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Module 2 Mekong Resources, Benefits to people, and Planning Issues session 1 : The Mekong and its water resources. Module Objective.
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Module 2 Mekong Resources, Benefits to people, and Planning Issuessession 1 : The Mekong and its water resources
Module Objective • Participants can identify Mekong water/ relate resources, current benefits to basin peoples, potentials for future development, and able to define key issues for planning water resources development.
“..the Mekong River Basin and the related natural resources and environment are natural assets of immense value…” 1995 Agreement
Upper Basin Lower Basin Mekong River Basin • China • Myanmar • Laos • Thailand • Cambodia • Viet Nam • Discharge: 475 km3 / year • Area: 795,000 km2 Murray-Darling Discharge: 12.6 km3 / year Area: 1,073,000 km2
Mekong River Basin • Upper Mekong Basin (UMB) • 18 % of total flow (China 16% & Myanmar 2%) • Lower Mekong Basin (LMB) • 625,000 km2 • 82 % total flows • Cambodia – 18% • Lao PDR– 35% • Thailand – 18% • Viet Nam – 11%
Mekong River Basin • Main regions • Upper Mekong Basin For most of its length, it flows Through narrow valleys in the Mountain in China. Upper Basin is narrow, with few tributaries And gives 18% of the total flow
Manwan and Dachaoshan dams, Feb 2003 20 km
Mekong River Basin • Main regions • Upper Mekong Basin • Lower Mekong basin • Highlands
Mekong River Basin • Main regions • Upper Mekong Basin • Lower Mekong • Highlands • Central/Isan Plateau
Mekong River Basin • Main regions • Upper Mekong Basin • Highlands • Central / Isan Plateau • Cambodian plain and Great Lake
Mekong River Basin • Main regions • Upper Mekong Basin • Highlands • Isan Plateau • Cambodian plain and Great Lake • Delta
Hydrological Regime • Hydro. Regime depends on climatic conditions of wet and dry seasons. • High water period from Sept – Nov; Low flow period from Feb. – April. • Flood season in mainstream and tributaries, from June-July to Nov-Dec accounts for 85-90% of total annual water volume. • Peak month of Sept accounts for 20-30% of annual flow.
20% Contribution to Mekong flows 35% 16% Climate • Monsoonal climate • dry season November to May • wet season June to October
The % contribution of flow from China to average monthly flow at … The % contribution of flow from China to average monthly flow at … % • Flow from China dominates the dry season hydrology of the Lower Mekong • Flood season flows mostly originate within Laos and the lower basin
20 m River variability Flooding
3 commonly identified water quality issues Sediments in the water Salinity ( NE Thai & VN Delta) Eutrophication
Water quality monitoring • Trends in total suspended sediment (TSS) in the Lower Mekong Basin
Salinity • In NE Thailand where there has been concerns for salinity, 4 of 5 sites show a decrease • most concern sites in Vietnam (9) show also a decrease. Eutrophication • Mostly a problem in VN delta • 40 sites in the delta show an increase in phosphorus • 31 site in delta show increase in nitrogen • ( both N & P are parameter used eutrophication)
Water quality In summary • It is quite good when compare with many other international rivers !