Delineating ravinous areas on aerial photographs and satellite Imagery-A comparative study

Extensive areas along Yamuna, Chambal and their tributaries in Uttar Pradesh, Rajasthan and Madhya Pradesh have been severely eroded forming ravines of various depths. These areas offer great potential for the development of agriculture and forestry after reclamation. In order that they are reclaimed and managed properly, precise data on their nature and extent are needed. Morphometric analysis of ravine lands along Chambal and Kunwari rivers near Bhind, Madhya Presdesh has been carried out using 1:25,000 scale aerial photographs. Landsat imagery for the same area has been interpreted to find out the relative recognition of morphometric units earlier interpreted on air photos. It was observed that while aerial photographs provide data regarding depth, width, slope and frequency distribution of ravines at a greater detail, Landsat imagery helps in delineation of broad reclamative groupings which would be useful for Large Area Planning (LAP). A multistage approach involving the use of both air photos and satellite imagery seems to be the possible answer for preparing a Ravine Map of India.