Coastal vulnerability
assessment for southeast coast of India using Coastal Hazard Wheel
Palpanabhan Kasthuri Bavinaya, Moorthy Prabhakaran, Tune Usha, Gowrappan Muthusankar
and Chokkalingam Lakshumanan
Disaster Advances; Vol. 17(2); 23-30;
doi: https://doi.org/10.25303/172da023030; (2024)
Abstract
Rapid urbanization coupled with climate change increases the vulnerability of coastal
areas to different types of hazards. To understand and assess the vulnerability
of the coastal environments, a published methodology Coastal Hazard Wheel (CHW)
was adopted for the coastal taluks of Tamil Nadu. This methodology provides information
on vulnerability of the coast by five major hazards. They are: Ecosystem Disruption,
Gradual Inundation, Saltwater intrusion, Coastal Erosion and Flooding. The vulnerability
assessment is carried out based on the datasets namely geomorphology, wave exposure,
tidal range, flora/fauna, sediment balance and climate. The coastal regions of Tamil
Nadu are evaluated based on the vulnerability severity levels of the hazards. The
assessment depicts that 46% of the Tamil Nadu coastline is highly vulnerable to
flooding, making flooding the most prevalent coastal hazard. About 10% of the coastal
areas have very high vulnerability to saltwater intrusion, 43% of the coastal areas
have high vulnerability to erosion, 54% of the coastal areas have high vulnerability
to gradual inundation and 58% of the coastal areas are moderately vulnerable to
ecosystem disruption.
These appraisals are useful to support management decisions at local, regional and
national level for the coastal management, mitigation and adaptation in response
to climate and sea level change. Four types of ecosystems are based on their habitat
type and distribution. They are marine, estuarine, coastal interface and coastal
freshwater. The habitats on these ecosystems vary depending on their adaptability.
These ecosystems also provide protection to coasts from the effects of climate change.
They act as a basin during flooding from high rainfall and storm surges. Carbon
sequestered within oceans is called blue carbon. Mangroves and salt marshes act
as a reservoir of this carbon. Only 2% of the earth surface is covered by these
ecosystems but stores ten times more carbon per unit area than other ecosystems.
Non climatic pressure on ecosystems also increases rapidly due to rapid urbanization,
industrial and agricultural outlets.
