Abstract
It is widely known to exert the influence with big meltwater from winter to summer on the river quality in the snow region. Especially, the influence of meltwater reaches in early summer, and forms a big element that can decide the hydrological circulation and the water environment characteristic of the valley in the multi snow area , for example, the Sea of Japan side region and the Hokkaido. Moreover, the influence includes many things in the area with mild winters where the snow melting is frequently caused for the snowfall period compared with the cold snowfall region. Then, authors have been researching from the viewpoint of the river quality and the snowfall water quality in the Uono river basin in Niigata Prefecture that flows in the heavy snowfall area(Morimoto and others 2011 etc.). The overall consideration was especially done from the viewpoint of the snowfall water quality and the river quality by using the hydrological observation result of going until 2008 - 2011(river and snowfall water) in this text about the water quality formation of the snowfall and the snow melting period in the clement snowfall region.
