Water Resource Assessment and Management in Himalayan Catchments through Remote Sensing and GIS Technology

Abstract
Mountains are the “Water Towers” of the 21st Century. More than half of the humanity relies on the fresh water that accumulates in mountains. Unlike a resource like oil for which coal, wind or nuclear power can be alternative, water has no substitute. Scientific management for sustainable development of mountain water resources must therefore, becomes a global priority in a world moving towards water crises in this Century. The Himalayan Mountains harbors a network of catchments, which feed all major rivers of Indian sub-continents. The present investigation is a preliminary assessment through Remote Sensing and GIS approach of the effects on the increasing and complex array of human impact upon the hydrological regime of the selected catchments of the Koki River. This study is set in the forest cover and open landscapes with relatively inactive tectonic environment.

Understanding the comparison among the calculated runoff (SCS method), observed runoff and water balance(TM method) has been achieved for 2-3 years data using Remote Sensing and GIS approach. The result and conclusions are-

The study demonstrated that interactive of spatial data and applying empirical methods in GIS provide a powerful tool of water resources assessment.
In agricultural catchments during 1994 and 1995 the observed runoff is about 19.4% and 16.7% of annual rainfall respectively, whereas the calculated runoff is only 3.2% and 3.8%.
In forest catchments the observed runoff was recorded during the year 1994 and 1995, which was 18% and 27% of the rainfall respectively.
The annual mean runoff calculated as 261.76 mm. The maximum percentage of runoff takes place during the months of August, September and October. The annual average surface runoff volume from catchments is 15.56 M cum.
The catchments undergo a period of moisture deficit during the month of January to June, from July to August region has a surplus, which is again followed by a period of deficit.
Such studies can be beneficial for hill people who can according to the periods of deficit or surplus take crop that are less or more water consuming. Water management steps also can be taken well in advance seeing the periods of deficit and surplus