HR: 1330h
AN: H22D-0965    [PDF]
TI: Thermal infrared remote sensing and its usefulness in determining regional stream temperatures
AU: * Cherkauer, K A
EM: cherkaue@pasture.ecn.purdue.edu
AF: Purdue University, Dept. of Ag and Bio Engineering 225 South University Street, West Lafayette, IN 47907-2093 United States
AU: Handcock, R N
EM: rebeccah@u.washington.edu
AF: University of Washington, Earth and Space Sciences, Seattle, WA 98195-1310 United States
AU: Kay, J E
EM: jenkay@u.washington.edu
AF: University of Washington, Earth and Space Sciences, Seattle, WA 98195-1310 United States
AU: Kampf, S K
EM: stephk@u.washington.edu
AF: University of Washington, Dept. of Civil and Env. Eng., Seattle, WA 98195-2700 United States
AU: Gillespie, A R
EM: alan@rad.geology.washington.edu
AF: University of Washington, Earth and Space Sciences, Seattle, WA 98195-1310 United States
AU: Burges, S J
EM: sburges@u.washington.edu
AF: University of Washington, Dept. of Civil and Env. Eng., Seattle, WA 98195-2700 United States
AB: Stream temperatures are an important water quality variable in the Pacific Northwest, especially due their impact on health of regional salmon and steelhead runs. With several of these runs classified as threatened or endangered by the National Marine Fisheries Service in the last decade, monitoring of regional stream temperatures has never been more important. Networks of in-situ temperature observation sites tend to be costly to install and maintain, limiting their ability to monitor large regions in detail. Thermal infrared (TIR) remote sensing from aircraft and satellite based platforms have the potential to provide high resolution regional information about stream temperatures at a specific time. We present results from a three-year study, conducted to investigate the usefulness of TIR images in monitoring and observing regional stream temperatures. This project compared satellite-, aircraft- and ground-based TIR sensors with a network of in-stream temperature loggers and volunteer observations to assess the accuracy and uncertainty of TIR derived stream temperatures. Accuracy and uncertainty of temperatures extracted from the TIR images are strongly related to our ability to correct imagery for the effects of surface emissivity, atmospheric conditions and thermal scattering from the near-bank environment. Limited observations of atmospheric water vapor are of particular concern, however, total column water predictions from a meso-scale atmospheric model can be a useful substitute. The biggest limiting factor in using remote sensing for the evaluation of regional stream temperatures is the resolution of the sensor. Satellite-based sensors are unable to fully resolve all but the largest regional rivers. Higher-resolution aircraft-based images can resolve most regional rivers and stream, but may be unable to yield accurate temperatures in the presence of dense riparian zone vegetation. Very high-resolution images from the ground-based TIR sensors can resolve detailed temperature patterns within the stream, but image noise and the look-angle relative to the stream's surface become significant in analysis.
DE: 1860 Runoff and streamflow
DE: 1871 Surface water quality
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2003 Fall Meeting