HR: 16:20h
AN: H44B-02    [Abstracts]
TI: Fragmentation and Flow Regulation of the World's Large River Systems
AU: * Reidy, C
EM: cathy.reidy@emg.umu.se
AF: Landscape Ecology Group, Ume† University, Department of Ecology and Environmental Science, Ume† University, Ume†, SE-90187 Sweden
AU: Nilsson, C
EM: christer.nilsson@emg.umu.se
AF: Landscape Ecology Group, Ume† University, Department of Ecology and Environmental Science, Ume† University, Ume†, SE-90187 Sweden
AU: Dynesius, M
EM: mats.dynesius@emg.umu.se
AF: Landscape Ecology Group, Ume† University, Department of Ecology and Environmental Science, Ume† University, Ume†, SE-90187 Sweden
AU: Revenga, C
EM: crevenga@tnc.org
AF: Global Priorities Group, The Nature Conservancy, 4245 North Fairfax Dr., Arlington, VA 22203 United States
AB: Humans have extensively altered river systems through impoundments and diversions to meet their water, energy and transportation needs. Here we present a global overview of flow regulation and channel fragmentation by dams in the world's large river systems (LRSs), which comprise a total virgin mean annual discharge (the discharge before any significant human manipulations) of some 790,000 m3s-1, or 60% of the world's river runoff. Over half of the systems (172 out of 292) are impacted by dams, including the eight most biogeographically diverse. In terms of summed LRS discharge and catchment area, the proportions of impacted rivers are 84% and 88%, respectively. The greatest flow regulation (428%) is reported for the Volta river system in Africa, and regulation is beyond 250% in both the Manicougan and Colorado systems in North and Central America. Dam-impacted catchments experience higher irrigation pressure and about 25 times as much economic activity per unit of water as do unaffected catchments. In view of projected changes in climate, land use and water stress, these findings can be used to identify ecohydrological risks associated with further impacts on large river systems.
UR: http://www.emg.umu.se/research/river/projekt/projcneng.html#Fragmentation
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1808 Dams
DE: 1856 River channels (0483, 0744)
DE: 1857 Reservoirs (surface)
DE: 1860 Streamflow
SC: Hydrology [H]
MN: Fall Meeting 2005