Erosión y desertificación.-Tracing sediment sources in Royan Drainage basin, Iran

Abstract

ABSTRACT For successful soil conservation measures, obtaining information about the relative importance of sediment source and their shares in sediment production is required. Tracing or source studies are emphasized in recent years due to their privileges. In this research, sediment sources were identified using tracing method. A small earth dam is constructed at the outlet of Royan Drainage Basin in 1993. In this study, sediments were sampled from dam reservoir, different sources were also sampled. Fifteen tracers were first selected for tracing which are: the amounts of N, Carbon, Cr, Co, Mg, K, Na, smectite, cholorite, illite, kaolinite, PH and two magnetic properties consisting of XLF and XFD. The samples were analyzed in the laboratory for these parameters and different statistical methods were applied to the data including Nonparametric Kruskal Walis Test, Stepwise Differentiation Function Analysis. The contribution of each sediment source in sediment yield was obtained by optimization of multivariate composite model which shows Karaj Formation (EV) contributes %32.86, Quaternary unit (Q) %30.92, gully erosion %26.77, Shemshak Formation (Js) %4.69, Upper Red Formation (M1) %2.35 and Lar Formation (Jl) %1.41 of sediment yield and have the highest contributions in sediment yield respectively. The results of this research can be used in soil conservation projects for execution of suitable management strategies.