Reasons for the Kerala Floods of 2018

I am deeply distressed as I write this blog: Uttarakhand in 2013, Chennai in 2015 and now Kerala – nature’s fury made much worse by human folly! Such disasters will continue and we will not learn any lessons, nor take preventive actions. Even though your primary purpose is to do well in the Civil Services Examination, please remember that the changing climate is already affecting all of us. Whether you make it to the Civil Service or not, become an eco-warrior!

Why did the Kerala floods occur and why have they caused so much damage?

There are multiple and interconnected reasons for the disaster:

1.   Extreme rainfall over a short period.

2.   Human settlements on the floodplains of rivers.

3.   Deforestation and developmental activities on the Western Ghats.

4.   Building multiple dams and unscientific method of opening the sluice gates during heavy rain.

1.   Extreme Rainfall over a short period

During the first two weeks of August 2018, Kerala received three times the amount of rain it normally gets at this time of the year. Two districts alone, Idukki and Wayanad, received almost as much rain as the normal rainfall that the entire state gets during this time.

Can we attribute the extreme rainfall to global warming and climate change? It is clear that the observed frequency, intensity, and duration of some extreme weather events have been changing as the climate system has warmed. Global warming has led to:

·      An increase in the likelihood of extremely hot days and nights

·      More evaporation that may exacerbate droughts and increased atmospheric moisture that can increase the frequency of heavy rainfall and snowfall events.

However, the extent to which climate change influences an individual weather event (such as the Kerala rainfall) is more difficult to determine. Right now, we can say that extreme weather events are becoming more common across the world and it is reasonable to connect this phenomenon to global warming.

2.   Human settlements on floodplains of rivers

The floodplains on either side of rivers are exactly what the term suggests: a buffer zone which absorbs flood waters. In the past, floodplains were used for growing crops at the right time. In recent decades, however, given the population growth and development pressures, illegal construction on floodplains has been rampant and Kerala is no exception. During the August floods, the buildings on the floodplains were the first to go.

3.   Deforestation and developmental activities on the Western Ghats

While the Western Ghats block the clouds and cause rain, the forests on the Ghats also absorb lot of water and release it slowly. Given the destruction of the forests, the water now just flows away into the narrow strip of Kerala’s land. Further, the flow also causes landslides on the treeless slopes. In addition to deforestation, rampant and unregulated development has been destroying the ecology of the Western Ghats.

In 2010-11, two successive committees (headed by Madhav Gadgil and Kasturirangan, respectively) recommended the declaration of an Eco-Sensitive Zone (ESA) for the Western Ghats. The recommendations also included a ban on mining, quarrying, new dams, and all polluting industries in the ESA. Unfortunately, all the concerned states (Kerala, Karnataka, Tamil Nadu, Gujarat, Maharashtra, and Goa) opposed the establishment of the ESA and the recommendations were never implemented. Karnataka is against the very idea of ESA, while the other five states have raised questions about the demarcation of ESA and the specification of prohibited activities.

4.   Building and mismanaging multiple dams

It is not often realised that dams could be very dangerous, especially in the current context of climate change and extreme rainfall events. In addition to several problems posed by dams (human displacement, destruction of biodiversity, etc), our reservoirs are not managed scientifically. In 2015, Chennai was flooded because three reservoirs were opened at the same time.

In Kerala, there are 42 large dams and it is said that the sudden opening of many dams caused flooding of rivers. How much water should be let out and when? In order to answer these questions, the reservoir managers have to consider many factors: need for hydro power and irrigation water, forecast of rains yet to come, potential for floods, etc. There is as yet no proper decision-support system available to dam managers.

All these four aspects have to be considered for avoiding or mitigating disasters. Beyond rescue and rehabilitation, we need to plan ecological reconstruction and conservation.