BHUBANESWAR: In the state’s hilly districts along the Eastern Ghats, landslides are on the rise. While Kandhamal is yet to recover from the massive landslide at Kalinga Ghat last month, fresh ones at various locations in the neighbouring Gajapati district following the deep depression have already claimed two lives this week.
Even as the state government continues its work on developing a Landslide Early Warning System (LEWS) under the World Bank-funded Odisha State Capability Resilient Growth Project, researchers blame the calamity to climate change and rapid clearing of forests and green cover from the face of the Eastern Ghats.
Assistant professor at the School of Earth, Ocean and Climate Sciences (SEOCS) of IIT-Bhubaneswar Yengkhom Kesorjit Singh said landslides in the region have been a continuous process. But, climate change is behind its increasing frequency now. “There is a thick soil profile above the Eastern Ghat’s plutonic rocks. This soil profile is eroding faster due to irregular and increasingly heavy intensity of rainfall,” he said.
Rajat Kumar Patnaik, research scholar at the SEOCS, who has been studying the landslides in Eastern Ghat districts including Gajapati and Ganjam since the last five years attributed the increasing landslide frequency to geological formations with the triggering factor being rainfall.
In recent times, he said, increased anthropogenic activities (human interventions like unscientific road cutting, clearing of forests and felling of trees) in the hilly areas have led to rise in frequency of rainfall and landslides.
“Landslides in these districts happened previously too. But today, the intensity is more. Geologically, this is a weak region. Over the years, there has been a change in the composition and weathering of rocks and soil due to rainfall and temperature changes, only weakening them further,” said Patnaik whose last case study was the multiple landslides at Kalinga Ghat in Kandhamal district.
Rainfall pattern has been the major disruptor. “Earlier, high intensity rainfall lasted for a short period of time which has increased manifold and spread over more days and more land across the hilly districts in the region these days. Hence, landslides are today distributed across Kandhamal, undivided Koraput, Ganjam and Gajapati districts,” he added.
The last fatal landslide in the region was recorded in October 2018 when Cyclone Titli hit Odisha. It claimed around 14 lives in Barghara village under Gangabada panchayat in Gajapati. Patnaik said 300 to 350 landslides, including the small and big ones, were reported in Ganjam and Gajapati districts, particularly in areas along the Mahendragiri, during the time.
To arrest the frequency of landslides, unscientific clearing of trees for construction of roads has to be immediately stopped, opined Utkal University’s geology professor Durga Shankar Pattanaik. “Over the years, there have been numerous fractures on the rocks of Eastern Ghats and once rain percolates into these fractures, the adhesion between the overlying and underlying rocks loosens and leads to landslides,” he explained.
Pattanaik said roots of trees worked as an adhesion between the rocks but with their felling to build or widen roads, that support has gone. “Which is why, the overlying rocks have become unstable and under heavy rainfall impact, they roll down,” he said.