Remote sensing and GIS based sea level rise inundation assessment of Bhitarkanika forest and adjacent eco-fragile area, Odisha

Remote sensing and GIS approach were utilized for inundation assessment mainly based on accurate digital elevation map (DEM) and land cover (Level II classification) prepared using high spatial resolution (2.5 m) stereo pair CARTOSAT-1 image and LISS III image of respectively. ERDAS-LPS 9.3 software along with Arc Map 10.0 was utilized for generating DEM which was overlaid on land cover for inundation assessment. In terms of area, the total forest land cover (16909.1 hectare) was classified into four major forest classes i.e. littoral mangrove forest (16234 hectare, 96%) > scrub forest (442.3 hectare, 2.6%) > evergreen nonmangrove forest (215.6 hectare, 1.3%) > deciduous open forest (17.2 hectare, 0.1%). The other ecologically fragile land covers like water bodies (unlined canals/drains, perennial lakes/ponds, dry river streams, perennial river streams, wetlands (inland natural and coastal wetlands) and wastelands (open scrubland, dense scrubland and sandy coastal area) occupied 6480 hectare, 2070.1 hectare and 1118.9 hectare respectively. Based on elevation, land cover area were classified into five inundation sensitive zones viz. very high (up to 0.5 m elevation), high (0.5 -1.5 m), medium (1.5 -2.5 m), low (2.5 – 3.5 m) and very low (> 3.5 m) sensitive zone. For littoral mangrove forest, scrub forest and evergreen non-mangrove forest 10% (1544.5 hectare), 7% (36.6 hectare) and 12% (25.1 hectare) of their total area were in very high sensitive zone. In both the inland and coastal wetland, the maximum area was under high sensitive zone (0.5 -1.5 m elevation) i.e. 517.7 hectare and 489.5 hectares respectively. The present work has delineated vulnerable land cover and its findings will help in planning adaptation measures to minimize the risk due to SLR.