SR-1/2002-03 : Application of remote sensing and GIS in water logging studies

Abstract

Waterlogging is one of the major land degradation processes that restrict the economic and efficient utilisation of soil and land resources in command areas. Since Independence, various irrigation schemes, for providing water for agriculture and drinking have been taken up by central and state agencies in India. In these schemes very little effort have been made for proper drainage. Due to obstruction of natural drainage by way of construction of roads, railways, aerodrome, various structures etc., causes the ponding of monsoon runoff on the upstream of the structures. This has happened at many places, which in turn has disturbed the surface hydrology of the areas. Subsurface waterlogging occurs due to rise in water table and water remaining in the root zone, which adversely affects the crops because of inadequate ground water drainage.

In view of this situation it is becoming imperative not only to monitor the problem over time and space but also to look at it in totality for its prevention and control. Waterlogging information had been generated through conventional surveys using cadastral maps and / topographical sheets - a tedious, time-consuming and impractical process, especially in rugged or inaccessible terrain. The conventional means are however, not only difficult and time consuming but also laborious due to vagaries of the weather. Remote sensing is one of the key tools in monitoring local, regional and global environment issues. The development of aerial photograph interpretation and the subsequent advances in satellite remote sensing and image processing techniques have enabled the detection, mapping and monitoring of waterlogged areas in a timely and cost-effective manner. Advantages of the information acquired by satellite remote sensing are of synoptic coverage, repetitive and the easiness to compare the data before, during and after monsoons.

This report attempts to present the information about the extent of waterlogging , conventional methodology in brief and application of remote sensing technique in detail.