Kerala flood less intense than deluge of 1924, so why was damage as great?

Kerala’s once-in-a-lifetime rainfall was 2,378 mm over 88 days, four times more than normal–but 30 per cent less and spread over 61 days more than the deluge of 1924, the most intense flood in the state’s recorded history, submerging as it did almost the entire coastline.

So why was the flood of 2018 as devastating as the 3,368 mm rainfall that Kerala received 94 years ago (locally called the “deluge of 99”, since it occurred in the year 1099 of the Malayalam calendar).

That’s because Kerala has reduced its capacity to deal with such extreme floods by allowing illegal stone quarrying, cutting down forests and grasslands, changing drainage patterns and sand mining on river beds, said experts.

“Rampant stone quarrying and digging of pits is the reason behind the landslides and landslips, which worsened the situation in the Kerala floods,” Madhav Gadgil, ecologist and founder of the Centre for Ecological Sciences at the Indian Institute of Science, Bengaluru, told IndiaSpend.
“These quarries cause deforestation and block the natural streams, which help in reducing the intensity of the floods.”