TITLE:
A Simplified Concept to Test Erosion or Sedimentation Potential along a Tidal River in the Ganges-Brahmaputra-Meghna Delta
AUTHORS:
Md. Kabirul Islam, Md. Munsur Rahman
KEYWORDS:
Suspended Sediment Concentration, Sediment Surplus System, Sediment Deficit System, Residual Flow-Sediment Regime
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.10 No.4,
April
19,
2022
ABSTRACT: The
Payra is a tidal river with meandering planform in which around 6.5 km long landmass is formed naturally during the last 40 years that is
selected for an establishment by the Government of Bangladesh. However, the
site experiences intermittent erosion at several locations and poses threat to
the newly developed infrastructures. In the present study, a Rouse type simple
model is used to estimate the equilibrium profiles of suspended sediment
concentration below which the system is likely to be eroded and regarded as “Sediment
Deficit System, SDS” and above which the system is likely to be sedimented and regarded as “Sediment
Surplus System, SSS”. The model was then tested at the study reach using the measured flow-sediment data
complemented by field observation and Landsat images-based planform analysis.
The analysis revealed that the residual flow-sediment regime in the study site
is representing the “sediment deficit system” that
causes continuous threat for erosion throughout the tidal cycles. Therefore,
the availability of new landmass should not be the only criterion for the quick
selection of a project site, and residual flow-sediment regime needs to
consider as an additional parameter for such decision-making process.