Mirdar Harijany and Kohestani [14], in a study to propose suitable formula for calculation of sediment yield in Sajaserud basin (Zanjan province), established correlation coefficients of sediment yield with twelve physical factors of basin including (area,
basin perimeter, the greatest length of basin, equivalent diameter of watershed area, compactness coefficient, length and width of equivalent rectangular, time of concentration, basin slop, mean elevation of basin, drainage density and height difference) as the independent variables.