Effects of Landslide and Forest Fire on Rainfall Threshold to Induce Bedload Discharge in Watershed in Republic of Korea

Junpyo SEO, Kihwan LEE, Changwoo LEE, Dongyeob KIM, Choongshik WOO, Heonho LEE, Taro UCHIDA and Wataru SAKURAI

In Korea, there are six sites that are using hydrophone (Japanese pipe microphone) developed in Japan. In this study, the rainfall threshold for the occurrence of bedload events was analyzed in forest disaster sites and control site. As a result, the total rainfall amount and the peak rainfall intensity among the rainfall characteristics were analyzed to be the best representations of bedload events. The difference between the bedload events and the rainfall threshold was clear in control site (normal forest), landslide site and forest fire site. In the control site, the rainfall threshold of bedload events was high, while the rainfall threshold of bedload events was low in the landslide and the forest fire site. In the forest fire site, the rainfall threshold of the bedload events was found to be higher after three years of forest fire damage. Therefore, an urgent soil erosion control work seems to be required to prevent the second damages in damaged forests.

2018/1 294-300