Land-use survey of Idukki District

Abstract

The growing population pressure and limited availability of land necessitates proper utilization of the available land through scientific land-use planning. Realizing this fact, a project using multiband aerial photography was taken up with following objectives: identification and mapping of areas under various land uses, study of geomorphology, identification of potential groundwater areas and identification of areas requiring soil conservation and reclamation measures. The major land-use classes mapped are agriculture, forest, wasteland, water bodies and public use. These are further subclassified. Some of the important observations are the reduction in the area under forest and the existence of a large area under wasteland. Geomorphological maps prepared depict slope, relief, drainage and vegetation. With the help of structural and geomorphological maps, the technique of identifying potential groundwater areas has been demonstrated. The land-use maps have a classification accuracy of 86 per cent whereas the accuracy of slopes in geomorphological maps is 72 per cent. The locational accuracy of the land features is 50-150 m on the ground. Visual interpretation of LANDSAT images led to the identification of nine land-cover classes while digital analysis enabled identification of twelve land-cover classes. Significant changes in land cover over a decade (1973-1982) have been noticed. This information has been used for preparation of a detailed land-use plan for the Idukki District.