Difficulties in Predicting Snow-induced Landslides

Abstract

Unlike rain, snow tends to accumulate and remain on the ground, melting over time. To better predict the occurrence of landslides during the snow cover season, it is necessary to make an accurate estimate of the timing and intensity of meltwater flowing out from the bottom of a snow pack. Although meltwater can be estimated by the degree-day or heat balance methods in the snowmelt season, it is difficult to estimate the melt water in the early period of the snow pack season and when rain falls on an accumulated snow. This is due to the complicated nature of the heat balance compared to the snowmelt season and to unknown variables such as the water-holding capacity of the snow cover. At the same time, the water equivalent of a snow pack is believed to affect slope stability in terms of load and glide. However, the details of these mechanisms are not clear due to the uneven distribution of snow and the complex interrelationships between the snow load and the sliding and ground surfaces. Compounding this is the relation between pore water variation and slope stability, which is difficult to ascertain due to repetitive loading and unloading.