Effect of 2018 Flood on Land use changes of Achankovil River Basin, Kerala, South West Coast of India

Abstract

The paper discusses the change in land use of Achankovil river basin of Kerala before and after the flood in 2018. A base map of the basin boundary and main stream course is created with the help of GIS (Arc GIS 9.1) from toposheet 1:50000 scale from which the land use map is digitized keeping the scale. Imagery data from google earth is used for updating land use map which is used for field work. Field level information of the basin is input into the land use map and updated with the help of GIS. GPS reading of all the sampling locations is integrated with the land use map to understand the distribution of land use categories and its possible influence on the sampling parameters. Land use map was prepared in April 2018 and repeated in September 2018 in view of the unexpected flood in the state during August 2018. Eight stations such as Achankovil, Konni, Omalloor, Konathumoola, Kaippuzha, Attuva, Pallippad and Veeyapuram covering upstream, midstream and downstream are selected for assessing the impact of flood on land use. From the comparison of land use maps before and after flood, it is clear that the flood has damaged a total of 28.15% land use of Achankovil basin fully or partially. Among the total loss, mixed crops faced the highest damage of 61.81% ,14.79% loss to paddy field, 14.76% of fallow land and 5.92% settlement with mixed tree crops were damaged.