Application of Remotely-sensed Data To Regional Analysis and Assessment of Stream Temperature in the Pacific NorthwestEPA Grant Number: R827675
Title: Application of Remotely-sensed Data To Regional Analysis and Assessment of Stream Temperature in the Pacific Northwest
Investigators: Burges, Stephen J. , Booth, Derek B. , Gillespie, Alan R.
Institution: University of Washington - Seattle
EPA Project Officer: Hahn, Intaek
Project Period: April 1, 2000 through March 31, 2003 (Extended to March 31, 2004)
Project Amount: $998,395
RFA: Regional Scale Analysis and Assessment (1999) RFA Text | Recipients Lists
Research Category: Ecosystems , Ecological Indicators/Assessment/Restoration
Description:The principal goals of the proposed work are to develop efficient methods for regional assessments of stream temperature and to demonstrate how the methods can be applied to assess effects of land use on stream temperature. We will evaluate the utility of remotely sensed thermal infrared (TIR) and visible images of streams and stream corridors for increasing the spatial coverage of regional stream temperature analysis and assessment. We chose to focus on water temperature to illustrate and explore methods for water quality assessments because water temperature is biologically important, it is affected by anthropogenic activities, and surface (skin) temperature can be measured from remote instruments that detect TIR signals.
Three applications of remotely sensed, thermal and visible, images to regional stream temperature assessments will be considered:
1) Locating ground stations in a temperature monitoring network. The objective is to evaluate whether remote imagery can be used to identify stream reaches that have strong temperature gradients. This information will be used to determine the length of stream that can be represented by a monitoring station, to evaluate whether temperature monitoring stations are representative of streams in the basin, and to identify reaches in a stream network that may not require monitoring because temperature is likely to be uniform and cool.
2) Remote measurement of stream temperature. There are three objectives for this application: i) to develop empirical relationships between surface (top 100 ym) and kinetic (moving and mixed) temperature in relatively shallow water (<1 m); ii) to identify the information (data quality) lost when using remote platforms (i.e., aircraft and satellite) to determine temperature; and iii) to characterize the types of stream that are amenable to remote temperature monitoring. If stream temperatures can be estimated from images with known and acceptable levels of confidence, then regional temperature assessments will be less sensitive to the uncertainty associated with sampling temperature at a relatively small number of ground stations.
3) Remote collection of local, spatially distributed data for stream temperature analysis. While remote measurement of stream temperature may not be feasible for smaller streams, temperature in these streams may be strongly influenced by near-stream ground temperatures. The objective is to estimate ground (and shallow ground water) temperatures using remote imagery and incorporate this information in a stream temperature model. This application will improve representation and analysis of stream temperature dynamics.
We will analyze and assess summer water temperatures throughout a moderate size (<100 km2) stream basin in the Puget Sound Lowland ecoregion of Washington State. The stream basin has land use and physical conditions representative of many basins in the region. Data will be collected from three platforms: ground, aircraft, and satellite. Ground-based measurements of hydro-meteorological conditions will be made continuously at ground stations and, synoptically, using field surveys. Thermal infrared data will be collected using a hand-held, forward-looking infrared (FLIR) radiometer at ground stations. The radiometer will be mounted on an aircraft to collect TIR and visible images of streams and stream corridors. Thermal infrared (TIR) and visible images of the basin will also be obtained from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) which will be mounted on the Earth Observing System (EOS) satellite AM-1. Additional ground-based instruments will be deployed for contemporaneous, detailed characterization of temperature.
Application 1, Locating ground stations ..., will be evaluated using aircraft-based FLIR images and a ground-based survey of stream temperature in the selected basin.
Application 2, Remote measurement of stream temperature, will be evaluated using TIR images collected on the ground and from aircraft and satellite, as well as detailed temperature measurements at ground stations.
Application 3, Remote collection of data for stream temperature analysis, will be evaluated using an existing hydrologic simulation model that accounts for hillslope, groundwater, and open channel processes under low-flow conditions. The EPA model, Hydrologic Simulation Program Fortran, is suitable and will be our first choice. Stream temperature will be simulated using existing algorithms, though some modification may be necessary to incorporate spatially distributed data provided by remote imagery.