Inundation Risk Assessment for Nagapatinam Coast, Tamil Nadu, Southeast Coast of India - Monitoring and Prediction of Tropical Cyclones in the Indian Ocean and Climate Change - page 364

Table 1: Areal extension of inundation (km 2 ) under various categories of land use
for 1 to 5 m run up height

Land use/Land cover 1 m 2 m 3 m 4 m 5 m

Agriculture land 1.53 7.408 20.802 40.223 59.089

Aquaculture 0.653 0.892 1.595 2.840 4.122

Creek 5.129 6.235 8.478 11.016 13.012

Fallow land 0.000 0.004 0.035 0.168 0.345

Forest blank 0.001 0.014 0.261 1.854 2.850

Land with scrub 5.591 10.203 20.274 35.554 49.726

Land without scrub 2.052 3.163 5.635 11.039 16.455

Mangrove 3.166 4.342 5.795 8.247 12.157

Marshy vegetation 0.714 0.924 1.505 2.603 3.829

Mud flat/ Tidal flat 12.292 17.762 29.172 41.529 49.859

Plantation 2.616 4.846 8.647 14.812 22.209

River / Canal 9.139 10.696 13.399 17.565 21.124

Salt affected area 0.002 0.018 0.074 0.193 0.515

Salt pan 0.303 0.532 2.040 4.189 7.139

Sandy area 10.644 12.975 17.153 25.244 31.967

Scrub forest 0.001 0.006 0.079 0.504 0.898

Settlement 1.415 2.375 4.790 10.212 17.661

Waterlogged area 2.681 3.522 4.882 6.331 7.715

Total area of submergence 56.399 85.915 144.616 234.121 320.673

If we consider a run up height of three metres, mud flat, sandy area, land
with scrub creeks and river mouth are most affected by the inundation. The
area under submergence for settlement, agricultural, plantation and mangrove
lands are respectively 4.7, 20.8, 8.6 and 5.8 km 2 . Under four-metre run up
height, inundation extends beyond the coastline and valuable land cover viz.,
agricultural, plantation, mangrove and settlement areas are very well affected.
For a run up level of five metres, agriculture land, plantation, settlements
and mangrove lands are highly affected. Under this scenario, nearly seven
towns and 63 villages (Fig. 6) are expected to be severely affected. The total
number of houses and population in these villages and towns are 1,32,939 and
5,99,682 based on 2001 census data.
In order to obtain precise information of area and population that may get
affected due to inundation, 2010 Google Earth high resolution images were
obtained and digitized into a map layer of settlement. An overlay of resulting
settlement layer with 5-metre run up height inundation map reveals that 16.28
km 2 of settlement area becomes submerged under this scenario (Fig. 6). Since
the 2004 tsunami run up height was around 2.6 to 5.6 m (Murthy et al., 2006)
along the Tamil Nadu coast, the entire settlements falling under this category
can be considered to fall under highly vulnerable category.