Climate changes

Mustang: to leave or to stay, this is the question

The Nepalese district of Mustang – previously called reign of Lo – together with other Himalayan regions of high altitude presents a fragile ecosystem where the population lives in equilibrium with the few available resources.  In Mustang, human settlements with low demographics are located at an altitude between 2’800 and 4’000 m; The climate is dry and cold. The population, culturally Tibetans and Buddhists, live of subsistence agriculture, breeding and small exchanges with China (Tibet) and with the fertile plains of Pokhara, further south).

Inside the villages, the decisions are taken collectively and at the head of the community there is an annual switch done between a group of representatives (1 representative for each family). Local charismatic figures play a fundamental role in the development of the region because the government institutions are not so present and rather weak.

The climate change caused by the global warming has generated important consequences in the Himalayan region, in term of water regime and water availability. These ecologic changes have a direct impact on the human settlements. In particular, the principal problems that the inhabitants of these regions have to face are :

• reduction of the ice and snow mass (water reserve), which has for consequence the reduction of the water for irrigation during the dry season, resulting in a drastic reduction of the agricultural productivity;
• intensification of the violence of the precipitations during the monsoon (summer) with a sudden augmentation the level of the water and a greater vulnerability of the settlements and of the agricultural lands facing the risks of landslides and erosion of the soil.
• furthermore, the melting of the glaciers increases the risks of sudden flooding in case of displacements of the glacial lacs.

This situation significantly weakens the self-sustaining capacity of local populations and the quality of their habitat. Kam For Sud, in collaboration with the earth science institute of SUSPI and the Lo Mustang Foundation, and with the financial support of the Foundation Assistance Internationale, has studied the situation of three villages seriously harmed by the water crisis : Samdzong, Yara and Dheye, faced with the eventuality of transferring the whole settlements to a place with more fertile and secured lands. The principal objective of the project is to identify the most appropriated and sustainable strategy to face the actual climatic challenge. In practice, we had to respond to the question : Is it appropriated to transfer an entire village or not? If yes, at what costs can this be done successfully? If not,  what are the means by which we can resolve local water problems?

A multidisciplinary working group composed of an environmental engineer (Daniel Bernet), a geologist (Christian Ambrosi), a civil engineer specialized in sustainable habitat (Daniel Pittet), a climatologist and glaciologist (Giovanni Kappenberger), an economist (Michele Passardi), a represent of the Lo Mustang Foundation (Tsewang Gurung) and the Nepalese coordinator of the Kam For Sud projects (Rajan Shrestha) have thoroughly analyzed the question, studying the possibilities to overcome the water deficiency and the natural dangers with a technical intervention, analyzing data and meteorologic and climatic models and putting side by side a series of parameters of the original settlements place with the ones of the potential new places. We furthermore spoke with all the concerned families and took in great consideration the sociocultural aspects as well.

The quantity of water necessary for the irrigation of the settlements is far superior the the water needed for domestic uses. Consequently, we should start by questioning the change of the agricultural productivity due to climatic changes, and with it, the feeding of the community. All the three villages of Samdzong, Yara and Dheye depend of water resources that come from snow (the mountain’s snow, which is a form to gather water, melts and becomes gradually available downstream during spring). However, because of global warming, the snow is always less abundant. The available water resources are already fully used and there is thus no margin to compensate for the reduction of the snow mass. The working group has identified technical solutions to improve the storage, reduce the losses along the irrigation canal and to  improve the methods to distribute the water to the different fields. However, the data study and the climatic model has shown a dramatic result for Mustang : we expect an increas of temperature of 6 to 10 degrees by the end of the century. Bearing this in mind, the technical solution that were considered would solve the problems just for a short time, while the same initial question would have to be considered again shortly.

It seems impossible for Samdzong and Dheye to adapt themselves and stay in the actual settlements, reducing the quantity of available water, this is, reducing the agricultural productivity. Among the three settlements, Yara would be the unique village that could reduce the water consumption, and thus the agricultural production, diversifying its own economic activities. Its particular position, on the way of the sites of religious interests, make it attractive from a touristic point of view. In Yara, the development of the services (food supply, accommodation, etc…) could compensate for the loss of agricultural productivity and allow the people to stay in their own village, despite the climate changes.

Also the measures aimed at lowering the risk of natural dangers (especially landslides) in the current settlements of Samdzong and Dheye appear negligible in comparison with predicted drastic reduction of water for irrigation of the fields. In the case of Yara, on the other hand, the question of securing the village was addressed with a view to longer-term residence: it was discovered that Yara is located above an area affected by a deep landslide that makes the land unstable and buildings partially at risk of collapse (a phenomenon already observed in the past). The landslide currently has a modest activity, with acceleration during rainy periods. A mapping of the landslide and associated morphostructures was produced, signaling on this map the more dangerous and safer areas for future constructions.

In the mean time, security measures for the village will be taken (construction of positional gabions at the base of unstable slopes, reduction of losses along the irrigation canals, avoid water stagnation).

The settlements of Samdzong and Dheye will thus have to be transferred on the territories of Namashung (water basin 6 times larger than the one of Samdzong) and Tchangchung (water basin 36 times bigger than the one of Dheye) respectively, both supplied by ice sources at least partially. This guaranties water sufficient to the villages, at lest until the end of the century and probably also for the next one.

Although the elders of both communities reluctantly leave their home village, the strong social cohesion, the deep feeling of belonging to the community and the concern for the future of the next generation incline them to comply with the decisions of the majority without hesitation.

However, if on one side the displacement to the principal valley insures sufficient water  for sustaining the community, the transfer implies new problems that will be solved  with great care in order to have a smooth transfer. In the Kali Gandaki, the principal Valley of Mustang, a strong day wind, to which the inhabitants of Samdzong are not used to deal with, blows every day. The new settlements should be protected from it. For this reason reason, an urban scheme that respects the traditional architecture but meanwhile creates a space inside the village protected from the wind was developed. Also for individual houses, a modular architectural concept has been studied that adapts itself to the needs of families of different sizes and to the will of the communities to redistribute the land in new settlements in equal parts among the families.

On the other hand, two events of detritus flows linked to the collapse of glacial lakes in the Chumaka Khola basin (in 1984 and 1987) invaded the area destined for the future Namashung fields with gravel and blocks of dimensions up to more than 2 cubic meters . A volume of 40,000 cubic meters of material to be removed has been estimated from the map of the deposit thicknesses. Only medium-sized blocks can be removed, which can be used for the construction of a protective reef along the Kali Gandaki river bank, upstream of the area designated for cultivation.

For the planification of the details of these interventions, in particular to secure the water supply (drinking water and water for irrigation of the fields) in the new settlements of Namashung and Tchangchung and to  improve the captation and the distribution of water in Yara, Kam For Sud will have a specific technical consultancy in a second phase of the project.

Reports

The report is written in 4 books; a report for each village and a summary report. All reports are in English and can be downloaded below :