Coastal inundation risk assessment using multi-mission satellite altimeter and digital elevation models

Abstract

One of the most significant impacts of climate change is sea-level rise. The rate of global sea levels is expected to continue rising in the future, which would cause severe damage to coastal areas and threaten the nearby population. This study aims to determine the inundation of coastal areas caused by the effects of rising sea levels using a combination of satellite altimeters, Global Positioning Systems, and Digital Elevation Models. The inundation scenarios for the return periods of 5, 25, 45, 65, and 85 years were successfully simulated using the hydrological model obtained from altimetry data. The inundation scenarios were overlain on land elevation datasets to estimate the inundation risks. Vulnerability assessments of inundation risk maps were analysed in ArcGIS environment to develop maps for vulnerable areas and populations. The study revealed that by the year 2100, sea level is projected to be rising at the rate of between 32cm to 50cm for the sub-chosen sea over the Malaysian seas. The results from the assessment also show that Kelantan area is highly vulnerable to the sea-level rise event. At the local scales, nearly 1km2 of total land area is projected to be inundated under the smallest scenario. Under the higher sea level scenarios, over 8.2 km2 is potentially inundated with up to 46,000 people around the coastal and flood plain area of Kelantan, especially near Kota Bahru, could be affected. This study has successfully shown the integration of hydrological model to produce the inundation risk maps, taking into account the extent of land area covered under sea level at different scenarios. Findings are valuable to help the local authorities in developing strategic coastal management plans to address challenges of the climate change.