Determination of specific contribution of suspended sediment sources in Vaz watershed using geochemical characteristics

Accurate information about the source of suspended sediment in river systems is necessary because supply enhancement of fine-grained sediments to a river system through human activities leads to overloading of suspended sediment, which affects water quality and the ecosystem. In addition, quantifying the relative contribution of different sources is vital to determine the best methods for suspended sediment control. Therefore, reliable information needs about the origin of transported fine-grained sediments by rivers. The purpose of this study is the fingerprint of suspended sediments using geochemical characteristics using the R software Fingerpro package in various land uses/covers of the Vaz watershed in Mazandaran province. In this research, 30 soil samples were collected from different land use, including forest, rangeland, agricultural land, and the streambank as sources of sediment yield, and one sample of suspended sediment at the outlet watershed. Geochemical characteristics of the soil and 59 sediment samples were measured using the ICP-OES GBC Integra device. Then, suitable tracers were identified for the fingerprint of suspended sediments using range tests, Kruskal-Wallis, and discriminant function analysis, in the Fingerpro package of R software including K, Li, P, V, Cr, Fe, Cu, Ga, Ge, Rb, Sb, Ba, Nd, Ta, and W. The separation results of the land use/covers contribution in the yield of suspended sediment with the GoF index showed with the rate of 80.68 that the contribution of agricultural, rangeland, forest, and streambank was with rates of 0.18, 7.90, 5.69, and 86.21 percent, respectively. Finally, the contribution of each source to the yield of suspended sediment per hectare was calculated. Results showed that the streambanks and forests had the highest and lowest participation in the yield of suspended sediment per hectare with rates of 0.513 and 0.0007 percent, respectively. The results also showed that the special contribution of stream bank lands at land uses for agricultural, rangeland, and the forest was the rates of 320.62, 394.61, and 732.85, respectively. The fingerprint results using the geochemical method for managers and planners provide valuable information about the resource contribution of suspended sediment yield to implement management programs for soil and water conservation.