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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>David T. Long</dc:contributor>
  <dc:contributor>David W. Hyndman</dc:contributor>
  <dc:contributor>Bryan C. Pijanowski</dc:contributor>
  <dc:contributor>Sarah M. Woodhams</dc:contributor>
  <dc:contributor>Sheridan K. Haak</dc:contributor>
  <dc:creator>Karen G. Wayland</dc:creator>
  <dc:date>2003</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;The&amp;nbsp;&lt;/span&gt;relationship&lt;span&gt;&amp;nbsp;between&amp;nbsp;&lt;/span&gt;land&lt;span&gt;&amp;nbsp;use and stream chemistry is often explored through&amp;nbsp;&lt;/span&gt;synoptic&lt;span&gt;&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;of rivers at&amp;nbsp;&lt;/span&gt;baseflow&lt;span&gt;&amp;nbsp;conditions. However,&amp;nbsp;&lt;/span&gt;baseflow&lt;span&gt;&amp;nbsp;chemistry is likely to vary temporally and spatially with&amp;nbsp;&lt;/span&gt;land&lt;span&gt;&amp;nbsp;use. The purpose of our study is to examine the usefulness of the&amp;nbsp;&lt;/span&gt;synoptic&lt;span&gt;&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;approach for&amp;nbsp;&lt;/span&gt;identifying&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;relationship&lt;span&gt;&amp;nbsp;between complex&amp;nbsp;&lt;/span&gt;land&lt;span&gt;&amp;nbsp;use configurations and stream water quality. This study compares biogeochemical data from three&amp;nbsp;&lt;/span&gt;synoptic&lt;span&gt;&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;events representing the temporal variability of&amp;nbsp;&lt;/span&gt;baseflow&lt;span&gt;&amp;nbsp;chemistry and&amp;nbsp;&lt;/span&gt;land&lt;span&gt;&amp;nbsp;use using&amp;nbsp;&lt;/span&gt;R&lt;span&gt;-&lt;/span&gt;mode&lt;span&gt;&amp;nbsp;&lt;/span&gt;factor&lt;span&gt;&amp;nbsp;&lt;/span&gt;analysis&lt;span&gt;. Separate&amp;nbsp;&lt;/span&gt;R&lt;span&gt;-&lt;/span&gt;mode&lt;span&gt;&amp;nbsp;&lt;/span&gt;factor&lt;span&gt;&amp;nbsp;analyses of the data from individual&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;events yielded only two consistent factors. Agricultural activity was associated with elevated levels of Ca&lt;/span&gt;&lt;sup&gt;2+&lt;/sup&gt;&lt;span&gt;, Mg&lt;/span&gt;&lt;sup&gt;2+&lt;/sup&gt;&lt;span&gt;, alkalinity, and frequently K&lt;/span&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;, SO&lt;/span&gt;&lt;sup&gt;2-&lt;/sup&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;, and NO&lt;/span&gt;&lt;sup&gt;-&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;. Urban areas were associated with higher concentrations of Na&lt;/span&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;, K&lt;/span&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;, and Cl&lt;/span&gt;&lt;sup&gt;-&lt;/sup&gt;&lt;span&gt;. Other retained factors were not consistent among&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;events, and some factors were difficult to interpret in the context of biogeochemical sources and processes. When all data were combined, further associations were revealed such as an inverse&amp;nbsp;&lt;/span&gt;relationship&lt;span&gt;&amp;nbsp;between the proportion of wetlands and stream nitrate concentrations. We also found that barren lands were associated with elevated sulfate levels. This research suggests that an individual&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;event is unlikely to characterize adequately the complex processes controlling interactions between&amp;nbsp;&lt;/span&gt;land&lt;span&gt;&amp;nbsp;use and stream chemistry. Combining data collected over two years during three&amp;nbsp;&lt;/span&gt;synoptic&lt;span&gt;&amp;nbsp;&lt;/span&gt;sampling&lt;span&gt;&amp;nbsp;events appears to enhance our ability to understand processes linking stream chemistry and&amp;nbsp;&lt;/span&gt;land&lt;span&gt;&amp;nbsp;use.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.2134/jeq2003.1800</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Society of Agronomy</dc:publisher>
  <dc:title>Identifying relationships between baseflow geochemistry and land use with synoptic sampling and R-mode factor analysis</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>