Layer: Geothermal Favorability Model
This layer represents relative geothermal favorability in Washington State. The color scale provides a ranking of favorability for exploration and development of moderate- to high-temperature geothermal resources; warmer colors indicate higher favorability. The color scale is based on weighted raster overlay layers, including: (1) modeled geothermal potential; (2) proximity to transmission lines, and (3) elevation restrictions. The model is not meant to be used to locate areas for exploration on a site-specific basis, and should not be used at a scale greater than 1:250,000.
Using newly compiled and collected data, a Geographic Information System (GIS)-based analysis of relevant spatial datasets was used to determine the spatial association between various geologic and thermal features, infrastructure, and land-use to gain a broad understanding of geothermal resource potential and favorability for development in Washington State. The geothermal favorability model of Washington State was constructed by first performing multiple iterative GIS processes (various methods of density and proximity analyses, interpolation, and data combination) on volcanic vents, young silicic intrusive rock bodies, thermal/mineral springs, temperature gradients measured in wells, faults, earthquakes, electric transmission lines, and elevation datasets.
The geothermal favorability model shows relatively high favorability in localized areas of the Columbia Basin as well as areas within the South Cascades. The model also illustrates the challenges of developing geothermal resources in Washington Stateómost areas of the state with potential resources are remote, with little infrastructure or accessibility. Proximity to transmission lines, elevation, and land use restrictions significantly impact geothermal favorability, rendering potential resource areas unfavorable for exploration and (or) development, including most of the thermal areas along the crest of the Cascade Range. However, the potential for local, small-scale geothermal power production remains an option for some remote locations.
The widespread low-temperature geothermal resources in the Columbia Basin and elsewhere have considerable potential for direct-use applications in district heating, agriculture, and industry; continued efforts to understand the nature and distribution of low-temperature geothermal resources could reduce exploration costs and make development for direct-use applications economically attractive over large areas of the state.
See the companion report (Boschmann and others, 2014) for detailed discussion of modeling and results. The raster dataset is also available in the downloadable data file [favorability_model] within the file geodatabase [geothermal_favorability.gdb].
Boschmann, Darrick E.; Czajkowski, J. L.; Bowman, J. D., 2014, Geothermal favorability model of Washington State: Washington Division of Geology and Earth Resources Open File Report OFR 2014-02, 26 p., 1 plate, scale 1:900,000. [http://www.dnr.wa.gov/publications/ger_ofr2014-02_geothermal_favorability.pdf]
Boschmann, D. E.; Czajkowski, J. L.; Bowman, J. D., 2014, Washington State geothermal favorability model databaseóGIS data: Washington Division of Geology and Earth Resources Digital Data Series 9, version 1.0.