The delineation of reclamative groups of ravines in the Indo-Gangetic alluvial plains using IRS-1D LISS-III data

Ravines, the intricate network of gullies and almost the penultimate stage of soil erosion by water, need to be reclaimed and their fertility restored, and normal fertile land needs to be protected from eroding away. Information on the nature, extent spatial distribution and temporal behaviour of ravines is a prerequisite in this endeavour. Spaceborne multispectral measurements by virtue of synoptic coverage at regular intervals hold immense potential for deriving the desired information in a timely and cost-effective manner. We report here the results of a study that was carried out to delineate the reclamative groups of ravines in the Bhind district of Madhya Pradesh, central India, using Linear Imaging Self-scanning Sensor (LISS-III) data from the Indian Remote Sensing Satellite (IRS-1D) mission. The approach essentially involves on-the-screen monoscopic visual interpretation of false colour images generated from pre- and post-monsoon LISS-III digital data after geo-referencing to Survey of India topographic maps at 1:50?000 scale, on a Silicon Graphics workstation using ERDAS/IMAGINE version 8.3, in conjunction with the ground truth and information on the terrain's relief derived from topographical maps. Information on land use/land cover derived from temporal LISS-III data enabled three reclamative categories of ravine to be delineated, namely shallow, medium and deep. The area under deep, medium and shallow ravines has been estimated to be 112?ha, 12?700?ha and 28?600?ha, respectively. The land use/land cover of these units further helped in identifying the areas requiring immediate attention.