Study of bathymetry and sedimentation in Tondano Lake

Abstract

Tondano Lake is the largest lake on the northern peninsula of Sulawesi, which is naturally formed at an altitude of 680 m above sea level. Tondano Lake extends from north to south, while the width of the lake leads from west to east, the width of the lake varies from 3 to 5 kilometers, and the length of the lake in the longest part is 12.8 kilometers. The sedimentation or silting of Tondano Lake is one of the problems that can disrupt the ecological function and socio-economic life of the people who live and live around the lake area. The purpose of the study was to determine the rate of silting of the lake from 2015 to 2020. The study was carried out from June to October 2020, at Tondano Lake, Minahasa Regency, North Sulawesi. The analytical method used is the descriptive research method that describes the variables and phenomena that occur. Bathymetry data for 2015 was obtained from the bathymetry map 2015 by the Sulawesi River Region I. While the bathymetry data for 2020 was obtained from the results of a research survey from December 2019 to June 2020. The results of the analysis of bathymetry maps in 2015 and 2020 showed that there was a changing depth, in 2015 the maximum depth was 31.81 m and the average depth was 12.88 m. In 2020, the maximum depth is 30.22 m and the average depth is 12.66 m. Based on the results of spatial analysis, it is known that there is a siltation rate of 4.4 cm per year in Tondano Lake.