Extreme rainfall events and urban floods in the growing cities of India

Abstract

There has been an increasing trend of urban flood disasters in India over the past several years. An attempt has been made in the present study, to examine urban flood caused by heavy rainfall events (≥ 65 mm) and very heavy rainfall events (≥ 125 mm) for the growing cities in India for the period from 1969 to 2010. Also, the trend analysis of occurrences of heavy rainfall along with favourable synoptic situations has been discussed. Bhopal and Jaipur have shown decreasing trend in seasonal heavy rainfall events. Trend is significant for Bhopal only. Ahmedabad, Hyderabad, Pune and Bangalore show increasing trend in seasonal rainfall though not significant in heavy rainfall events. Monthly trend for heavy rainfall events (≥65 mm) show significant negative (decreasing) trend for the month of June for Lucknow, August for Bhopal and September for Hyderabad. Monthly trends in heavy rainfall events (≥65 mm) show significant positive (increasing) trend for the month of June for Bangalore and Patna, August for Hyderabad and September for Bhubaneswar. In rest of the cases monthly trends are in different. Overall there is no systematic trend in the heavy rainfall events.