ABSTRACT
The quantification based on hillslope processes such as the Universal Soil Loss Equation (USLE or its revised version RUSLE) (Wischmeier, 1978) or on monitoring the volume loss in hillslope check-dams, do not consider fluvial processes such as bedload. Although bedload is generally ignored for estimating SSY, it is essential to quantify the total sediment delivery of basins. These contributions could exceed over 50% of the fraction between suspended load and bedload (Schick & Lekach 1993, Turowsky et al. 2010), especially in semiarid environments (Graf & Lecce 1988, Powell et al. 2001, Millares et al. 2014). Although reservoir sedimentation is a serious problem which reflects the consequences of soil erosion, it also provides an opportunity for understanding erosion and sedimentation transport processes at a basin scale. Based on the accumulated volume in medium to large dams, it is possible not only to estimate the total production of sediment but also to distinguish between erosion processes by assuming a natural separation of sediment along the dam. This hypothesis consists of the assumption of a suspended sediment and bedload separation (submerged area and tail) along the body of the dam, as reported in other field studies (Duck & McManus 1994, Rowan et al. 1995, Snyder et al. 2004, Minear et al. 2009).
