The baseflow correlation method with multiple gauged sites

SummaryLow streamflow estimates are required for water quality and quantity management purposes. The present research investigates the baseflow correlation method using information from multiple gauged sites to estimate low flow statistics at a partial record site. The baseflow correlation method is an information transfer technique that is used to estimate low streamflow statistics at a partial record site by correlating a limited number of measured streamflow discharges during baseflow conditions at the partial record site with those at nearby-gauged sites. Traditionally, the baseflow correlation method has been employed using a single gauged site to transfer information to the partial record site. Seven new estimators using information from multiple gauged sites are proposed and examined in this research, and compared to the baseflow correlation method with a single gauged site. A delete-one cross-validation is performed to assess the baseflow correlation estimators by employing daily streamflow values at more than 1300 USGS HCDN gauged sites. A comparison of using multiple gauged sites with using a single site shows that the performance can be improved by using multiple site information, especially when less than 10 baseflow measurements are used.