[MGI25-P15] Temporal and spatial variations of stream water chemistry observed in the Mt. Norikura headwater catchment
Keywords:perennial snow patch, groundwater, ephemeral stream
From the results obtained in water quality investigation, it was found that HCO3-, Ca2-and SO42-concentration of spring water on a gully is higher than that of ephemeral stream water. Based on field survey, it is presumed that the spring water is provided in the depth deeper than the depth of interflow which generated for several days after rainfall. Additionally, comparatively high SO42- concentration suggests that SO42- is generated by oxidation of ferric sulfide. Despite during a non-rainfall period, Surface stream that has these qualities was observed at one observation point during the whole observation period. It suggests that perennial snow patch stably supply below a ground water locally. Besides, from the results obtained in water quality investigation on debris land, it was found that the spatial difference of water quality of interflow is big considerably.