Simple modeling of sediment production caused by ice needles on bare slope

Yuma NAKAZAWA, Taijiro FUKUYAMA, Daizo TSUTSUMI

Abstract

Compared to mass movement such as landslide or debris flow, sediment yield due to freezing and thawing is minor phenomenon in terms of amount of sediment. However, this type of sediment yield is repeated over a wide area of bare slopes every winter, resulting in the production of large amounts of sediment over a long period of time. Therefore, accurate prediction of the sediment yield is essential task for integrated sediment management throughout a basin. In this study, a field experiment was conducted to monitor the amount of sediment yield by ice needle formation during a winter. In addition, the effectiveness of the prediction method using a theoretical approach was confirmed by comparing the experimental result and the prediction. We also developed a simple empirical model to estimate the sediment yield due to ice needle formation based on the result of the field experiment. As a result, it is confirmed that the simple model can estimate the amount of sediment yield only by the temporal change of air temperature and precipitation as input values, and the estimated sediment amount is comparable with the observed one by the field experiment.

Key words

ice needles, surface erosion, simple prediction model, field observation