地表糙度与水力糙率间关系的试验研究

Research on Relationship Between Surface Roughness and Hydraulic Roughness

地表粗糙度是反映地表起伏变化与侵蚀程度的指标。目前,它与水力糙率之间关系的研究结果还没有统一的结论。在上方来水条件下,从水力学的角度出发,探讨了地表粗糙度与水力糙率之间的关系,地表糙度受土壤的理化性质、降雨或上方来水情况等因素的影响很大,具有随机性;地表糙度对水力糙率的作用是一个动态变化的过程,并不总是呈现一种变化规律,在这中间存在一个临界值,在临界值后,二者的变化规律趋向稳定。

Surface roughness is an indicator to reflect the ups and downs and the degree of erosion on the earth surface.Till now,the relationship between the surface roughness and the hydraulic roughness had many statements.For the lack of the research in this field,this paper discussed the relationship between the surface roughness and the hydraulic roughness in the method of Hydraulic under the condition that the direction of the coming water from the upside.The results are as follows：（1） Factors of physicochemical properties of soil,precipitation or upslope runoff affected significantly on surface roughness thus making it a random value;（2）Effect of surface roughness on hydraulic roughness was a dynamic process and it did not present a single variation rule between which there exist a critical value and only after that value will the rule stay steady.This paper obtained the critical value of sand in 0.6315 and red soil in 0.9337 preliminarily.