Effects of Rock Fragments Cover on Interrill Soil Erosion and Its Sheet Flow Velocity
Date Issued
2006
Date
2006
Author(s)
Chang, Yu-Han
DOI
zh-TW
Abstract
The main purpose of this study is to investigate the effects of rock fragments used as mulch cover on interrill soil erosion and the velocity of sheet flow. The soil used in the soil erosion tests was collected from a mountainside at Sindian, Taipei County. Soil erosion tests were repeated, cover rates of 0%,15%,30% and 50%, types of completely exposed to the surface and partially embedded into the soil, using a rainfall simulator with a rainfall intensity of 39 mm/hr. The results showed that while the rock fragments were completely exposed to the soil surface, the infiltration effectively increased, however the rock fragments were partially embedded into the soil, the infiltration was different. Both types of completely exposed to the surface and partially embedded into the soil were found to be able to decrease soil erosion. The rock fragments which were completely exposed to the surface could reduce soil erosion more effectively. For the rock fragments which were partially embedded into the soil, soil erosion and cover rate seemed to exist a non-linear relationship. The reason for that may because that the sheet flow on the soil surface was different. After measuring sheet flow velocity, watching test’s DV (Digital Video) and reviewing paper, it could be found that sheet flow at the rainfall intensity of 39 mm/hr could not detach soil particles. In this study, sheet flow could only transport soil particles detached by raindrop impact. In other words, Splash erosion dominated the interrill erosion.
Subjects
紋溝間土壤沖蝕
石塊覆蓋
薄膜流流速
石塊放置方式
interrill erosion
rock fragment cover
velocity of sheet flow
rock cover type
Type
thesis