Anne-Marie Hagman, Mika Marttunen

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Multicriteria decision analysis in lake
restoration projects

• Anne-Marie Hagman, Mika Marttunen Ilkka
  Sammalkorpi

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Backround

• C. 1500 lakes need restoration. Hundreds of
  initiatives of restoration projects to the
  Regional Environment Centers
• The estimated costs exceed the available
  government funding
• Need for a systematic and transparent method to
  prioritize these initiatives and to identify the
  lakes in which restoration need and opportunities
  for the successful outcome are highest.
• A multi-criteria decision analysis approach is
  currently being developed in the Finnish
  Environment Institute for the systematic
  comparison of the lakes in the municipality of
  Mäntsälä and in the Uusimaa region in southern
  Finland.

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Multicriteria method for the priorization

• 1. Minimum criteria (example activity, use of
  lake, state of lake, nature protection status)
• 2. Quality of the background information of the
  lake/project (water quality, foodweb, loading,
  activity)
• 3. Feasibility estimate division into 3
  categories urgent important useful) based
  on use and state of the lake and overall
  feasibility of the project
• 4. Final ranking by the Web-Hipre model

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Web-hipre-model

• 1. Choosing the objectives and attributes for the
  comparison. Two main value trees have been
  developed for that
• - State of the lake
• - Recreational and nature values of the lake
• 2. Assessing the performance of each lake in
  respect to each attribute
• 3. Defining the relative importance of the
  attributes
• 4. Calculating priorities for each lake by using
  Web-HIPRE model
• 5. Analysing the results and drawing diagrams and
  other figures

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Criteria of the model (state of lake)

• Water quality Total phosphorus,Chlorophyll-
  a, occurence of oxygen depletion, elevated
  pH values, Secchi depth
• Fish stock -chl-a/TP ratio (indirect indication
  of high planktivore density)-CPUE and cyprinid
  of Nordic multimesh gillnets
• Algal blooms frequency and intensity of blooms
  reported from the beaches by health authorities
  or citizens

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Criteria of the model (use of lake)

• Current use beaches, cottages, tourism,
• camp areas, nature trails
• Potential use attainment (lakes distance to the
  nearest town in this case)

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The Uusimaa-region

• Totally 86 lakes compared
• 58 lakes pass through to the second phase
• 25 lakes have enough information -gt phase 3
• 8 lakes conclude to urgent-group -gt
  Prioritization with the Web-HIPRE-model

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Classification of the restoration need

• Two priority values for each lake-Recreational
  and nature valuesuse-Ecological status of each
  lakestate
• Are calculated with the Web-HIPRE-model
• Plotting these priorities helps to analyse the
  differences in the status and the use of the lakes

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The priority values for the ecological status of
Uusimaa lakes. The higher the priority value the
poorer is the condition.
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The priority values for the recreational use of
Uusimaa lakes. The higher the value, the higher
is the use of lake.
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The result of the analyses
High need for restoration
Advises to local volunteer lake managers
No need for restoration
Regular monitoring
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Conclusions

• All eight lakes which restoration needs were
  highest have already restoration projects in the
  Uusimaa region. And all projects have been
  funded.
• Background information of lakes can be saved and
  easily updated and new priority values can be
  calculated.
• The method is flexible and characteristics of
  different areas and different background
  information can be taken into account.