A new research findings published in the journal Natural Hazards reveals
A new study, using a broad range of criteria and data, suggests Dhaka is the second most vulnerable city to flooding after Shanghai. The new research, A flood vulnerability index for coastal cities and its use in assessing climate change impacts, published in the journal, Natural Hazards, looks not just at cities’ physical characteristics but also at their socio-economic and institutional systems, to assess the impact of flooding.
S F Balica, N G Wright & F Van der Meulen conducted the research. Dhaka and Kolkata come next in queue mainly because of their location prone to storm surges, coastline length and river discharge. Other cities covered in the study, in order of vulnerability, were Rotterdam, Buenos Aires, Marseille, Osaka and Casablanca.
“Based on the indicators related to population , cultural heritage, shelters, flood cultural behaviour (awareness and preparedness) and percentage of disabled population. Using these criteria, Shanghai stands out as the most vulnerable to coastal floods, mainly due to its high number of people living in coastal flood-prone areas, fewer shelters.
The second most vulnerable city to coastal floods is Dhaka for similar reasons. Kolkata and Manilla are third/fourth most vulnerable, while Osaka and Buenos Aires come next. The City of Rotterdam ranks seventh place from the nine cities studied. The population living in coastal area is smaller and has a high social resilience” the research report said.
Marseille and Casablanca are less socially vulnerable to coastal floods.
According to the research, in terms of hydro-geological exposure, Shanghai is the
most exposed to coastal floods. This is mainly due to its lengthy coastline and the high amount of river discharge.
Following vulnerable city is Manilla, largely due to its exposure to tropical cyclones and flooding. The recent tropical storm Typhoon Ketsana in 2009 illustrates this exposure of Manilla and the surrounding area to environmental threats.
Rotterdam city ranks fifth with a very high soil subsidence and a high Rhine river discharge.
The city of Buenos Aires ranks the sixth, with a very high river discharge value but very few kms of coastline, storm surge, number of cyclones. Marseille and Osaka are coming close in the rank as seven and eight.
The least vulnerable from all the examples is Casablanca with small number of cyclones in the last 10 years, few kms along the coast and no river discharge. However, this is not implying that the city is not vulnerable to coastal floods. All these cities have already been subjects of coastal floods with loss of life and significant damage costs. The new Natural Hazards study offers a more substantive analysis of the impact of exposure to extreme weather conditions and rising sea-levels. The researchers created an index which, they hope, can be used in differing scenarios to make policy-makers more aware of their cities’ vulnerabilities and, along with water authorities, define what measures should be taken.
The Coastal City Flood Vulnerability Index (CCFVI) uses 19 component factors which include economic and social ones, such as how much attention is given by local or national governments to protect people, business and property through investing in various forms of preventive and emergency resilience.
In their paper the researchers focused on nine large cities in low-lying, deltaic environments with soft sedimentary coasts (estuaries, lagoons, mangroves, dunes, beaches). These cities experience both the influence of river discharge and of the sea and they are, by consequence, very vulnerable to impacts of climate change.
-With The Independent input
