Separation of the Relative Contribution of Different Land Covers in Bed Sediment Yield in Vaz River Using Geochemical Characteristics

Identification of sediment resources and their associated pollutants and contribution separation of land uses / land cover in sediment production is a valuable tool in spatial prioritization of soil conservation practices at watersheds. The present study was conducted with aim of bed sediment Fingerprinting using the geochemical method in Vaz watershed in Mazandaran Province. Thirty soil samples from different land covers were collected as sediment sources, and a sample of bed sediment at the basin outlet was measured. The geochemical characteristics including 59 elements were measured using ICP-OES. Then, using the combination of range tests, Kruskal-Valis and DFA test in FingerPro package at R software, 15 elements including K, Li, P, V, Cr, Fe, Cu, Ga, Ge, Rb, Sb, Ba, Nd, Ta, and W were selected as the optimal tracers. The results with a goodness index of fit of 78.31 showed that the contributions of agricultural, rangeland, forest, and stream bank lands in the bed sediment yield were with rates of 2.77, 3.61, 12.14, and 73.84 %, respectively. Finally, the relative contribution of each source in sediment yield for each hectare was calculated and the results showed that stream bank and rangeland with the relative contribution of 0.43 and 0.0008 percent for each hectare have the highest and lowest participation in sediment yield, respectively.