Tide information of Qiantang River

The largest and most spectacular tide in China is the Qiantang River tide, with a tidal head as high as 8 meters, and its advancing speed is nearly 10 meter per second. Its spectacular scene, surging and magnificent, is like a thousand troops marching hand in hand, making a thunderous sound, which is really a wonder of the world. Qiantang River flows into the East China Sea in Hangzhou Bay. Its mouth is wide outside and narrow inside, with a width of 100 km, and the narrow place is only a few kilometers. As soon as the seawater enters the estuary, the water surface is very wide, and the deeper it goes, the more restricted it is by the topography on both sides. The sea water has to accumulate more and more. In addition, the water flowing out of Qiantang River is blocked, which makes the water level rise, like a vertical water wall. When the seawater in the back keeps pouring in, it forms a spectacular scene that the back waves catch up with the front waves and the waves overlap.

Qiantang bore was formed in the Eastern Han Dynasty at the latest, and the custom of watching tides appeared in the Eastern Jin Dynasty, which was famous in the Southern and Northern Dynasties. It was fierce in the Tang Dynasty, but it became big in the Song Dynasty.

The spectacular Qian Jiangchao is not only influenced by the gravity of the moon and the sun, but also related to the trumpet-shaped mouth of Qiantang River. On the south bank of Qiantang River, nearly 500,000 mu of land was reclaimed to the east of Zheshan Mountain, which blocked the estuary like a peninsula, making the section from Zheshan Mountain to Qiantang River 12 like a small belly bottle, which is easy to retreat when the tide rises. The width of the outer mouth of Hangzhou Bay is 100 km, which is only a few kilometers away from the outer 12 section. The riverbed in the eastern part of the estuary suddenly rises and the beach is shallow. When a large number of tides flood in from the mouth of Qiantang River, it is difficult for the river to retreat because of the rapid contraction of the river surface. Secondly, it is related to the excessive sediment deposition under the Qiantang River. Sediment blocks and rubs the tidal current, making the front slope of the tidal current steep and gentle, thus forming a wave to catch up with the previous wave, wave after wave, and wave after wave.