Activities > Soil Compaction [ || Soil Moisture || Geology & Soil Texture || Biological Soil Crusts || Fire || Vegetation Dynamics || Soil Compaction || Wind Erosion || Climate || Repeat Photography || Land Use History || Spatial Modeling || ] The vulnerability of soil to compaction is related to its particle size distribution. Well-sorted soils (which consist of particles of relatively uniform size), such as sand dunes, do not compact significantly, while poorly-sorted soils (containing a wide range of particle sizes ), which typically occur in the desert on alluvial fans, are prone to high levels of compaction. Soil moisture content is also important, and soils moistened by rainfall are more vulnerable to being compacted than dry soils. Once highly compacted, recovery is a function of wetting and drying cycles, freeze-thaw loosening, and bioturbation as roots and animals penetrate the denser soils. Defining both vulnerability to and recoverability from soil compaction depends first on an understanding of geomorphic surfaces, including surficial particle size distribution. Definition of compaction recovery also requires knowledge of climatic processes such as rainfall timing and amounts, which are, int turn, strongly affected by elevation.
For compaction vulnerability, the study includes: Collecting representative samples of desert soils for laboratory analysis Georeferencing these samples and attempting to correlate with the representative geomorphic surface that they represent Performing laboratory compaction analyses on them using a standard ASTM technique (Proctor compaction tests) Statistically analyzing the samples to scale between the point measurement and landscapes
Using geospatial techniques to distribute the resultant vulnerability measures over landscape scales For compaction recoverability, activities include:
Products Webb, R.H., 2002, Recovery of severely compacted soils in the Mojave Desert, California, USA: Arid Lands Research and Management, v. 16, no. 3, p. 291-305. Prose, D.V., and Wilshire, H.G., 2000, The lasting effects of tank maneuvers on desert soils and intershrub flora: U.S. Department of the Interior, U.S. Geological Survey Open File Report 00-512, 26 p. [ || Overview || Activities || Products || Photo Gallery || Glossary || Links || Feedback || Sitemap || ] |
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