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Climate Change Risk for Hydropower Schemes in Himalayan Region Bidur Raj Gautam, Fengting Li,* and Guo Ru UNEP-TONGJI Institute of Environment for Sustainable Development, College of Environmental Science and Engineering, Tongji University, Shanghai, China 200092 climate change on these infrastructures have not yet received required attention. Hydropower is among the most vulnerable areas to global warming because water resource availability is closely linked to climate change. Hydroelectric plants are highly dependent on predictable runoff patterns. Greater unreliability of dry season flows, in particular, poses potentially serious risks to water supplies in the lean season. Therefore, increased climate variability, threatens the potential for hydropower generation. The existing hydropower plants may not function with designed capacity, as the low flows might be decreasing in dry season while flow might increase beyond its design capacity in peak Monsoon. Climate change will result in significant change in temperature and precipitation pattern resulting in change of river discharge. Climate change will cause drier winter and shorter but intense monsoon; increasing risks of flooding and landslides.4 There is evidence that Himalayan glaciers have been melting at an unprecedented rate in recent decades resulting in increase in the number and size of glacial lakes forming (GLOF) at the new terminal ends behind the exposed end moraines.5 These in turn give rise to an increase in the here is a worldwide consensus that climate change is a potential threat of glacial lake outburst floods occurring. Such real, rapidly advancing, and widespread threat. This is a disasters often are very devastating as they sweep almost crucial issue in Himalayan because of its possible impact on everything on their way. water resources, biodiversity, and consequence on economic Mountain systems are particularly sensitive to climate growth of the region.1 Himalayan glaciers are natural buffers of changes. Small changes in climate can produce significant hydrological seasonality, releasing meltwater during summer regional or larger-scale effects. Because of climate change, hydropower infrastructure and facilities are at risk from and early autumn in particular influencing runoff into lowland increased flooding, landslides, sedimentation, and more intense rivers, recharging river-fed aquifers, and contributing wellbeing precipitation events (particularly during the monsoon). Any of almost 800 million people living in catchments of rivers GLOFs outburst or large flooding can destroy number of originating from glaciers.2 projects at once, as there are many projects in the same basin. The Himalayan region is region is home to the nations of Above-mentioned risks should be investigated to analyze the Nepal, Bhutan, the Indian states of Arunachal Pradesh, economic benefit of designing hydropower plants with the Uttarakhand, Sikkim, Himachal Pradesh. and the regions of possibility of future lowered capacity, provisioning for increased Tibet, Jammu, Kashmir, and Ladakh. The Himalayan ranges river sedimentation and increased flood protection.1 The have most of world’s highest peaks including Mount Everest. It growing demands for water and electricity, coupled with is also source of three of the world’s major river systems, the reduced dependability of low season flows under climate Indus Basin, the Ganga-Brahmaputra Basin and the Yangtze change and need for flood protection would suggest the need Basin. Figure 1 shows contribution of snowmelt and rainfall for a greater role for expensive and more controversial storage contribution on river discharge in Himalayan region. River hydro facilities as an adaptation response, as opposed to the discharge in the northwestern and far eastern Himalayan region conventional run-of-river schemes. However, storage hydro contains a significant amount of water from snowmelt. These facilities might not be feasible in all location and they come glaciers and monsoon rain fed rivers along with high slopes with their own problems. Dams might in fact exacerbate makes Himalayan region attractive location for development of societal vulnerability to another climate change impact hydropower projects. There are hundreds of hydro projects (GLOFs), because the breach of a dam following a GLOF dotted all over Himalayan region particularly in India and might result in a second flooding event of multiple magnitude. Bhutan. Nepal, Pakistan and China are also building numbers of hydro projects in their part of Himalayan and plan to build many more. There are many hydro projects in same river Received: June 4, 2014 almost in cascaded fashion. However, threats associated with Published: June 27, 2014
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© 2014 American Chemical Society
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Environmental Science & Technology
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Figure 1. Contribution of snowmelt and rainfall contribution on river discharge in Himalayan region.3
A hydro project built in one country can also effect water flow in another country, so strong regional cooperation among countries in this region. Therefore, sensible decision-making is required on a case-by-case basis to incorporate climate change issues in decision-making.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]; Phone: +862165983302; Fax: +862165985059. Notes
The authors declare no competing financial interest.
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REFERENCES
(1) Pathak, M. Climate Change: Uncertainty for hydropower development in Nepal. Hydro Nepal, , January, 2010, (6) 31. (2) Immerzeel, W. W.; Beek, L. P. v.; Bierkens, M. F. Climate change will affect the Asian water towers. Science 2010, 328, 1382−1385. (3) Bookhagen, B. Hydrology: Himalayan groundwater. Nat. Geosci. 2012, 5, 97−98. (4) NIC 2009−03D. India: The Impact of Climate Change to 2030, A Commissioned Research Report, April 2009. (5) Bajracharya, S. R.; Mool, P. K.; and Shrestha, B. R. Impact of Climate Change on Himalayan Glaciers and Glacial Lakes: Case Studies on GLOF and Associated Hazards in Nepal and Bhutan, ICIMOD, 2007.
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dx.doi.org/10.1021/es502719t | Environ. Sci. Technol. 2014, 48, 7702−7703
