A Study of a River Ice Fluctuation given to Water Level in an ice-covered River

Abstract

In an ice-covered river, it is important to clarify relation between river ice fluctuation and water level change. In this study, we carried out observation of water level, water temperature, air temperature, and photography from sky. Frozen area was computed from this photograph. This result showed clearly that river ice progresses towards up-stream from down-stream. Moreover, it was shown that formation of river ice is related to river width, river bed gradient, and water depth. One-dimensional mathematical model of river ice fluctuation which can calculate river flow and river ice was built. The result of this model clarified that, formation of river ice raises water level and dissolution of river ice drops water level.