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2/14/2003 N.C.KINGMA 1 Geomorphology - design of flood control strategies. Drs. Nanette C. Kingma
Transcript of Geomorphology - design of flood control strategies.adpc.net › casita › Course Modules › Flood...
2/14/2003N.C.KINGMA1
Geomorphology - design of flood control strategies.
Drs. Nanette C. Kingma
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Geomorphology - design of flood control strategies.
Geomorphology can contribute to the choice and design of flood control.Most cases relating to the interactions among flooding, sedimentation and channel behaviour.
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Contribution of geomorphology to flood control planning.
Flood warning and emergency actions;Structural Flood control measures e.g.
Role and limitations of storage reservoir: location in relation to other natural hazards;silting up;stream effect due to loss of sediment load of the river ⇒channel changes
River channel improvements: re-alignments, bankstabilization, enlargements;
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Contribution of geomorphology to flood control planning.
Monitoring past & present:Main aim: to prevent deposition within the channel and confine the channel so that it will not migrate laterally and shift the flood prone zone.Needed: fluvial empirical relationships
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Contribution of geomorphology to flood control planning.
Flood warning and emergency actions;Structural Flood control measures e.g.
Role and limitations of storage reservoir: location in relation to other natural hazards;silting up;stream effect due to loss of sediment load of the river ⇒channel changes
River channel improvements: re-alignments, bankstabilization, enlargements;
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Contribution of geomorphology to flood control planning.
Site selection for controlled and temporary storage of floodwaterSite selection for soil & water conservation works.(large amounts of sediments in river channels can cause aggradation and channel shifting)(cost-benefit flood control works)
Control of land use on floodplains; hazard zoning.
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Fluvial stability survey for a reach of the Yakima river for siting of facilities.
Legend:
stable for next 25 yearsunstable ; threathenedby channel migration..
Used; sequential AP study over 35 years.
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Map of avulsion of the Yakima river due to a dike breach of a gravel pit.
River now undercutting the embankement of the interstate highway.
It is not always possible to make short-term predictionon a braided river but alonger-term “worse-case” analysis is also possible.
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