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)
Chuanhui Gu Ph.D., Assistant Professor (Creator)
Institution
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/

Abstract: Air temperature can be an effective predictor of stream temperature. However, little work has been done in studying urban impacts on air-stream relationships in groundwater-fed headwater streams in mountainous watersheds. We applied wavelet coherence analysis to two 13-month continuous (1 hr interval) stream and air temperature datasets collected at Boone Creek, an urban stream, and Winkler Creek, a forest stream, in northwestern North Carolina. The main advantage of a wavelet coherence analysis approach is the ability to analyse non-stationary dynamics for the temporal covariance between air and stream temperature over time and at multiple temporal scales (e.g. hours, days, weeks and months). The coherence is both time and scale-dependent. Our research indicated that air temperature generally co-varied with stream temperature at time scales greater than 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 these periods. 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 the forested stream, which is probably due to heated surface runoff during summer thunderstorms or leaking stormwater or wastewater collection systems. Our results provide insights into air-stream temperature relationships over both time and scale domains. Identifying controls over time and scales are needed to predict water temperature to understand the future impacts that interacting climate and land use changes will have on aquatic ecosystem in river networks. Copyright © 2014 John Wiley & Sons, Ltd.

Additional Information

Publication
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 (wileyonlinelibrary.com) DOI: 10.1002/hyp.10225
Language: English
Date: 2014
Keywords
stream temperature, urban, multi-scale, time series, Southern Appalachians

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