CADDIS Volume 2: Sources, Stressors & Responses
Urbanization & climate change
An increasing number of studies are considering the potentially interactive effects of urbanization and climate change on stream ecosystems (Palmer et al. 2009). Some studies have focused on interactions between urbanization and climate change-associated changes in precipitation and runoff (Kaushal et al. 2008, Franczyk & Chang 2009, Han et al. 2009); others have examined interacting effects on stream temperature.
Nelson & Palmer (2007) and Nelson et al. (2009) developed models to predict the separate and combined effects of urbanization and climate change on small mid-Atlantic streams. They found that:
- Water temperatures were highest under the scenario of increased urbanization plus a warming climate, especially in midsummer when there was heated runoff from impervious surfaces (Fig 31).
- Water temperatures exceeded the “good growth” temperature maximum for coldwater fish species (28°C) on an average of 49 days per 10-year period under the urbanization plus climate change scenario, vs. 24 days per 10-year period in the urbanization alone scenario (Fig 32).
- Water temperatures exceeded the “good growth” temperature maximum for coolwater fish species (32°C) only rarely, and only in the urbanization plus climate change scenario.
Click below for more information on specific topics
Figure 31. Projected maximum daily water temperatures for the year 2090 under four scenarios: baseline (B), urbanization (U), climate change (C), and urbanization plus climate change (U+C).
From Nelson KC et al. 2009. Forecasting the combined effects of urbanization and climate change on stream ecosystems: from impacts to management options. Journal of Applied Ecology 46:154-163. Reprinted with permission.
From Nelson KC et al. 2009. Forecasting the combined effects of urbanization and climate change on stream ecosystems: from impacts to management options. Journal of Applied Ecology 46:154-163. Reprinted with permission.
Figure 32. Predicted number of summer days with water temperatures > 28°C (summed over a 10-year period), at 15 sites ranging from low to high average baseflow, for four scenarios: baseline, urbanization, climate change, and urbanization plus climate change.
From Nelson KC & Palmer MA. Stream temperature surges under urbanization and climate change: data, models, and responses. Journal of the American Water Resources Association 43(2):440-452. Reprinted with permission.
From Nelson KC & Palmer MA. Stream temperature surges under urbanization and climate change: data, models, and responses. Journal of the American Water Resources Association 43(2):440-452. Reprinted with permission.