Abstract:
During a Cyclone storm surge related forecasting and warnings in Bangladesh
are provided by Bangladesh Meteorological Department (BMD) by giving
forecasting and warning of the expected storm surge height during a cyclone.
This forecasting does not give any forecasting regarding areas that might be
inundated due to the storm surge. This study focuses on developing a storm
surge inundation model using Delft3D using current state of the art in storm
surge inundation modelling. This research is based on the super cyclone
Amphan, which made landfall on May 20, 2020, across the Sundarbans from the
west Bengal-Bangladesh coast. Its wind speed ranged from 155 to 165 kmph
with gusts up to 185 kmph.
At first the tide model is developed. Then after the calibration and validation of
the tide model it is run using atmospheric forcing generated from the cyclone
model. Cyclone model is run by using IMD and JTWC best track data of cyclone
Amphan. Then calibration and validation of the cyclone model shows that the
pressure field and wind filed data produced using JTWC best track data shows
better R2 and NSE values as compared to IMD. Due to this reason pressure field
and wind field data produced using JTWC best tack data is used to force the
storm surge inundation model to simulate cyclone Amphan. Then water levels
at fours BIWTA water level stations are calibrated and validated. Finally
inundation scenario is also compared with two inundation maps for the
validation of the inundated area produced by the storm surge inundation
model. One is produced by NAWG by survey during Ampahn and another one
is inundation map produced using Sentinel-1 SAR images during Amphan.
There are some findings related to challenges and different aspects in different
stages of storm surge modelling in a data scarce region like Bangladesh that will
help researchers to help storm surge inundation related studies in future
