UNDP (2010) Why water, including GLOFs, is a key sector for the country-Nepal?
Water resources play an important role in the overall development of Nepal. Nepal has a theoretical hydropower potential of about 83,000 MW. The source of livelihoods of majority of the population is agriculture. Both of these sectors are heavily dependent on water resources. In such a context, Nepal has very little alternative to water resources development for food security, people’s livelihoods, industrial growth, environmental sustainability and by and large the economic prosperity of the country.
However, owing to sharp altitudinal variation: 65 – 8848 m in 160 km (see Figure 1), uneven annual distribution of rainfall (75% in 4 months) make water sector of Nepal as one of the most vulnerable sectors; the impact of climate change has put an additional stress to it. Climate cycle and water cycle are closely linked, so that any change in one of these systems induces a change in another one.
Climate change impact ranks high on water resources and hydropower of Nepal in terms of certainty, timing, severity and importance.
1.Observational records and climate projections have revealed that water resources are highly vulnerable to climate change with wide-ranging consequences on human societies and ecosystems.
2. Water related disasters such as floods, landslides; reduced low flows are all associated with climate change. Likewise, increasing temperature enhances the likelihoods of Glacial Lake Outburst Floods (GLOFs) in the Nepal Himalayas. Major infrastructure including fertile agriculture fields, as well as settlements and forests are located along the major river banks susceptible to floods including GLOFs. Potential GLOFs may damage lives, property and environment along the river valley hundreds of kilometres downstream from the GLOF source.
Nepal does not have any proven reserves of fossil fuels. A large portion of Nepal’s foreign earning goes for the import of petroleum products. Therefore, development of hydropower is one of the potential options in order to reduce the dependency on imported fossil fuels and to save the foreign earning for other development works. Furthermore, because of the growing global concern of climate change, Nepal’s hydropower sector could play a significant role in the emission trading as a source of clean energy. Nepal’s electricity is predominantly a hydro-based and most of hydropower plants are the run-off-river types, which are generally designed for low flows.3 Studies show that there will be decreasing low flows during non-monsoon seasons in the river as a result of climate change, which might have direct adverse impacts on Nepal’s hydropower generation. Besides, Nepal’s economy is largely dominated by subsistent agriculture, which in turn very much depends on availability of water for irrigation. Increasing temperature may result in decreased river flows on the one hand and increased irrigation water requirement on the other, which may adversely affect the agriculture production.
Predicted water stresses as a result of climate change will create additional conflicts within the society. Extreme events like floods and landslides will generate forced migration as well as adverse environmental impacts like loss of biodiversity. The water stresses will have greater burden on the poorer sections of the society living already under more vulnerable social and economic conditions. Climate change through its impact on water resources will bring additional stresses to the societies already having other social, economic and political stresses. Adaptation technologies being used so far in the water resources sector are mostly of conventional type such as open water storage ponds. Adoption of new technologies like sprinkler, drip irrigation system requires financial and skilled human resources as well as strong political will.
DESCRIPTION OF THE WATER SECTOR INCLUDING GLOFS
Nepal has more than 6000 major rivers, majority of them are fed by snow and glacier melts. Nepal’s annual average rainfall is about 1700 mm, about 75% of which occurs during the summer monsoon season (June-September). Nepal has around 660 lakes of more than 1 hectare.4 Groundwater remains an important source of water, particularly in the Terai and Kathmandu Valley….
