Water temperature modeling of Lake Ranau, Sumatera Island

The Lake Ranau lies at 538 m above sea level, located in South Sumatera and Lampung Provinces. The maximum depth of the lake is 220 m and volume is 19.92¢ I0' m' Lake temperature influences the transportation and transfora­ tion of chemical mass, phytoplankton and detritus in the water body. We model the water temperature by applying the derivative equation of heat-conductive Fourier and the momentum and continuity current 2D multi layer from Navier­ Stokes equation. To solve the equations we use finite difference method and nu­ me rical scheme with Alternating Direction Implicit (ADI), The wind, shoreline and bottom morphology are considered as a boundary condition, While the cur­ rent velocity from rivers flow can be ignored The model reveals that current pat­ tern forms eddy current at each layer, and temperature distribution tend to be similar to the observation especially arround hot water inflow sites.