摘要
黄土坡面各种侵蚀方式以水流能量、侵蚀物质及侵蚀微地貌３种作用方式相关联，水流能量是制约侵蚀物质和侵蚀微地貌时空分异的本质原因。研究表明，雷诺数（Ｒｅ）、弗罗德数（Ｆｒ）及过水断面单位能量（Ｅ）为判定不同侵蚀方式出现的水动力学指标。并运用实验方法确定出细沟侵蚀的动力临界为：Ｒｅ≥１４８６，Ｆｒ≥６．５１９，Ｅ≥１．３８７ｃｍ。
The various erosion ways of loess sloping face are connected by the three action ways of running water energy, sediment and microland feature eroded; the running water energy is the essential reason that restrict the time space difference of sediment and micro land feature eroded. The results show that Reynolds number and Froude number, as major indexes of running water state, can be treated as mechanics indexes. Running water cause soil ersion, so unit energy of water carrying section should be treated as major parameter for reflecting variation of erosion degree and erosion pattern. For selecting the proper parameter from the three water mechanics indexes,we found critical kinetic indexes and coefficient of variability as rill occurred through experiment and statistics. The result is, Re≥1 486, C V =0.204. It shows the Reynolds number can be regard as a key index,and Froude number and unit energy of water carrying section can be regard as auxiliary indexes.
基金
中国科学院重点课题
国家自然科学基金
