Abstract
In Lake Komuke, located in the northeast of Hokkaido, salinity and water level, and groundwater level of the vicinity of tidal flats were observed in the tidal flat in the snowmelt season to summer, and numerical analysis of the infiltration flow accompanied by snowmelt. In field observation results, water level in terrestrial groundwater level and tidal flats, landward groundwater level was higher in the snowmelt season than the other season. From further results of numerical analysis, the salinity in tidal flat was forced not to increase widely in the case of high landward groundwater level than in the case of low landward groundwater level. Moreover, up-welling was slightly strong in the case of high groundwater level, and made sediment salinity lower. The aquatic organisms can live in low salinity zone kept in the tidal flat in the spring season. It is the evidence that the many birds feeding these aquatic organisms in the spring season are frequently observed.
