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Malaysia Water Research Journal
1 INTRODUCTION
River and sea hydrodynamic processes such as tidal and waves are causing
the erosion and sedimentation in the estuary. The tidal area (i.e. the intertidal
zone), receives continuous alternating current which is vulnerable to changes
due to sediment transport. The morphology of the river and the beach slope,
roughness grooves, the type and shape of the grooves, the orientation of the
coast, meeting creeks and vegetation also play a role in the sediment transport
processes. In addition, sea level changes and vertical land movement is seen
to contribute to the dynamics of sediment transport. Deposition and erosion
resulting from the sediment transport process affect the navigation system, the
flow of water, flora and fauna as well as the aesthetics value of the area.
Sea level is influenced by changes in the geoid, human activity, greenhouse
effect, changes in the volume of water bodies and sea basin. Changes in the sea
level increased the flood level, current velocity, longer seawater intrusion, loss of
property and coastal areas, the risk of disease and adverse effects on agriculture,
aquaculture, water quality and socio-economic development. The magnitude
of the sea level rise impact is also affected by the vulnerability characteristics
of the coastal area. Changes in environmental surroundings affect the tide and
eventually the benchmark for the estuary. Sea level rise increases the depth of
the sea water and the hydraulic and hydrodynamic processes of an area are
subsequently modified.
Siti Waznah et. al. (2010) stated estuaries and rivers are often the high
deposition area, serves as a trap for the minerals from river and sea materials
from being transported to the shore. Furthermore, the tidal river upstream
direction to play a role in determine the direction of sediment transport in shallow
waters (Jing et. al., 2013). Tides and waves carries sediment from the ocean to
the estuary resulting the dynamic and continuous events of filling and sediment
entrainment within the area.
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Institut Penyelidikan Hidraulik Kebangsaan Malaysia (NAHRIM)
National Hydraulic Institute of Malaysia (NAHRIM)