In forested areas, rainfall changes in size and velocity as it passes through the canopy, resulting in throughfall with physical characteristics that differ from those of gross rainfall. These differences can affect soil erosion processes, highlighting the need for a clearer understanding of throughfall dynamics. This study compared the drop size distribution (DSD) and kinetic energy (KE) of raindrops in throughfall and gross rainfall using data from three optical disdrometers. The disdrometers were installed at three locations on the Chuncheon campus of Kangwon National University: a Korean pine (Pinus koraiensis) stand, an oak (Quercus mongolica) stand, and an open site. Results showed that total rainfall was greater at the open site than in the forest stands. However, the number of raindrops smaller than 1mm in diameter was higher in throughfall. In terms of volume ratio by drop diameter class, raindrops smaller than 3 mm were more dominant in gross rainfall, while those larger than 3 mm were more prevalent in throughfall. During the same rainfall events, the DSD of throughfall was more varied than that of gross rainfall. Notably, in the oak stand, throughfall during the leaf-fall period closely resembled the DSD of gross rainfall. Additionally, hourly KE analysis revealed that throughfall carried greater energy than gross rainfall, indicating a higher potential for impacting the forest floor. These findings suggest that throughfall exhibits a more diverse DSD than gross rainfall, primarily due to the splashing and aggregation of raindrops on foliage and branches. A better understanding of these patterns is essential for improving the accuracy of soil erosion modelling in forested areas.
저자
Mirae Han [ Department of Forestry and Environmental Systems, Kangwon National University ]
Inyoung Lee [ Department of Forestry and Environmental Systems, Kangwon National University ]
Kidae Kim [ Department of Forestry and Environmental Systems, Kangwon National University ]
Sukwoo Kim [ Division of Forest Science, Kangwon National University ]
Corresponding Author
