Evaluation of Recurring Flood Disasters in Indian Cities: High Urban Vulnerability Vs. Extreme Weather Events

Tuesday, 17 July 2018: 17:50
Oral Presentation
Devi JOSHI, Former Director Geological Survey of India, India
In recent decades flood disasters have become a recurring menace to human-settlements in India. Here, it is imperative to focus on urban areas as they are the permanent settlements having extensive systems for housing, transportation, sanitation, education, health and other utilities, concentrated within a limited area. To understand the flood devastation suffered by the urban communities, an analysis of the recent floods (Mumbai, 2005; Kedarnath, 2013; Srinagar, 2014; Chennai, 2015) was undertaken. Two of the disaster events are highlighted here. Extreme rainfall event of November 2015, in the megacity of Chennai located on a coastal landscape, gave rise to catastrophic floods resulting in hundreds of human fatalities, loss of property, damage to infrastructure, and disruption of basic services like health, education, etc. An evaluation of the devastation reveals that uncontrolled urbanization encroaching over wetlands, marshes and natural drainages, was responsible for the Catastrophic floods. The flood disaster of June 2013, in the sacred town of Kedarnath, located in the Higher Himalayan terrain, was triggered by intense rainfall followed by breach of a glacial lake, resulting in thousands of human fatalities and diruption of tourism in the area. However, the devastation was mainly caused by high vulnerability of the town, inherited from unplanned urbanization and its siting on the hazardous floodplain of Mandakini River.

Present study concludes that the flood disasters occurred due to uncontrolled urbanization imparting high vulnerability to the built environment. However, the extreme rainfall events have played to enhance the severity of the flood hazard. Moreover, fourth assessment report of IPCC, warns that climate change would increase the risks of hydro-meteorological disasters in South Asia. Besides, weather patterns also indicate more frequent occurrence of such events in future, necessitating a comprehensive strategy for adaptation, mitigation and urban renewal for reducing the vulnerability and strengthening resilience of our cities.