Using Sediment Deposited in Small Reservoirs to Quantify Sediment Yield in Two Small Catchments of Iran

Asghar Kouhpeima,Seyed Ali Asghar Hashemi,Hassan Ahmadi,Sadat Feiznia

doi:10.5539/jsd.v3n3p133

Abstract

Sediment deposition in reservoirs is a serious off-site consequence of soil erosion in Semnan Province, Iran. So far insufficient and less reliable sediment yield data have been collected for these regions. The large number of available sediment deposition rates in reservoirs makes the use of reservoir sediments very attractive for regional-scale studies of sediment delivery. This paper however discusses a methodology combination of both source fingerprinting technique and reservoir sediment survey to provide reliable data on sediment yields of geological formation for two small catchments, Iran. The study first assessed the volume and mass of deposited sediment in reservoirs. Secondary a fingerprinting technique have been used to identify the contribution and then specific sediment yield of each geological formation to reservoir sediment. Results indicate that there is some variation in specific sediment yield (SSY) among geological formations in two catchments: i.e. 10.31 t ha-1 year-1 to 0.41 t ha -1 year -1 and emphasize the importance of Quaternary units and Upper Red formations as the dominant surface source within two catchments. This is the important finding to support design and implementation of sediment control strategies in these catchments.

Highlights

The construction of reservoirs for water supply or flood control has been a priority for the Government of Iran for the last decade
Sediments in reservoirs and lakes have been used for decades to assess sediment yield (e.g. Dendy et al, 1973; White et al, 1996), this was mostly done through larger reservoirs or lakes that have more or less uniform hydrologic conditions through time, which are mostly linked to larger catchments
The profile Dry bulk density (dBD) analysis result from pits indicates that dBD varies spatially both within the reservoir and vertically in the profile

Summary

Introduction

The construction of reservoirs for water supply or flood control has been a priority for the Government of Iran for the last decade. Sediment yield can be monitored by using measuring sediment deposition rates in lakes, reservoirs or small ponds (e.g. Van den Wall Bake, 1986; Neil and Mazari, 1993; McManus and Duck, 1985; Foster, 1995; White et al, 1996; Verstreaten and Poesen, 1999, 2001c). If potential source materials can be distinguished on the basis of their fingerprints, the likely provenance of the www.ccsenet.org/jsd sediment can be established using a comparison of the properties of the sediment with those of the individual potential sources (Walling et al, 2008) The application of this approach comprises two basic steps. This paper discusses a methodology combination of both source fingerprinting technique and reservoir sediment survey to provide reliable data on sediment yields of geological formation for two small catchments, Iran

Methods

Results

Conclusion