ACCURACY FOR DISCHARGE MONITORING OF VARIOUS VELOCIMETRIC TOOLS USING A UNIFIED TECHNIQUE FOR INTERPOLATION AND EXTRAPOLATION OF VELOCITY

Abstract

Various velocimetric tools like ADCP, image-processing technique, radio current meter and electro-magnetic sensor were used to conduct simultaneous measurement of river discharge in Uono River. The comparison of measurement accuracy of the above tools was conducted by using two unified interpolation and extrapolation techniques of point-velocities like DIEX (Dynamic Interpolation and EXtrapolation) method and a previous method. The results indicated that 1) the surface velocity measured by the above velocimetric tools gave good agreements with the ADCP data, 2) the relative errors of discharge in the previous method was large due to the treatment of lateral velocity profile near banks and float coefficients, and 3) the relative errors of discharge in the DIEX method may remain low even with a few measured velocities.