论文部分内容阅读
北半球自西向东流动的河流,由于受地转偏向力的影响,一般是北岸淤积,南岸冲刷,而钱塘江却恰恰相反。据分析,钱塘江河口北岸长期为冲刷区,而南岸为强淤积岸。这是怎么回事呢?钱塘江河口北岸的杭嘉湖平原基本被第四纪松散沉积物覆盖,而澉浦、尖山附近地区为燕山运动时期岩浆活动留下的基岩残丘。北岸岸线坍塌后退的同时,澉浦、尖山一带由于残丘屏障作用岸线稳定,逐渐演化成呈半岛状突出的陆地。而澉浦长山闸与慈溪市西三闸一线以西(河口段),是钱塘江河口区径流与潮流共同作用区,该线以东(河口湾)是以潮流作用为主的区域。钱塘江河口附近“北冲南淤”现象大致要以澉浦一带为界,东西两侧在成因上有所差异。一、澉浦以东河口湾水域钱塘江是一条水清沙少的山溪性河流,年均输沙量只有668万吨,且主要沉积在澉浦以西水域。澉浦以东
In the northern hemisphere, the rivers flowing from west to east are generally silted up on the north bank and washed off on the south bank due to the influence of turnaround and turning force, while the Qiantang River is the opposite. According to the analysis, the north bank of the Qiantang River Estuary is a long-term scouring area, while the south bank is a strong silt bank. What happened? The Hangjiahu Plain on the north bank of the Qiantang River estuary was basically covered by Quaternary loose sediments, while the areas around Xupu and Jianshan were bedrock remnants of the Yanshanian magmatic activity. While the north coastline collapsed and retreated, the shoreline in Xupu and Jianshan areas gradually became a peninsula-shaped land due to the barrier effect of the residual hillock. The Xiantu Changshan Gate and the west of the West Third Tributary of Cixi City (estuary section) are the co-acting areas of runoff and tidal current in the estuary of the Qiantang River, and the east (estuarine) tidal flank is the area dominated by the tidal current. Near the mouth of the Qiantang River “North red silt ” phenomenon roughly to the Tupu area as the boundary, the east and west sides of the genetic differences. First, the east of Xupu estuary Bay Qiantang River is a stream of small rivers and streams, with an average annual sediment transport of only 6.68 million tons, and the main sediment deposition in the west of Xupu waters. To Pu east