LAND DEGRADATION AND ITS SPATIAL TEMPORAL CHANGES INDUCED BY NATURAL EVENTS IN ANDAMAN ISLANDS

Abstract

Land degradation has emerged as a global issue which necessitated appropriate techniques to monitor and technologies to manage them. In the present study changes in land degradation status (2004 – 2013) in Andaman Islands was carried out using remote sensing data in addition to assessing the effect of tsunami and its after effect on land degradation. The island suffers mainly from water erosion, acidity, coastal water logging and salinity of varying degrees. The results indicated that salinity and water logging have become severe from slight in the meantime it recorded 25% increase in area. Similarly erosion has become moderate from slight wherein 10% increase in coastal erosion was observed. Agricultural areas recorded the maximum increase in soil erosion at 28.5 t/ha in the post tsunami period while it was only 20.5 t/ha in 2004 followed by plantation crops. Raised beds has helped to leach out the salts resulting in significant reduction in salinity, SAR, Na+, Ca2++Mg2+, Cl- and SO42- level.