Air-Stream Temperature Correlation In Forested And Urban Headwater Streams In The Southern Appalachians

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Jeff Colby Ph.D, Professor (Creator)
Appalachian State University (ASU )
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Abstract: Air temperature can be an effective predictor of stream temperature. However, little work has been done in studying urbanimpacts on air-stream relationships in groundwater-fed headwater streams in mountainous watersheds. We applied waveletcoherence analysis to two 13-month continuous (1 hr interval) stream and air temperature datasets collected at Boone Creek, anurban stream, and Winkler Creek, a forest stream, in northwestern North Carolina. The main advantage of a wavelet coherenceanalysis approach is the ability to analyse non-stationary dynamics for the temporal covariance between air and streamtemperature over time and at multiple temporal scales (e.g. hours, days, weeks and months). The coherence is both time andscale-dependent. Our research indicated that air temperature generally co-varied with stream temperature at time scales greaterthan 0.5 day. The correlation was poor during the winter at the scales of 1 to 64 days and summer at the scales of 1.5 to 4 days,respectively. The empirical models that relate air temperature to stream temperature failed at these scales and during theseperiods. Finally, urbanization altered the air-stream temperature correlation at intermediate time scales ranging from 2 to 12 days.The correlation at the urban creek increased at the 12-day scale, whereas it decreased at scales of 2 to 7 days as compared with theforested stream, which is probably due to heated surface runoff during summer thunderstorms or leaking stormwater orwastewater collection systems. Our results provide insights into air-stream temperature relationships over both time and scaledomains. Identifying controls over time and scales are needed to predict water temperature to understand the future impacts thatinteracting climate and land use changes will have on aquatic ecosystem in river networks.

Additional Information

Gu, C.1*, Anderson, W.1, Colby, J.2, Coffey, C.2 (2014). Air-Stream Temperature Correlation In Forested And Urban Headwater Streams In The Southern Appalachians. Hydrological Processes. Published online in Wiley Online Library ( DOI: 10.1002/hyp.10225
Language: English
Date: 2014
stream temperature, urban, multi-scale, time series, Southern Appalachians

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