1. The effects of urban land use on stream temperatures
Angela Perez-Toro, Delyn Martinez, Evan Portier, Jennifer Daugherty, Jian Ang and
Kendyl Crawford

2. Natural causes of stream temperature rising
Air temperatures
Physical aspects of a stream (location, i.e. glacier, lake, spring, wetland, etc.)
Physical characteristics (shading shoreline, depth)
Watershed Elevation & Tributaries (mix velocity)

3. Various impacts on watersheds

4. Temperatures are changing in stream and rivers in the U.S.
Annual mean increased by °C
More rapid in, but not confined to, urbanizing areas.
Typically correlated with increases in air temperatures, which could be caused by global warming and urbanization.
(Source: Sujay S Kaushal, Gene E Likens, Norbert A Jaworski, Michael L Pace, Ashley M Sides, David Seekell, Kenneth T Belt, David H Secor, and Rebecca L Wingate)

5. Causes of stream temperature rising
Streamside trees are usually removed.
Drainage from hot paved surfaces increase stream temperatures.
Exposed irrigation channels are also another source of heat.
Shading of streams by vegetation can reduce stream temperatures by as much as 10°C.

6. Streams in urban landscape expected to be higher in temperatures
Forested Landscape
Urban Landscape

7. Flat Lick Branch above Frog Branch
Hogue Creek
Flat Lick Branch above Frog Branch

8. Elevation and temperature are not correlated

11. The effects of rising water temperatures
Could have important effects on eutrophication, ecosystem processes, contaminant toxicity and loss of aquatic biodiversity.

12. Why do we care?
Increased water temperatures = decreased dissolved oxygen.
Some species of fish have high oxygen demands, such as trout & salmon.
Temperature also influences the rate of photosynthesis by algae.
Increases metabolic rate (fish) = need more food and release more waste.

13. Potomac River uses Recreational fishing Commercial fishing Crabbing
Oystering
Clamming

14. Mitigation can decrease negative human impact
Pavement coloration
Storm water treatment ponds
Streamside buffers
Shading
Green infrastructure planning
Pervious surfaces
Pipe materials

15. Socioeconomic factors
Improve air quality
Increased fishery yield
Enhance appearance of a community
Increased property values

16. Recap of experience

17. Sources http://www.bluecrab.info/forum/index.php?topic=28253.0

18. Questions???