<?xml version='1.0' encoding='utf-8'?>
<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>Jeff P. Raffensperger</dc:contributor>
  <dc:contributor>Colin A. Penn</dc:contributor>
  <dc:contributor>Jessica M. Driscoll</dc:contributor>
  <dc:creator>Sydney Foks</dc:creator>
  <dc:date>2019</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Optimal hydrograph separation (OHS) uses a two-parameter recursive digital filter that applies specific conductance mass-balance constraints to estimate the base flow contribution to total streamflow at stream gages where discharge and specific conductance are measured. OHS was applied to U.S. Geological Survey (USGS) stream gages across the conterminous United States to examine the range/distribution of base flow inputs and the utility of this method to build a hydrologic model calibration dataset. OHS models with acceptable goodness-of-fit criteria were insensitive to drainage area, stream density, watershed slope, elevation, agricultural or perennial snow/ice land cover, average annual precipitation, runoff, or evapotranspiration, implying that OHS results are a viable calibration dataset applicable in diverse watersheds. OHS-estimated base flow contribution was compared to base flow-like model components from the USGS National Hydrologic Model Infrastructure run with the Precipitation-Runoff Modeling System (NHM-PRMS). The NHM-PRMS variable&amp;nbsp;&lt;/span&gt;&lt;i&gt;&lt;span class="html-italic"&gt;gwres_flow&lt;/span&gt;&lt;/i&gt;&lt;span&gt;&amp;nbsp;is most conceptually like a base flow component of streamflow but the&amp;nbsp;&lt;/span&gt;&lt;i&gt;&lt;span class="html-italic"&gt;gwres_flow&lt;/span&gt;&lt;/i&gt;&lt;span&gt;&amp;nbsp;contribution to total streamflow is generally smaller than the OHS-estimated base flow contribution. The NHM-PRMS variable&amp;nbsp;&lt;/span&gt;&lt;i&gt;&lt;span class="html-italic"&gt;slow_flow&lt;/span&gt;&lt;/i&gt;&lt;span&gt;, added to&amp;nbsp;&lt;/span&gt;&lt;i&gt;&lt;span class="html-italic"&gt;gwres_flow&lt;/span&gt;&lt;/i&gt;&lt;span&gt;, produced similar or greater estimates of base flow contributions to total streamflow than the OHS-estimated base flow contribution but was dependent on the total flow magnitude.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3390/w11081629</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>MDPI</dc:publisher>
  <dc:title>Estimation of base flow by optimal hydrograph separation for the conterminous United States and implications for national-extent hydrologic models</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>