Velocity profile and depth-averaged to surface velocity in natural streams: a review over a large sample of rivers using current meters and ADCP measurements.

EDF (Électricité De France) is the world's largest electricity generator, with an installed capacity of about 130 GW. In order to safely operate the plants, optimize natural resources and fulfill ecological requirement, EDF has installed, since 1946, a sensor network dedicated to the monitoring of hydro-climatologic parameters.

 

In the context of non-intrusive methods for measuring flood discharge (LSPIV, SVR[1]), understanding the depth-averaged to surface velocity ratio is crucial. The depth-averaged to surface velocity ratio is here called α. This study analyzes a substantial sample of gaugings data (current meters and ADCP methods), totaling around 6,500 observations collected at various EDF sites. For current meters measurements, three methods are employed to compute α : fitting of a log- and a power-law and using the measured surface velocity. For ADCP measurements, three methods are applied to approach α : fitting of power-power, constant-no slip and 3-point-no slip law by using the Qrame[2] application.

 

This study aims at creating an alpha coefficient database (classified by riverbed, hydraulic radius, etc.) directly usable for non-intrusive streamflow measurements. 

[1] LSPIV (Large-Scale Particle Image Velocimetry), SVR (Surface Velocity Radar).

[2] QRame (QRevint Adcp Massive Exctraction), INRAE, 2023.