Mapping and monitoring of degraded lands in part of Jaunpur district of Uttar Pradesh using temporal spaceborne multispectral data

Apart from soil erosion by wind and water, the major land degradation proce sses operating in irrigated commands in arid and semi-arid regions are wate rlogging and subsequent salinization/alkalinization. Remote sensing data ha ve been used successfully in studies of the spatial extent, magnitude and t emporal behaviour of lands affected by such processes. In this work we inte rpreted Landsat Multispectral Scanner images acquired during 1975 and Lands at Thematic Mapper data acquired during 1993, in conjunction with ancillary information and adequate ground data, to derive information on the extent and spatial distribution of various degraded lands, namely salt-affected so ils, waterlogged areas and eroded lands in part of the Jaunpur district of Uttar Pradesh. The results indicate a significant shrinkage in the spatial extent of salt-affected soils (of the order of 49.76%) over the period 1975 to 1993. A similar trend was observed in the temporal behaviour of waterlo gged areas, but an increase (6.45%) was found in the spatial extent of erod ed lands. The methodology employed and the observations made are described here in detail.