GEOMORPHOLOGICAL STUDIES FOR DISASTER MITIGATION - A CASE-STUDY OF THE KRISHNA-DELTA, ANDHRA-PRADESH, INDIA

The geomorphology of an area plays a significant role in understanding the impact of cyclonic storms, in association with torrential rains, tidal waters, etc. Hence, the Krishna river delta area, which had been swept by at least 16 severe cyclonic storms and about 60 cyclones in the past 100 years, was selected for a case study. Geomorphological st udy of this highly cyclone prone delta of India, based on interpretati on of Landsat-TM and IRS LISS-I and -II data on the scale 1:250 000 ha s led to preparation of a flood hazard map. This flood hazard map, bri ngs out very clearly the areas which are potentially safer, as well as those areas prone to different degree of flooding due to tidal waters , heavy rainfall, etc. Further, an attempt is made to identify various causative factors responsible for the untold damage, which could have been averted. Poor dispersion of plumes near the drain/creek outfalls and presence of extensive standing flood waters provided a vital clue for identifying choked drains at vulnerable points. Finally, suitable flood alleviation measures were suggested.