摘要
不同河流形态间的交替转化,伴随着河流阻力规律的变化。为研究基础河型的演化规律,在实验室条件下,通过控制初始河道弯曲度、河宽以及流量,对正弦派生曲线弯道短期演变的特征规律,如河岸线、水流动力轴线和地形变化等进行了研究。结果清晰地表明了不同工况下河道的不同发展特征,"大水"条件下河道容易渠道化,河岸线趋于顺直,河道宽度主要受到初始河道弯曲度及水流流量的影响。总体来看,用非黏性泥沙作为实验材料,实验河道易向着游荡型方向发展,但在一定的时间段内,存在着典型弯曲河道演变特征,且可明显地观察到床面对流量的非线性响应特征。实验结果能为天然河流的平面形态演变研究提供支持。
Flow resistance law changes with the transformation of river patterns. To understand evolution laws of fundamental channels,initial channel sinuousness,channel width and dominant discharge are controlled to simulate short-term development of sine-generated meander river in laboratory conditions. Various measurements on the bank-line,flow field,and bed topography clearly indicates that different initial river conditions lead to different development characteristics. For example,( 1) in the "High Flow"runs,initial sine-generated channels gradually become channelized on the whole( bank-lines tend to be straight);( 2) the river corridor width mainly depends on the meander amplitude in the experiments,which is mainly controlled by sinuousness and water discharge;( 3) braided rivers are generally easy to produce by non-cohesive sediment in flood plains,but there exist typical meander river processes in a certain period;( 4) discharge influences the riverbed nonlinearly. The experiment results offer a basis for further study on the morphological evolution of largescale natural rivers.
作者
宋晓龙
白玉川
SONG Xiao-long;BAI Yu-chuan(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China;Institute for Sedimentation on River and Coastal Engineering,Tianjin University,Tianjin 300072,China;State Key Laboratory of Hydro-science and Engineering,Tsinghua University,Beijing 100084,China)
出处
《泥沙研究》
CSCD
北大核心
2018年第4期16-23,共8页
Journal of Sediment Research
基金
国家自然科学基金(51279124)
关键词
正弦派生
弯曲度
河宽
流量
河道演变
sine-generated
channel sinuousness
channel width
dominant discharge
river processes