water quality concerns after wildfire author - gene surber, extension service, montana state...
DESCRIPTION
General Impacts, cont. Increase water temperature Lower water levels Soil and ash pollution Red SlurryTRANSCRIPT
Water Quality Concerns After Wildfire
Author - Gene Surber, Extension Service, Montana State University,
Editor - James E. Knight, Extension Service, Montana State University
General Impact of Wildfires
Loss of vegetation canopies
Increase in erosion
General Impacts, cont.
Increase water temperature
Lower water levels Soil and ash pollution Red Slurry
General Impacts – cont.
Nutrient movement Nitrate, organic
nitrogen, potassium, calcium, magnesium
Returns to pre-burn levels within 1 to 2 years
Soil and Water Quality
Changes in soil pore space
Changes to infiltration rates
Run off rates
Physical Water Quality
Temperature More sunlight reaches
streams and soil Aquatic life Livestock
Sediment and Turbidity
Suspended sediment Bedload Turbidity
Algae
Nearly all water have some form
Increased temperatures, increases growth
Blue-green alage
Chemical conditions - pH
Neutral = 7
Over 7 = alkaline
Under 7 = acidic
Chemical conditions - Alkalinity
Ash in stream Above 8.5 – livestock
problems
Chemical Conditions - Salinity
NOT same as alkaline TSD (total dissolved solids) Abrupt changes, problems w/ livestock Expressed as ppm or mg/l
Nutrients - Nitrogen
Nitrates – convert to nitrites
Nitrites decrease oxygen carrying capacity of blood
Nutrients - Phosphorus
Binds to soil Following storms – can wash into surface
waters Eutrophication – aquatic plants
Nutrients – Dissolved Oxygen
Cold water fisheries - between 8 and 13 mg/l
Cold water holds more oxygen
Soil temperatures increase after fire
Cyanide
Red fire retardant slurry
Acutely toxic to salmonids
Other Chemicals
See table 3 - handout