An analysis of recent floods, which ravaged Greater Hyderabad recently, point to the fact that though the intensity of rain was lower compared to the August 2000 and earlier floods, the impact was higher due to indiscriminate urbanisation and encroachment of drains.
Three low pressure areas, which formed in quick succession over West Central Bay of Bengal and moved across coastal AP over to Telangana and adjoining areas between August 25 and September 27, 2016, resulted in heavy rains in three spells over coastal AP and Telangana. The death toll was put at 52, loss to crops and infrastructure at Rs.2,200 crore and the estimated loss in Hyderabad city alone was put at Rs.1,157 crore, according to Telangana Government estimates.The high magnitude of destruction and damage occurred partly due to the natural disaster but they were mainly man-made due to encroachments along water ways and illegal constructions on lakes and river beds, says former Director of the India Meteorological Department P.V. Rama Rao, who analysed the three systems based on rainfall data obtained from the IMD.
During the southwest monsoon season (June to September) low pressure systems form or move over west central and adjoining North West Bay of Bengal off Andhra and South Odisha coasts trigger, activate or even revive monsoon flow over AP and Telangana.The low pressure systems increase rainfall in their vicinity and in the areas along the path followed by them. They cause vigorous monsoon with very low clouds and heavy rains, especially in the west and south and greatest in the southwest sector of the system.Southwest monsoon is the main rainy season over Telangana and AP.
During the present southwest monsoon season, Telangana received 90 cm, coastal AP 67 cm and Rayalaseema received 39 cm of the average total rainfall respectively.