Build lighter structures, ensure proper drainage and use local knowledge to future-proof the region
This article is part of a special edition on the Himalayas, published in February 1-15, 2023, issue of Down To Earth magazine
Development in the Indian Himalayan region is characterised by a simple golden rule–one size does not fit all. Delhi’s high-rise buildings cannot be built in Mussoorie, amongst the mountains. In the Himalayas, attention must be paid to the local area; while Leh is rocky, hard and dry, Arunachal Pradesh is soft, moist, full of biodiversity and green.
Of course, there are some overarching challenges that are common; for instance, climate change and the heavier precipitation during the monsoons being experienced now leads to landslides and other more serious disasters. Moreover, melting glaciers are leading to glacial lake outburst floods (GLOFs are a sudden release of water retained in a glacial lake). The Himalayas have been carved out of the collision of tectonic plates and the geological forces continue to raise the mountains vertically. This leads to serious seismic activity and culminates in earthquakes that are difficult to predict. Small tremors are felt far more often than heavier earthquakes.
Hence, due to these factors, the western, central and eastern Himalayas all have different characteristics.
Ever since scientific temper and methodology were established, there have been plenty of geological studies, committees and Supreme Court rulings in relation to the different aspects of the Himalayan regions, but none have borne fruit. So the question now is, how do we plan amidst all these bizarre challenges, natural and human-made? We can start with a plan that takes into consideration localised knowledge on how the land is settled. Tectonic-induced fault lines are known about locally and do not require a lot of scientific studies to understand. For instance, Gangtok, Sikkim, is settled on a series of ridges that are located north to south. These ridges have been present for several million years, and all the rainwater in the area is drained from several rivulets that run in both westward and eastward directions from the top into larger rivers downhill and ultimately into the Teesta.
The natural draining ecosystems have evolved over a long time and are sustainable and critical. Many of these drains or rivulets have been “trained” or “engineered”, but the efficacy some-times does not match the sudden gush of rainwater, which leads to flooding and erosion. Due to this, and the fact that people build carelessly when the sun shines and bear the brunt when monsoons arrive, there is loss of life and property. Now, climate change adds to the burden in the form of cloudbursts.
In 2011, an earthquake of 6.8 magnitude on the Richter scale hit Sikkim–its epicentre was in Dzongu, North Sikkim—and shook Gangtok and other parts of the state for more than 45 seconds. It damaged monasteries and other buildings, including the state secretariat, that were old and ill conceived. However, apart from four buildings that had to be dismantled, the rest of Gangtok and other towns were spared. All the hydroelectric plants were also safe. In a way this was a stress test. Many buildings have since been constructed, perhaps with better design. It remains to be seen whether an earthquake of a higher magnitude would override this.
Looking at Joshimath, which is in a state of subsidence, the people have perhaps overbuilt. However, the risk was known all along. The answer to why nothing was done about it is possibly a major political and administrative lapse.
This then brings forth the question of design. Designing to future-proof Himalayan cities and other projects is an exercise fraught with cascading risks and ascertaining them is one of the key challenges. Several times, roads that bank on the hillside have stormwater drains higher than them. Further, the shoulder of the road does not touch the drain, leaving ample space for grass and dense vegetation to grow, blocking the drain. Consequently, during monsoons, we see a series of landslides caused by overflow into the hill side, which causes all kinds of problems, especially if there is a village below the road. Apart from the design, implementation is also critical.
One way to facilitate risk reduction is taking the sustainable development goals (SDG) and making them central to the planning and execution process. The SDG framework is powerful and can be legislated; this was nearly done in Sikkim. Emphasis on points such as finding ecological solutions to erosion or building roads in an environment-friendly manner can ensure the commitment to people, environment and planet.
We also have to think about the carrying capacities of places. Mountains do not have much flat land and hence we have to build along the hillslopes. There is a way to do this in a manner that does not compromise the land stability. The slope also may require stabilisation, using suitably-designed breast walls (these protect natural sloping ground from the cutting action of natural agents). Rain and other waste water can be sent to the nearest natural nullah that drains into the rivulet below.
Finally, are we prepared for climate tourists? Last year, a massive number of people visited the Himalayan cities just to get away from the heat of the plains. This has led to a spurt of building activity in response to demand all across the region. Therefore, the political economy will be the decider–those in the seats of power must recognise that we have to look very carefully at carrying capacities and other complexities of mountain cities. Not doing so will only see more disasters.
All this requires some meticulous planning and engineering design. Engineers and contractors do acquire some practical knowledge, but we must find a way to ensure that this is scientifically tested, documented and converted into manuals for both safety and proper construction processes. The question that still remains, however, is whether we will ever learn from our mistakes.
(Views expressed are personal)
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The city of Gangtok, Sikkim. Photo: iStock.png)
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