The Indian states of Tamil Nadu and Andhra Pradesh experienced the worst deluge during the months of November and December in 2015, due to “freak weather” conditions that developed in the Indian Ocean. On the 1st December 2015, Chennai (Tamil Nadu’s capital city) received a record 490 mm of rain over a 24 hour period. While many link these developments to an exceptionally strong El Niño phenomenon, the Indian Meteorological Department insisted that this could not be explained by the El Niño alone; rather it is an outcome of interplay between several factors, including upper air divergence (a phenomenon in which lower-level moisture supply remains high and upper air evacuation of the moisture is strong) and formation of low pressure systems.
Radical Shifts in Weather Patterns
The 2015-2016 El Niño has been predicted to be the “strongest ever”. While many parts (mainly the tropics and sub-tropics) of the world are affected by sweltering heat and drought, others are hit by heavy downpour. 2015 was the hottest year ever recorded, in terms of both land and ocean temperatures. India has been one of the world’s worst-hit countries. El Niño is known to have impacted both the south-west and north-east monsoons in the country. While the south-west monsoon ended with a deficiency of 14 percent, the north-east monsoon was forecast to be above average, which indeed was the case.
Such occurrences of high episodic rainfall have become more frequent and intense. Studies show that there has been a “10 percent increase per decade in the level of heavy rainfall activity since the early 1950s” and “the number of very heavy events has more than doubled.” Scientists of the Indian Institute of Tropical Meteorology have warned of more such “erratic behaviour”, which they regard as “regional manifestation of climate change.”
India has been a victim of many such episodes in the past few years – the 2005 Maharashtra floods (that devastated the business hub of India, Mumbai); the 2013 Uttarakhand floods (that killed more than 5,000 people and obliterated many pilgrimage centres) among them; and the latest being the floods in Tamil Nadu in which the port city of Chennai saw its worst rainfall in 100 years.
What Caused Chennai’s Floods – Are Disasters more Human-made than Natural?
There is one common element in all these disasters; that apart from the obvious extreme weather event, what really aggravated the ‘disaster’ was the human element, or rather human intervention. In cities such as Mumbai and Chennai, poor urban planning was what caused the real ‘disaster’. Haphazard urbanisation, encroachments, poor reservoir management, blocked drains, massive construction drive and indiscriminate solid waste disposal – are all to blame for the disaster that struck Chennai.
Rapid and unplanned urbanisation – expansion of transport systems and housing, and creation of Information Technology (IT) corridor and special economic zones (SEZs) among others – has come at the expense of many critical ecosystems that should have been catchment areas. The marshlands of Pallikaranai have been reclaimed to erect multi-storey residential and industrial buildings. Ironically, even the National Institute of Ocean Technology, which looks into repercussions of construction on water bodies and provides environmental impact assessments on various other subjects, occupies a part of the marshlands (reduced from a 50 square kilometre freshwater swamp to a meagre 4.3 square kilometre one).
In another instance, the British (colonial) administration had built the Buckingham Canal in early nineteenth century for the purposes of canal navigation and water management in the city (mainly due to the volatility in rainfall patterns causing both flooding and drought). It is said to have the capacity to carry up to 5,600 cusecs of water. This canal, which could have saved Chennai from the 2015 deluge, was wrecked by a Mass Rapid Transit System. Furthermore, the new airport has been built on the floodplains of River Adyar. To cut a long story short, the IT corridor, SEZs, engineering colleges, residential complexes, expressways and bypass roads – all these are mostly occupying erstwhile drainage courses, wetlands, lakes and other water bodies.
Another cause for the flooding was identified as disastrous reservoir management. Chennai has forecasting and early warning systems such as the Doppler Weather Radar in place. Although various meteorological agencies had warned of heavy rainfall in late November and early December in the city, no major steps were taken to manage the reservoirs appropriately by releasing adequate amount of water (accompanied by prior warnings to the people residing in the catchment areas and/or by evacuating them) before the heavy rains had begun. For instance, the mismanagement of Chembarambakkam reservoir has been pinpointed as one of the biggest factors behind flooding in many parts of the city. The storage was set at high levels and in fact when the rainfall was minimal between November 24 and November 30, the storage levels were kept at 85-88 percent of the total capacity of the reservoir. Hence, when it rained intensely the following day on December 1 (to the tune of 48 centimetres), the reservoir was breached and the outflow had to be augmented (almost 29,000 cubic feet per second (cusecs) over 12 hours) to such an extent that Adyar River swelled up and inundated many low-lying areas.
The fact that Chennai did not learn from the Mumbai disaster, which occurred not so long ago in 2005, is quite apparent. The question remains if Mumbai itself has done enough since then to prevent another disaster of similar or higher scale and intensity. After the 2005 floods, Mumbai might have put in place a robust flood prediction and warning system, including automatic rain gauges and disaster control room for transmission of real-time data. But on the city planning and infrastructure front, builders are exploiting loopholes to go ahead with their projects including on salt-pan lands. Many damage-control measures that were announced to improve the drainage system and to revive Mithi River (that served as a storm water drain earlier but its banks had broken as it had been reduced to a sewer due to human activities) as per the recommendations of a committee that was set up by the State Government of Maharashtra have either missed the deadline (and are moving at snail’s pace) or have been implemented in an shoddy manner, raising the risks of flooding further rather than alleviating them. Like in Chennai, the drainage systems of Mumbai are not equipped to handle high episodic rainfall.
The Far-fetched Implications of Urban Flooding
Urban flooding is an issue that India cannot afford to take lightly, especially at a time when its cities are growing rapidly. Cities are the economic centres – of manufacturing, services, R&D (research and development) and so on. More than 500 people are said to have lost their lives in the Chennai floods. They have reportedly caused a loss of US$3 billion to the Indian economy, with the IT companies alone suffering a loss of US$60 million. However, what has also been noticed is the reality that the insurance penetration in India is very low with reported insurance claims of just US$300 million from the General Insurance Corporation of India (the sole reinsurance company in the Indian insurance market). This needs to change as the insurance sector is one of the foremost drivers of policy change in environmental risk assessment and management. It would be more proactive in brainstorming and putting in place sustainable and risk aversive solutions to tackling environmental challenges confronted by cities since it ends up being the worst-hit sector when such disasters strike, creating huge physical and financial losses.
Talking about the far-fetched effects of such disasters, when cities are struck by them, the implications are not just local; their impacts are felt across the globe. For instance, the 2011 Bangkok floods took a toll on the global business and consumer confidence by disrupting manufacturing and production in a number of sectors. In the same vein, if India desires to translate its national programme – “Make in India” – into a successful venture, the government would have to regularise urbanisation and increase its cities’ resilience through sound adaptation strategies, so that investor confidence is not dampened.
Cities at Risk on a Global Scale: The Need for International Response
Looking at the larger picture, Indian cities are not the only ones that are being pressured by such vagaries of environmental change and indiscriminate developmental activities. Much of the developing world is struggling to cope with these challenges. While Bangkok (Thailand) has repeatedly been affected by floods (almost an annual phenomenon), Jakarta (Indonesia) has also been in the news for flooding events including in 2015 when even the Presidential Palace and the National Museum were inundated, mainly due to insufficient pumping capacity. A drought-hit São Paulo (Brazil) was struck by floods in 2015. Shanghai (China) is at risk of being submerged not because of rising sea levels but land subsidence (caused by poor water management and more specifically, unregulated ground water extraction). Even though some of these cities are known to receive heavy annual rainfall, the damaging effects are increasing while the mitigation efforts are not in commensurate with the risks being faced by them. Cities such as Mumbai, Jakarta, Shanghai are below sea level and this adds to the problem. Therefore, besides the rainfall, a slight rise in sea level could result in sea water coming in and further exacerbating floods.
Even in the ‘developed’ world, the challenges are plentiful. In the U.S., the December 2015 floods that affected the states of Missouri, Texas, Illinois, Arkansas, Oklahoma, Mississippi, Tennessee, Alabama, Kentucky and Indiana generated economic losses worth US$4 billion. In the month of December alone, floods in the U.S. and the U.K. have led to insured losses to the tune of US$4.2 billion. Cities such as New York and London have overstretched infrastructure as well. The mistakes that Mumbai and Chennai are making right now have already been made by the developed countries in the past. Despite measures being taken, the uncertainties in weather and climatic patterns have nullified them.
All these stories point to the fact that much more needs to be done at the international level to save these cities – that are densely populated and are also the financial centres that drive the international economy. As the Paris climate deal is enforced, one aspect that every nation state needs to take into consideration is helping cities become more resilient to the environmental/climatic/physical challenges. As countries have agreed to dedicate significant amount of resources to adaptation, this is one area that the international community cannot afford to neglect as it affects them all – whether it is in urban planning or setting up early warning systems. Through climate diplomacy, countries could cooperate in this direction and mitigate the effects of disasters (such as flooding caused by freak weather events) on cities. India, being home to some of the most disaster-prone cities of the world, needs to lead international efforts just as it did in the case of the global solar alliance.
Dhanasree Jayaram is Project Associate, Manipal Advanced Research Group (MARG), Manipal University, Karnataka, India
Disclaimer: The views expressed in this article are personal.