Morphometry of Tes Lake in Bengkulu, Indonesia

Tes Lake is a natural lake located in Bengkulu, Indonesia. The data on Lake Tes is minimal; therefore, morphometry data of the lake is needed to determine its layers and usage by people. This study aimed to determine the surface and subsurface morphometric dimensions of Lake Tes. Lake mapping used the survey method by creating paths around the edges of water bodies and measuring cross-paths of 3,179 grids of water depth points with a fixed-jumping acoustic technique, which was processed further using ArcGIS software. The results showed that the surface dimension of Lake Tes covered an area of 1,620,800 m², with a measured circumference of 11,855.07 m and an SDI value of 5.17. The maximum length was 1,433.01 m, and the maximum width was 962.13 m. The subsurface dimension’s maximum depth was 21.90 m, with an average depth of 8.40 m and a relative depth of 0.57 m. The subsurface dimension of Lake Tes had a volume of 14,124,110 m³ with a VD value of 1.15. The residence time of lake water was approximately 121.20 days, with a water discharge of about 22.01 to 40.84 m³/sec. The water clarity was around 0.22 to 0.47 m, and the compensation depth was approximately 0.60 to 1.27 m. Lake Tes has low stability and is susceptible to mixing.