Summary of U

The motivation for writing U.S. Geological Survey Open-File Report 85-95 was to (1) show that the linear regression approach of transferring low-flow statistics (e.g., 7-day, 10-year low flow) from an index station to a partialrecord site was biased and (2) propose an alternative unbiased estimator. Most analysts who use a mathematical technique, use linear regression analysis to relate base-flow measurements to concurrent daily flows at an index station. Therefore it is important to document that this technique is biased. The purpose of this summary is to clarify the important conclusions presented in Open-File Report 85-95.