Watershed prioritization using remote sensing and geographical informationsystem: a case study from Guhiya, India

Land resource development programmes are applied generally on a watershed b asis. Delineation of watersheds within a large drainage basin and their pri oritization is required for proper planning and management of natural resou rces for sustainable crop production. An integral part of Guhiya basin (wit h an area of 1614 km(2)) was studied for priority watershed delineation wit h the objective of selecting watersheds to under take soil and water conser vation measures using remote sensing and Geographical Information System (G IS) techniques. Using the terrain information derived from geocoded satelli te data and 1:50,000 topographic maps, 68 watersheds were assessed on the b asis of their erosivity and sediment-yield index values. Thematic maps of l andform, landuse and land-cover, and slope were digitised using ARC/INFO. O n the basis of sediment yield index values the watersheds were grouped into very high, high, moderate and low priorities. High priority watersheds wit h very high SYI value (> 150) need immediate attention for soil and water c onservation whereas, low priority watershed having good vegetative cover an d low SYI value (< 50) may not need immediate attention for such treatments . (C) 2001 Academic Press.