Opinion

Climate change-induced flood in Thame village: Responsibility of design and construction professionals

It is not only the vernacular architecture but also vernacular planning that needs to be emulated to address the climate change problem successfully at least for the emerging cities

By Jiba Raj Pokharel

Thame village

The monsoon is continuing to play havoc in different parts of Nepal. Last Friday, the Thame River swelled beyond imagination when a glacial lake burst upstream. The flood was so devastating that it swept a school, hotel and clinic along with 20 houses in Thame village.

Nepal receives rain both in winter and summer. Whilst the winter rain forms a miniscule 3 per cent of the total average rain of about 1,500 millimeters, the summer shower is a hopping 97 per cent. The summer rain consists of 14 per cent of the pre-monsoon, 78 per cent of the monsoon and 5 per cent of the post-monsoon rain. The pre-monsoon begins from April and ends around early June, while the monsoon continues till August. The post-monsoon rain falls from September till October. This year, the monsoon entered Nepal on June 10, three days before the usual arrival on June 13.

The monsoon is a blessing as well as a curse in Nepal. It is a blessing as much of the staple food of Nepal, paddy, is planted with the help of the monsoon rain. It is also a curse because it triggers floods and landslides. The monsoon has already claimed more than 180 lives this year when more than a week is yet to pass.

It is clear now that the instant flood in the Thame River was due to the glacial lake outburst that took place upstream of Thame village. Thame may be a tiny village, but it is notable as the native place of legends like Tenzing Sherpa, who first scaled Mount Everest. Glaciers are snow-fed rivers, and glacial lakes are snow lakes. Glacial lakes generally explode when the temperature rises, leading to ice melt. The rise is generally due to global warming as well as climate change apart from a few exceptions.

The exceptional first glacial lake outburst is said to have occurred about 450 years ago in the Seti Khola basin when the glacial lake Macchapucchre suddenly exploded. It was such a cataclysmic event that it is said to have deposited debris about 50 meters deep in Pokhara Valley. Since then, some 14 events are said to have occurred originating in Nepal and further 10 emerging in China. The most memorable is the one that hit the Dudh Koshi River basin due to the explosion of the Dig Sho lake, which damaged a hydro power plant and 14 bridges downstream as well as loss of lives.

This glacial lake outburst flood also woke up the otherwise sleeping Nepali government which led to the installation of a pre-warning system followed by the construction of check dams to counter the likelihood of a Chho Rolpa explosion. Fortunately, the mishap did not occur, which otherwise would have flooded areas as far as Sunsari district of Nepal. It is said that there are about 24 glacial lakes that are vulnerable and are likely to burst any time in the future.

Questions arise as to what can be done in the wake of such disasters in Nepal. Climate change has been caused by carbon emitting countries, including our neighbours India and China. Nepal's carbon emission is virtually nil at about 0.22 per cent. But it has been one of the most vulnerable countries to climate change. The carbon-emitting countries should come to the rescue of countries like Nepal, which, however, has been at best a half-hearted attempt.

Climate change has dominated national and international attention these days. Barely a week passes without a conference or seminar about climate change in any city. One of such seminars was held in Kathmandu entitled 'Professionals and Climate Change' last Friday. It was organised by Society of Nepali Architects together with Regional Urban Planning Society of Nepal and the Society of Consulting Architects and Engineering Firms and inaugurated by Purna Bahadur Tamang, Minister of State for Energy, Water Resources and Irrigation. The technical session made a flying start with the keynote address by Tushar Sogani, an eminent architect of India. It was followed by three panel discussions which focussed on Climate Change and Governance, Construction and Emissions as well as Building a more Sustainable Future.

It was clear that the construction sector ranked third on triggering climate change. It is mainly due to the use of materials like cement and steel which have a high carbon print. Their alternatives could be vernacular materials like bamboo, mud and the like. Tests have shown that bamboo-reinforced soil competes with the strength of brick masonry in cement mortar of 1 in four proportion. Moreover, a bamboo grid structure could easily take the floor loads. It is thus suitable for residential constructions which occupy almost 90 per cent of all constructions.

But acceptability may be an issue here. While it is affordable even for rural people, urban people addicted to reinforced cement construction would not easily accept bamboo and soil. In that case, one has to choose between the adverse impacts of climate change and the fascination for modern materials. It is the responsibility of the professionals to convince them and choose the former in order to save the planet earth from possible extinction.

In fact, it is not only the vernacular architecture but also vernacular planning that needs to be emulated to address the climate change problem successfully at least for the emerging cities. The planning consisting of construction in elevated areas leaving the underlying areas open has multifaceted advantages. This can be seen in the planning of the traditional cities whether they be in the valley or outside. The flooding encountered in the Kathmandu Valley's cities will be a thing of the past if planned accordingly. It will also reflect the much-needed identity in contemporary cities.