Background: From a social point of view, the water area
around the mouth of the Kawal river, Bintan regency, is a tourism area,
settlement, fisherman harbour, and seagrass conservation area that affects the
sustainability of coastal activities and conditions such as abrasion,
sedimentation and changes in coastline. Current patterns and wind speeds around
the region are strongly influenced by winds blowing from the dominant monsoon
system in Southeast Asian waters.
Aims: This study analyses the seasonal hydrodynamic
characteristics, particularly surface current patterns, in the Kawal Estuary,
eastern Bintan Island, Indonesia, a monsoon-dominated area intensively utilised
for tourism, settlements, seagrass conservation, and fisheries activities.
Study Design: A numerical hydrodynamic modelling approach
was employed to simulate and evaluate seasonal variations in the magnitude and
direction of surface currents over a one-year period.
Place and Duration of Study: The study was conducted in the
Kawal estuary, Bintan Island, Indonesia, covering a one-year simulation period
from December 2020 to November 2021.
Methodology: Hydrodynamic simulations were performed using
the MIKE 21/3 Flexible Mesh integrated flow model. Seasonal surface current
characteristics were examined across representative tidal conditions, including
flood and ebb phases under spring and neap tides. Model validation was
conducted using tidal data and in situ current measurements obtained from a
Recording Current Meter deployed in March 2021. Surface current magnitude and
direction were analysed at four representative locations within and around the
estuary.
Results: The modelling results show good agreement with
observations, achieving validation accuracies of 81.69% for tidal data and
85.04% for field current measurements. Surface current patterns exhibit
pronounced spatial and seasonal variability, with predominantly northeastward
flow at the northern and southern locations, while the frontal area displays
greater directional variability. Two dominant flow patterns were identified,
characterised by southwest–south and northeastward directions associated with
tidal reversals. Peak surface current velocities consistently occur during the
flood tide phase.
Conclusion: The Kawal Estuary exhibits complex seasonal
surface current dynamics controlled by monsoon forcing, tidal variability, and
estuarine geometry. These findings provide essential baseline information for
understanding sediment transport pathways, supporting coastal management and
navigation planning, and enhancing the sustainability of estuarine ecosystems
in monsoon-influenced tropical regions.
Author(s) Details
Reni Wijayanti
Research Center Oceanology, National Research and Innovation Agency,
Jakarta 14430, Indonesia.
Dewi Surinati
Research Center Oceanology, National Research and Innovation Agency,
Jakarta 14430, Indonesia.
Risandi Dwirama Putra
Naval Architecture Department, Faculty of Engineering, Raja Ali Haji
Maritime University, Tanjungpinang 29411, Indonesia.
Agus Mulyono
Research Center for Environmental and Clean Technology, National Research
and Innovation Agency, Bandung 40135, Indonesia.
Ida Narulita
Research Center for Climate and Atmosphere, National Research and
Innovation Agency, Bandung 40135, Indonesia.
Muh. Rahman Djuwansah
Research Center for Environmental and Clean Technology, National Research
and Innovation Agency, Bandung 40135, Indonesia.
Please see the book here :- https://doi.org/10.9734/bpi/crgese/v6/7067
