Water resources planning for a river basin with recurrent wildfires

Area of Science:

• Environmental Science
• Hydrology
• Ecology

Background:

• Recurrent wildfires in Northern Portugal's Beça River basin
• Significant impacts on soil erosion, nutrient export, and water quality

Purpose of the Study:

• Evaluate river water quality, specifically dissolved phosphorus concentrations (1990-2013)
• Analyze the influence of burned area and river flow on phosphorus levels
• Assess water quality against ecological and human consumption standards

Main Methods:

• Utilized the ECO Lab tool within Mike Hydro Basin software
• Analyzed long-term data (1990-2013) on river flow, burned area, and phosphorus concentrations
• Compared phosphorus levels with established water quality benchmarks

Main Results:

• Phosphorus concentrations are influenced by burned area and river discharge, with hydrologic conditions being dominant
• Higher phosphorus levels observed during dry years with lower river flow
• Water quality exceeded ecological standards in 2005 and 2009-2012; human consumption standards in 2009; multiple use standards in 2010
• River Covas identified as having the best water quality and potential for human consumption

Conclusions:

• Wildfire impacts on water quality are significant, particularly under dry conditions
• Climate change may exacerbate wildfire frequency and intensity, posing future risks
• Proposed forestry measures include converting maritime pine stands to mixed conifer and hardwood species to mitigate impacts