从黄河下游河道平面和断面形态特征、河型沿程变化、河槽淤高与外延相互反馈、河口拦门沙消长、及蚀退型三角洲海岸地貌过程诸方面,论述了冲积扇—三角洲系统适应环境功能与自组织行为。指出了这种自组织行为完全是为了将流域来沙均匀地分布在扇三角洲面上和同步地均匀分布在三角洲沿岸。因此,坚持沿线长期计划放淤及河口三角洲流路计划改道是解决黄河下游泥沙问题的根本出路,也是解决黄河下游洪水问题的一种由突变变为均变、化害为利的措施,是使区域走向可持续发展之途的措施。

By the analysis of the plane and section form of stream channel,the channel pattern changing in a downstream direction,the feedback each other between aggradation and elongation of channel,the growth and decline of estuarine barrier bar,and the geomorphic process of delta coastof erosion retreat pattern in the lower Yellow River,the paper brings out:(1) the function of self-adapting environment and the self-organizing behaviours of fan-delta system,which are divided into two kinds,linear and non-linear; (2) the multi-level character of the behaviours and the entirety of its functional effect on system;and (3) the cycle nature of order changing by self-organization,involving autocycle and allocycle. The analysis indicades thatthe self-organizing behaviour of fan-delta system is perfect for dispensing uniformly sediment over the surface of alluvial fan-delta as well as on delta coast zone.Three management countermeasures for the lower Yellow River are suggested:(1) long term warping in the downstream direction in a planned way,(2) arranging the flow path of the main river on the delta in a planned way,(3) as a perspective mouth rivercourse,arranging the reach ofthe Yellow River below Qinghezhen through Tuhai He river to empty itself into the Bohai sea.These are a fundamental way out for handling sediment issue of the lower Yellow River.And they are also the basic measures for eliminating flood hazard of the lower Yellow River by turning an abrupt change into a progressive change and turning bane into boon.And they are also the major measures for this area to turn into a sustainable development.