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The Mekong is one of the world’s longest rivers connecting six Asian countries, China,
Myanmar, Laos, Thailand, Cambodia, and Vietnam. People and fish, as well as many other species
in this biologically rich region, are directly connected to the river, so that what impacts
the river also impacts them. A river of life and livelihood, the Mekong
provides for navigation, agriculture, and for the rich, naturally-produced fishery that
is the primary protein source for more than 50 million people.
Computer models and visualization tools can help people develop an integrated view of
river life and provide a scientific basis for critical decisions about regional development
and sustainability. The Mekong River Commission, or MRC, collects
river flow data used to develop hydrology models within a decision-support framework.
The MRC is upgrading a Mekong version of the popular Soil Water and Assessment Tool, or
SWAT model, to predict how river flow might change in response to such factors as climate
change and proposed regional development projects, including mainstream and tributary dams designed
for irrigation and hydropower. The U.S. Department of State, the U.S. Geological
Survey, and university partners are developing a graphic visualization tool, or GVT, to present
SWAT model results, thereby helping policy makers and planners communicate and evaluate
complex river scenarios. This GVT allows SWAT users to read and display
input and output files with enhanced graphical capacity, zoom in and zoom out, and split
screen for multiple parameters or file sets of different scenarios, such as with and without
a project or dam. The U.S. State Department, USGS, and private
contractor FISHBIO supported the first meeting of the Mekong Fish Monitoring Network in Phnom
Penh, Cambodia, in February 2012. The MRC, the lower Mekong Basin nations, universities,
and nongovernmental organizations all participated in this meeting to help increase fisheries
knowledge and data sharing. The life of the Mekong teems with boat traffic
and trade year round above the surface, while seasonal floodwaters initiates the migration
and netting of an abundant fishery below the water.
Fish catch corresponds to the depth of annual flood, which varies seasonally and annually
depending on degree and timing of snowmelt and monsoon rains.
Bridge faces show the colored marks and banding of recurring flood levels which corresponds
to height of banks and stilted homes and use of floating houseboats.
The river grade and bottom depth varies along the rivers course and contributes to the wide
variety of fish species and different guilds by habitat association and migration patterns.
Some fish guilds are more dependent on deep pools and slackwater environments, while others
require moving water to migrate and spawn upstream, downstream, or onto to the floodplain
during high water flows. The U.S. Department of State, USGS, MRC, and
the Autonomous Port of Phnom Penh coordinated a training workshop with Mekong Nationals
to use specialized sonar and GPS equipment to conduct a hydrographic survey of the confluence
of the Mekong, Tonle Sap, and Bassac Rivers around Phnom Penh.
Features of bottom depth, width, and roughness can be seen graphically and with additional
river surveys add to enhanced modeling capacity for integrated river management.
The flow regulation that results from upstream dams may benefit some Mekong River residents,
but changing natural water flow patterns can be problematic for sustaining the rich biodiversity
of fish in the Mekong, particularly species with long-distance migratory behavior.
Migration patterns of important species can be graphically captured in the visualization
to aid impact assessments of proposed dams with increased understanding of fisheries
ecology of the Mekong. Forecast Mekong is working with the Mekong
River Commission to apply advanced computer applications, hydrographic surveys, and SWAT
visualizations that will enhance the integration of knowledge and models of river life of the
Mekong Basin from the headwaters to the delta. The six nations that share the Mekong River
will all benefit from a commonly held understanding of the benefits, impacts, and trade-offs of
water resource development. Scientific visualization provides a powerful
tool to more effectively integrate the ecology and management of the Mekong for people, fish,
and wildlife.