Abstract
Field observation of snow cover related to landslides in the snow season is extremely difficult to perform. Because of this, the mechanism of outbreak of landslides in the snow season has been explained inferentially and has not been clarified based on field observation data . Therefore, the purpose of this report is to clarify the influence of snow cover and snowmelt upon landslides based upon field observation data. The author reviewed the results of snowmelt observation in Arai city, Niigata prefecture, where the Niigata Experiment Station was located, and also calculated the rate of occurrence of landslides in the Jouetsu District in Niigata based on the results . Morever, the author reviewed the mechanism of outbreak of landslides in the snow season by using field observation data obtained at two landslidezones in Niigata Prefecture.
