RIVER FLOW OBSERVATION METHOD ICE-COVERDR RIVERS

Abstract

There are approximately 210 observation stations on Class A rivers in Hokkaido, at which water depth and river discharge are measured. At approximately 70％ of these stations, the river freezes over, and fluctuations of river discharge are small during winter. Although improvement of discharge measurement at ice-covered rivers has been attempted, no effective measurement methods have been developed for winter. Instead, the same method is employed all year round.

Based on onsite survey results, this paper proposes a new method of measuring discharge at ice-covered rivers. The method is time -efficient, cost-efficient, and as accurate as existing methods. In addition, the applicability of Acoustic Doppler Current Profiler, a device capable of discharge measurement in shallow water, at ice-covered rivers is assessed.