Characterisation of sediment deposition of Bolgoda lake using acoustic and sampling methods

Abstract

Bolgoda Lake is one of the main water resources in the western province, which has two major basins explained as Bolgoda south and north lakes. Lake sedimentation is a serious dilemma for water scarcity, productivity, and flooding effect. So, identification of sediment characteristics is most critical. The attempt of this study is to identify the sedimentation pattern, sediment type, and mineral composition of the sediment from the data collected from core sampling, grab sampling, and the bathymetric data obtained from spot depth eco sounder that combines with Magellan 510. Hence, grain size distribution (GSD), scanning electron microscope (SEM), and bathymetric surveys were utilised to recognise sediment type, heavy metal composition, and sedimentation pattern, respectively. These analyses revealed that bottom sediment has poorly sorted, very fine skewed, physical characteristics have statistical distribution and discover the sediment type as sandy silt. Also, bathymetric analysis upholds the sedimentation pattern that accumulates sediment from the left bank to the right bank of the Bolgoda lake via the water column and to identify the sediment distribution along the lake bottom.