Saturday, Dec 02, 2023

Torrential Rains, Floods, And Landslides Put Himachal Hills At High Risk

Torrential Rains, Floods, And Landslides Put Himachal Hills At High Risk

Scientists say the rise in temperature and humidity in the coming years will aggravate problems for the mountain population  

Chandigarh-Manali highway blocked after landslide
Vehicles stuck on Chandigarh-Manali highway after a landslide blocked the road, near Mandi. Photo: PTI

Twenty-one per cent surplus rain, massive flash floods and a spate of landslides that snapped road communication for days in Himachal Pradesh—a state known for witnessing frequent natural disasters, fatalities and human displacements—is a fresh warning about the increased vulnerability of the hills to extreme weather events.

This happening in June, when the state witnesses a surge in incoming tourists, was indeed unprecedented and a clear blow to the state’s tourism industry, horticulture economy, physical infrastructure and fragile ecology. The disruption of more than 300 link roads, key National Highways and connectivity left the state's population severely affected by the early monsoon.

Until the first week of July, 35 people had lost their lives and property worth Rs 180 crore was damaged. Losses incurred due to damage to horticulture crops and vegetables are yet to be assessed.

Onkar Sharma, the state’s Principal Secretary (Forests and Disaster Management), who has been closely monitoring the situation on an hourly basis and organising relief operations says: “What worries us more is that most extreme weather events—rains, cloud-bursts, thunderstorms, landslides or floods are happening most unexpectedly. The whole pattern of weather-related events has undergone a change over the past few years. The rains don't happen when needed but create real havoc untimely. The intensity and scale is also high, and so are the damages.” 
There is also a human element involved that makes rain-related events highly risk-prone. Massive cutting of the hills to make roads, National Highways or four lanes, new constructions and deforestation are also some of the contributing factors. The debris dumped or thrown on the mountain slopes flow downstream with stormwater. It sweeps everything that comes in its way. 

The Chandigarh-Manali highway, for example, remained blocked for two to three days because of the landslides. The rocks, boulders and shooting stones caused blockades after the torrential rains and landslides.

The highway has been witnessing mountain cutting for Kiratpur–Manali four-lane project. The flash floods at Khotinallah near Aut (Mandi) near Pandoh caused by heavy downpours left the tourists bound for Manali stranded on the road, making them to spend the night in their vehicles.
The problems are not over as yet. The Indian Meteorological Department (IMD) on July 3 issued a fresh warning about the rains and flash floods. The tourists have been advised to take their journeys only if urgent.

As the state is also prone to cloud bursts and melting of glaciers (forming glacial lakes or floods) the monsoon is bound to bring more miseries to the hill population, especially in the districts of Kullu, Lahaul-Spiti, Chamba, Kangra and Mandi.

Dr Suresh Attri, principal scientist and climate change expert at the state’s Department of Science, Technology and Climate Change shares some alarming facts based on scientific studies in the state.

“The climate change action report prepared in 2012 had already forecasted an increase in the extreme weather events in the state. There is a notable rise in the temperature and also an increase in the intensity of rains,” he says. 

“The overall rainfall may not be very high at the end of the year yet the downpour in a particular period may be a record-breaking. You can very well imagine its impact—flash floods, landslides, flooding and breaking-up of mountains, already destabilised by cuttings and blasting to make highways,” he adds.

Frequently, flash floods, he says, are accompanied by movements of rocks, boulders, loose debris and uprooted trees. The houses, roads and bridges coming on their way get washed away and cattle perish.

“I can say these are man-made disasters, not natural disasters. The humans and machines like JCBs and excavation used for cutting hills and trees for infrastructure projects leave no scope for drainage or scope for the natural flow of the stormwater. People have built houses in nullahs blocking the natural flow of the rainwater through the hill slopes. This is the reason for the flash flood and movement of soil blocks by force water,” says Dr Attri. 

Lahaul-Spiti, a high-altitude tribal district, is facing new challenges on account of climate-induced factors. The melting of the glaciers first created a flood-like situation in the Chandra-Bagha River and lately, the formation led to the submergence of apple orchards along the riverbanks.

“The rate with which the glaciers are melting could create a serious threat of flash floods in the Lahaul Valley. Even last year, a massive landslide led to the blocking of the river flow resulting in the rise of the water,” recalls Arun Bodh, a native of Keylong.

Lahaul was one area of Himachal Pradesh which earlier never had seen monsoon rains but now the Valley has become vulnerable to flash floods because of infrastructure activities, including hydro-power projects.

As per the data shared by the Indian Meteorological Centre Shimla, there was 21 per cent excess rain in June 2023. The state recorded 121.7 mm of rainfall against normal rainfall of 101.1 mm.

Kataula in Mandi district received the highest rainfall in a day with 163.3 mm on June 24. Four active western disturbances had affected the state during the month of June, resulting in scattered to fairly-widespread rainfall, the department said.

The state received four spells of heavy to very heavy rainfall in the district of Shimla, Solan, Sirmaur, Chamba, Kangra, Mandi, Bilaspur, Kinnaur, Una and Hamirpur from June 23 to 26. Monsoon hit most parts of Himachal Pradesh on June 24.

Maximum rain in the month of June was recorded in 2013 with 241 mm (143 per cent excess), whereas the lowest rainfall was witnessed in 2012 with 28. 8 mm (71 per cent deficit).

Shimla—the capital town in Himachal Pradesh—facing perennial problems of water crisis during peak summers, struggled with the drinking water crisis not because of drying-up of the source of supply but flash floods.

The flash floods had carried a very high volume of silt leaving the river polluted. “The pumping at Giri River was stopped as turbidity (ratio of silt) was all-time high continuously due to rains. The overall water availability at Shimla got dropped to 20.69 MLD on June 29 against 46.38 MLD earlier supplied in Shimla, a senior official of Shimla Jal Prabandhan Nigam confirmed.