What month is the most spectacular spring tide in Qiantang River?

On the Mid-Autumn Festival in August of the lunar calendar, because the earth revolves around the sun on the short axis of the elliptical orbit, the sun and the moon are closest to the earth, and the energy to attract tides is the greatest, thus forming an annual mega-tide. ?

There will be a flood season from September 17 to 23, especially August 18 (September 2 1 Sunday), which is the most spectacular and the best time to watch the tide in Qiantang River.

The tidal bore phenomenon is twice a day, and it changes periodically every month according to the gravity changes of the earth and the moon. Every lunar month will get bigger or smaller at the beginning and end of the month. It also changes periodically every year, which happens to be the biggest day on August 18th of the lunar calendar.

Watching the tide is very important.

The tidal bore of Qianjiang River can be seen from a distance but not played near. According to the characteristics of the tidal bore in Qiantang River, the spectacular tidal scene is often a dangerous place, and the advancing speed and destructive ability of the tidal bore can not be confronted by flesh and blood. When the tidal bore comes, people must not compete with it, lest people be washed away by the tide and cause casualties. In addition, don't go down the dike pond to watch the tide on the river beach and groin.

The entrance and exit left on the standard dike pond is necessary for the inspection and maintenance of the dike pond, and the concrete platform on the waterfront side of the dike is a part of the dike pond structure, which is by no means for people to watch the tide and swim. To avoid the tide below the bend, the tide in this place often rushes to the pond and can't dodge. It is necessary to obey the dissuasion and command of the police and observe the order of tide watching.

Tidal bore is also called tide, which is called tidal bore during the day and tidal bore at night. Tidal bore is one of the rare natural phenomena in the world. Abroad, it only occurs in a few estuaries, such as the Seine River in Britain, the Seine River in France and the Amazon River in South America, but it is not as typical and spectacular as the tidal bore of Qiantang River in China.

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. When a large number of tides flood in from the mouth of Qiantang River, because the river surface shrinks rapidly, the tides can't rise evenly, so the back waves push the front waves, and the front waves can't run fast, and the back waves catch up and overlap with each other.

Secondly, it is related to the sediment deposition under the Qiantang River, which plays a role in blocking and rubbing the tidal current, making the front slope of the tidal current steep and gentle, forming tidal bore after wave after wave, wave after wave.