Fingerprinting of Water Sediments of Beheshtabad Basin Using Natural Soil Tracers

Fingerprint method determines the contribution of sediment in the land units. In this method, a suitable composite (set) of diagnostic properties and a multivariate mixing model are employed to estimate the relative contribution of sediment sources to sediments transported to watershed outlet. The purpose of this study was to determine the contribution of different sediment sources in the Beheshtabad watershed with 308 km2 area. For this purpose, 36 soil samples were taken from sedimentary sources (0-5 cm depth) and 10 sediment samples from watershed outlet. In each of the sources, initial traces were evaluated by Kruskal-Wallis test. In the second stage, an optimal combination of tracers for each source was obtained using diagnostic analysis functions, and finally, in the next step, the contribution of each user in sediment production for each sampling method was determined using Collins et al. model. The contribution of agricultural, rangeland, rainfed and residential land use was equal to 67.88, 7.63, 19.40, and 5.10 %, respectively. Results showed agricultural has maximum share in sediment with 67.88percent. Due to the fact that the contribution of sediment in agricultural lands in the study area is high, special attention should be paid to the way of agricultural operations.