Wayanad’s Hume Centre for Ecology & Wildlife, which warned of landslides, urges separate weather warning system for Kerala’s Western Ghats region

Other experts call for high-resolution weather prediction model in wake of tragedy
Rescue operations in Wayanad, Kerala
Rescue operations in Wayanad, KeralaX@DefencePROkochi
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The Hume Centre for Ecology & Wildlife in Wayanad had warned the administration that landslides would occur in Mundakkai village and surrounding areas. The warning was apparently not heeded as the landslides eventually killed 276 people, while an equal number are missing.

C K Vishnudas, director of the Centre, has stated that Kerala’s Western Ghats region (districts such as Wayanad and Idukki) need a separate, more specific weather warning system.

This is due to two reasons, according to Vishnudas. The Ghats region receives around double the average state rainfall due to the influence of orographic features on the monsoon.

Moreover, there is a huge population in the landslide-prone regions, compared to the core monsoon regions along Kerala’s coast.

Other experts note that only an accurate monsoon forecast can help authorities issue an early warning about an impending monsoon-induced catastrophic landslide. Extreme rainfall is a major trigger for landslides in Kerala, according to C Muraleedharan, deputy director general (Retired) of the Geological Survey of India (GSI).

M G Manoj, a scientist with Cusat’s Advanced Centre for Atmospheric Radar Research, stated, “We need a high-resolution weather prediction model for generating operational weather forecasts. The present version, with a resolution of 12 km, is insufficient to cater to the needs of Kerala. Furthermore, sufficient rain gauges in the Ghats region should be used to validate the forecast and realised weather, thereby ensuring the model’s reliability.”

Warnings ignored?

Vishnudas said his organisation, which has been collecting rainfall data from over 200 locations in Wayanad, had alerted the district administration about the possibility of landslides a full 16 hours before the disaster. The centre had issued the alert at 9 am on July 29.

“We have a comprehensive rainfall monitoring system in Wayanad, with over 200 weather stations that provide daily data. Our data showed that Puthumala, the closest weather station to Mundakkai, received 200 mm of rain on July 28 and another 130 mm overnight. It’s significant to note that 600 mm of rain can cause a landslide. Given this, we promptly alerted that further rainfall could lead to a landslide,” said Vishnudas.

He explained that the area received 572 mm of rain within 48 hours after the first reading on July 28, eventually triggering the devastating landslide that claimed almost 250 lives.

“We had passed on the information to the district administration. However, we don’t know what the authorities did with it,” said Vishnudas.

The Hume Centre for Ecology has consistently shared rainfall information for the past four years. In 2020, their warning about an impending landslide in Mundakkai led to the successful relocation of people, preventing casualties. “Every day, we provide alerts to the local communities and the government,” Vishnudas said.

Since June 1, several locations in Wayanad, including Puthumala, Lakkidi, Thondernad, and Manikkunnu Mala, have experienced over 3,000 mm of rainfall. “In 50 days, these areas have become highly rainfall saturated. To make things worse, the regions are extremely vulnerable to landslides when exposed to severe rainfall. This is precisely what has occurred in Wayanad,” Vishnudas explained.

“In the early phase of the monsoon, we typically witness normal rains ranging from 100-150 mm. However, in the final phase, we observe the development of large, dense clouds over 200 sq km, leading to exceptionally heavy rainfall and subsequent landslides. We must track and monitor these clouds and rainfall data to ensure the safety of those living in these areas,” he added.

After the 2019 landslide at Puthumala, only two kilometres away from Mundakkai and Chooralmala, the GSI reported that the people in the affected area should be relocated to a stable location.

Any further modification to the affected slope should be avoided, and the natural flow path of the streams should be maintained. The outpour had slowed on July 30, but it was not enough to avert the tragedy that struck Mundakkai and Chooralmala in the wee hours that day.

According to the India Meteorological Department’s (IMD) forecast, the area should experience rainfall ranging from 64 mm to 204 mm (orange alert) over the course of a 24-hour period, Chief Minister Pinarayi Vijayan stated during his media briefing on July 29.

However, the area where the accident occurred received 200 mm of precipitation in the first 24 hours, 372 mm more in the following 24 hours, for a total of 572 mm over just 48 hours, as Vishnudas had noted.

Neetha K Gopal, IMD head in Thiruvananthapuram, confirmed that while they were not expecting a major rainfall event, they were anticipating some intense periods of rain in northern Kerala.

“Based on our observation, the cumulative effect of the rain resulted in disorderly situations in Wayanad. The soil was already saturated from the torrential rainfall the previous day, and the additional precipitation throughout the fatal night caused the calamity. The IMD is now investigating methods to incorporate a nocturnal analysis of the meteorological variables during the high season, taking into account the precipitation patterns in Kerala,” Gopal told DTE.

The heavy rain affecting north and central Kerala for the past two days is expected to continue for a few more days. This is due to an offshore trough at mean sea level that persists along the western coast, from south Gujarat to Kerala. Strong westerly and north-westerly winds in the lower levels over Kerala will likely cause the state to experience heavy rainfall for the next two to three days. 

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