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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>J. R. Nimmo</dc:contributor>
  <dc:contributor>J. A. Izbicki</dc:contributor>
  <dc:contributor>P. M. Martin</dc:contributor>
  <dc:creator>K.A. Winfield</dc:creator>
  <dc:date>2006</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;With the goal of improving property-transfer model (PTM) predictions of unsaturated hydraulic properties, we investigated the influence of sedimentary structure, defined as particle arrangement during deposition, on laboratory-measured water retention (water content vs. potential [θ(ψ)]) of 10 undisturbed core samples from alluvial deposits in the western Mojave Desert, California. The samples were classified as having fluvial or debris-flow structure based on observed stratification and measured spread of particle-size distribution. The θ(ψ) data were fit with the Rossi–Nimmo junction model, representing water retention with three parameters: the maximum water content (θ&lt;/span&gt;&lt;sub&gt;max&lt;/sub&gt;&lt;span&gt;), the ψ-scaling parameter (ψ&lt;/span&gt;&lt;sub&gt;o&lt;/sub&gt;&lt;span&gt;), and the shape parameter (λ). We examined trends between these hydraulic parameters and bulk physical properties, both textural—geometric mean,&amp;nbsp;&lt;/span&gt;&lt;i&gt;M&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;g&lt;/sub&gt;&lt;span&gt;, and geometric standard deviation, σ&lt;/span&gt;&lt;sub&gt;g&lt;/sub&gt;&lt;span&gt;, of particle diameter—and structural—bulk density, ρ&lt;/span&gt;&lt;sub&gt;b&lt;/sub&gt;&lt;span&gt;, the fraction of unfilled pore space at natural saturation,&amp;nbsp;&lt;/span&gt;&lt;i&gt;A&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;e&lt;/sub&gt;&lt;span&gt;, and porosity-based randomness index, Φ&lt;/span&gt;&lt;sub&gt;s&lt;/sub&gt;&lt;span&gt;, defined as the excess of total porosity over 0.3. Structural parameters Φ&lt;/span&gt;&lt;sub&gt;s&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;i&gt;A&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;e&lt;/sub&gt;&lt;span&gt;&amp;nbsp;were greater for fluvial samples, indicating greater structural pore space and a possibly broader pore-size distribution associated with a more systematic arrangement of particles. Multiple linear regression analysis and Mallow's&amp;nbsp;&lt;/span&gt;&lt;i&gt;C&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;p&lt;/sub&gt;&lt;span&gt;&amp;nbsp;statistic identified combinations of textural and structural parameters for the most useful predictive models: for θ&lt;/span&gt;&lt;sub&gt;max&lt;/sub&gt;&lt;span&gt;, including&amp;nbsp;&lt;/span&gt;&lt;i&gt;A&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;e&lt;/sub&gt;&lt;span&gt;, Φ&lt;/span&gt;&lt;sub&gt;s&lt;/sub&gt;&lt;span&gt;, and σ&lt;/span&gt;&lt;sub&gt;g&lt;/sub&gt;&lt;span&gt;, and for both ψ&lt;/span&gt;&lt;sub&gt;o&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and λ, including only textural parameters, although use of&amp;nbsp;&lt;/span&gt;&lt;i&gt;A&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;e&lt;/sub&gt;&lt;span&gt;&amp;nbsp;can somewhat improve ψ&lt;/span&gt;&lt;sub&gt;o&lt;/sub&gt;&lt;span&gt;&amp;nbsp;predictions. Textural properties can explain most of the sample-to-sample variation in θ(ψ) independent of deposit type, but inclusion of the simple structural indicators&amp;nbsp;&lt;/span&gt;&lt;i&gt;A&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;e&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and Φ&lt;/span&gt;&lt;sub&gt;s&lt;/sub&gt;&lt;span&gt;&amp;nbsp;can improve PTM predictions, especially for the wettest part of the θ(ψ) curve.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.2136/vzj2005.0088</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>ACSESS</dc:publisher>
  <dc:title>Resolving structural influences on water-retention properties of alluvial deposits</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>