| Title | Flooding, structural flood control measures, and recent geomorphic research along the Red River, Manitoba, Canada |
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| Author | Brooks, G R ; St.
George, S |
| Source | Geomorphic approaches to integrated floodplain management of lowland fluvial systems in North America and Europe; by Hudson, P F (ed.); Middelkoop, H (ed.); 2015 p. 87-117, https://doi.org/10.1007/978-1-4939-2380-9 5 |
| Image |  |
| Year | 2015 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120319 |
| Publisher | Springer New York |
| Document | book |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Manitoba |
| NTS | 62H/03; 62H/06; 62H/11; 62H/14; 62H/15; 62I/02; 62I/03; 62I/07 |
| Area | Red River; Winnipeg; Lake Winnipeg; Assiniboine River |
| Lat/Long WENS | -97.5000 -96.5000 50.5000 49.0000 |
| Subjects | surficial geology/geomorphology; hydrogeology; flood potential; flood plains; floods; precipitation; alluvial deposits; groundwater regimes; structural analyses; structural controls;
Quaternary |
| Illustrations | location maps; photographs; plots; tables; flow charts |
| Program | People Support |
| Released | 2015 04 30 |
| Abstract | The Red River, Manitoba, Canada, is a low-gradient, meandering river that traverses the broad, flat Red River Valley on the northeastern portion of the Great Plains of North America. The shallow
stream-cut valley occupied by the river has insufficient capacity to contain large discharges, which allows higher magnitude flows to overtop the valley sides and spread up to 40 km across the adjacent clay plain. Major flooding impacts communities
and rural areas, including the City of Winnipeg, and has caused significant flood disasters in the nineteenth and twentieth centuries. Since 1950, an array of structural flood control measures has been constructed (and some later upgraded) to
mitigate flooding, including two diversion canals, a flood control dam, dyking (linear and ring dyking), and elevated earthen pads under structures. Multidisciplinary research initiated following the 1997 Red River flood provided a geomorphic context
to the flood problem in support of decision making towards enhancing the flood-protection infrastructure. Based on flood signatures in the growth rings of bur oak trees (Quercus macrocarpa Michx.), the historic flood-of-record in 1826 is interpreted
to be the largest Red River flood since at least 1648. An assessment of the decrease in river gradient arising from regional differential uplift revealed that the broad, shallow flood character is intrinsic to the landscape of the Red River Valley
and that the contemporary rate of uplift is causing an insignificant change to the extent of flooding. An investigation of the evolution of the genetic floodplain indicates that fluvial geomorphic processes are not significantly enlarging or
infilling the shallow stream-cut valley at rates relevant to altering the modern flood problem. Although flood management along the Red River is heavily dependent on structural measures, the design discharge of the integrated flood control works
protecting Winnipeg has recently been enhanced to a 700-year return period, which reduces the flood hazard substantially. |
| GEOSCAN ID | 292066 |
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