Ecological Approach for Mitigation of Urban Flood Risks
|1Energy & Wetlands Research Group, Centre for Ecological Sciences [CES], Indian Institute of Science, Bangalore – 560012, India.
*Corresponding author: firstname.lastname@example.org
Floods in an urbanised landscape refer to the partial or complete inundation from the rapid
accumulation or run-off resulting in the damage to property and loss of biotic elements
(including humans). Urban ﬂooding is a consequence of increased impermeable catchments
resulting in higher catchment yield in a shorter duration and ﬂood peaks sometimes reach up
to three times. Thus, ﬂooding occurs quickly due to faster ﬂow times (in a matter of minutes).
Causal factors include combinations of loss of pervious area in urbanising landscapes,
inadequate drainage systems, blockade due to indiscriminate disposal of solid waste and
building debris, encroachment of storm water drains, housing in ﬂoodplains and natural
drainage and loss of natural ﬂood-storages sites. Flood mitigation in urban landscape entails
integrated ecological approaches combining the watershed land-use planning with the regional
development planning. This includes engineering measures and ﬂood preparedness with the
understanding of ecological and hydrological functions of the landscape.
Bangalore is experiencing unprecedented urbanisation and sprawl in recent times due
to concentrated developmental activities with impetus on industrialisation for the economic
development of the region. This concentrated growth has resulted in the increase in population
and consequent pressure on infrastructure, natural resources and ultimately giving rise to a
plethora of serious challenges such as climate change, enhanced green-house gases emissions,
lack of appropriate infrastructure, trafﬁc congestion, and lack of basic amenities (electricity,
water, and sanitation) in many localities, etc. This study shows that there has been a growth
of 632% in urban areas of Greater Bangalore across 38 years (1973 to 2010). Urban heat
island phenomenon is evident from large number of localities with higher local temperatures.
The study unravels the pattern of growth in Greater Bangalore and its implication on local
climate (an increase of ~2 to 2.5 ºC during the last decade) and also on the natural resources
(76% decline in vegetation cover and 79% decline in water bodies), necessitating appropriate
strategies for the sustainable management.
Citation : Ramachandra T. V., Uttam Kumar and Bharath H. Aithal, (2012), Ecosystem Approach for Mitigation of Urban Flood Risks. Chapter 7, In: Ecosystem Approach to Disaster Risk Reduction (Eds. Anil K. Gupta and Sreeja, S. Nair). Published by National Institute of Disaster Management (NIDM), Ministry of Home Affairs, Govt. of India, IIPA Campus, New Delhi - 110002, India, pp 103-119.