Evaluating Relationships Between Land Cover, Stream Temperature, and Stormwater Management at Local and Watershed Scales in Four Urban Catchments Near Philadelphia, PA
Abstract
We are compiling high-resolution stream temperature and land cover analyses at multiple spatial scales as part of a multi-institution effort to inform stormwater management and stream restoration in the Philadelphia region. We combine 15-minute stream temperature data collected at high spatial resolution in the Wissahickon (17 sites), Naylors Run (10 sites), Pennypack (7 sites), and Jenkintown (4 sites) watersheds. We continue to add measurement sites as part of an expanding citizen science program; 16 locations across 3 watersheds are currently monitored by volunteers. As part of a regional focus on headwater restoration, many sites are focused near tributary headwaters and near installed or planned green stormwater infrastructure. We also measure temperature of overland flow into and out of two stormwater basins to evaluate how much these projects influence stream temperatures. The stream sites are spaced as closely as 0.1 km to discern the impact of local land cover variation on temperature. The watersheds in this study have a range of urbanization, from 27% developed and 48% vegetation (Wissahickon) to 52% developed and 24% vegetation (Naylors Run). Analyses include land cover distribution in the area draining to each measurement site at distances of 10 m, 100 m, 500 m, 1000 m, and entire watershed. Daily temperature metrics including minimum, maximum, mean, range, and steepest 1-hour change, on days with and without storms, are compiled by month, season, and year. Preliminary results from the Wissahickon watershed show that aggregating the data by season or year obscures temporal trends that occur at monthly scales; furthermore, monthly correlations seem to be stronger and more consistent at the watershed scale compared to more local scales. Watershed-scale correlations in the Wissahickon are strongest during cooler months (Nov-Feb), with vegetation correlating negatively (Spearman R < -0.85) and development positively (Spearman R > 0.78) with higher daily minimum, maximum, and mean temperatures. This project explores the complex relationships between stream temperature, land cover, and stormwater management strategies while also engaging local community volunteers and watershed partners to work toward water quality solutions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H43Q2317B
- Keywords:
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- 1848 Monitoring networks;
- HYDROLOGY;
- 1871 Surface water quality;
- HYDROLOGY;
- 1879 Watershed;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY