Case Study

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Case Study

• Aim to provide data from a real Catchment for you
  to practice some of the modelling techniques on..

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Halladale River
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Why the Halladale?

• Afforestation took place at the start of 1996
• Forestry important to the highland region
• 12 of the land forested
• Important economically
• Potential for growth of industry
• Fishing is also important
• Commercial and recreational
• Does forestry harm the fishing industry?
• Are the continued development of both of these
  sustainable?
• What are the long term effects of increased
  forest on the quantity and quality of the rivers
  in the Highland Region?

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New forest in the Upper Halladale
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Looking North from the Hope (1995)
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Feb 1996
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March 1996
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July 1998
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Research Study

• Forestry Commission, SEPA, MLURI, Freshwater
  Fisheries Authority
• Impact of Forestry on Environment?
• Studied the catchment since 1996
• Ultimately make recommendations on the
  sustainability of continued forest development

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(No Transcript)
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Monitored flow from a very small area
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Gauging Station
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Spot samples of Stream Chemistry
SEPA also monitor stream chemistry at Dalhalvaig
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Conclusions after 4 years of the study

• For the majority of the time water quality was
  unaffected by the 1996 afforestation.
• The only noticeable affect was during high flow
  events when Rock Phosphate fertiliser
  applications when phosphate concentrations in the
  stream increased dramatically.
• In periods of persistent rainfall during the
  summer and autumn when flowas are high there is a
  reduction in the river water pH (increased the
  acidity). Highly acidic water will kill salmon
  eggs.
• During very Lowflows there is concern about
  point source pollution from some of the
  settlements that lie adjacent to the lower
  reaches of the Halladale.
• There were know obvious changes to the
  subcatchment hydrology as a consequence of
  afforestation. In particular there was no effect
  on the frequency of high and low flow events.
• There were know obvious changes to the
  subcatchment hydrology .

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Inference

• Continued development of forestry in the region
  as a whole is sustainable because in this study
  the affects of forestry are minimal.
• Are they correct to draw this inference?
• If not why not? (Particular attention to the
  limitations of this study)
• How might these problems be resolved

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Conclusions

• Where possible use digital data sets and GIS to
  determine catchment boundaries
• Water balance and visual inspection of data can
  give insight into dominant processes
• Sustainability of designs should be proven