Kerala, after the floods: State faces worst deluge in 94 years; similar disasters likely to become common, says report

- Chaitanya Mallapur

Mumbai: Kerala now faces the ravages of the worst monsoon floods in 94 years, with  373 dead  and more than 1.2 million in relief camps after 2,378 millimetre (mm) of rain over 81 days between 1 June and 20 August, 2018–4 percent above normal or three times more than the Indian average for that period—according to  data  from the  India Meteorological Department (IMD).

With extreme weather events and variability increasing in  urban  and  rural  India, as IndiaSpend has previously reported, flooding is likely to become more common, the outcomes  attributable  as much to poor planning as climate change. In Kerala, the monsoons have generally decreased, and that was a reason the state was unprepared for such a ferocious monsoon, an IMD official  told  the Times of India on 21 August, 2018.

Idukki, an epicentre of the flooding where  51 died , recorded the highest rainfall in Kerala and second-highest rainfall (3,521 millimetres) of any Indian district over these 81 days, 93 percent above normal, IMD data said. The highest rainfall in India was recorded over this period in Karnataka’s Udupi district (3,663 millimetres), which, however, was no more than 18 percent above its normal.

Kodagu in Karnataka, where  12 died  after the district was ravaged by floods, faced the heaviest rainfall in  64 years , 290 percent above normal, between 9 August to 15 August, 2018, according to IMD data.

Kerala received 255 percent excess or above-normal rainfall (98.4 millimetres) between 9 August and 15 August, 2018, five times more than India’s average for that period, while Karnataka received 80 percent above-normal rainfall (50.3 millimetres) over the same period, 54 percent above India’s average, IMD  data  show.

In Kerala, 776 villages in 14  districts  were flooded, with 1,398 houses “fully damaged” and 20,148 “partially damaged”, according to the government.

In 1924, Kerala  received  3,368 millimetres of rainfall over 21 days, a deluge that appears to have been more intense than the 2,378 millimetres over 81 days in 2018. While there is no direct causal link between the latest floods and climate change, deforestation and human transformation of flood plains and mountain tops have been  implicated .

Climate change, however, is the larger backdrop against which recent floods in India have been playing out, with more intense, more uncertain rainfall.

Heavier, more uncertain rainfall

Rain events in greater than 100 millimetres in urban India have  increased  over the past 100 years, there is an overall increasing trend of events exceeding 100, 150 and 200 millimetres since the 1900s, and an increasing variability in recent decades, IndiaSpend  reported  on 29 August, 2017.

India accounts for a fifth of deaths globally due to floods and heavy rain, with 1,07,487 people dying nationwide over 64 years between 1953 and 2017, according to Central Water Commission  data  presented to the Rajya Sabha (Parliament’s upper house) on 19 March, 2018. Damage to crops, houses and public utilities was reported to be Rs 365,860 crore–or as much as  3  percent of India’s current gross domestic product–the data show.

On average, more than 1,600 people die every year in floods, which disrupt the lives of nearly 32 million people, the  data  show. More than 92,000 cattle are lost every year, seven million hectares of land—or nearly twice the size of Kerala — is affected and damage estimated at about Rs 5,600 crore.

India could see a six-fold increase in population exposed to a risk of severe floods by 2040, according to study published in Science Advances, a peer-reviewed journal, IndiaSpend  reported  on February 10, 2018, and a 2018 World Bank  study  has warned that climate change could lower the standards of living of  nearly half of India’s population by 2050.

Extreme rainfall  events in central India, the core of the monsoon system, are  increasing  and moderate rainfall is  decreasing –as a part of complex changes in local and world weather–according to a clutch of Indian and global studies  reviewed  in 2015 by IndiaSpend.

The damage caused by such heavy rains and floods are exacerbated, as we said, by poor planning. “The main reasons of floods have been assessed as high-intensity rainfall in short duration, poor or inadequate drainage capacity, unplanned reservoir regulation and failure of flood control structures,” said a March 2018  reply  from the government to the Rajya Sabha, Parliament’s upper house.

The average total rainfall during the peak monsoon season of July and August has declined since 1951, but the variability of rain during these months has increased — deluges are more severe, and dry spells more frequent, as evidence from Karnataka indicates. As August rainfall in the southern Malnad districts has  raised groundwater levels  by more than 4 metre, other districts to the west and north report similar declines, the result of three years of drought.

The August deluge in Karnataka

Despite floods in Kodagu, Chikmagalur, Dakshina Kannada and Udupi districts during the monsoon of 2018, Karnataka received 634 millimetres of rainfall, no more than 3 percent above normal (615 mm) between 1 June and 20 August, 2018, according to official  data , and 9 percent above India’s average for that period.

The coastal district of Udupi received, as we said, India’s highest rainfall for 2018, 3,663 millimetres or 18 percent above the normal (3,108 mm) over the 81 days in question. Between August 9 and August 15, 2018, Udupi received 640 millimetres, 167 percent above normal, followed by Kodagu (508.2 millimetres) and Dakshina Kannada (465 mm).

As many as  161 people  are reported to have died in Karnataka;  12 dead  in Kodagu, as on 20 August, 2018, according to an official release.

About  64 houses were damaged  in Udupi on 14 August, 2018, due to heavy rains and wind, amounting to a loss of Rs 35.8 lakh.

Kodagu, which endured the most flood damage, recorded 290 percent more rainfall than normal (130.3 millimetres) between 9 August and 15 August, 2018.

Idukki worst affected but most excess rain in Thiruvananthapuram

While Idukki  recorded  679 millimetres of rain between 9-15 August, 2018, 438 percent or four times above normal, it was the capital, Thiruvananthapuram, that recorded 617 percent or six times more rain than normal, the most excess rainfall in any Kerala district.

In the first 20 days of August 2018, Kerala received the highest rainfall for the entire month in 87 years, with Idukki district breaking a 111-year record for highest rainfall in a month, the Times of India  reported  on 21 August, 2018.

Thrissur received the least excess rainfall: 180.3 millimetres in actual terms, 76 percent above normal, between 9 August and 15 August, 2018.

(Mallapur is an analyst with IndiaSpend.)