IRS-1C data application in watershed characterization and management

Watershed characterization and management aims at the optimum utilization of land and water resources on a sustained basis. For a precise inventory of a watershed, components like drainage density and pattern, slope percentage and direction, physiography, soils, land use and land cover, were visually interpreted using the geocoded false colour composites (FCCs) of IRS-1B LISS II and IRS-1C LISS III at 1:50 000 scale. The land use and land cover study indicates that the major land utilization types are single crop (28.8%); double crop (14.3%); scrub land (43.1%); degraded notified/open forest (7.2%); rock outcrop (3.8%) and water bodies (2.8%). The dominant soils are loamy-skeletal, Lithic Ustorthents; loamy-skeletal, Lithic Ustochrepts; fine calcareous, Typic Ustochrepts; fine, Vertic Ustochrepts, and very fine, Typic Haplusterts. The soils are grouped into IIIs, IIIes, IVes and VIes land capability classes; N1, N2, S1, S2 and S3 soil site suitability classes and Wt 1.2, Wt 1.3, Wt 2.5, Wt 3.4 and Wt 3.5 soil degradation classes. Based on soil types, percentage slope, drainage density, bifurcation ratio and constant channel maintenance ratio, the soil conservation modules like field bunding, contour bunding, Nala lining and Nala plug/cement check dams were erected. Soil conservation modules, particularly field bunding/ contour bunding improved the moisture status in soils of subdued plateau and upper pediment and resulted in a better harvest of crops under monocropping. Grading and terracing of lower pediments helped to harvest run-off into farm ponds for further recycling of water for agro-horticultural crops. Nala lining and Nala plug/cement check dams in the valley regions have helped in improving the irrigation potential for crops under double cropping system and agroforestry on the plateau top by further reducing the denudation process.