黄河口清水沟与刁口河流路演变过程对比分析

Comparison of fluvial processes on Qingshuigou and Diaokouhe Channels in the Yellow River Delta

为探讨人类活动对黄河口流路演变的影响,以清水沟及刁口河流路为研究对象,采用实测资料分析方法,对比分析了两流路1964-2015年水沙条件及河道横、纵、垂向几何形态及冲淤变化。研究表明:两流路演变过程均具有阶段性,改道初期,发生大范围的快速淤积;改道中期维持的时间往往与水沙条件的变化有关,若水沙条件较好,则河道淤积减缓甚至发生冲刷,若水沙条件较差,河道演变迅速由中期转至后期;改道后期,河道迅速萎缩,滩唇淤高,横比降增大,形成地上悬河,地上悬河的形成标志着下一次改道即将开始。清水沟第IV阶段受清8改汊和调水调沙影响,主槽冲深,河道相对稳定。

To study the impact of human activities on the processes of the Yellow River Delta, the changes of water and sediment volumes, vertical and longitudinal geometric adjustments in the Qingshuigou Channel and the Diaokouhe channel, and the processes of scour and deposition in 1964-2015 were analyzed. Results showed that large-scale rapid deposition occurred.at the beginning of the diversion. The second stage was often related to water and sediment conditions, deposition rate in channel reduced down, and even scour occurred if water flow and sediment conditions were suitable. Otherwise, the channel processes turn to the next stage immediately. At the third stage, sediment deposited in the main channel and its vicinity area rapidly. As a result, main channel was shrinkage, and the transverse slope increased;the elevation of main channel was higher than the floodplain elevation, which indicated that the next channel shift will occurrence. The main channel was deepened and the width was quasi-stability in the fourth stage of the Qingshuigou Channel due to artificial diversion at the mouth channel in 1996, and later phase by man-made floods created by the water and sediment regulation scheme since 2002.