Effect of Absorption of Light on River Water Temperature

Abstract

Cold water release from a dam is a problem awaiting solution: specially for river fisheries, this is an urgent problem. Some facilities capable of effective use of sunshine to warm up water y be one of the solutions. From this standpoint, this paperma aims at making clear the formation process of river water temperature laying errphasis on the effect of day-light. We carried out simutations together with observations of river water tenperature and related weather conditions. As a results, we concluded that the absorption ratio of day-light within a water coluim is nearly 1.0, even if water depth is less than 30cm.