Urban green spaces for climate change

Flash floods and extreme rainfall events are becoming common occurrences now. The recent flood in the Kashmir valley has brought to the focus how nature plays havoc if interventions are inappropriate.

In the year 2005, India’s highly populated city Mumbai was completely shut down due to extreme rainfall and flooding, with flood waters to a depth of 0.5 m to 1.5 m in low-lying areas, causing severe economic losses and damage to infrastructure.

A team of World Bank and climate change experts noted that though the city is prone to frequent floods as being in a tropical region and receiving abundant monsoon rains.
The risk to flood was aggravated by the manmade geography; especially due to inhibition of natural runoff surface water and loss of network of drains, rivers, creeks and ponds that drain directly into the sea (Ranger et al. 2011) and the unplanned urbanisation is again believed to have affected the flood management capacity of the Kashmir valley causing extensive damage.

The IPCC fifth assessment report (IPCC, 2014) predicts more extreme weather events and now there is a strong case to develop climate adaptation and disaster risk reduction in Indian cities to avoid losses.

 However, current urban development policies clearly lack environmental planning and climate adaptation strategies. The open and urban green spaces are decreasing at alarming rates in many Indian cities with growing urbanization.

Loss of space
A study by researchers from the Indian Institute of Science note that Bangalore city has lost much of its open spaces and urban wetlands due to urban sprawl, which has affected the drainage network, local hydrology and the groundwater table.

The percentage of green cover is worse in cities like Chennai (5.17 per cent), Hyderabad (2.25 per cent) and Kolkata (nil), although a few metros fare better ,like New Delhi (20 per cent) and Mumbai (16 per cent) as per the Forest Survey of India latest report (FSI, 2011). Such lack of urban open and green spaces and increased built-up areas causes increased surface runoff and floods when there is extreme rainfall.

Urban green spaces reinforce the process of carbon sequestration and mitigate the effects of climate change, help in abatement of air pollution, reduce urban heat island effect and improve the hydrology by preventing surface runoff and also provide groundwater recharge.

Green spaces can act as buffer by acting as natural storm water drains in cases of extreme events like floods, thus reducing extreme weather-related disaster risk in the cities, which is a cost effective “soft engineering” strategy for climate adaptation.
The National Mission on Sustainable Habitat, which is one of the eight national missions on climate change, unfortunately does not recognise the importance of green space in climate adaptation and disaster risk reduction and the State Action Plans on Climate Change (of 15 States reviewed by the author, see Dhanapal and Panda (2014) for list of reviewed SAPCC) also does not highlight the importance of urban green spaces and Maharashtra that experiences recurrent flood in Mumbai is yet to come with an State Action Plan.

There is strong requirement of interventions from urban local bodies and the government to prevent the conversion of open and green spaces for development with shortsighted economic benefits without valuing its ecosystem services.

The IPCC fifth assessment report strongly recognises the importance of ecosystem based approached to climate adaptation, and it is time that in India the urban development planning and the National and State Plans on Climate Change recognize the use of such cost effective adaptation measures for building climate and disaster resilient cities.