Water Stewardship Information Sources

Citation Mannerstrom, M, Leytham, M, Costa-cabral, M and de Lima, G. 2014. Flood hazard assessment approaches for climate change. 6th International Conference on Flood Management.
Organization Northwest Hydraulic Consultants
URL http://www.abrh.org.br/icfm6/proceedings/papers/PAP014391.pdf
Abstract/Description or Keywords This paper discusses three different flood hazard assessment approaches to account for
climate change in Western Canada. The study areas are quite different in terms of affected community,
physiographic conditions and layout, and each area will need to confront distinct flood hazards and flood
management challenges. The first study evaluates flooding at small aboriginal communities in the Coastal
Mountains along the Lillooet River. The Lillooet River has seen unusually large peak-flow increases over
the past several decades and an adequate future degree of flood protection must be determined for these
isolated communities. In this case, evaluation of future conditions relied on analysis of the historic stream
flow record. The second example describes conditions at the City of Surrey on the south coast. With sea
levels projected to rise by 1 m over the current century, increased flooding in this area will primarily be a
function of rising seas, but increased rainfall, particularly during the winter, is also expected to strain
internal drainage systems. In this case, evaluation of the effects of sea level rise on flood protection relied
on continuous simulation of ocean levels and interior flood levels under current and projected future
conditions. The third, and most complex case, involves flooding in the British Columbia Lower Mainland
associated with potential future increases in peak flows on the Fraser River. Evaluation in this case relied
on analysis of simulation results from work by the Pacific Climate Impacts Consortium in which a VIC
hydrologic model of the Fraser River basin was run with driving data from multiple GCMs. The different
assessment approaches and results will be compared and outstanding issues will be highlighted. The
flood hazard assessment issues and approaches discussed in this paper are believed to be applicable to
a number of locations.
Key Words: Flood Flow Estimates, Climate Change Impacts, Flood Management.
Information Type conference article
Regional Watershed Lower Fraser, Howe Sound & Sunshine Coast
Sub-watershed if known Lilloet River, Fraser River
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Project status complete
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