How monsoon havoc coupled with developmental projects increased the vulnerability of the hills to extreme weather events

By Vivek Saini 

Over the last five days, an interaction between a western disturbance and a monsoon trough caused heavy rainfall over Himachal Pradesh, Uttarakhand, Punjab, and Haryana, resulting in landslides, flash floods, and severe damage to highways and other infrastructure. The monsoon surge across the west coast and parts of northern India in the last week has resulted in a 2% extra rainfall over the country on July 9, according to the India Meteorological Department. We will examine how Climate Change and construction activities in the fragile Himalayan ecosystem is responsible for the current havoc in the Himalayan states. 

Why landslides and flash floods are recurring phenomena in the Himalayas 

The most common naturally occurring hazards that have an impact on people’s lives and means of subsistence are landslides. Compared to worldwide events, the frequency of occurrence in the Indian Himalayas is relatively high. The current period of hefty rainfall is caused by the convergence of three weather systems: the Western Disturbance over the Western Himalayas, the cyclonic circulation over the northwestern plains, and the axis of the monsoon trough flowing across the Indo-Gangetic Plains. This is not the first time this alignment has occurred, and it is a common occurrence during the Monsoon season. However, changes in monsoon patterns caused by global warming have made a difference. Temperatures on land and at sea have been steadily rising, increasing the air’s ability to retain moisture for more extended periods.

As a result, the influence of climate change in the growing frequency of extreme weather events in India has grown stronger with each passing year. Five hundred eighty landslides occurred in the Indian Himalayas between 2004 and 2017, 477 of which were precipitation-related, accounting for 14.52% of all landslides worldwide. These numbers may potentially be higher; for instance, according to NASA GLC data, there were 691 landslides in the Indian Himalayas between 2007 and 2015, resulting in 6306 fatalities.

How climate change and anthropogenic activities inducing the landslides in the Himalayas

In the Himalayan region, landslides are primarily influenced by natural factors like rainfall and seismic activity, as well as anthropogenic factors like the building of large-scale constructions like roads, tunnels, and hydroelectric power plants, as well as climate change. The Himalayan belt in North-West India comprises a young mountain chain and diverse geological topography.

Unfavorable geological characteristics, drainage patterns undermining the hydraulic regime, groundwater conditions, deforestation, and glacier melting are to blame for the incidence of landslides in the area. For activities involving slope failure in North India, Jammu & Kashmir, Uttarakhand, and Himachal Pradesh (HP) are also well known. Roads in India’s Himalayan area sustain significant damages each year as a result of both substantial and minor landslides. 

Chhaya Namchu, Program manager at Socratus, told CFC, “The impacts that we see in landslides, flash floods and rampant disaster is unfortunately only visible and discussed during monsoon. Anthropogenic and human activities further accelerate climatic effects on the hills. The hills do not have the tools to evaluate the vulnerability of the hill areas and the requirements for appropriate planning and infrastructure. The unregulated growing tourism has led to infrastructures (buildings and roads) built for the plains and may not be in alignment with the fragile ecosystem there. We have to understand that hill states cannot withstand the same infrastructure that is planned in non-hilly areas, which is generally the rest of India. With growing urbanization, tourism, aspirations and human interventions – planned hill infrastructure, GIS mapping, early warning systems and disaster preparedness must also grow alongside.”

“The hill infrastructure, community planning and policies must be tailored keeping the fragile ecosystem in mind. Long-term engagement, studies, policies and planning must be put in place year-round and over the years to maintain the biodiversity and human settlements in place truly,” she added. 

Himalayas are prone to More Landslides Due to Climate Change

The Himalayas are the most extensive ice reserve on Earth outside the two polar regions since they are home to almost 100,000 km2 of glaciers. The Intergovernmental Panel on Climate Change predicted in 2022 that under moderate carbon emissions, Himalayan glaciers will lose 10–30% of their mass by 2030. The Himalayas are also warming more quickly than the global average. From the Himalayas in the east to the Hindu Kush and Tian Shan mountain ranges in the west, High Mountain Asia spans thousands of rocky, glacier-covered miles.

High Mountain Asia’s yearly monsoon patterns and rainfall are shifting due to the planet’s warming climate. On the steep terrain, heavy rain, such as the kind that falls during the monsoon season from June through September, can cause landslides, which can cause disasters ranging from the destruction of towns to the disruption of drinking water and transportation systems. Over 7 million people were displaced by monsoon flooding and landslides in the summer of 2019 in Nepal, India, and Bangladesh.

Scientists from the National Oceanic and Atmospheric Administration (NOAA), Washington; Stanford University, California; and NASA’s Goddard Space Flight Centre worked together on the study, which discovered that rising temperatures will result in more heavy rains in some regions, which may increase the likelihood of landslides. 

When comparing precipitation and landslide trends between the future (2061-2100) and the past (1961-2000), the study team used NOAA’s model data to project Landslide Hazard Assessment for Situational Awareness (LHASA) into the future.

According to the study, more landslides in this area, particularly in regions that are currently covered by glaciers and glacial lakes, might result in cascading calamities like landslide dams and floods that have an impact on communities downstream, often hundreds of miles distant.

They discovered that as the climate warms, intense precipitation events are projected to become more frequent. In some places, this may increase the frequency of landslip activity.

References:

1. https://internal.imd.gov.in/press_release/20230709_pr_2421.pdf
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14. Image source: https://twitter.com/DobhalAnkush/status/1677943984596070401?t=nBJLYIo8k8IE-YkwyyAurQ&s=19