Abstract:
Floods are probably the most recurring, widespread, disastrous and frequent natural
hazards of the world. Bangladesh is one of the worst flood-affected countries due to
its unique geographical and geological condition. Geographically Bangladesh is
surrounded by India from north, east and west and by Bay of Bengal from south.
Geologically Bangladesh is situated in a depression area which is called Bengal
Basin. This is why all major rivers meet in this basin. This is the one of the main
reason of flood in Bangladesh. The north east zone of Bangladesh is one of the most
susceptible areas which are prone to flooding. Flood forecasting and flood warning,
flood hazard mapping and flood risk zoning are quite effective non-structural
procedures in managing floods that decreases the risks and disasters which floods
may cause.
In view of this an attempt has been made in the present work to simulate flood
inundation for Upper Meghna River and also to verify the inundation with
RADARSAT imagery. Flood patterns and inundation behavior has also been derived
from satellite imagery. This study introduces the verification of inundation from 1D-
2D hydrodynamic modeling and flood inundated area mapping for Upper Meghna
River. Time series analysis of satellite imagery and model output has been analyzed
to look for the inundation behavior in Upper Meghna River. DEM of 300m
resolution is used to generate the various maps for the floodplain depended on Upper
Meghna River. SOBEK 1D and 2D hydrodynamic module have been used for
floodplain inundation modelling.
Results indicate that upstream of the Upper Meghna River in Brahmanbaria and
Kishoregonj is more vulnerable to flooding compared to downstream. Flooding in
the Upper Meghna follows a common pattern except 1998 flood. Brahmanbaria in
the study area is vulnerable to flood inundation compare to other district.Model
results also show that the upstream of the Upper Meghna River in Brahmanbaria and
Kishoregonj is susceptible to flooding. Both model and satellite images show that
left bank of the Upper Meghna River is vulnerable to flood inundation.
