An Evaluation of New High-Resolution Image Collection and Processing Techniques for Estimating Shrub Cover and Detecting Landscape Changes
Research funded by the U.S. Department of Defense (DoD), U.S. Department of Energy (DOE), and the U.S. Environmental Protection Agency as part of the Strategic Environmental Research and Development Program (SERDP) evaluated novel techniques for collecting and processing high-resolution images in the Mojave Desert. Several camera types, lens, films, and digital processing techniques were evaluated on the basis of their ability to correctly estimate canopy cover of shrubs. A high degree of accuracy was obtained with photo scales of 1:1000 to 1:4000 and flatbed scanning rates from films or prints of 300 lines per inch or larger. Smaller scale images were of value in detecting retrospective changes in cover of large shrubs, but failed to detect smaller shrubs. New image-processing software, typically used in light microscopy, forensics, and industrial engineering, make it possible to accurately measure areas for total cover of up to four dominant shrub species in minutes compared to hours or days of field work. Canopy cover and individual shrub parameters such as width, length, circumference, and shape factors can be readily measured yielding size distribution histograms and other statistical data on plant community structure. These novel techniques are being evaluated in a four-year study of military training impacts at Fort Irwin, California. Results will be compared among the new and conventional imagery and processing, including 1-meter (m) pixel IKONOS images. The new processes create georectified color-coded contour maps of shrub cover for use with Geographic Information System (GIS) software. The technique is a valuable new emerging tool to accurately assess vegetation structure and landscape changes due to military or other land-use disturbances.
- Research Organization:
- Bechtel Nevada Corp. (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC08-96NV11718
- OSTI ID:
- 781476
- Report Number(s):
- DOE/NV/11718-517; TRN: AH200123%%525
- Resource Relation:
- Conference: 18th Biennial Workshop on Color Photography and Videography in Resource Assessment, Amherst, MA (US), 05/16/2001--05/18/2001; Other Information: PBD: 1 May 2001
- Country of Publication:
- United States
- Language:
- English
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