人造淡水湖(児島湖)における塩分の収支推定について(その3) ―湖内における各種拡散現象 付 山陰豪雨による中海の塩分低下―

Abstract

The salinity distribution in Kojima lake is determined by fresh water inflow from riversand salt supply originating from sea water and underground water.In order to estimate these salt supply, the field surveys were carried out on the diffusionprocesses in lake water and bottom mud.In lake water, diffusion process is not isotropic and the ratio of horizontal and verticaldiffusion coefficients is about l0~.In bottom mud, the upward transport rate of salt is so large that its effect on salinitydistribution in lake water is not negligible.An extraordinary decrease of salinity in Nakano Umi caused by San'in heavy rainfall andthe slow recovery to its normal salinity distribution were shown in supplement, for an exampleof stable density stratification in a closed lake with narrow mouth.