World’s greatest cities were founded on the banks of rivers (or other water sources such as lakes) to provide for not only drinking water but other basic amenities such as sanitation and transportation. What worked as a boon for our first urban dwellers has become a bane for our present cities.
While rivers flood due to natural causes from time to time, what has made this natural phenomenon a disaster is its increasing frequency and intensity due to interference by man.
Indian cities are growing at an unprecedented speed. Every day thousands migrate to urban areas in search for a better life creating pressure on the existing resources.
In the absence of an adequate infrastructure of drainage, sanitation and roads, there has been an increasing trend of urban flood disasters in India over the past several years. The most notable amongst them are Hyderabad in the year 2000, Mumbai in 2005, Kolkata in 2007, Srinagar in 2014 and Chennai in 2015. The issue is now once again making headlines due to last week’s floods in Mumbai.
While floods in a city indirectly affect almost every resident as communication and transportation are disturbed, low and middle-income groups are likely to be affected more. These groups are more vulnerable due to their limited capabilities to deal with a disaster because of poor quality and insecure housing; inadequate infrastructure; and lack of provision for health care, emergency services, and disaster risk reduction.
Impact Of Climate Change
Urban flood usually starts with very heavy and localised downpour which the existing infrastructure cannot manage. This severely disrupts public transport, electricity and communications and also plays havoc with the urban economy.
Heavy rainfall is always a complex geographical phenomenon and cannot be attributed to a single cause. For example, the 2015 flood in Chennai was explained associated the El Niño effect on the North East monsoon. The flooding of Mumbai in 2005 involved an interplay of four geographical factors, mainly the development of a low-pressure area over the northwest Bay of Bengal, intensification of the monsoon, strengthening of the Arabian Sea current of the monsoon, and the super positioning of a meso-scale off-shore vortex over northeast Arabian Sea (localised heavy clouds over the sea).
Global climatic changes have a profound and long term impact on natural phenomenon such as those mentioned above, thus disturbing their intensity, duration, frequency and spatial distribution. Climate scientists have long warned about changing monsoon rainfall patterns in India.
A recent report by the Intergovernmental Panel on Climate Change (IPCC), the United Nation’s climate change body has argued an increased risk of flooding and alterations in rainfall patterns due to global warming. As opposed to the situation a few decades back, there are now more incidences of high-intensity rainfall concentrated over a short span of time and area instead of a steady monsoon season.
Is Unplanned Growth The Real Culprit?
What makes the effects of global climatic changes even more severe is the inability of our cities to cope up with the changing situation. Most of the sewerage and drainage network is old and unable to deal with the new challenges faced by our cities. They cannot handle the volume of water and are often blocked due to structural faults or pollution due to unwanted materials (plastic and other non-biodegradable).
As new constructions come up on hitherto permeable land, the runoff into drains increases. With the land hunger increasing, most of the cities also see real estate development encroach upon floodplains, thus obstructing floodways and disturbing the natural flow the water body.
Urbanisation thus has five major hydrological effects:
(1) increased water demand, often exceeding the available natural resources
(2) increased wastewater, burdening rivers and lakes and endangering the ecology
(3) increased peak flow
(4) reduced infiltration and
(5) reduced groundwater recharge, increased use of groundwater, and diminishing base flow of streams.
We are thus committed to mainstream disaster risk reduction by investing in resilient infrastructure, urban planning, land use, etc. to not only reduce the risk of flooding but reduce the losses of lives and livelihoods in case it occurs. While India has adopted this voluntary framework almost two years back, changes on the ground regarding civic planning, infrastructure and disaster mitigation is yet to be seen.
Much of the blame for unpreparedness of Indian cities to deal with natural hazards is put on municipal corporations. While most of the municipalities have been shamefully negligent of their duties, they alone cannot be blamed. The planning and development authorities are under the state governments (urban planning is a state subject). As a result, those who plan the cities have no accountability and those who are elected have no authority. While globally, cities are driving responses to deal with climate change, devolution of power to the city mayor and municipalities remain a mere formality.
Thus what is needed is a locally driven strategy to combat climate change and disaster management. It’s time that environment and disaster management are mainstreamed into the urban planning process in acknowledgement of the reality of climate change. Currently, the response of our city governments is ad hoc, and responsive, i.e. steps are taken to fix the damage caused by a calamity rather than planning in advance.
Complex challenges like this require a multi sectoral approach which should be ideally designed with inputs from multiple stakeholders. There must be an integration of climate sensitive sectors such as water, roads, sewerage, housing and so on rather than the current fractured approach of various departments. Local level planning would also make the process more flexible to deal with on ground challenges.