Lake Malaren future flooding risks

1
Stockholm-Mälar RegionApplication of climate
change research in spatial planning

• Challenges
• DSF
• Mapping and VA
• Key results
• Conclusions

Michael Viehhauser, Inregia AB / WSP group,
Stockholm
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Challenges

• Production of regional and detailed flooding
  maps
• Assessing vulnerabilities
• Communication of flood-risks uncertainties
• Feedback from concerned stakeholders
• Implementation of results in spatial planning

Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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DSF Stockholm Mälar Region
Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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DSF Stockholm Mälar Region

• Efforts made in the region
• Regional seminar
• Newsletter (4 numbers)
• Presentation of results at various regional
  conferences
• Discussion of results with concerned
  stakeholders
• Forwarding results (maps and VA) for
  implementation in municipal planning

Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Lake Mälarens water levels until today

Max. allowed level
Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Lake Mälarens future inflow patterns

Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Lake Mälarens future flooding risks

600
580
Highest possible future water level (worst case)
560
540
520
Decreased return time of Autumn 100 y flood ?
E/A2 10 years ? H/A2 25 years
Mälarens höjdsystem (cm)
500
100 y flood level
480
460
440
420
400
Source SMHI
Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Lake Mälarens regional mapping

Uppsala
Västerås
Stockholm
Ekerö
Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Mapping four municipalities

Stockholm
Västerås
Uppsala
Ekerö
Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Critical flooding levels
Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Key results

• Risk and vulnerability levels are low
• New construction of lock-gates will help to
  avoiding floods
• Security margin gt 1.5 m compared to normal
  water level is standard in many municipalities
• Higher awareness among planners still necessary
• Many new housing projects along the water
  fronts make thorough analysis indispensable

Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Conclusions

• Tasks to meet the challenges are widely
  fulfilled
• Planning and implementation of higher lock-gate
  capacities is a vital process that needs high
  attention
• SEAREG results have become part of regional and
  municipal spatial planning activities
• Further work on regional climate models and
  related awareness building is necessary
• Continued dialogue between planners and
  scientists of high value even in the future
• Adaptation as a coming major challenge

Michael Viehhauser, SEAREG, Tallinn 03 March 2005
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Danke für Ihre Aufmerksamkeit!Thank you for your
attention! Tack för er uppmärksamhet!Kiitän
kaikesta saamastani huomiosta!Tänan tähelepanu
eest!
Michael Viehhauser, SEAREG, Tallinn 03 March 2005