Assessment of waterlogging in Sriram Sagar command area, India, by remote sensing

Abstract

Waterlogging is becoming a serious problem in irrigated command areas of India. The study area is the Sriram Sagar command, which is about 120 km north of Hyderabad. An attempt has been made to make an assessment of the waterlogged area and those areas sensitive to waterlogging during the pre and post monsoon periods in the Sriram Sagar command using remorely sensed and field data. Indian Remote Sensing Satellite (IRS-1A-LISS-II) digital data (Computer Compatible Tapes) of 12 April and 6 October 1989, were analysed to assess the areas affected by waterlogging and those areas sensitive to waterlogging. The validation of the IRS-derived waterlogged areas, was done using available water table depth data and other field information. The results obtained from this study indicate that in April and October 1989, areas of some 388 and 540 km2 were waterlogged and about 698 and 802 km2, respectively, were sensitive to waterlogging (where the water table lies between 1 to 2 m, respectively, below the ground surface. It is suggested that periodic assessment of waterlogging, using remotely sensed data, should be carried out in the Sriram Sagar command. The IRS data have been proved to be very succesful for the assessment of waterlogging. Density slicing and principal component analysis are useful techniques in making an assessment of waterlogged areas in irrigated command areas.