Theme 8-8-Identification of potential water harvesting sites using GIS & remote sensing technologies - A case study of Sadiyagad watershed, central Himalaya, India.

Abstract

The identification of water resources and its proper management practices are very essential with respect to the population growth and their increasing needs. Geographical Information Systems (GIS) and Remote Sensing (RS) are powerful tools to manage and analyze spatially distributed information. ArcView, a powerful desktop GIS to visualize, update, analyze geographic information, and create quality presentations that brings the power of interactive mapping and analysis, was used in the present study. An attempt was made for the identification of potential water harvesting sites which can fulfil both the drinking and irrigation needs of the population living in the Sadiyagad watershed.

The GIS and Remote Sensing techniques provided the base information on the land-cover and land use maps, the pattern and placement of villages, forest, agricultural land and road network. Using an elevation contour map prepared in ArcInfo (version 3.4); a Digital Elevation Model (DEM) was prepared in ArcView (version 3.0) on a desktop computer system. From the DEM model we have developed models for Flow Direction, Flow Accumulation, Stream Channels and finally Unique Basins to split the whole watershed into 9 basins. Spring criteria and stream criteria maps were developed using the land use and infrastructure maps to reach our final target of finding the suitable sites for the construction of storage tanks. In all 40 sites were identified which could be developed for harvesting runoff water for the purpose of irrigation and other domestic uses. Out of these, 21 sites are within 100m from the road and easily accessible; about 50Km2 area can be irrigated within 1/2km distance from these potential sources in the Sadiyagad watershed.