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ABSTRACT
Most computer models used in the flood
risk analysis of rivers have inadequate functions in its spatial
analytical capabilities and without sediment transport simulation
capacity or suitable equations to represents correctly in-situ
hydraulic processes. As a result, the current research presents the
development of a new total bed material load equation using multiple
linear regression analyses that is applicable for rivers in Malaysia.
It was developed and embedded as a modified version of HEC-6 model and
named SEDFlood model. The model is best suited for rivers having
uniform sediment size distribution with a d50 value within the range
0.37 mm and 4.0 mm and performs better than the commonly used Yang,
Graf and Ackers-White total bed material load equations. A
user-friendly, menu-driven GUI for two and three-dimensional (2D &
3D) digital floodplain delineation was developed through ArcView GIS
and SEDFlood tight coupling procedure. It is capable to produce quick
analysis (snapshots) at any desired discharge time steps in flood risk
mapping procedure. Field measurements were carried out to validate the
hydraulic setting and the accuracy of model outputs. The feasibility
of simulating a flood event along a river channel and floodplain was
tested for Pari River catchment’s area located in Ipoh, Malaysia.
Flood risk analysis were conducted for the design flood events for 10,
50, 100-year Average Recurrence Interval (ARI). The design rainfall
duration of 30, 60 and 120 minutes for the present and future land use
conditions (year 2020) were considered in the simulation scenarios.
The result of this research indicates that GIS is an effective
environment for floodplain analysis and its integration with hydraulic
model is not only feasible but also mutually beneficial for both GIS
users and hydraulic modelers.
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