Calgary, 2013 Montreal, 2017 Houston, 2017
Flooding within the urban landscape: a hydrogeomorphologist’s perspective
Pascale Biron
• Damage caused by rivers following the passage of hurricane Irene in 2011 in the MRC Brome-Missisquoi
Flood management in Quebec: reactive ratherthan proactive approach
Photos: Simon Lajeunesse
Hydrogeomorphology: two key elements for the natural dynamics of rivers
http://www.mfwwc.org/floodplain.html
Spiral flow (helical)
Meanders migrate laterally
Rivers flood regularly
Bankfull level reachedeach 1.5 – 2 years
Photo: Copyright Louis Maher; Earth Science World Image Bank
http://guiers.siaga.pagesperso-orange.fr/Le-Guiers/Lit-Min-Maj.htm
+ riparian wetlands(integrity space)
hydrogeomorphologicalapproach: levels really reachedby floods (≠ statisticalapproach)
Ice-jam flood on the Matane River
Are part of the minimum space required for streams – essential within freedom space from a hydrological and ecological perspective
http://www.hendersondesign-build.com
Example of wetland restoration des milieux humides on the Calapooia River (Oregon)
Included within the flood space
Rivière Matane (aval)Rivière Yamaska Sud-Est (amont)
Rivière de la Roche
Rivière Yamaska Sud-EstBiron et al. (2014)
Riparianwetland
Urbanenvironment(Cowansville)
Upstream of Cowansville
Freedom space: Is it feasable?
Rivière Veyle (north of Lyon, France)Photo: Hervé Piégay
Freedom space in VermontVermont Agency of Natural Resources
Budget of 3 billion € in the Netherlands
Water qualityWildlife habitat
Cost due to flood damages
Recreational activities ($$)
Spirit of communities
Relationship between impervious cover and surface runoff (from FISRWG, 1998)
Ontario: the hurricane Hazel (1954) effect
Toronto received 210 mm of rain in 12 hours
81 lives lost, $25 million in 1954 dollars.
https://trca.ca/conservation/flood-risk-management/history/
Flood management in Ontario
http://conservationontario.ca/what-we-do/flood-management
Europe: the early 2000s flood effect
York (UK) November 2000
http://ec.europa.eu/environment/water/flood_risk/implem.htm
https://www.gov.uk/check-flood-risk https://flood-warning-information.service.gov.uk/long-term-flood-risk
Citizens must be informed…
France
https://www.ecologique-solidaire.gouv.fr/prevention-des-inondations
US
https://msc.fema.gov/portal
https://www.cehq.gouv.qc.ca/zones-inond/carte-esri/index.html
Quebec flood maps
Flood maps: pdf documents
End of the study zone…
Flood limits??
Rigaud, west of Montreal
End of the study zone…
Working upstream to mitigate floods downstream (Belford, UK)
• Frequent flooding• Steep slopes• Shallow soil• Soil compaction (intensive
agriculture)
Belford
Wilkinson et al. (2010)
Watershed: 5.7 km2
Wilkinson (2010)
Examples of runoff attenuation features (RAF) (Wilkinson et al., 2010)
Runoff Attenuation Feature (RAF) used in the Belford watershed (Wilkinson et al., 2010)
Photos of RAF at full capacity (a) and before 6 September 2008 flood (b), with photos showing flow diversion during (c) and after (d) this event (Wilkinson et al., 2010)
96 mm of rain in 36 hours
http://wwtonline.edie.net/news/researchers-back-natural-flood-engineering#.U4zFjCgvDKA
Modelling
Wilkinson et al. 2010)
Modelling
Wilkinson et al. 2010)
Modelling
Wilkinson et al. 2010)
Modelling
Wilkinson et al. 2010)
Modelling
Wilkinson et al. 2010)
Flood in Morpeth –6 September 2008 event(no flood in Belford)
Coaticook: 2 major floods in the summer 2015
10 June 2015
http://www.lapresse.ca/la-tribune/estrie-et-regions/201508/03/01-4890134-une-tempete-de-grele-cause-des-dommages-a-coaticook.php
3 August 2015
Bassin versant du ruisseau Pratt:Similitudes avec ruisseau Belford(22 km2)
Waterville
Compton
Coaticook
Dixville
Vermont (É-U)
CoaticookCentre-ville
Fond de carte: Orthophotos 2013, MRC de Coaticook
Ruisseau Pratt (Coaticook):
Ruisseau Pratt in Coaticook(looking downstream), rebuilt as is after the summer 2015 floods
18 août 2015
Ruisseau Pratt in Coaticook(looking upstream)
18 août 2015
Ruisseau Pratt upstreamof Coaticook
18 août 2015
Freedom space problem?
septembre1924
avril 1982
avril 1994
août 2004
avril 2011
janvier 2014 juin
2015
juin 1943
février 1998
1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2016
février 2016
août 2011
Début données CEHQ Waterville
Crue hivernale
Crue printanière
Crue estivale
19431998avril 2011201410 juin 2015 = 76 mm de pluie
10 juin 2015
Recoupement entre 1881 et 1945Présence des méandres abandonnés
jusqu’en 1945
Rivière Coaticook
1945
Rivière Coaticook
1966
Rivière Coaticook
1979
Rivière Coaticook
1993
Rivière Coaticook
2007
Rivière Coaticook
2013
Rivière Coaticook
1945 - 2013
Rivière Coaticook
1945 - 2013
0
1
2
3
4
5
6
1940 1950 1960 1970 1980 1990 2000 2010
Supe
rficie
de
mili
eux
natu
rels
(en
hect
ares
)4.7 hectares
Flood management: from grey to green infrastructure
http://www.vacd.org/~winooski/VtRainGardenManual.pdf
2015
Sponge city in China
http://www.initiatives.com.hk/sponge-city.html
Objective: better absorb rain to improve the environment.By 2020, 20 percent of cities should have modern sewer systems and infrastructure that allows for efficient absorption of water, with the number rising to 80 percent by 2030
http://www.phillywatersheds.org/what_were_doing/documents_and_data/cso_long_term_control_plan
PDEP (2006) http://www.elibrary.dep.state.pa.us/dsweb/Get/Document-48477/07_Chapter_6.pdf
Parking lot of Mountain Equipment, Longueuil Vinci Consultants, http://www.vinciconsultants.com/realisations.php
Seoul
Seoul https://www.quora.com/Is-it-possible-to-purify-the-Cooum-River-in-Chennai-and-bring-it-back-as-it-was-in-the-1940s
http://www.100resilientcities.org/you-cant-stop-urban-flooding/
“Nature has ways of dealing with water. We sometimes get in the way of those processes… We just need to move the water through our community as quickly as possible with as little damage as possible.”
Conclusions• Integrating hydrogemorphological concepts is
essential in flood management.• Quebec is lagging behind in the use of green
strategies to increase infiltration in urban zones (e.g. porous pavements, green roofs, naturalwetlands).
• Absolutely key to inform citizens about the flood risk so that they can adapt a more flood-resilientapproach (e.g. European flood directive)
• Flood mitigation: for each 1$ invested, 5$ saved
Remerciements
• Thomas Buffin-Bélanger, Simon Massé (UQAR)• Guénolé Choné (Concordia) • Marie Larocque (UQAM) • Simon Lajeunesse (MRC Brome Missisquoi)
http://www.eaurmc.fr/espace-dinformation