1. The Urban Watershed Unit 1, Topic 1

2. 1 Urban vs. Suburban vs. Rural

3. 2 The value of vegetation »Ecosystem services »Oxygen production »Pollution absorption »Natural cooling »Erosion control »Wildlife habitats »Aesthetic value

4. 3 Heat island effect © censam.mit.edu

5. 4 Air pollution »Urban areas have higher levels than rural areas, why? »Increased combustion »Industrial processes »Development »Tall buildings »Less vegetation »How could cities reduce local air pollution?

6. 5 Impervious surfaces and water

7. 6 Watersheds © NJ Water Supply Association

8. 7 What is water quality?  Assessment based on abiotic and biotic parameters  Reflects land use activities and air quality in the watershed  Assessment based on abiotic and biotic parameters  Reflects land use activities and air quality in the watershed

9. 8 What can be in the water?  Point source pollutants  Non-point source pollutants Sewage Industrial waste Oil spills Agricultural waste Sewage Litter Household chemicals Oil and gasoline Industrial particulates Air pollution Pesticides, herbicides, etc… Lawn fertilizers

10. 9 Land use and water quality

11. Abiotic water quality parameters

12. 11 Dissolved oxygen  measure of how much oxygen gas is dissolved in a body of water  Measured in parts per million (ppm)  1 ppm = 1 milligram of substance (mg) dissolved in 1 liter (l) of water >6.0 ppm: lots of animals can survive in the water <4.0 ppm: animals begin to stress out, bigger that require more oxygen may begin to die <2.0 ppm: animals cannot survive for more than a short period

13. 12 Factors that affect DO  Oxygen demanding wastes  Plant nutrients  Turbulence  Turbidity  Temperature  Oxygen demanding wastes  Plant nutrients  Turbulence  Turbidity  Temperature

14. 13 Temperature  Varies by season and time of day  Affected by surrounding landscape  Organisms have temperature tolerance ranges  Temperature affects metabolic rates and DO levels  Varies by season and time of day  Affected by surrounding landscape  Organisms have temperature tolerance ranges  Temperature affects metabolic rates and DO levels

15. 14pH  measure of the acidity or alkalinity of a liquid  pH scale ranges from 0 (most acidic) to 14 (most basic); 7 is completely neutral, pure water (H 2 O)  What can extreme pH levels do to proteins?  Most organisms have an optimal pH range of 6.5-8

16. 15 Aquatic acidification  Results in decreased biodiversity  Sources:  Acid deposition  Sources:  Acid deposition  Sulfur based  Nitrogen based  Sulfur based  Nitrogen based  Industrial and mining discharge  Organic acid from logging and landfills  How can acidification be avoided?

17. 16 Alkalinity  Measure of the buffering capacity  Carbonate, bicarbonate, hydroxide concentrations  limestone  Measure of the buffering capacity  Carbonate, bicarbonate, hydroxide concentrations  limestone

18. 17 Nitrate (NO 3 - )  Naturally occurring nitrogen- containing nutrient needed by plants Aquatic nitrogen cycle

19. 18 Phosphate (PO 4 3- )  Naturally occurring phosphorus nutrient needed by plants  Usually a limiting factor for plant growth  Naturally occurring phosphorus nutrient needed by plants  Usually a limiting factor for plant growth

20. 19 Nitrate and phosphate pollution  Human activities add nitrates and phosphates to aquatic systems (cultural eutrophication)  These act as fertilizers and result in "blooms" of algae  This starts a process that may end in a mass die-off of animal life.

21. 20 Mass die-off of fish in Narragansett Bay due to anoxia.

22. 21 Chloride  Toxic to freshwater organisms at higher than natural levels  Why? (hint: think back to BIO I Honor tonicity lab)  How does excess salt get into fresh water bodies?  Toxic to freshwater organisms at higher than natural levels  Why? (hint: think back to BIO I Honor tonicity lab)  How does excess salt get into fresh water bodies?

23. 22 When is water quality at risk?  DO < 5 ppm or mg/L  pH < 6.5  Nitrate >1.0 ppm  Phosphate > 0.1 ppm  Chloride > 1000 ppm (1 ppt…point of reference the ocean averages 34 ppt)  DO < 5 ppm or mg/L  pH < 6.5  Nitrate >1.0 ppm  Phosphate > 0.1 ppm  Chloride > 1000 ppm (1 ppt…point of reference the ocean averages 34 ppt)