Determination of Landuse Factor in EPM Model by Using Remote Sensing Indices, Tarik Dam Basin, Rudbar, Guilan Province

One of the main problems in the management of watersheds in the country is the lack of information and data. Due to the lack of Sediment Measurement stations in most country's watersheds and insufficient data, empirical models can be important tools for the preparation of these layers. EPM model is used in experimental models, the use of these models to estimate erosion and sediment in basins without data has the costs and difficulties in providing map. In EPM model, the user factor is one of the factors that can be provided through remote sensing with good accuracy and at lower costs. Tarik dam Basin in the west of Rudbar, Guilan province, was considered as study basin. The area of basin was 6102.1 ha with average elevation of 11296 m. Digital elevation model (DEM) from satellite SRTM radar were provided and the required maps were provided from DEM and satellite images. Land use map was prepared based on visual interpretation of Google Earth images and field views. The user factorof EPM model based on the conventional method (field views and corresponding table) and mean opinions of three experienced expert was appointed for each landuse unit. A number of indicators associated with a landuse such as NDVI, PVI, SAVI and MSAV were extracted on ETM satellite image in 2011. The average indices for every land use were calculated by Software of remote sensing, and by using a linear regression model, the relationship between the user factor and remote sensing indicators were analyzed. At the next stage, other factors of model based on traditional methods was carried out in determining and estimating of erosion. The erosion of basin was again estimated by using all previous factors and by more appropriate index. The best relationship between vegetation index (VI) and user factor of model was obtained that correlation coefficient was 0.793.