The Characterization of Hydrodynamic Flow Patterns in the Kawal River Estuary, Bintan Island, Indonesia

Abstract

One of the pivotal oceanographic factors impacting the hydrodynamic attributes of the waters within the Kawal River Estuary is the prevailing current. This current pattern in the Kawal River estuary exhibits a dynamic nature, primarily under the influence of wind and tidal dynamics. The Kawal River Estuary, as a confluence zone of riverine and oceanic currents, manifests as a dynamically evolving aquatic environment. The investigation was conducted at the Kawal River Estuary in Bintan Regency during the months of September 2021 and January 2022. The research employed the MIKE 21 software, examining two distinct tidal states: high tide and low tide. In September, the sound velocity values averaged 1538.647 m/s at the water surface, 1539.984 m/s within the water column, and 1541.436 m/s at the seabed. In contrast, January recorded sound velocity values of 1534.517 m/s at the surface, 1535.613 m/s within the water column, and 1536.312 m/s at the seabed. Current velocities in September ranged between 0.02 m/s and 0.037 m/s, with a predominant southward direction, while in January, they varied from 0.02 m/s to 0.59 m/s, also exhibiting a southward trajectory. Notably, the swifter current velocities observed in January are attributed to the influence of the northern season.