摘要
通过对长江中游３类河型各河段洲滩分布特点的研究，将长江中游的边滩沉积分为凸岸边滩、口岸边滩、顺直边滩及三角滩４类。其中凸岸边滩又可分为雏形边滩、半成熟边滩和成熟边滩３个亚类，它们分别发育于曲流的不同演化阶段，顺流向边滩长度与垂直流向的边滩长度之比（Ｐａ／Ｐｅ）值由大变小，沙体形态由半月型变为顺流向窄长型．再变为垂直流向的窄长型；凹岸边摊的Ｐａ／Ｐｅ值与半成熟边滩接近．平均为５．３；顺在边摊的几何形态是窄长型，Ｐａ／Ｐｅ值平均为１４．７；三角滩平面上呈三角形，剖面上呈透镜状，发育于分流河口及分汉河口区。最后阐述了各类边滩的形成机制和演变特点。
The point bars of the middle Yangtze River can be divided into four types, such as convex bank point bars of meander, concave bank point bars,straight channel point bars and triangular bars. The convex bank point bars can be subdivided intoembryo, half-matured and matured point bars based on the evolution stages, the ratio of the length of paralell (Pa) to length of perpendicular(Pe)to flow direction decreases from embryo to matured point bars for three types,and the shape of the bar changes from narrow - and - long type to half - moon type, then to narrow - and - long type perpendicular to flow direction. Pa/Peof concave bank point bars averages 5.3, which is near that of half - matured point bar. The geometry of straight point bar is typically narrow - and - long.Pa/Pe averages 14.7. Triangular bars develop at the distribuary mouth, the plane geometry of the bar is triangular and its cross section is lenticular.
出处
《江汉石油学院学报》
CSCD
北大核心
1994年第4期22-27,共6页
Journal of Jianghan Petroleum Institute
基金
中国石油天然气总公司部级资助
关键词
河流
沉积特征
长江
边滩
recent sedimentation
fluvial deposit
depositional feature
Yangzi river
(point bars)
