ENVIRONMENT-CHINA: Dam Plans Open Gates to Tough Choices Ahead By Gordon Ross Dated 25 Feb 2010 (http://www.ipsnews.net/news.asp?idnews=50457)
Gordon Ross reported that the construction of a small dam on a tributary to the Nu, just south of the Three Parallel Rivers World Heritage Site of the United Nations Educational, Scientific and Cultural Organisation (UNESCO), is nearly complete". Just for the record, Nu River flows from the Tibetan highlands through China’s western Yunnan province, cutting between two mountain ranges before rushing through Burma into the Andaman Sea. It is home to a third of the country’s Christian ethnic groups and a diverse ecosystem of 7,000 species of plants and 80 rare or endangered animals and fish.
At present, China holds the record of longest dam in the world with the completion of the Three Gorges Dam, which spans the Yangtze in Hubei province. With a total capacity of 22,500 MW, many ponders why does China still need to build more dams. Has greed really eaten up China?
It cannot be argued that hydroelectric dams are a source or renewable energy and many countries, Malaysia included, are aiming to build these dams in a move to offset a county's nett carbon emissions. Unfortunately, this renewable energy is not of natural build-up. Construction of a hydroelectric dams requires a large area of the river and also land if diversion of river is to occur. In short the construction of the dam destroys the biodiversity of the river and the ecosystem which it supports. In general, the biodiversity of the river; the aquatic animals especially migrating animals, plants, microorganisms, the ecosystem in which the river supports and feeds; herbivors, carnivors and human community will lose not only home but also survival.
The only option to save all the biodiversity is to remove the biodiversity to another location, which is almost impossible and too tedious. When a life is removed from its ecosystem, it does not guarantee its survival in the new location. Same goes for the human communities, it is impossible to replace their culture, lifestyle and environment. China government promises hopes to the human communities by relocating them, providing new jobs and homes. The question is: does the human communities have any choice or say in this matter?
Answering your question, i assume human communities do not have any choice or say in this matter. Looking at china, this issue is also very serious in our country, malaysia. Browsing though the net i came accross an article on the estbalishment of hydroelectric dams across sarawak by the year 2020. in the name of development of industry in Sarawak and the promise to allow more job opportunities and infrastructure Malaysian government is ready to proceed with this project.
ReplyDeletewhat is future of the indigenous people? do they know that they will be evacuvated from their long inhabited land for generations.they are told that there will be job oppotunities and development, however they are not being informed of the sacrifises thay have to make in order to allow malaysia to be largest power supply country accross southeast Asia including Brunei, Indonesia and the Philipines as part of ASEAN Interconnection Master Plan.Environmentalist has already fighting against the Bakun Dam project and there comes many other just waiting for their turn to show its identity in the limelight. Only development is focussed here and the indigenous people do have any say. they are not even aware of the consequences until they face it.Please view the article.This article and the future of the indigenous people reminds me of the movie "Avatar" will there be a hero to save these people too..........
http://news.mongabay.com/2009/0903-moses_sarawak_dams.html
Power, profit, and pollution: dams and the uncertain future of Sarawak
Kara Moses, special to mongabay.com
September 03, 2009
Effects on Humans
ReplyDeleteWhile dams are helpful to humans, they can also be harmful as well. One negative effect of dams is the fact that the artificial lakes created by dams become breeding grounds for disease. This holds true especially in tropical areas where mosquitoes (which are vectors for malaria) and snails (which are vectors for Schistosomiasis) can take advantage of this slow flowing water.
For humans, another disadvantage of the construction of dams is that if they built close enough to residential areas, the relocation of residents will be necessary. This is true of the Three Gorges dam that is being built in China. The Three Gorges dam will submerge a large area of land, forcing over a million people to relocate. "Dam related relocation affects society in three ways: an economic disaster, human trauma, and social catastrophe", states Dr. Michael Cornea of the World Bank and Dr. Thayer Scudder, a professor at the California Institute of Technology.
Effects on the Earth Itself
Dams have been found to alter the overall climate of the Earth. This is because dams generate methane, a greenhouse gas. Methane is emitted from reservoirs that are stratified, in which the bottom layers are anoxic (i.e. they lack oxygen), leading to degradation of biomass through anaerobic processes.[5] As a result of the climate alterations, the following is a list of possible effects:
• Rise in sea level (leads to flooding in lower elevation areas)
• Shift of climatic zones to the poles (leads to major agricultural
disaster, among other effects)
• Unmanaged ecosystems may face new climate based stresses
Effect on water resources as precipitation and evaporation may change A dam also acts as a barrier between the upstream and downstream habitat of migratory river animals, such as Chinook salmon and steelhead trout in the USA[1], and Atlantic salmon in Europe. Dams block their migration upstream to spawning areas, threatening to decrease reproduction numbers and reduce the species population. In light of this consequence, efforts have been made to allow the fish a passage upstream, and newer dams often include artificial "fishways" or "fish ladders".
1. Some communities have also begun the practice of transporting migratory fish upstream to spawn via a barge.[1] Fish sometimes have difficulty migrating downstream through a dam, meaning that downstream populations are often reduced unless, the fish are able to swim safely through the dams’ spillways. Permanent inundation caused by reservoir flooding also alters the wetlands, forests and other habitats surrounding the river. Further ecosystem disruption occurs along the banks of the river and downstream. The areas surrounding riverbanks are of a particularly rich bio-diversity, supported by the natural flooding of a dam-free river. Dammed rivers reduce flood rates, and this has negative consequences on the floodplains downstream that depend on seasonal waters for survival. The comparatively invariable ecosystem created by a reservoir-river supports a far-reduced range of wildlife. Dams hold back sediments that would replenish down stream ecosystems naturally. Endemic species may or may not survive the environmental change, and new species are likely to adopt the altered habitat as a home. However, since dams change a key ecosystem to which all surrounding ecosystems have adapted dam construction nearly always reduces wildlife diversity, for better or for worse.
References
1. ^ a b Mann, Charles C; Mark L. Plummer (August 2000). "Can Science Rescue Salmon?". Science, New Series 289 (5480): 716–719.
2. ^ Silenced Rivers: The Ecology and Politics of Large Dams, by Patrick McCully, Zed Books, London, 1996.