Reservoir Sedimentation Assessment using Remote Sensing for Maithon reservoir

Abstract

An eroded sediment particle originating from the catchment enters the reservoir by propagating along with the river inflow. At the location where the river meets the reservoir, the cross-sectional area of the river suddenly increases and hence flow velocity decreases. The coarse particles settle at the mouth of the reservoir, whereas the fine particles settle further down in the reservoir. Thus, reservoir storage capacity reduces significantly due to sedimentation, so its assessment is of prime importance for water resources development projects. The sedimentation assessment of the Maithon reservoir has been carried out using Landsat-8 and sentinel-1A dataset by using NDWI, Density slicing and Ostu’s Algrothim remote sensing techniques. The analysis results are compared with the bathymetric survey of Maithon Reservoir of the year 2019, and the variation in the results has been calculated. The results obtained using the Otsu histogram thresholding technique, carried in ArcGIS software, had a deviation of 4.65%. The density slicing method carried out in ERDAS Imagine software had a deviation of 5.01 %. The variation of 5.01% indicates that density slicing provides reliable results in estimating the live storage of the reservoir. Furthermore, the density slicing method allows for a more refined delineation of water bodies but may require manual selection of pixel values. The results obtained using the NDWI technique had a deviation of 3.22 %, which is relatively low compared to those obtained using Ostu and density slicing techniques.