Principle and Verification of the Semi-scale Experimental Method for Soil Conservation
Similarity plays an important role in the soil erosion experiments.This study presents a semi-scale method to simulate the processes of soil conservation by check dams in a small watershed on the Loess Plateau of China.During experiments,the model-prototype ratio of geomorphic variables was kept constant under each rainfall event.Consequently,experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with cheek dams.Thus it can predict the amount of soil loss in a catchment.This study also mentions four criteria,similarities of watershed geometry,grain size and bare-land,Froude number (Fr) for rainfall event,and soil erosion in down-scaled models.The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments.The B-Model,a large scale model,simulates watershed prototype.The two small scale models,Da and Db,have different erosion rates,but are the same size.These two models simulate hydraulic processes in the BModel.When kDB,the relative efficient of the Da-Model to B-Modal was 0.4 in these experiments,the amount of soil loss in the Da-Model was very close to that in the B-Model,and the difference between two models was less than 50%,except the first rainfall event,in which field rainfall intensity (2.70 mm/min) in the Da-Model was 63.9% more intense than the designed intensity (1.65 ram/rain) resulting from human error.When kDs Was 0.4 in these experiments,the amount of soil loss in the Db-Model was close to that in the B-Model,and the difference between two models was less than 55%,except for the second rainfall event (soil loss error was 81.2%).Moreover,the experimental results show that the prototype deposition depth was strong correlated with model deposition/erosion depths.Obviously,with a semi-scale physical model,experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau,China.
loess plateau check dam semi-scale model similarity condition soil loss
Xu Xiangzhou Zhang Hongwu Wang Guangqian
School of Civil & Hydraulic Engineering, Dalian University of Teehnology,Dalian, 116024, China Department of Hydraulics and Hydropower Engineering, Tsinghua University,Beijing, 100084, China Department of Soil and Water Conservation, Chung-Hsing University,Taichung, 40227, China
国际会议
The 5th International Yellow River Forum (第五届黄河国际论坛)
郑州
英文
385-393
2012-09-24（万方平台首次上网日期，不代表论文的发表时间）