Madhav Gadgil, May 2016. Photo: Syed Shiyaz Mirza/Wikimedia Commons, CC BY-SA 4.0.
Kottayam: Madhav Gadgil, the head of the Western Ghats Ecology Expert Panel (WGEEP), which prepared the noted Gadgil Committee report, said if the Kerala government had heeded the report’s recommendations, the extent and the intensity of landslides in Kerala in 2019 and 2020 could have been much lower.
The report was submitted to the Government of India on August 31, 2011.
In an email interview with The Wire Science, Gadgil – reacting to the human death toll reaching 49 after landslides at Pettimudi, near Munnar – said the landslides have been “disasters waiting … to happen”.
In 2011, WGEEP had designated this part of Kerala a region of highest ecological sensitivity, or ecologically sensitive zone 1 (ESZ1). “In Kerala, rainfall increases steeply with elevation,” Gadgil said. “High rainfall and steep slopes render localities susceptible to landslides, so ESZ1 areas are susceptible to landslides.”
“We strongly recommended avoiding … the construction of buildings and roads, quarrying or mining, replacement of natural vegetation by plantations or levelling of the land using heavy machinery. Therefore, we expect that in ESZ1 areas, such disturbance … would mean greater danger of landslides.”
“Unfortunately, not only have our recommendations to bring such disturbing activities to a halt been ignored – the pace at which these disturbances are taking place has increased over the last nine years.”
In March 2017, T.V. Sajeev, a forest-entomologist, and Alex C.J., a landscape ecologist – both at the Kerala Forest Research Institute, Peechi – presented a study that drew the ire of quarry owners and operators. They had found that there are 5,294 quarries occupying 7,157.6 ha in Kerala. Of this, Central Kerala had 2,438 quarries covering 3,610.4 ha. Idukki district in particular had 328 quarries over 258.59 ha.
According to the duo, shockwaves from blasting rocks could have gradually weakened other rocks that then increased the risk of slides. Their study presented correlational evidence of this hypothesis.
So “regrettably the Pettimudi landslide tragedy,” Gadgil said, “was no surprise.”
According to him, the Pettimudi landslide is very similar to what happened in Puthumala in 2019. “I understand that a big rock overtopping the tea plantations had slipped down over the settlements of Tamil dalit labourers, leading to this horrifying tragedy,” he recalled.
“The extent of intact natural vegetation is the third component for assignment of ESZ1. Landslides are under check in areas with intact natural vegetation because the roots bind the soil,” according to Gadgil.
There’s also the matter of vapour condensing when there is an updraft. “The Western Ghats force moisture-laden winds coming from the Arabian Sea to rise, resulting in high levels of rainfall on the western slopes and the crestline of the Ghats,” Gadgil explained. “Elsewhere, air may rise if the ground below is locally heated. This happens wherever the original vegetation cover of the land has been replaced by cement-concrete jungles – of cities, highways and rocks exposed due to mining and quarrying.”
Indeed, Gadgil said the entire west coast is plagued by blatant violations of coastal regulations. These include highway construction that destroys what tree cover remains and activities for the Vasco Da Gama Coal Port in Goa, the Tadadi Coal Port in Karnataka and the Vizhinjam Coal Port in Kerala.
A.V. George, a senior environmental scientist, said the state disaster management plan also needs to be modified in light of the Pettimudi landslides interpreted together with the climate crisis. “The change in rainfall patterns – from raining in June and July to [also raining in] August has been noticeable in the past two years,” he told The Wire Science. He also expressed concern over the increasingly common fact of short but intense bursts of rain, which quickly increase water levels in an area and trigger flash floods.
But the climate alone isn’t to blame. N.C. Narayanan, a water policy and sustainability expert at the Centre for Policy Studies, IIT Bombay, noted flash floods are also caused by deforestation.
When they were released, the Gadgil Committee report’s recommendations prompted expressions of resentment in Kerala. The report recommended dividing ecologically sensitive zones as ESZ1, ESZ2 and ESZ3 based on their ecological fragility, and specified dos and don’ts for each. The don’ts in particular included not licensing sand and rock mining activities in ESZ1 zones and demanded that all mining must cease by 2016.
Abhish K. Bose is a Kottayam-based journalist.