Inundation mapping – a study based on December 2004 Tsunami Hazard along Chennai coast, Southeast India

Tsunami impact study has been undertaken along Chennai coast starting from Pulicat to Kovalam. The study area Chennai coast is mainly devoted to prepare large scale action plan maps on tsunami inundation incorporating landuse details derived from satellite data along with cadastral data using a GIS tool. Under tsunami inundation mapping along Chennai coast an integrated approach was adopted to prepare thematic maps on land use/land cover and coastal geomorphology using multispectral remote sensing data. The RTK dGPS instruments are used to collect elevation contour data at 0.5m intervals for the Chennai coast. The GIS tool has been used to incorporate the elevation data, tsunami inundation markings obtained immediately after tsunami and thematic maps derived from remote sensing data. The outcome of this study provides an important clue on variations in tsunami inundation along Chennai coast, which is mainly controlled by local geomorphologic set-up, coastal zone elevation including coastal erosion protection measures and near shore bathymetry. This study highlights the information regarding most vulnerable areas of tsunami and also provides indication to demarcate suitable sites for rehabilitation.