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Contents contributed and discussions participated by Ian Gabrielson

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Ian Gabrielson

The Mekong | The Economist - 1 views

www.economist.com/...erways-survive-its-development

Freshwater The water system Drainage basins and flooding Competing demands for water global_perspectives student_resources teacher_resources water_conflicts water IB Global Politics Management issues and strategies Power Sovereignty and International Rela

shared by Ian Gabrielson on 12 Feb 16 - No Cached
  • The Mekong region is Asia’s rice bowl: in 20
  • support the world’s biggest inland fishery, accounting for a quarter of the global freshwater catch, feeding tens
  • millions of pe
  • ...14 more annotations...
  • 14 lower Mekong countries (Myanmar, Laos, Cambodia, Thailand and Vietnam) produced more than 100m tonnes of rice, around 15% of the world’s total.
  • The region’s fertile soil depends on nutrient-rich sediment that the Mekong carries downriver, mainly during the rainy season from June to October;
  • The region boasts remarkable biodiversity; only the vast basins of the Congo and the Amazon compare to or surpass it
  • here are more than 20,000 types of plant and nearly 2,500 animal species; freshwater dolphins and giant catfish; spiders 30 centimetres across and, in a limestone cavern in Thailand, a day-glo pink, cyanide-secreting millipede
  • he human diversity is striking, too: Tibetan monks pray; Burmese traders buy and sell; Cambodian fishermen cast nets; Thai farmers reap; Vietnamese markets float. The history is as rich as the soil. The Bud
  • a smiled while resting at the northern Lao city of Luang Prabang. Angkor Wat on the Mekong-fed Tonle Sap lake was among the biggest cities of the preindustrial world. The Khmer empire that built it dominated South-East Asia for longer than there have been Europeans in the Americas.
  • s its currents are rechannelled down copper conduits to power far-off cities the river itself will be trapped behind a series of concrete walls. Its fisheries, agriculture and biodiversity will suffer; the lives lived on its banks will be reshaped with scant regard for the feelings of those who lead them
  • t least 86,000 have been built over the past six decades, providing 282 gigawatts (GW) of installed hydroelectric capacity by 2014
  • y 2020 it wants an astonishing 350GW of installed hydropower capacity; in the European Union that would be enough to meet about three-quarters of total electricity needs. The dam at Wunonglong, about 300 metres long and more than 100 metres high, will provide a smidgen less than one of those extra gigawatts. The other 13 are expected to add 15.1GW mor
  • Downriver countries intend to build another 11 large dams on the Mekong, with dozens more planned for its tributaries
  • he dams will change the quality of the water in the river and the rate at which it flows. Some of this change could be for the better. Dams can prevent flooding by regulating the flow of water downstream. But some Mekong riverbank agriculture would not welcome too steady a flow
  • Increasing water in the dry season would shrink riverbeds, leaving less space for crops—millions of Mekong-basin dwellers grow vegetables on riverbanks. Reducing water in the rainy season produces smaller floodplains with less sediment deposited in them, impoverishing the soil.
  • According to International Rivers, an environmental NGO, the full cascade of dams planned for the Lancang would trap nearly all of the sediment coming from China, cutting the water’s sediment load in half.
  • And the dams lower down could worsen the problem; the clear, “hungry” water that flows from them in spates will carry away existing sediment in riverbanks and riverbeds. Some of that will be deposited farther still downstream; some will wash uselessly out t
  • Ian Gabrielson on 12 Feb 16
     
    Excellent set of articles about the situation in the Mekong
Ian Gabrielson

Water: All dried up | The Economist - 2 views

www.economist.com/...are-potentially-disastrous-all

water china economist ib_geog2009 Freshwater The water system Competing demands for water Management issues and strategies Drainage basins and flooding water_scarcity water_conflicts water_resources

shared by Ian Gabrielson on 28 Oct 13 - No Cached
  • Ian Gabrielson on 28 Oct 13
     
    "All dried up Northern China is running out of water, but the government's remedies are potentially disastrous"
Ian Gabrielson

Five Controversial Dams ~ Introduction | Wide Angle | PBS - 3 views

www.pbs.org/...3103

Conflict_and_Peace global_perspectives student_resources ib_geog2009 Freshwater Management issues and strategies Competing demands for water

shared by Ian Gabrielson on 29 Nov 12 - No Cached
  • Ian Gabrielson on 29 Nov 12
     
    "For many developing countries hungry for energy sources, hydropower is an attractive option. But dams also can place heavy burdens on surrounding populations and eco-systems. While China touts its Three Gorges dam - the world's largest - as environmentally friendly, the United States has begun tearing down a number of its own structures for safety, economic, and environmental reasons. To broaden your knowledge of dams around the world, explore below the economic, environmental, social, and political aspects of five big dam projects in Turkey, Brazil, Laos, Lesotho, and China. "
Ian Gabrielson

Save the Mekong - 0 views

www.savethemekong.org/issue_detail.php

ib_geog2009 Competing demands for water Freshwater

shared by Ian Gabrielson on 16 Oct 12 - No Cached
  • Ian Gabrielson on 16 Oct 12
     
    An excellent website that looks at the key issues surrounding building Dams upstream on the Mekong. Good for international and local conflicts
Ian Gabrielson

River fieldwork - 3 views

www.geography-fieldwork.org/...stage1.htm

ibgeog ib_geog2009 Freshwater Drainage basins and flooding discharge hydraulic radius velocity

shared by Ian Gabrielson on 24 Sep 12 - No Cached
  • Ian Gabrielson on 24 Sep 12
     
    "Hydraulic radius = cross sectional area / wetted perimeter. Hydraulic radius is a measure of the efficiency of the the river channel. The higher the hydraulic radius, the more efficient the river channel is. The more efficient the river is, the more energy the water will have to move downstream (so as hydraulic radius increases, velocity increases) carry load (so as hydraulic radius increases, the river's competence and capacity increases) increase the rate of erosion (in the upper course, as hydraulic radius increases, there is a higher rate of vertical erosion, so gradient increases; further downstream where the river is closer to base level, as hydraulic radius increases, there is a higher rate of lateral erosion)."
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