KOCHI: Around 13% of the state’s territory is extremely susceptible to landslides. Moreover, Idukki, Palakkad, Malappuram, Pathanamthitta and Wayanad are highly vulnerable regions.
The stark revelations have been made by an artificial intelligence (AI)-aided study by the Kerala University of Fisheries and Ocean Sciences (Kufos) in association with Michigan Technological University and Indian Institute of Tropical Meteorology, Pune.
Kufos prepared an AI-based landslide susceptibility map utilising deep learning technology, which provides an overall susceptibility overview of the state. The comprehensive research, spanning observations from 1990 to 2020, reveals a confluence of environmental stressors that exacerbate the state’s vulnerability.
The team is currently developing a mobile app for landslide mitigation. It will be ready within six months.
“First-order stream disturbances, slope toe cutting for road construction, and unscientific land-use practices are identified as significant contributors to the heightened risk. Additionally, slopes within the range of 10° to 40° are highlighted as highly prone to landslides,” said Girish Gopinath head of the Kufos department of climate variability and aquatic ecosystems who spearheaded the research.
The study, titled ‘Redefining landslide susceptibility under extreme rainfall events using deep learning’, has been published in the latest issue of science journal Geomorphology.
The research found a significant 3.46% rise in extreme landslide susceptibility zone in Kerala after the 2018 “extreme rainfall event.”
Idukki, Pathanamthitta, Malappuram, Palakkad, and Thrissur districts experience intensified landslide susceptibility, necessitating targeted intervention strategies, the study said.
“Kerala’s high-range regions, with approximately 31% of areas elevated above 600m, fall into extreme landslide susceptibility zones. This underscores the urgency of safeguarding not only populated areas but also ecologically-sensitive, high-altitude regions,” Girish said.
He said they collected 3,575 landslide samples from extremely susceptible zones and analysed them using the AI tool. “The landslide susceptibility map has been prepared from the data generated using AI-aided analysis,” he said.
A majority of the highlands region and slopes of the midland-highland transition zone of Kerala are highly vulnerable to landslides, where high-intensity rainfall is the dominant triggering factor, said the report.
The prevalence of tropical humid climate across the region enhances chemical weathering, resulting in the formation of thick soil stratum (rich in clay) over the crystallines, it said, adding that this unconformity between the crystalline rocks and the overburden forms the slip plane for the majority of (rainfall-triggered) landslides in Kerala.
“Rainwater trapping pits dug up along the slopes to recharge groundwater resources trigger landslides during heavy rain. Human activities in the periphery of Wayand and Idukki high ranges are a major factor contributing to landslides,” Girish said.
Kufos Vice-Chancellor T Pradeepkumar emphasises on the urgent need for coordinated efforts to address the root causes of landslide susceptibility.
“Kerala grapples with unprecedented challenges brought about by climate variability, including extreme rainfall events. Such research serves as a crucial tool for informed decision-making and strategic planning,” he said.
On slippery slope
Kerala landslide susceptibility map:
3.46% rise in extreme susceptibility zone after 2018 flood
31% of high ranges have elevation above 600m
Idukki, Palakkad, Malappuram, Pathanamthitta, and Wayanad districts highly vulnerable
Research
3,575 landslide samples collected for AI-aided analysis
Research based on landslide studies from 1990 to 2020
New landslide mitigation app to be released in six months