extrap: Software to assist the selection of extrapolation methods for moving-boat ADCP streamflow measurements

Computers & Geosciences
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Abstract

Selection of the appropriate extrapolation methods for computing the discharge in the unmeasured top and bottom parts of a moving-boat acoustic Doppler current profiler (ADCP) streamflow measurement is critical to the total discharge computation. The software tool, extrap, combines normalized velocity profiles from the entire cross section and multiple transects to determine a mean profile for the measurement. The use of an exponent derived from normalized data from the entire cross section is shown to be valid for application of the power velocity distribution law in the computation of the unmeasured discharge in a cross section. Selected statistics are combined with empirically derived criteria to automatically select the appropriate extrapolation methods. A graphical user interface (GUI) provides the user tools to visually evaluate the automatically selected extrapolation methods and manually change them, as necessary. The sensitivity of the total discharge to available extrapolation methods is presented in the GUI. Use of extrap by field hydrographers has demonstrated that extrap is a more accurate and efficient method of determining the appropriate extrapolation methods compared with tools currently (2012) provided in the ADCP manufacturers’ software.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title extrap: Software to assist the selection of extrapolation methods for moving-boat ADCP streamflow measurements
Series title Computers & Geosciences
DOI 10.1016/j.cageo.2013.02.001
Volume 54
Year Published 2013
Language English
Publisher Elsevier
Publisher location Amsterdam, Netherlands
Contributing office(s) Office of Surface Water
Description 8 p.
First page 211
Last page 218