GUEST COLUMN
VP Dimri
Disasters are classified as natural and man-made disasters. Natural disasters are events that occur naturally, such as earthquakes, cloud bursts followed by landslides and floods, wildfires, cyclones, tsunamis and volcanic eruptions. On the other hand, human-made activities are responsible for the disasters such as pollution, crowd crashes, fires, nuclear radiation, transportation accidents and industrial accidents.
The main source of some of these man-made and natural disasters is being considered due to rapid global warming, or in other words, climate change. After industrial growth the global temperature started rising. There are many positive forces for global warming, such as the rise in greenhouse gases like CO2 etc. Today the concentration of CO2 is 427 ppm and before the Industrial Revolution, it was 280 ppm or less. The rise in CO2 level pushed the global temperature, and 2024 is considered the warmest year so far. The impact of global warming is seen in the melting of glaciers, changes in rainfall patterns, sea level rise, drought and flooding, extreme weather events, etc.
These are global changes; however, there are some local impacts also by so-called human errors. So, natural disasters and man made disasters are very well coupled. In fact there are cascading effects from natural disasters to manmade one. After heavy rainfall which is natural, there is a possibility of landslides which may block the pathway of rivers creating artificial lakes. And if an artificial lake is burst then there rivers and riverlets will be flooded. However, man-made disasters can be classified into many categories such as creation of infrastructures such as establishing new township and roads along rivers and riverlets; air pollution due to industry, fire; human error commonly known as accidents such as transportation, fires, urban flooding, etc.
The situation becomes worse when the above man-made approach is followed in highly fragile regions. One of such fragile areas is Himalaya extending about 2,500 kilometres from the northern and north eastern part covering 11 States and 2 Union Territories of India. There are Uttarakhand, Himachal Pradesh and Jammu and Kashmir in the north west of Himalaya. Here we will be discussing disasters in Uttarakhand as currently this State is under severe problems due to natural and man-made disasters.
Geologically, Himalaya is the result of pushing of the Indian tectonic plate to collide with the Euasian plate about 40-50 million years ago. As both the plates have equal rock density, then no sinking or subduction and intense pressure forced the land upwards, creating the highest mountain on earth with crust crumbles, folded and the process of rising is still continuing. As a result, the Himalaya is very very fragile. This is one of the reasons for natural disasters such as earthquakes. Recently, Uttarakhand has been witnessing consistent rainfall and also cloudbursts. These are also natural but its excess is related to landslides, flooding etc.
The landslides are blocking the roads and destroying property and killing human life. On the other hand, cloudburst is now very frequently causing big disasters. A cloud burst took place recently on August 10 in Tamak Nala, Niti valley in Chamoli district. The valley has experienced many cloudbursts. Earlier, one such cloudburst was in Tapovan on February 7 in 2021 causing massive flash floods and heavy damage to the Tapovan and Rishiganga hydropower project with rocks and ice avalanche.
Many scientific studies show that it was not a cloud burst but an avalanche. The road distance between these places Tapovan and Tamak Nala is approximately 30-35 kilometres on the main road from Jyotirmath-Malari highway. The cloud burst in Tamak Nala and Tapovan originated from high altitude Naina Devi mountain range with lenticular clouds.
Due to cloudburst, Tamak Nala got flooded and rocks and mud in the stream washed out the road and recently constructed bridge by Border Road Organisation. The flood Nala meets Dhauliganga which also got flooded. On the other hand a tributary of Rishiganga in Tapovan- Raunthigad and Rishiganga also meet Dhauliganga. There are many tributaries of Dhauliganga such as Girthi Ganga, Amrit Ganga and Bagini Nala. Finally Dhauliganga meets Alaknanda at Vishnuprayag which is one of five Prayags in the upper Ganga basin. Disaster along the tributaries are natural but man made infrastructures and roads can be avoided along the banks of rivers. First, we have to study the natural pathway of expected flood after cloud bursts. New townships should not be constructed along these pathways. One such example is the Dharali tragedy of August 5, 2025 in Uttarkashi district. The entire township of more than 150 hotels, shops and homes was washed out. The tragedy took place on Kheer Ganga, tributary of Bhagirathi river. Unfortunately, such constructions were allowed along the pathway of tributaries.
In conclusion, the increase of natural disasters is due to climate change and butterfly effects meaning a small change in a system like temperature rise or man made disturbance can have its effect later. This is what we are seeing dramatic man made changes like creation of townships along the pathway of tributaries in the Himalaya.
(A Padma Shri recipient, the author is an eminent scientist who has worked in various institutions. Views expressed are personal)
