坡面流与坡面侵蚀动力过程研究的最新进展*

在回顾了坡面流及坡面侵蚀过程研究的简史与现状的基础之上,全面总结了坡面流形成机理及其模式、坡面流水动力学特性、坡面侵蚀动力过程及其侵蚀产沙模型诸方面研究的最新进展,并对坡面流各要素分析及坡面小侵蚀陡坎的形成等进行了一些探讨。最后,提出了坡面流及坡面侵蚀过程研究中存在的主要问题及未来展望。

THE RECENT DEVELOPMENT OF THE STUDY ON OVERLAND FLOW AND HILLSLOPE PROCESSES

On the basis of reviewing the history and present situation of the study on overland flow and hillslope processes, the author summarized the recent development in following fields—the forming mechanism, hydraulic features and models of overland flow, the processes and models of hillslope evolution. It shows that, with theories and methods of geomorphology, hydrology, hydraulics and sediment movement mechanism, to study the erosion dynamic processes and its critical conditions is one of the current frontiers of overland flow and hillslope processes. Finally, the problems and futures of the researches in these fields were put forward.In Addition, some new ideas about the hydrological factors of the overland flow and the formation mechanism of small erosion holes on the slope were also given in this paper. It shows that critical Flow Reynolds Number (R_e) and Energy Per Unit Section (E_s) can be main critical hydraulic parameters to determine whether rill flow appears; the critical Flow Kinetic Energy (E_v) and Critical Shear Stress(τ_c) can be secondary parameters; the critical Froude Number (F_r)≥1 can be one of the essential conditions for the rill flow generation. It is also found that all of the flow potential energy are transformed into the kinetic energy. And water flow is so thin that rainsplash becomes very severe in the joint between trough of rolling wave and slope surface, where the small erosion holes appear firstly.