摘要
浅沟侵蚀是黄土区坡面侵蚀重要的侵蚀类型,通过模拟试验发现了浅沟侵蚀形态发育过程中宽深比的变化规律及其水流流态特性。结果表明:浅沟沟槽侵蚀发育重要参数宽深比的变化规律与是否进行耕作处理关系密切,随着侵蚀的进行其宽深比逐渐减小,并且稳定在1左右;浅沟水流属于紊流,其雷诺数随着坡度和雨强的增大而增大。耕作和汇水面积的增大造成雷诺数的波动范围变大;浅沟水流在急流和缓流之间不断转换。相同条件下,耕作使得浅沟水流的弗汝德数Fr值变小,且随着雨强和坡度的增大,耕作对弗汝德数的影响越来越小。研究结论对完善黄土区坡面侵蚀研究具有重要意义。
Ephemeral gully erosion is an important erosion type in loess area.Study on ephemeral gully erosion is the weakness of slope erosion process in loess area at present.Initial study on morphological development of ephemeral gully erosion and hydrodynamic characteristics of groove erosion flow has been done based on indoor simulation experiment.The results showed that： there was no significant correlation among change of width-depth ratio in ephemeral gully groove and rainfall,slope and catchment area,but the change was closely related with whether tillage;the width-depth ratio decreases gradually with the development of ephemeral gully erosion,and then reached a basically stable value（1）.Ephemeral gully flow belongs to turbulence,and its Reynolds Number （Re） increased with the increase of slope and rainfall;the fluctuation range of Re increased caused by the increase of tillage and catchment area,and ephemeral gully flow continuously changed from supercritical flow to subcritical flow.Under the same condition,Froude number（Fr） of ephemeral gully flow became smaller due to tillage,and this effect became smaller with increase of rainfall and slope.
出处
《水土保持学报》
CSCD
北大核心
2010年第5期92-96,100,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(50709041
50779074)
国家自然科学基金创新研究群体基金项目(50721006)
国家"十一五"科技支撑计划课题(2006BAB06B06)
中国水科院博士生学位论文创新研究资助课题
关键词
浅沟侵蚀
形态发育
水动力学特征
股流侵蚀
黄土高原
ephemeral gully erosion
morphological development
hydrodynamic characteristics
concentrated-flow erosion
Loess Plateau
