【摘要】 本文详细分析了1958年以来的演变过程.说明1958～1978年间,北支河槽特性从受落潮流影响转为受涨潮流控制,使北支在河流动力、地貌、水文、沉积等方面起了一系列的变化,因此对其本身及南支产生了影响. 自1979年以来,南、北支会潮点进入北支河段内,北支上口段产生了一股较强的涨潮落潮流,对北支的淤积形态、河流地貌、水文等方面都起了新的变化,使北支河槽更加动荡不定.而北支的存在对南支仍产生不利影响. 文章并对今后发展趋势作了估计. 最后指出,为了切断南北支相互之间的干扰,有利于北支的综合利用和南支的整治,建议在北支上口建闸活堵,并将此工作纳入长江口综合治理规划中,进行通盘考虑.更多还原

【Abstract】 The evolution of the North Branch Channel of the Yangtze River Estuary from 1958 to 1982 has been analysed in great detail. Jt shows that in the first period (1958-1978) the characteristics of the channel of the North Branch had been changed. The channel which was usually influenced by the ebb-tide current had been gradually controlled by the flood-tide current (measured by value v ), thus causing a series of changes in the mechanics, river geomorphology, hydrology and sedimentation in the North Branch Channel and some effects on the South Branch Channel as well as itself. For example, water and sediment flow from the upper section of the North Branch Channel into the South Branch Channel and sea water flows upstream in the North Branch Channel in the winter and spring seasons.Because there is more sediment deposited in the North Branch Channel, the speed of propagation of tidal wave becomes slower, the point where the two flood-tide currents coming from the North and the South Branch Channels meet has been moved into the upper reach of the North Branch Channel since 1979(the second period). Stronger flood-tide and ebbtide currents are produced at the upper section of the North Branch Channel. There are some new changes in the form of sedimentation, river geo-morphology, hydrology, etc., in the North Branch Channel, for example, the upper section being scoured and the lower deposited, the river channel becoming more unstable and more banks being collapsed. The speed of deposit is doubled and the North Branch Channel decreases to some extent. The existence of the North Branch Channel is still having unfavourable influence on the South Branch Channel.It is also estimated that in the future the characteristics of the river channel will not change, the South Branch Channel will exert more stronger influence on the North Branch Channel than ever and such situation will continue for a certain time.Finally, it is suggested that in order to get rid of the interference between the two branches, to utilize the North Branch Channel comprehensively and to harness the South Branch Channel, and also to consider the effect which will happen after the completion of the plan of water being transferred from the south to the north, a dam for blocking up the channel should be built at the upper section of the North Branch Channel. This work should be put into the comprehensive harnessing plan of the Yangtze River Estuary and overall consideration must be given.更多还原