Why The Wayanad Landslide Must Not Fade From Memory

It is just a few weeks since the devastating landslide of Wayanad of July 30 and the news is already disappearing from media platforms. It is in the nature of news cycles that new developments replace the old – almost like the box office, where new drama replaces the old to hold viewer attention. For the families of more than 300 lives lost and many families that lost their life’s savings, what happened on that night will never be forgotten nor will the trauma disappear.

The scale of the event was such that it caught the attention of the country, and even outside. Once again after the floods of 2018, international attention focused on Kerala for some time. Again, there were analyses and discussions in the media. There was enough politicking too with accusations and counter-accusations between the Centre and the State governments. There were media reports of scientific evidence being planted.

Lost in this din were questions on how such loss of lives and property can be avoided in the future. If excessive rainfall over a short period caused the July 30 event, the scientific consensus is that such extreme weather events are only going to increase in the coming years and decades.

As early as 2007, the Intergovernmental Panel on Climate Change stated in its Fourth Assessment Report (IPCC-AR4) that with the changing climate, the South Asian region is likely to see more extreme weather events with increased intensity. More recently, scientists working on atmospheric science have noted that the Indian Ocean is likely to move to a “permanent heatwave” situation. What this means is that from the present average of 20 heatwave days over the Indian Ocean in a year, it could move to 220 to 250 days in a year by 2100. The surface temperature could increase anywhere between 1.4℃ to 3℃ between 2020 and 2100.

Even within the larger Indian Ocean marine ecosystem, the Arabian Sea is seen to be warming fast, with the number of marine heatwave days increasing by approximately 20 days per decade between 1982 and 2019. In recent years, scientists have noted the formation of deep rain-bearing clouds over the southern Arabian Sea, making it more thermodynamically unstable.

What this means is that more of the rainfall during the southwest monsoon will be due to convectional events, and would come in shorter bursts rather than the seasonal cyclicality that Kerala was used to for centuries. In 2019, the director general of the India Meteorological Department (IMD), Mrutyunjay Mohapatra, told Mongabay-India that the monsoons have already become more erratic.

Rainfall data on the progress of the southwest monsoon over Kerala from June 1 till mid-August seems to prove this observation right. In spite of the heavy bursts, one of which caused the Wayanad landslide, the cumulative rainfall is 11% less than the IMD average.

First came the settlers and then the tourists

Wayanad is a late bloomer among plateaus. The plateau is at an altitude where the prevalence of malaria is high. Unlike the Idukki plateau where pioneering settler-agriculturists started moving in, in the late 19th Century, braving the disease, settlers moved into Wayanad after the discovery of synthetic malaria drugs after the 1940s. Before that, it was the land of indigenous communities in enclaves. The tourism boom for Wayanad had been in the recent decades when the affluent and mobile from cities such as Bengaluru started travelling to the plateau district for extended weekends.

According to the Census data, Wayanad district had a settled population of 75,149 in 1901, which grew to 817,420 by the 2011 Census. The settler boom decades started after the 1941 census (106,350) and stabilised by the 2001 census (780,619). In short, between 1941 and 2001, the population of the district grew by 7.34 times over these six decades. Compare this with the fact that between 1901 and 1941 the population had only grown by 1.41 times.

Even though district-wise historical figures are not available, tourism in Kerala has grown since the launch of the “God’s own country” campaign in the mid-1990s. According to the Kerala Government’s Tourism Department data, tourist arrivals into the state grew from 6.16 million in 2003 to 22.52 million in 2023. Out of the 19.21 million tourists who visited Kerala in 2022, 1.51 million visited Wayanad.

Unlike Alappuzha or Ernakulam districts, Wayanad is not a popular destination on the maps of foreign tourists. In 2022, only 1967 foreign tourists visited Wayanad out of the 1.51 million – a measly 0.13%.

Like the other districts of Kerala, Wayanad too has been receiving a growing number of domestic travellers, who have larger purses to spend on their travels, want to stay in newer locations and demand newer experiences. In 2022, out of the 18.86 million Indians who travelled within the country, 71.5% visited Kerala. The result – resorts have mushroomed even in hitherto isolated locations of the mountain district. Not connected by either railway or airport, Wayanad has become a destination for fast cars.

Theatre of natural sound and fury

Wayanad is at the serrated southwestern edge of the Deccan Plateau. The Wayanad plateau is contiguous to the Mysore plateau, and its eastward slopes are drained by the Kabini river, which flows northwards through the district before turning east and joining the Kaveri in Karnataka. At the western edge of the Wayanad plateau, which has an average altitude between 800 to 1,000 metres above sea level, the Western Ghats ridge rises to up to 2,000 m. The ridge then drops sharply westwards to the plains, within a few kilometres. The high ridge continues southwards into the Nilgiris, forming the Mukurthi ridge. Road access to the Wayanad plateau from the west is through gaps within the mountains of this ridge.

The western face of the ridge that runs along the Wayanad and the Nilgiri plateaus stands sharply in the way of the southwest monsoons. The western face of the ridge is drained by multiple rivers that later form the Chaliyar river, which flows westward and joins the sea near Kozhikode. The river is only 169 km long.

As the low clouds, heavily-laden with moisture, move over the Kerala plains, they are obstructed by these mountains. Unable to carry their loads over the ridge, these rain clouds dislodge copious amount of water on the steep slopes. In its impact, soil and rocks come loose at times, and roll and slide down the slopes.

This obviously has been happening over the geological past. The fact that the west-flowing rivers have been carrying immense amounts of silt is visible from the wider continental shelf along the Arabian Sea coast when compared with the Bay of Bengal coast.

The Iruvanjippuzha river, along which the July 30 landslide happened, is a tributary of the Chaliyar. Even among the west-flowing rivers, the Chaliyar river has had a strong erosional impact that looks plausible from the concave-shaped headwork that the river has carved for itself. A report prepared by the Hume Centre for Ecology and Wildlife Biology, highlights the vulnerability of Wayanad to landslides.

It is dangerous to forget too soon

Landslides have happened in Kerala in the past and will happen in the future. The added dimension is the prognosis of more frequent and intense extreme rainfall events in the coming years. If lessons are learnt from the July 30 event, then loss of lives and property can be minimised in the future.

Of essence to this preparedness is for individuals and communities to have scientifically-verified information that can be acted upon, along with a “do how” for taking action. To start with, weather information has to be locally relevant and granular. The IMD has six rain gauge stations and one automated weather station in Wayanad. Even though that is a higher number than many other districts, it still is not spread out enough to capture local variations.

As part of a citizen science initiative, the Hume Centre has established a network of 180 rain gauges, operated by families across the district. However, the data from this decentralised network does not get assimilated into the official information system.

The IMD’s weather forecast itself is of low local relevance. The alerts are meant at the district level, and with wide variation within districts, at best give a broad idea of what to expect, rather than actionable information. Of more use have been the forecasts of amateur weather watchers such as Pradeep John – known in social media as the Tamil Nadu Weatherman

Similarly, in landslide-prone zones, the risk maps have to be integrated into the system through which panchayats and municipalities grant permissions for constructing buildings. Just as how a person buying land checks in with the local self-government if the land is earmarked for future development projects, individuals should be able to know what risk they are getting into by buying a property in a landslide zone. For this, data needs to be available at a locality level.

With repeated returns of extreme weather events in the last decade, there is a greater experienced understanding of what could be the effects of climate change. However, this knowledge is not effective without a detailed action plan to deal with these events. That can be the only tribute to those who did not wake from their sleep on July 30.

(Published under Creative Commons from Mongabay-India. Read the original article here)