An integrated coastal exposure modelling approach to assist mangrove ecosystem based disaster risk reduction (Eco-DRR) in Tamil Nadu, India

Abstract

This paper attempts to measure the role of the mangrove ecosystem in minimizing coastal exposure using the InVEST (V3.9.0) Coastal Vulnerability Assessment (CVA) model in Tamil Nadu, India. The result depicts that the exposure value of the Tamil Nadu coastal stretch varies from 1.71 to 4.78 on a five-point scale. More than half of the coastal segments in Tamil Nadu have high to very high exposure, whereas nearly 10 % of the coastal segments are recorded under very low exposure. The model demonstrated that having the existing mangrove patches in the Pichavaram and Muthpet regions significantly reduces the exposure value from 3.47 to 2.80 and 4.78 to 2.10, respectively. Further, the present study modelled the impact of future Sea Level Rise (SLR) on the mangrove ecosystems using a static inundation modelling approach under different Representative Concentration Pathways (RCPs). Results depict a significant loss of mangrove habitats from 9.55 % to 58.33 % and 20.88 % to 48.02 % for both the Pichavaram and Muthupet mangrove regions, respectively, by the end of this century (2100). Since the coastal hazards are expected to intensify, our results can benefit policymakers by highlighting the prioritized areas and location-specific interventions for fostering Ecosystem-based Disaster Risk Reduction (Eco-DRR) strategies.