Changing water regime and adaptation strategies in Upper Mustang Valley of Upper Kaligandaki Basin in Nepal

Prem Sagar Chapagain , Jagat K. Bhusal

1. Central Department of Geography, Tribhuvan University, Kathmandu, Nepal

2. Chairperson, The Society of Hydrologists and Meteorologists Nepal, Kathmandu, Nepal

1 Introduction

Climate change is a matter of global concern. The average global temperature rose by 0.74 °C over the last hundred years(1906–2005) (IPCC, 2007), and the average rate of warming in the Nepal Himalayas is 0.4 °C per decade. Changes in the Himalayas could affect the lives and livelihoods of more than 1 billion people living in the river basins downstream. There is clearly rising trend of temperature in Nepal and it is more prominent in higher altitude regions of the country (Shresthaet al., 1999). Recent studies show the progressively higher warming in higher altitude of the whole Himalaya and the rate of temperature rising is 0.01 °C in the eastern Himalayas (Newet al., 2002; Shrestha and Devkota, 2010). Climate change impacts are strong, both positive and negative, and they directly affect the high Himalayan agro-pastoral-based communities, especially their water requirements for drinking and irrigation, food production, and food security.

Climate change effects on food production suggest that agriculture productivity will increase at temperate high latitudes, and it will decrease at lower latitudes of tropical and subtropical areas (Cline, 2008; Cribb, 2010). It has been predicted that agriculture production in temperate countries in the north could increase by 8% to 25% by 2050, whereas in the south, especially in India, it will decrease by 30%(Cline, 2008). In this context, this paper examines the water regime in the cold arid region of the Upper Kaligandaki Basin and the local adaptation strategies of agro-pastoral-based production systems in the region.

Bordered by the Tibet Autonomous Region of China to the northeast, the Upper Kaligandaki Basin is located in the trans-Himalayan region of Nepal (Figure 1). The Himalayas are geologically young, fragile, and subject to continuous denudation. The mountains’ steep slopes and many river gorges preclude dense settlements, and arable land is limited (NTNC,2008). The basin covers an area of 3,200 km2, with an elevation ranging from 2,800 to 8,168 m a.s.l.

The basin lies in a rain shadow and receives very little rain, less than 300 mm annually (DHM, 1999). The climate of the district is generally dry with strong winds and intense sunlight. The maximum temperature that has been recorded in summer is 26 °C and the winters are very cold, with temperatures ranging to -20 °C.

In 2010 a seasonal road was built to the once-inaccessible High Mountain area. This has not only created growth opportunities but has also widened economic disparity gaps, accelerated environmental degradation, heightened cultural integration, and contributed to the haphazard growth of settlements which were already begun to notice (Tulachan, 2001). Although the lower part of the area lies within the world-famous Annapurna Trekking Circuit, local settlements have benefited little from tourism because of their off-route locations. Therefore, the means of livelihood in the cold and arid zones of Nepal in general, and specifically in the Mustang Valley, continue to reflect adaptation for survival in the context of global warming and habitat degradation (Simon, 2010).

Figure 1 Upper Kaligandaki Basin in the Mustang Valley, Nepal

2 Methods and materials

This study was based on analysis of available rainfall,temperature, and river discharge data of the Nepal government’s Department of Hydrology and Metrology. We utilized continuous data from four monitoring stations, Muktinath, Lomanthang, Ghami, and Jomsom, of the Upper Mustang Valley from 2000–2012. Water balance was calculated using parameters such as rainfall, outflow, evapotranspiration, and deep percolation. Data on evapotranspiration and deep percolation were not available in the basin, so the water balance was calculated based on total rainfall minus outflow. The outflow data were available from the gauge station of Kaligandaki River at its outlet in Upper Mustang Valley at Jomsom.

In addition, two weeks of fieldwork were conducted in January 2011 in the Tiri, Phalek, and Dhagarjung villages in the Upper Mustang Valley. These villages are about two and a half hours’ walking distance from the Jomsom airport.Data were collected using questionnaire surveys, focus group discussions, personal observations, and key informant interviews. There are 47 households in Dhagarjung, 68 in Phalek, and 23 in Teri. Of these, 10 households from each of the three villages were randomly selected for the questionnaire survey. One focus group discussion and one key informant interview were conducted in each village.

3 Discussion

3.1 Water regime

The upper part of the Kaligandaki Basin lies in a rain shadow and receives very little precipitation. Annual precipitation over the area near the basin outlet is 300 mm, whereas the driest part of the basin gets only 145 mm annually (DHM, 1999, 2000).The area between 2,800 and 3,000 m a.s.l. has a cold temperate climate and is the wettest part. Tundra ranges above 5,000 m a.s.l.and is covered with snow year-round. The climate of the district is generally dry with strong winds and intense sunlight. The winters are very cold, with temperatures ranging to -20 °C.

Climate change is a matter of global concern. Recent preliminary research indicated that the temperature in the study area has a rising trend of about 0.02 °C per year (Baidyaet al., 2008;Practical Action Nepal, 2009), while the lower part of the Upper Kaligandaki River Basin has incurred an increasing trend in annual precipitation (Gauchan, 2010). Based on observed monthly precipitation, the annual volume of water is 705 million cubic meters, but the water balance is negative and is emptying by 355 million cubic meters annually in the study basin.

We analyzed observed Kaligandaki River flow data and precipitation data of the basin (DHM, 2010) from the climate change perspective. There are clear indications of climate change effects on local water regimes. The annual runoff volume that is discharging out through the basin and the total annual volume of water falling over the basin area(3,200 km2) as precipitation are summarized in Figure 2.

Figure 2 Annual runoff and rainfall volume from the 3,200 km2 area of the basin

The long-term mean annual precipitation computed by arithmetic mean is 220 mm, which is equivalent to 705 million cubic meters. The annual water volume discharging out of the basin amounts to 1,060 million cubic meters (DHM,2008). The water balance is negative and is emptying by 355 million cubic meters annually. Our analyses of recent data(2000–2012) indicated that except during the pre-monsoon months (March, April, and May), runoff exceeded precipitation inputs (Figure 2, Table 1).

The runoff/rainfall ratio is approximately 1.50. Theoretically, the natural runoff/rainfall ratio should be close to 1.0,but due to evapotranspiration, deep percolation, and other losses, the ratio never actually reaches 1.0. An assessment made on the Kosi River in Nepal found that there is about an 8.46% contribution to annual flow from snow and glacier melt: a maximum monthly contribution of 22.52% in May and a minimum monthly contribution of 1.86% in January(WWF, 2009). However, the recorded rainfall over the Kaligandaki River Basin may not be accurately representative due to rare information on precipitation (annual snowfall) records above 4,000 m a.s.l. Also, runoff contributing to groundwater aquifers could originate outside of the basin.However, there are clear indications that snow and glacier contribution, including groundwater contribution, is appreciable in the study basin. The present study found that the snow melt contribution in the Upper Kaligandaki River Basin could reach up to 40% (Figure 3). This suggests that environmental conditions could worsen if temporal and spatial variations become wider due to climate changes and warming in the future.

Table 1 Seasonal volume of water (input and output) at the Upper Kaligandaki Basin

3.2 Livelihood and adaptation strategies

Historically, water has been considered a productive and symbolic resource in this basin (Hamilton, 1819). Water has been highly contested between individuals, communities, and social groups, and water rights were closely tied with the fraternal polyandry system of marriage practiced until recently in the region. Although this marriage system has almost died out by now, the impartible inheritance system has left the people divided into social classes (Basnet, 2007).

Traditional agro-pastoral production systems focus on growing cereal crops,i.e., wheat, buckwheat, potatoes, and barley. In addition, herdsmen keep livestock such as yaks,goats, sheep, and cattle. Both of these systems have been affected by climate change and globalization. The decline in water sources (springs and streams) is of great concern in this basin because people living there depend greatly on the local environmental resources to eke out their living. Importantly, climate change is altering snowfall amounts,which in time results in less water available for irrigation for the traditional agro-pastoral production system. People freely graze livestock on highland pasture land but, given the very low moisture-holding capacity of the soil, the grazing productivity has been decreasing in line with changing snowfall and rainfall patterns. Sharp declines in snowfall and water have severely affected the pasture productivity,which in turn has negatively affected the whole farming and livelihood diversification. In response, local people have implemented the following adaptive strategies.

Figure 3 Decrease in river flows, snow-fed and non-snow-fed rivers in Nepal

Strategy 1:Set new community rules and regulations for irrigation water use

Farmers have established a new water governance system and set new rules for irrigation water utilization. Traditionally, each village constructed one large pond to store stream water for gravity irrigation to the surrounding farmland. As recently as 15 years ago, one household could completely irrigate its own farmland and then the next household could completely irrigate its land. Now there is not sufficient water stored in such ponds, so each household gets irrigation water for a fixed number of hours (3–4 hours),irrespective of the farm size and its distance from the water storage pond. The time duration decreases depending upon the amount of water available at the stream and stored in the pond. Because of this rule, farmers whose agricultural land is far from the village are deprived as they get the least water.

Strategy 2:Construct new water infrastructure

Traditionally, farmers constructed mud wall ponds for storing water. However, water infiltration is high through the local coarse colluvium soil, so it was necessary to first cement the canals from the spring sources to the ponds. Recently, farmers have started to replace the traditional mud ponds with concrete water storage tanks (Figure 4).

Farmers have also started to lift Kaligandaki River water up to their villages. In Teri village they installed an electric motor and a pipe at the river bank and now lift water to the top of the village, enabling gravity irrigation.This success has encouraged other villages in the Upper Mustang Valley to do the same. In addition, farmers have constructed series of irrigation ponds on the mountain slope so that water that leaks from the storage pond can be captured in the downslope ponds and brought back to the village by a new canal.

Strategy 3:Gradually adopt new farming systems

It has already mentioned that, as previously described,the farmers in this region have traditionally grown limited crops such as wheat, buckwheat, potatoes, and barley. Previously, it was unthinkable to plant cash crops on cereal-growing land. Now this has been made possible by increasing temperatures and also by newly available markets and road transportation. Therefore, many farmers have started growing apples instead of cereal crops (Figure 5).This has proven to be economically beneficial and is the best option given the lack of water and the local labor shortage.In addition, farmers have started to grow many vegetables such as tomatoes, beans, carrots, onions, garlic, pumpkins,spinach, and coriander, especially in Teri village. There is high demand for such vegetables at local markets due to the increasing tourist use of the Annapurna Circuit, which is the first trekkers’ destination in Nepal and where about 90,000 tourists visit annually. Farmers are able get more income in comparatively less growing time. The local NGO, mainly the Annapurna Conservation Area Project (ACAP), and relatives and friends have encouraged these farmers by providing knowledge and other support; this farming system change is also supported by the government. Thus, changes in income and cropping patterns, as well as systemic changes in farming methods, are now taking place in the Upper Mustang Valley.

Figure 4 Traditional mud pond (left), and modern concrete tank (right) at Teri village

Figure 5 Apple plantations on former cereal-growing land in Teri village

Strategy 4:Adopt new irrigation methods on planting terraces

Climate change is a long process. Farmers have observed less snow on mountains and water in streams, which has compelled them to adopt new production strategies at the local level. For example, farmers have adapted by changing their traditional irrigation systems. As previously mentioned, high mountain areas have glacier-deposited soil that is coarse and water infiltration through it is high. In the past, there was sufficient water so farmers needed only one or two planting beds within a single terrace. Given the current situation of water scarcity, farmers have reduced the breadth of planting beds in their terraces; in Figure 6 the distance between bed A and bed B has decreased. As shown in the photo, a water canal enters from C and irrigates the planting beds. To irrigate bed A, canal water directly enters from D, and also the accumulated water on bed B flows to bed A via C. It is important that only small amounts of water be introduced at a time, rather than irrigating the whole terrace or even an entire planting bed at once. This prevents water loss from percolating downward through the coarse and sandy soil. This sort of technical knowledge was been developed by the farmers’ experience with the soils in this region.

Figure 6 Smaller planting beds in a terrace for water optimization in Teri village

Strategy 5:Abandon less productive land and distant land

Another adaptive strategy to water scarcity is land abandonment. Farmers have abandoned about 0.2 hectare of land per household in Dhagarjung and Teri villages and about 0.5 hectare per household in Phalek village. Land abandonment is very high in Phalek village, where each household has abandoned about 0.5 hectare of cultivated land within the last 15 years (Figure 7). As shown in the photo, farmers first abandoned distant cultivated land and thereafter land nearer to the village. This is primarily due to the water shortage, but is also the result of labor shortage as young people are no longer interested in agriculture. They prefer to either move to cities for employment or emigrate for foreign work opportunities.

Figure 7 Old and newly abandoned cultivated land in Phalek village

Strategy 6:Seasonal migration for household income

In the study villages, virtually every household participates in either short- or long-term seasonal migration to urban areas or to foreign countries for household income. Out of the total households of the Mustang district (3,305), 26.4 percent of households have recorded absent household member who has been living outside home for more than six months. The total population of such absent population is 10.6 percent of the total population of the district in 2011. Out of this absent population, male constitutes 69.2 percent. (CBS, 2012). In addition, during the off-agricultural season many people,mostly women, go to the cities of Gauhati and Dehradun in northeastern India for employment, while men involved in the food and livestock business work in the Dolpa district in Nepal.Due to recent environmental changes and their effects on agriculture, such migration is fairly compelled; young people now rarely live at home and participate in traditional farming activities. Thus, agriculture has become the sole responsibility of women and aged household members. However, farm laborers from Dolpa, Rukum, the Upper Mustang Valley, and Myagdi reverse-migrate during the planting and harvesting times.

4 Conclusions

Although climate change is a long-term process, it has already severely affected the water sources of the Upper Kaligandaki Basin. The trends of increasing temperature and decreasing precipitation in this cold arid environment will have long-term implications for infrastructure, regional geomorphology, and eventually the entire ecosystem. Local residents continually adopt various response strategies based upon their knowledge, experiences, and opportunities at the local level. The increasing tourism activities, development of roads, and possibilities of growing new crops are some positive aspects of these recent changes. Therefore, research studies at the local level are important to understand the wide range of adaptation mechanisms and challenges in the mountain regions of Nepal.

We are thankful to UNESCO IHP for the financial support for hydrological research in the Upper Kaligandaki Basin in 2011.

Baidya SK, Shrestha ML, Sheikh MM, 2008. Trends in daily climatic extremes of temperature and precipitation in Nepal. Journal of Hydrology and Meteorology, 5(1): 38–51.

Basnet GB, 2007. Water of Discord, Water of Unity: An Ethnography Study of the Struggle for Water Rights in Upper Mustang, Nepal. Ph.D.dissertation, University of Georgia, Athens, Georgia.

Central Bureau of Statistics (CBS), 2012. National Population and Housing Census 2011 (National Report). Central Bureau of Statistics,Kathmandu.

Cline WR, 2008. Global warming and agriculture. Finance & Development,45: 23–27. http://www.imf.org/external/pubs/ft/fandd/2008/03/cline.htm[Accessed on December 20, 2011].

Cribb J, 2010. The Coming Famine: The Global Food Crisis and What We Can Do to Avoid It. CSIRO Publishing, Melbourne, Australia.

Department of Hydrology and Meteorology (DHM), 1999. Daily Precipitation Records of Gandaki and Narayani Zone through 1996. DHM,HMG/N, Kathmandu, Nepal.

Department of Hydrology and Meteorology (DHM), 2000. Climatological Records of Nepal (1999–2000), DHM, HMG/N, Kathmandu, Nepal.

Department of Hydrology and Meteorology (DHM), 2008. Stream Flow Summary (1962–2006). DHM, HMG/N, Kathmandu, Nepal.

Department of Hydrology and Meteorology (DHM), 2010. Stream Flow of Kaligandaki at Syang (Digital Form), DHM, HMG/N, Kathmandu,Nepal.

Gauchan A, 2010. Climatic Risk and Hazards on Commercial Apple Farming in Mustang District. Paper presented on WMO Day-2010 Celebration by the Department of Hydrology and Meteorology,Pokhara, Nepal.

Hamilton FR, 1819. An Account of the Kingdom of Nepal [reprinted 1971,Bibliotheca Himalayica, New Delhi].

Intergovernmental Panel on Climate Change (IPCC), 2007. Climate Change 2007. The Fourth Assessment Report (AR4), IPCC, Geneva,Switzerland.

National Trust for Nature Conservation (NTNC), 2008. Sustainable Development Plan of Mustang. NTNC/GoN/UNEP, National Trust for Nature Conservation, Lalitpur, Nepal.

New M, Lister D, Hulme M, Makin I, 2002. A high-resolution data set of surface climate over global land areas. Climate Research, 21: 1–25.

Practical Action Nepal, 2009. Temporal and Spatial Variability of Climate Change over Nepal (1976 to 2005). Practical Action Nepal Office,Kathmandu, Nepal.

Shrestha AB, Cameron PW, Paul AM, Jack ED, 1999. Maximum temperature trends in the Himalaya and its vicinity: an analysis based on temperature records from Nepal for the period 1971–94. J. Climate, 12(9): 2775–2786.

Shrestha AB, Devkota LP, 2010. Climate Change in the Eastern Himalayas: Observed trends and model projections. ICIMOD, Kathmandu.

Simon T, 2010. What the Sami People Can Teach Us about Adapting to Climate Change. http://www.guardian.co.uk/environment/2010/mar/10/sami-finland-climate-change (accessed on September, 2012).

Tulachan P, 2001. Seasonal Migration and Trade: A strategy of survival by the Lobas of Lo Manthang. In: Susanne von der Heide and Thomas Hoffman (eds.). Aspects of Migration and Mobility in Nepal. Ratna Pustak Bhandar, Kathmandu, pp. 43–72.

World Wildlife Fund (WWF), 2009. Report on Climate Change Impact on Discharge at Koshi River Basin and Analyzing Regional Climate Model (PRECIS) Output and Extracting Meteorological Data in Appropriate Format for Input in Hydrological Model, WWF Nepal and Department of Hydrology and Meteorology (DHM), Kathmandu.