Erosion Limit of Sod on the Slope of Levees

Abstract

Many failures of levees due to running water are started with the erosion of the surface of levees by running water in an early stage of the failure. From the results of analysis of disaster cases and the results of experiments, it was clarified that sodded levees having vegetation on the surface of levees have much higher strengths against erosion due to running water compared to earth levees having no vegetation. Therefore, one of the important factors governing the safety of levees against failures by running water is the erosion resistance of vegetation on the surface of earth levee. However, previous studies were little made on the erosion chracteristics of the earth levees having vegetation both domestically and overseas nevertheless the importance of this theme.
This paper will present a method of on-site erosion test using a new device for checking the erosion mechanism and characteristics of earth having vegetation, the erosion characteristics of sod on the slope of levee determined by said method, and a method of predicting the erosion-resisting strength based on the results of the above. Finally, the applicability of the prediction method will be investigated on the basis of survey of sodded levee erosion by a large flood.