Wednesday, September 20, 2006


Ripendra on left.



Ripendra Awal (Nepal)
"Floodplain Analysis and Risk Assessment of Lakhandei River"
The Lakhandei river basin is located in Sarlahi district of Central Development Region of Nepal. This river, originates in the eastern Siwalik Hills, is one of the most flood prone rivers in the country because of flash flood during monsoon rainfall. The huge loss of life and damage to properties during floods in 1993, 1995 and 1997 necessitate for the flood plain analysis and risk assessment of this river.
Floodplain analysis and risk assessment involves the study of complex interaction of hydraulics of the river flow with topographical and land use features of the floodplains. This study will use the one-dimensional numerical model HEC-RAS, ArcView GIS and HEC-GeoRAS extension for ArcView GIS will be used as an interface between the two systems for the pre-processing and post-processing of the data. Spatial analysis functionality of the GIS will be used for risk assessment. The attempt will also be made for floodplain analysis by using two-dimensional flow model FESWMS-2DH for comparative study.
The methodology for flood risk assessment will follow the approach developed by Gilard (1996). For the visualization of the results, maps are also prepared for different return periods. This will serve as an effective and efficient decision making tool which will help administrators and planners to identify areas of risk and prioritize their mitigation/response efforts, and it will also help to general public be aware of the flood risk and prepare for mitigation activities.