Publications

Othman, AA; Ali, SS; Scheytt, T (2024). Comparison between multi RUSLE-SDR models for estimation of reservoir sedimentation: a case study of Dokan Lake Basin, Iraq-Iran. ENVIRONMENTAL EARTH SCIENCES, 83(13), 419.

Abstract
Reservoir sedimentation in mountainous watersheds, such as the Zagros mountains, is high. Reservoir sedimentation reduces water storage and threatens water resource management. This study aims to simulate reservoir sedimentation in Dokan Lake, Iraq for 55 years, beginning in 1959. Multiple combinations of the revised universal soil loss equation-sediment delivery ratio (RUSLE-SDR) method have been tested using geographic information system (GIS) and remote sensing techniques. Two types of satellite precipitation data, six Digital Elevation Model (DEM), Harmonized World Soil Database (HWSD), and AQUA eMODIS NDVI V6 data have been used to prepare forty-eight RUSLE-SDR models. These models have been evaluated using three sets of in situ measurements (one topographic map and two bathymetric data sets) to select the suitable models. The rate of error test shows that the best model by far is model #38, which has an error of less than 8.31% for the three in situ measurements. The annual reservoir sedimentation rate (between 1959 and 2014) at Dokan Lake is 0.0034 km3y-1 (6,347,800 tony-1). This rate has been decreased to 0.0027 km3y-1 (2018 to present) due to short-term fluctuations in precipitation and temperature and construction of the Sardasht Dam, which contributed to the decrease in the amount of the water mass reached to Dokan lake. The sediment delivery ratio which is based on the basin model shows better results than the sediment delivery ratio which depends on the IC model although the SDR IC model is working well, too. As a result of neglecting this aspect, one-third of Dokan Lake volume has been lost already due to reservoir sedimentation. The results show that the GPM data is better than the TRMM data in estimating the R factor. Moreover, the best RUSLE-SDR model shows that the MODIS land cover (MCD12Q1) performs better than the AQUA eMODISNDVI V6 to estimate the cover-management (C) factor, which comprises the preventing effects of the crop or vegetation cover. We propose constructing check dams in the Dokan Lake basin to reduce reservoir sedimentation is among the most important measures to increase the dam's lifespan.

DOI:
10.1007/s12665-024-11713-z

ISSN:
1866-6299