摘要
为了探究土石混合崩积体坡面细沟跌坑发育情况,采用室内放水冲刷试验,通过设置4个流量(2,4,8,12 L/min)和4种砾石含量的土石混合崩积物(砾石质量比例0,10%,30%,50%),研究不同条件下细沟跌坑的发育特征。结果表明:在不同冲刷时段,跌坑数量变化为3~17个,跌坑平均深度为1.10~5.93 cm,细沟纵断面形态系数为2.97~19.97。各跌坑参数随冲刷时间的延长总体呈增大趋势,部分坡面在5 min或7.5 min时出现最大值;跌坑参数随流量的增加总体呈先增大后减小趋势,8 L/min流量条件下出现最大值,而随着砾石含量增加总体呈增大趋势;流量对跌坑发育的影响大于砾石含量。各跌坑参数与流速、阻力系数及曼宁粗度系数密切相关,径流剪切力是描述跌坑发育的最适合水动力学指标,可用线性函数表达。
In order to explore the drop pit development on soil-rock mixed colluvial deposit slopes,a scouring test was conducted in laboratory.Four soil-rock mixed colluviums(0,10%,30%,50%gravel in mass ratio)under different flow discharges(2,4,8,12 L/min)were tested.The results were as followed:the number of drop pit varied from 3 to 17,the average depth of drop pit was between 1.10 to 5.93 cm,and the profile form indices were between 2.97 and 19.97.The number of drop pit,the depth of drop pit,and the profile form indices all showed the increasing trend overall with the increase of scouring duration,whereas the maximum value appeared in some slopes at 5 min or 7.5 min.All drop pit parameters first increased and then decreased with the increase of flow discharge as a whole,and the maximum value appeared under the discharge of 8 L/min.The number of drop pit,the depth of drop pit,and the profile form indices increased with the increase of gravel content.The influence of flow discharge on the all parameters of drop pit was greater than those of gravel contents.Drop pit parameters were significantly correlated with flow velocity,resistance coefficient and Manning roughness coefficient.Shear stress was the best hydrodynamic parameter to describe the development of drop pit development as a linear function.
作者
蒋芳市
张海东
陈培松
林嘉辉
林金石
施悦忠
许永明
黄炎和
JIANG Fangshi;ZHANG Haidong;CHEN Peisong;LIN Jiahui;LIN Jinshi;SHI Yuezhong;XU Yongming;HUANG Yanhe(College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou 350002;Office of Anxi County Water and Soil Conservation Committee,Anxi,Fujian 362000)
出处
《水土保持学报》
CSCD
北大核心
2019年第6期27-33,共7页
Journal of Soil and Water Conservation
基金
福建省自然科学基金项目(2017J01459)
国家自然科学基金项目(41977071)
关键词
崩岗
崩积体
砾石
细沟侵蚀
跌坑
水动力学
benggang
colluvial deposit
gravel
rill erosion
drop pit
hydrodynamics
作者简介
第一作者:蒋芳市(1979—),男,福建大田人,讲师,博士,主要从事土壤侵蚀与治理研究。E-mail:jfsfafu@163.com;通信作者:黄炎和(1962—),男,广东饶平人,教授,博导,主要从事土壤侵蚀与治理研究。E-mail:yanhehuang@163.com。
