Wayanad landslide: So far 108 people have died in the landslide that occurred after heavy rains in Wayanad, Kerala, while 128 people are injured, who are being treated in different hospitals. Meanwhile, scientists have said that this accident has happened due to the increasing temperature in the Arabian Sea. According to scientists, due to the increase in temperature in the Arabian Sea, dense clouds are forming, due to which Kerala is receiving heavy rains in a short time and the risk of landslides is increasing. A senior climate scientist said this on Tuesday.
Meanwhile, scientists and experts on Tuesday called for landslide forecasting systems and construction of safe residential units for vulnerable populations. Extremely heavy rains triggered multiple landslides in Kerala’s hilly Wayanad district in the wee hours of Tuesday, killing over 108 people so far. Many people are still feared trapped under the debris.
S. Abhilash, Director, Centre for Advanced Atmospheric Radar Research at Cochin Institute of Science and Technology, said that due to the active monsoon offshore low pressure area, heavy rains have been occurring in Kasargod, Kannur, Wayanad, Calicut and Malappuram districts, due to which the entire Konkan region has been affected for the last two weeks. He said that the soil has become friable after two weeks of rain.
Abhilash said a deep ‘mesoscale’ cloud system formed off the coast in the Arabian Sea on Monday and caused extremely heavy rainfall in Wayanad, Calicut, Malappuram and Kannur, resulting in landslides. “The clouds were very dense, just like the ones seen during the Kerala floods in 2019,” Abhilash said. He said scientists have received reports of very dense clouds forming over the southeast Arabian Sea. He said sometimes these systems enter the land area, as happened in 2019.
Abhilash said, “Our research has shown that the temperature in the southeast Arabian Sea is increasing, due to which the atmosphere over this region, including Kerala, has become thermodynamically unstable.” The scientist said, “This atmospheric instability leading to the formation of dense clouds is linked to climate change. Earlier, such rainfall used to usually occur in the northern Konkan region, northern Mangaluru.”
Research by Abhilash and other scientists, published in the journal ‘npj Climate and Atmospheric Science’ in the year 2022, states that rainfall on the west coast of India is becoming more “convective”. Convective rainfall occurs when warm, moist air rises in the atmosphere. As altitude increases, pressure decreases, causing temperatures to drop.
According to the India Meteorological Department, several automated weather stations in Thrissur, Palakkad, Kozhikode, Wayanad, Kannur, Malappuram and Ernakulam districts recorded rainfall between 19 cm and 35 cm. “Most of the IMD automated weather stations in the region recorded more than 24 cm rainfall in 24 hours. Some rain gauges installed by farmers recorded more than 30 cm rainfall,” Abhilash said. The weather office said very heavy rainfall is likely at some places in the state in the next two days.
Meanwhile, scientists and experts on Tuesday called for landslide forecasting mechanisms and creation of safe residential units for vulnerable populations. Madhavan Rajeevan, former secretary in the Union Ministry of Earth Sciences, said weather agencies can predict extremely heavy rainfall but cannot say anything with certainty about landslides.
“Heavy rains do not always trigger landslides. We need a separate mechanism to predict landslides. It is difficult but possible,” Rajeevan said. “The conditions that cause landslides, including the soil type, soil moisture and slope, are known and it is important to develop a mechanism from all this information. Unfortunately, we have not done it yet,” he said. “When a river is in spate, we move people to safer places. We can do the same thing when there is heavy and continuous rain. We have scientific knowledge. We just need to convert it into a mechanism,” Rajeevan said.
Srikumar, a disaster risk management expert at the Kerala Institute of Local Administration, said more than 120 mm of rain for two to three days is enough to trigger landslides in the hilly terrain of the southern coastal state. “There are many landslide-prone areas in Wayanad. The only thing we can do is to move people to safer areas. The authorities should build monsoon-proof shelters for people living in such areas,” Srikumar said.
Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, said nearly half of Kerala is covered by hills and mountainous regions with slopes greater than 20 degrees, making these places prone to landslides when there is heavy rainfall. “Landslide-prone areas have been mapped in Kerala. Panchayats located in hazardous areas should be marked and people living there should be made aware. We need to monitor rainfall data in these areas and set up early warning systems to identify hazardous areas,” he said.
