Natural discharge measures from bridges with piers

Abstract

Measuring a river discharge from bridges with piers has beenquestioned. However, here, it is shown that now it is feasible to do it withoutlosing accuracy using acoustic Doppler equipment. The objectives of thiswork were to analyze the possibility of measuring from bridges with pierswith acoustic Doppler equipment and find if there is a difference betweenmeasuring upstream or downstream of the bridge. The discharge rate, theplain view, and cross-section hydrodynamics were evaluated and comparedanalytically and graphically in each section. Also, the intensity of the sus-pended sediments in each area was assessed. The results showed that thedifference between measuring upstream or downstream of a bridge is lessthan 1.5%. Hydrodynamically, a difference in flow direction was obtained dueto the curvature of the river and the bridge’s piers, but it does not affect theflow discharge measurement.Key words:Flow field measurements, acoustic Doppler profiler, hydrody-namic fields, beam intensity.