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!
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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.
