Monsoon in Kerala: When hills tumbled

Intense rain and man-made causes such as excessive quarrying and construction activity in ecologically sensitive areas in the Western Ghats wreak havoc in Kerala, a State that has barely recovered from the floods of last year.

Published : Aug 31, 2019 06:00 IST

Rescue workers at the landslide site at Kavalappara in Malappuram.

Rescue workers at the landslide site at Kavalappara in Malappuram.

On August 8, at around 5.30 in the evening, the frightening nature of the calamity that had gripped Kerala once again within a year became clear. At Puthumala in Wayanad district, a huge stretch of a hill, over-saturated with rain, broke free and rumbled down, burying an entire village along its path and a picturesque valley below.

Sixty-three houses on the hillside, buildings, a temple, a mosque, a post office, ,a dispensary at the base and 17 people were swept away or buried within minutes as the debris flow gained mass and girth on its way down.

Tonnes of mud, rock, uprooted trees and chunks of buildings were eventually spread over a large area and along a two-kilometre stretch downhill. Just an island of untouched greenery remained in the middle of the two mud-red channels that marked one of the two big landslides which were among the tens of others to hit Kerala this season.

According to local people, quite a few inhabitants of the village had not heeded last-minute warnings to evacuate to safer areas. But the majority, over 300 people at least, had moved to other places the previous evening or on the morning of that fateful day when people began to notice cracks on the ground and the initial signs of landslips.

Several localities near Puthumala experienced similar events on a varying scale in the intense rain in the region from August 7.

Darkness, heavy rain and wind hampered rescue efforts on several occasions during the crucial initial hours. The debris flowed like a river in the heavy rain and rescue workers could not move around because of the mud on the hillside.

Small streams that once flowed down the hill had reportedly dried out and construction and agricultural activities had made the hillside extremely fragile. The landslide that started near the crest of the hill soon became a torrent of muddy soil, rocks and boulders. On the other side of the hill, as rain continued unabated, several people were cut off from the rest of the world.

It was only 12 hours later, as the first bout of rain began to abate, that the outside world knew about a similar tragedy at Kavalappara, near Bhoodanam about 30 km from the flooded town of Nilambur, in the neighbouring Malappuram district. At about 8 p.m. on August 8, a hillside consisting of over 10 acres (one acre is 0.4 hectare) of rain-soaked mud and silt, huge boulders, trees and branches and buildings came down in a similar fashion there, burying yet another community. According to initial reports, over 20 families were buried under 50 feet of debris. In the first 12 days, only 46 bodies were recovered; 13 people were still missing. Searching with ground-penetrating radars had turned out to be futile because of the mud and stones strewn all over. Some bodies were recovered 6 to 7 km away several days later in a decomposed state, raising conflicting claims of identity from relatives. Some could be positively identified only after DNA tests.

An entire area remained inaccessible for days, and would have remained so but for earthmovers and daring rescue workers, including those from the police, the fire force, the National Disaster Response Force (NDRF) and the Army, who had a difficult task searching for bodies in the heavy rain underneath tonnes of mud and debris, as distraught relatives and neighbours continued their hopeless watch in silence.

A tribal colony with nearly 200 inhabitants, who were reluctant to move out, and some government employees were stranded inside a forest area nearby. Access from Nilambur town was cut off. And an entire region went without electricity or mobile connectivity in the initial days.

Similar landslides occurred with varying intensity throughout the ecologically fragile regions of the Western Ghats districts of Kerala in the hours that followed as the State struggled to come to terms with an evolving pattern of short but highly intense bouts of rain between long, deficient spells, causing floods and landslides on a large scale.

Chief Minister Pinarayi Vijayan said 80 small and large landslides were reported in eight districts of Kerala in the two days from August 8 alone, and many were in unexpected areas.

Atmospheric scientists say Kerala received 477 millimetres of rain (as against the normal of 78 mm) between August 7 and 11, an excess of 613 per cent during the period. It was more than the rainfall in Kerala during the floods in August 2018.

Until August 7, Kerala was among the rain-deficit States in India. But in the next six days, all districts except the southern-most districts of Thiruvananthapuram and Kollam were hit by very heavy rain and floods.

The defining images of the floods of 2018 were mostly inundated rivers, brimming dams, submerged cities and towns and villages, the destruction, loss of lives and the misery that came as a result, and the rescue efforts, especially by the fisherfolk, in boats in the heart of cities such as Kochi and Aluva, and the submerged rural settings of Kuttanad. This year, however, it was the mayhem wrought by landslides in the hills that defined the tragedy that followed the rains. Groups of fishermen, who gathered at fire stations in and around Kochi and in many other places which were under water in 2018, returned home after four days, without the need for any major rescue effort.

Storage levels in dams

Significantly, too, in almost all the major dams in the State except a few in Wayanad and elsewhere in north Kerala, storage levels were only 30 to 40 per cent of the capacity even after heavy rain. Last year, however, as the State was hit by excessive rainfall, the shutters of the 35 major dams in the State had to be raised for the first time in history, adding to the flood misery in downstream areas. All five overflow gates of the Idukki dam, the biggest in the State, were also opened for the first time in 26 years in 2018.

Except Thiruvananthapuram and Kasaragod, the remaining 12 districts were severely affected with flooding and landslides. The majority of the total 1,943 landslides studied by the Geological Survey of India (GSI) in 2018 were in Idukki (1,196), Palakkad (241), Wayanad (139), Malappuram (129), Thrissur (77) and Pathanamthitta (51) districts.

It is not known how many landslides took place this year, but the most destructive were in the two adjoining northern districts of Wayanad and Malappuram. Out of the 125 deaths reported from August 8 to 20, nearly 80 were at Kavalappara and Puthumala, the former being the biggest landslide tragedy in the State, killing 59 people.

Many people remained stranded as landslips and floodwaters marooned places, and daring rescue efforts continued for days despite the dangerous circumstances and terrain. Six tribal people, including a pregnant mother and her 11-year-old child, stranded in an island in Attapadi, for instance, were brought to safety through a ropeway across the flooded Bhavani river; rescuers also struggled to bring people to safety just before the opening of the Banasurasagar dam in Wayanad. Remarkable efforts went into retrieving bodies at Kavalappara and other places hit by landslides. There was heavy rain in the Nilambur region for over a week starting from August 1 and on the fateful day one of the highest rain spells in the State was recorded there. Several towns from Alappuzha to Kasaragod experienced heavy flooding.

In Kuttanad, a coastal plain region in Alappuzha district where many areas lie below mean sea level, nearly two lakh people needed to be evacuated on a war footing during the last floods. The limited capacity of the Vembanad lake and the Thottappally spillway worsened the flooding in the region and the Vembanad backwaters. Likewise, several bunds and embankments that secured the paddy polders and residential areas in Kuttanad from the backwaters were damaged, leading to alarming flood intrusion into these areas in 2018. Satellite studies had indicated “a 90 per cent increase in water cover in Kerala” because of the flooding in 2018, with low-lying areas of Kuttanad and the Kole lands of Thrissur showing a rise in the water level of five to 10 metres respectively.

A large number of people were moved to relief camps this year too. But the rain and floods were not severe and the major dams were not full, unlike last year. The floodwaters from three districts that drained out through Kuttanad could flow comparatively easily into the sea through two main outlets. Unlike in 2018, the shutters of the Thanneermukkam Bund and the Thottappally Spillway could be kept open. Moreover, unlike in 2018, when a high tide in the Arabian Sea delayed the discharge of floodwaters, the sea level was low when the heavy rains came this time and the floodwaters could drain out with less difficulty. Districts north of Kollam and Thiruvananthapuram received very high rain and the most intense downpours were reported from Palakkad, Kozhikode, Malappuram, Wayanad, Kannur and Idukki districts. Cochin international airport (212 mm rain in 24 hours) was closed like last time and the traffic was diverted to Thiruvananthapuram. Train services were disrupted. Several small bridges were washed away in the northern districts.

By August 10, in both Kavalappara and Puthumala, hopes of finding anyone alive under the debris had ended. Injuries on the bodies indicated that most of them were crushed or dragged to death in the landslide. On August 17, even after the use of ground-penetrating radar, 19 people were still missing, buried under the debris at Kavalappara.

Ecologically stressed

Significantly, almost all the landslides during 2018 and 2019, including those known under various names such as “debris flow”, “debris slides”, “slumps” and “creep”, happened in hilly areas long identified in studies by the Geological Survey of India (GSI), the National Centre for Earth Science Studies (NCESS) and the Western Ghats Ecology Panel (Gadgil Committee) report as “fragile and highly sensitive” to ecological stress. Among the nearly 20 regions identified as “Ecologically Sensitive Localities” in Kerala by the Gadgil Committee, for instance, were Wayanad, Banasurasagar, Kuttiyadi, Nilambur (near Kavalappara) and Meppadi (near Puthumala).

The GSI had concluded from studies last year that though incessant and excessive rainfall was the triggering factor for all the landslides that took place in 2018, the causative factors were both natural and man-made. The landslides occurred because of one or a combination of factors, according to the GSI study. They included “near vertical slope excavation and removal of lateral support in landslide areas; ‘toe erosion’ by rivers and streams; unscientific modification of original slopes for cultivation or construction; defective maintenance of natural drainage systems (streams), especially of smaller orders; weathered rock mass forming potential wedges and blocks; and physical characteristic and thickness of loose slope-forming mass.”

After the 2018 floods, government agencies had reported that nearly 14.8 per cent area of the State was prone to flooding and that the proportion was as high as 50 per cent in some districts; that 1,500 sq km area of the Western Ghats, especially in Wayanad, Kozhikode, Malappuram, Idukki and Kottayam districts, faced serious hazards from landslides; more than half of the land area in Kerala was susceptible to moderate to severe drought; and its highly populated and long coastline faced imminent threat of rising sea levels and severe erosion, as it was once again demonstrated during the Ockhi cyclone and the June-July months preceding the floods this year. In the months after the last floods, fishermen could not venture out to sea for nearly 40 days because of rough-weather warnings.

According to the Post-Disaster Needs Assessment (PDNA) document of the State government, after the 2018 floods, 209 landslides were reported by various Forest Divisions and 342 landslides were reported in areas under the State Revenue Department. Some of these landslides were 3 to 4 km in length and 20 to 30 metres in width and they mostly happened in slopes that were above 22 degrees. The most common among them took place on slopes of 22 to 28 degrees. The majority of the landslide sites were along the fringes of forests, “indicating that forest fragmentation disrupting slope continuity was a major causal factor”.

An assessment of the nature and extent of the damage this time is yet to be made.

Man-made factors as a cause of landslips and flooding have long been raised by environmental activists in the State, especially after the 2018 events, and they have continuously flagged the issues of widespread quarrying, construction activity and harmful agricultural practices in the fragile stretches of Kerala’s highlands, midlands and coastal areas. The effect of “development” in the floodplains of rivers was in ample evidence during the floods last year; and the devastation at Puthumala and Kavalappara has brought out the truth of the dangerous consequences of unbridled human intervention in the Western Ghats districts.

The Kerala Forest Research Institute (KFRI) has estimated that there are at least 5,924 quarries in the State, covering an area of 7,156.6 ha, with nearly 1,378 quarries within one km of reserve forests and 79 quarries with a total area of 85.83 ha within 500 metres of protected forests.

A few months after the floods last year, the Kerala government had conducted a series of assessments to estimate the damage to and loss and needs of critical sectors. The assessments estimated the total damage and losses to be around Rs.26,718 crore and total recovery needs at around Rs.31,000 crore. Yet, within months after the floods, environmentalists say, the State government took steps to relax the rules on establishing more quarries (by reducing the required distance limit of quarries from populated areas from 200 m to 50 m); to dilute rules governing the conversion of paddy and wetlands; to allow trees to be cut in the Cardamom Hill Reserves in Idukki district; and to regularise title deeds of encroachers and settler farmers alike without distinction.

As the first reports of the extreme nature of the rain and devastation in the hill districts of Kerala began to pour in this year, Chief Minister Pinarayi Vijayan said at one of his daily press conferences: “If there are environmental problems that increase the intensity of such disasters, the government will surely identify them and intervene to solve them.”

In the context of warnings about a likely increase in the frequency of extreme weather events, it received a lot of attention as the State stood perplexed at the enormity of the task of recovering from yet another catastrophe in a “resilient and sustainable manner”, as it had planned to do after the big floods last year, and finding the resources for it.

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