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Extended abstract 1- Introduction One of the important issues of water quality management is control the sediment load input to water resources. Also sediment load is a major factor in the detection of non-point pollution sources and the design and construction of water structures such as dams and reservoirs. Assessment of soil erosion and sediment yield in the watersheds is necessary to achieve proper land management and improve water and soil quality and quantity (Sadeghi et al, 2008). Afsari and Ghodousi (2011), evaluated13 different methods of estimation of sediment delivery ratio (SDR) under different climatic conditions.Results showed that Mou & Meng (1980) and Roehl (1977) methodswith lower relativediffersare the most appropriate methods in Khomein and Mezelghan watersheds.The purpose of this study, was to comparison of 45 different methods to estimation of sediment delivery ratio in three different climatic regionin Babolroud (Mazandaran province), Banadak Sadat (Yazd province) and Dehgolan (Kordestan province) watersheds. 2- Methodology In this study, after collecting the necessary data and sediment values measured at the outlet of the three watersheds (Babolroud, Banadak Sadat and Dehgolan), sediment delivery ratio was estimated using different methods and then the best methods was selected using statistical indices. For doing this, data from Ghoran Talar station (Babolroud watershed), Tezerjan station (Banadak Sadat watershed) and Dehgolan station (Dehgolan watershed) was used to measure of observed suspended sediment, also to predict SDR, soil erosion was estimated by EPM method. 3- Conclusion Results indicated that Renfro graphic method (1975), Swif & Lioyd method (2002) and SWAT method (2005) with relative differby 2.29%, 3.33% and 7.21% respectively, are the appropriate methods for estimating the sediment delivery ratio in Babolroud watershed that located in the north of Iran. These methods can be used to estimation ofsediment delivery ratio and also convert erosion to sediment in regions with similar climates (moderate and humid). Swif & Lioyd (2002), Roeal 2 (1962) and N Shaanxi CHINA methods with relative differby 6.87%, 8.59% and 15.67% respectively, are the best methods in Banadak Sadat watershed where located in the centre of Iran, thereforethese methods can be proposed for other areas with warm and dry climate. Also SWAT (1996), Central & Eastern USA and Vanani 2 (1975) methods with relative differ by 4.85%, 7.79% and 8.25% respectively, are the appropriate methods for estimating the sediment delivery ratio in Dehgolan watershed that located in the west of Iran, therefore can be used in regions with similar climates (semi-arid and cold).