Abstract
Radio current meters, which are installed on bridges or similar locations, emit radio waves at the surface of the river water and measure the surface velocity from the reflected waves using the Doppler effect. Fieldtest of Radio current-meter has been done on the Uono river for flood discharge measurement during snowmelt flood seasons in 1990 and 1991. In addition, 4 radio current-meter were set on the same bridge in 1991. All of the data were analysed and the estimation method of discharge from surface velocity data obtained, was proposed. The flow velocity and its direction (velocity vector) at a given point can also be obtained from the observation of the water surface at the point from two points on a bridge. Rooping characteristics of H-Q relation could be measured on the Furu-River.
