DEATH TRAP

Amitava Banerjee, HT, 25 Dec 2016, DARJEELING:THE DEADLY FALL Every year, Darjeeling Hills experience monstrous landslides that leave behind a trail of death and destruction. Fear grips the Darjeeling Hills each year with the advent of monsoon. Monsoons usher in the monstrous landslides leaving behind a trail of death and destruction in the Darjeeling Hills and neighbouring Sikkim.

In 2015, alone more than 35 people were killed in landslides, many others were injured and property damaged. Till mid-August this year, the toll stood at six.

Experts claim that the cause of the recent spate of landslides in this region is mainly anthropogenic. Though natural phenomena, like earthquakes, do have a catalytic effect, it is the irresponsible intervention by humans that has been triggering more landslides in the Hills in recent times.

Unplanned urbanization, deforestation, monoculture, mining and illegal stone quarrying are some of the main reasons responsible for the devastation, feel experts.

The explosion in human population has resulted in depletion of the forest cover. Rampant deforestation for agricultural land, new settlements and road connectivity, along with the increase in pollution levels have adversely affected the mountain’s ecosystem and, in turn, the weather pattern.

“Now, the intensity of rain has increased. There is usually a dry spell followed by intense rainfall over a brief period of time, thereby causing damage in the form of landslides. Geo-scientists claim that 50mm of rainfall in an hour is enough to trigger a major disaster in the Himalayas,” Wing Commander (Retd) Praful Rao of Save The Hills, an NGO working in the landslide-hit areas said. Sikkim witnessed the maximum number of human casualties on September 23, 2012, when numerous landslides, accompanied by flash floods — all triggered by a cloud burst in North Sikkim had claimed 47 lives, including that of Border Roads Organisation (BRO) and Indo-Tibetan Border Police (ITBP) personnel.

On June 30, 2015, Kalimpong alone registered 226 mm of rainfall in 7 hours, which is around 30 mm of rainfall per hour. Again, on July 8, Kalimpong registered 93 mm of rainfall. “The rainfall was so intense that in the 90 minutes, the total rainfall recorded was 57mm,” Rao said. This year too, the rainfall pattern seems to be similar. In July, all three major Hill towns (Darjeeling, Kurseong and Kalimpong) received more than the monthly average of rains with Kurseong having received three times the usual monthly average, said Rao. However, worst affected were the plains of North Bengal.

Siliguri received 354 mm of rain on July 24 along Jalpaiguri district recording some of the heaviest rainfall in recent memory. The Hills of Bhutan also received very heavy rainfall resulting in most of the rivers flooding the plains of Jalpaiguri. Most of the rain occurred in the second half of July with the Indian Meteorological Department (IMD) reporting the axis of the monsoon trough shifting close to the foothills. IMD had also flagged a Red Warning for Sub Himalayan West Bengal and Sikkim for most parts of the month of July 2016.

Rampant construction of roads, not well-designed and engineered, is another major cause of the landslides. “The natural drainage system of the mountains is getting affected because of the badly engineered roads that cause landslides. Wellengineered roads with proper drainage system, which does not allow water to stagnate, will definitely ease this problem,” Rao added. This year roads and highways suffered extensive damage. National Highway 10 connecting Sikkim and Kalimpong with the plains of Siliguri has numerous landslide and rock slip zones. The presence of several bottlenecks with constant rock slips makes driving very dangerous on the NH10. On July 9, this year Naresh Baraily, Manager of the Cinchona plantation in Mongpu and his driver Shyam Biswakarma were killed at Setijhora on the National Highway 10 when boulders rolled down the Hill and smashed their vehicle.

Similar is the condition of National Highway 55 and the Rohini Road connecting Siliguri with Darjeeling. National Highway 55 remained closed for 6 years owing to two major landslides, one at Paglajhora and the other at Ghayabari both on the Kurseong-Siliguri section. The road has been opened up with temporary repairs and regulated traffic.

“We have given a proposal to the Government of Sikkim, Government of West Bengal and the Highway Authorities that electronic boards be setup on both ends of Highways. The status of the boards can be constantly updated, displaying message whether the Highway is open or closed due to landslides; whether it is safe or not to travel. This will not only save precious human lives but also prevent serpentine traffic jams,”suggested Rao.

Illegal mining is another major concern. Lowgrade coal is found in small quantities in areas around Tindharia in Kurseong subdivision and Nimbong area of Kalimpong sub-division. Such illegal mining of coal resulted in a huge landslide in Tindharia with the entire region being declared a sinking zone.

Incidentally, landslides washed away a 500-m stretch at Paglajhora below Kurseong town on June 16, 2010. Altogether, 150m of road at Tindharia was washed away by landslides on September 28, 2011, resulting in the closing down of the Tindharia-Kurseong section of National Highway 55. “There is also a mining racket in Malbazar in the Dooars, which oversees the extraction of coal in Nimbong,” Roshan Rai of DLR Prerna, another NGO, said.

Construction boom, unplanned urbanization, constructions blocking natural waterways along with non-degradable plastic blocking drains have all contributed to the landslide menace.

However there are natural phenomena contributing to the vulnerability of this region. Darjeeling and Sikkim are prone to landslides because of their complicated geological set-up. Data available with the Geological Survey of India reveal that the first recorded landslide in the Darjeeling-Sikkim region dates back to 1899.

Since then, there have been innumerable landslides in the zone.

“The Himalayas have always been prone to landslides because of several geoenvironmental, morphometric and geomorphological factors, such as weak and sensitive slope-forming material, joints and fissures on hills, tectonic uplift and steeper slopes to name a few. Mining, excavation, deforestation and artificial vibration also trigger landslides. Add to this, heavy and incessant rain or a major earthquake,” said Saibal Ghosh, a landslide expert and superintendent geologist at the GSI’s Geohazards Research and Management Cell in Kolkata.

But what makes Darjeeling and Sikkim stand out is that they are marked with ‘Blue’ colour on the GSI’s Landslide Vulnerability Map, indicating that it is the most hazardous zone in the country. Only a few other patches in Northeast and a narrow strip in Jammu and Kashmir match its vulnerability.

“In fact, one of the deadliest landslides that hit the Darjeeling and Sikkim Himalayas was in the year 1968 — when a torrential rainfall triggered a few hundreds of landslides, killing several people and breaching the Darjeeling-Sikkim road at numerous locations. The extent of the damage caused in 1968 was so huge that restoration of the roads took more than a year,” Dr Ghosh said.