3 Increasing Trends in Tropical Cyclone Induced Surge Impacts ...
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Both vulnerability and model performance vary from one region to another. Thus,
location-specific validation of the storm surge inundation model is very important.
In line with this view, Dube et al. (2000) argued for location-specific storm surge
inundation model development and they devised models for the Andhra and Orissa
coasts of India. This study found a reasonable agreement between model simulated
inland flooding and what was observed. An integrated forecast system has been
developed by Madsen and Jakobsen (2004) for Bangladeshi coast by using the MIKE
21 together with other models’ components. This model served to analyse the storm
surge height and inland flooding caused by Super Cyclone in April 1991. In addition,
two more TC scenarios were analysed, and the authors found a reasonable agreement
of model results with the observed surge height.
Changes in the track characteristics of TCs, especially in some ocean basins,
have been observed. For instance, the TC tracks have been identified to move more
poleward (Kossin et al. 2014) and their translation speeds have slowed down (Kossin
2018). Until recently, there have been very few studies that analysed the impacts from
TC-induced storm surge under past and future climate change scenarios exclusively
for NIO region. Therefore, it is vitally important to analyse the impacts of both past
and future TC activities over NIO to reduce the carnage. For the projected TC tracks
and intensities, uncertainties always exist and thus it is essential to examine the model
bias for the climatology period before evaluating the future storm surge height and
their associated impacts. Current study has been conducted aiming to: (a) examine
both simulated and observed TC climatology for the periods 1990–2010 and 2075–
2099; and (b) analyse TC- induced storm surge height for the same period. This study
found crucial information for disaster managers regarding disaster preparedness and
responses.
3.2 Data and Methodology
3.2.1 Data Sources
3.2.1.1 Observed Data
TC information for running the Japan Meteorological Agency-Meteorological
Research Institute (JMA-MRI) storm surge model was obtained from the best track
data of the India Meteorological Department (IMD) because the IMD best tracks
include the mean-sea-level pressure, which is necessary for inclusion in the storm
surge model. Radius of maximum wind and that for 30-kt wind are not available for
all storms. Recently, the U.S. Navy Joint Typhoon Warning Center (JTWC) reported
this data for some TC cases over the NIO. When the radius of wind is not available
from both operational centres, estimate of TC size is done based on TC reports and
satellite images. This information is part of the TC track input to the storm surge
model.
39
Both vulnerability and model performance vary from one region to another. Thus,
location-specific validation of the storm surge inundation model is very important.
In line with this view, Dube et al. (2000) argued for location-specific storm surge
inundation model development and they devised models for the Andhra and Orissa
coasts of India. This study found a reasonable agreement between model simulated
inland flooding and what was observed. An integrated forecast system has been
developed by Madsen and Jakobsen (2004) for Bangladeshi coast by using the MIKE
21 together with other models’ components. This model served to analyse the storm
surge height and inland flooding caused by Super Cyclone in April 1991. In addition,
two more TC scenarios were analysed, and the authors found a reasonable agreement
of model results with the observed surge height.
Changes in the track characteristics of TCs, especially in some ocean basins,
have been observed. For instance, the TC tracks have been identified to move more
poleward (Kossin et al. 2014) and their translation speeds have slowed down (Kossin
2018). Until recently, there have been very few studies that analysed the impacts from
TC-induced storm surge under past and future climate change scenarios exclusively
for NIO region. Therefore, it is vitally important to analyse the impacts of both past
and future TC activities over NIO to reduce the carnage. For the projected TC tracks
and intensities, uncertainties always exist and thus it is essential to examine the model
bias for the climatology period before evaluating the future storm surge height and
their associated impacts. Current study has been conducted aiming to: (a) examine
both simulated and observed TC climatology for the periods 1990–2010 and 2075–
2099; and (b) analyse TC- induced storm surge height for the same period. This study
found crucial information for disaster managers regarding disaster preparedness and
responses.
3.2 Data and Methodology
3.2.1 Data Sources
3.2.1.1 Observed Data
TC information for running the Japan Meteorological Agency-Meteorological
Research Institute (JMA-MRI) storm surge model was obtained from the best track
data of the India Meteorological Department (IMD) because the IMD best tracks
include the mean-sea-level pressure, which is necessary for inclusion in the storm
surge model. Radius of maximum wind and that for 30-kt wind are not available for
all storms. Recently, the U.S. Navy Joint Typhoon Warning Center (JTWC) reported
this data for some TC cases over the NIO. When the radius of wind is not available
from both operational centres, estimate of TC size is done based on TC reports and
satellite images. This information is part of the TC track input to the storm surge
model.