Scientific reasons for the formation of the tide of the Qiantang River

1. Time of day: From the 16th to the 18th day of the eighth month of the lunar calendar, the sun, the moon and the earth are almost in a straight line, so the inertial centrifugal force generated by the gravitational force centroid movement of the sea water on this day and the combined force of the moon (day) gravitational force are the largest.

2. Geographical advantage: It is related to the trumpet-shaped shape of the Qiantang River estuary. Nearly 500,000 acres of reclamation land east of Zheshan on the south bank of the Qiantang River block the estuary like a peninsula, so that the tide of the Qiantang River is easy to advance and difficult to retreat from the Zheshan Mountain to the outer 12 kilometers, the outer mouth of Hangzhou Bay is as wide as 100 kilometers, and the outer 12 sections are only a few kilometers wide, the riverbed in the eastern section of the estuary rises suddenly, the beach is high and the water is shallow, when a large amount of tide water pours in from the Qiantang estuary, because the river surface shrinks rapidly, the tide does not have time to rise evenly, so it has to push the back wave and the front wave, layer upon layer.

3. Wind: The southeast wind often blows along the coast, and the wind direction is roughly the same as the direction of the tide, which promotes the tide.

The largest and most spectacular tide in our country is the tide of the Qiantang River, the tide head is as high as about 8 meters, the tide head propulsion speed reaches nearly 10 meters per second, its spectacular scene, surging, majestic, as if thousands of troops and horses marching together, making a thunderous sound, it is really a wonder of the world. The Qiantang River flows into the East China Sea in Hangzhou Bay, and the estuary is wide on the outside and narrow on the inside, reaching 100 kilometers wide at the point and only a few kilometers at the narrow point. As soon as the sea water enters the estuary, the water surface is wide, and the further it goes, the more it is constrained by the topography on both sides of the river, the sea water has to gush up, and it accumulates higher and higher, and the water flowing out of the Qiantang River is blocked, which promotes the water level to rise, like an upright water wall.

When the sea water behind continues to pour in, it forms a spectacular scene of the back waves catching up with the front waves, wave after wave.

The Qiantang tide was formed in the Eastern Han Dynasty at the latest, and the tide viewing custom appeared in the Eastern Jin Dynasty, famous in the Northern and Southern Dynasties, and was very violent in the Tang Dynasty, and the tide watching in the Song Dynasty became a scale.

In addition to the gravitational influence of the moon and the sun, the cause of the majestic Qianjiang tide is also related to the trumpet-shaped shape of the Qiantang River estuary. Nearly 500,000 acres of reclamation land in the east of Zheshan on the south bank of the Qiantang River like a peninsula block the estuary, so that the Qiantang River Zheshan to the outer 12 sections resemble a bottle with a big mouth and a small mouth, the tide is easy to advance and difficult to retreat, the outer mouth of Hangzhou Bay is as wide as 100 kilometers, and the outer 12 sections are only a few kilometers wide, the riverbed in the eastern section of the estuary rises suddenly, the beach is high and the water is shallow, when a large amount of tide water pours in from the Qiantang estuary, because the river surface shrinks rapidly, the tide does not have time to rise evenly, so that the back wave pushes the front wave, the front wave does not run fast, the back wave catches up, layer upon layer. Secondly, it is also related to the sediment under the Qiantang River, which blocks and rubs the tide, making the front slope of the tide steeper and the speed slowing down, thus forming the back wave to catch up with the front wave, one wave on top of the other, one wave higher and one wave surge.

The sea tide at the mouth of the Qiantang River in the country is surging and majestic, especially in the two or three days after the Mid-Autumn Festival, it is the most spectacular, the tide head is as high as 3 5 meters, the speed of advancing every second reaches nearly 10 meters, bringing 100,000 200,000 tons of seawater, and at the same time making a huge sound, as if thousands of troops and horses are galloping. Su Dongpo, a writer in the Song Dynasty, once wrote such a poem for it: August 18 tide, spectacular in the world.

High and low tides are a common natural phenomenon at the seaside. Two or three days after the summer calendar (i.e., the 15th), the tides are generally higher than usual all over the world. The ebb and flow tides are affected by the gravitational pull of the moon and the sun and the rotation of the earth, and when the earth, the sun, and the moon are exactly in a straight line, the gravitational pull of the sun and the moon is particularly powerful.

The Mid-Autumn Festival coincides with the 15th day of August in the summer calendar, and at this time, their positions are close to a straight line, so it is a common phenomenon that the autumn tide is larger. However, a big tide like the Qiantang estuary is rare in the world.

Why is the Qiantang autumn tide so spectacular and so punctual? This is a question that naturally comes to many people's minds. There are many folk legends about this, and of course, legends are just legends. The reason why the autumn tide is so prosperous in Qiantang is mainly due to its unique geographical conditions.

The mouth of the Qiantang River is wide on the outside and narrow on the inside. Shaped like a trumpet. It is about 100 kilometers wide at the mouth of Hangzhou Bay (Wangpanyang), but it is only a few thousand meters on the river near Yanguan Town, Haining.

When a large amount of tidal water from the open sea rushes into the narrow channel, the water level in the bay rises rapidly, and the water flowing out of the Qiantang River is blocked and difficult to escape, which in turn promotes the water level to rise. On the other hand, when the tide enters the Qiantang River, a sand hill across the estuary of the river becomes a wall, which makes the tide move forward suddenly slows down, and the tide behind it swells up rapidly, forming a back wave to push the front wave, and the tide head is getting higher and higher.

In addition, in the coastal areas of Zhejiang, southeast winds often blow between summer and autumn, and the direction of the wind is roughly the same as the direction of the tide rush, which also contributes to its momentum.

Many of the factors that favor the high tide are concentrated in the Qiantang River estuary, especially in autumn, so the autumn tide there has become a rare wonder in the world.

There are many reasons for the formation of the tide of the Qiantang River, one of which is that when the three points of the sun, the moon and the earth are almost in a straight line, the tide is subject to the largest gravitational force, which leads to the formation of the tide. The second is that the trumpet-shaped topography of the Qiantang River estuary makes it easy for the tide to advance and retreat from the Zheshan Mountain of the Qiantang River. The third reason is that the Qiantang River often blows southeast winds, and the wind direction is roughly the same as the tide flow, which promotes the tide.

How the tide of the Qiantang River was formed

The main reasons for the formation of the Qiantang River tide are the gravitational effect of celestial bodies and the centrifugal action of the earth's rotation, the special topography of the Qiantang River flare mouth in Hangzhou Bay, and the effect of wind. The tide of the Qiantang River is very spectacular, it is a natural wonder of the world, in the eighteenth day of August of the lunar calendar every year, the tide head of the Qiantang River is as high as about 8 meters, and its advance speed is very fast, it can reach nearly 10 meters per second.

The mouth of the Qiantang River is in Hangzhou Bay, and its estuary is wide on the outside and narrow on the inside, with a width of 100 kilometers and a narrow place of only a few thousand meters. The trumpet-shaped topography makes it more and more constrained by the banks of the river the further it goes, thus causing the sea water to gush, and the water flowing out of the Qiantang River is blocked by the terrain and promotes the water level**, so the tide is wave after wave.

In Hangzhou, as long as there are days when there is a tide, it is possible to see a high tide anywhere along the Qiantang River, and you can see two wonders in a day: morning tide and evening tide. The tide of the next day is generally 40 minutes later than the tide of the previous day. Also pay attention to safety when watching the tide.

The perspective of watching the tide is also different in places where it is not used. Generally, you can go to Haining to see the first line of tide.

How was the Qiantang River tide calendar formed?

1.The main reason for the formation of the tide of the Qiantang River is that when the sun, the moon and the earth are almost on the same straight line, the tide is subjected to the largest gravitational force, so the tide is formed, and another reason is that the topography of the Qiantang River estuary is presented as a Lachan Chang trumpet, which also plays a certain role in the formation of the tide.

2.The best time to observe the tide of the Qiantang River is generally around August 15 to August 20 of the lunar calendar, and the river water originates in Huangshan City, Anhui Province, and flows through Anhui and Zhejiang provinces.

3.Qiantang River is the name of the province established in Zhejiang Province in the early Ming Dynasty, is the largest river in Zhejiang Province, and is also one of the important birthplaces of Chinese civilization.

4.The tide of the Qiantang River is known as "the first tide in the world", is a great wonder of the world, the tide began in the Han and Wei dynasties, prevailed in the Tang and Song dynasties, has a history of more than 2,000 years.

First of all, this is related to the shape of Hangzhou Bay, where the Qiantang River flows into the sea, and its special topography, which is trumpet-shaped and has a large mouth and a small belly. The Qiantang River narrows and rises sharply from the west of Luopu, causing the capacity of the riverbed to shrink suddenly, and a large amount of tidal water crowds into the shallow channel.

The tide head is obstructed, and the tide behind it advances rapidly, forcing the tide head to stand steeply, break, and roar, resulting in a thrilling and spectacular scene. Secondly, the Qiantang River is located in the coastal area, and the southeast wind often blows, and the wind direction is roughly the same as the direction of the tide, which promotes the tide.

Every year in the eighth month of the lunar calendar, many people will gather in Hangzhou Bay to watch the tide of the Qiantang River. The formation of the Qiantang River tide is caused by the centrifugal action of celestial gravity and the rotation of the earth, coupled with the special topography of the horn mouth of Hangzhou Bay. Hangzhou Bay outside the Qiantang River, wide on the outside and narrow on the inside, deep on the outside and shallow on the inside, is a typical trumpet-shaped bay of early spikes.

At the beginning of the tide, the wide and deep mouth of the bay swallows a large amount of seawater, due to the rapid contraction of the river surface and becomes narrow and shallow, the upwelling tide does not have time to rise evenly, to the vicinity of Dajia Mountain, and encounters the underwater barrage sand bar, the tide forms a steep water strength, resulting in the initial tide peak. Southeasterly winds often blow along the coastal areas of Zhejiang in summer, which contributes to the tide.

On the 18th day of the eighth month of the lunar calendar, the sun, the moon, and the earth are almost in a straight line, and the gravitational pull of sea water is the greatest. Under the influence of the moon's gravity, the long incoming tide advances upstream at a rate of 5-7 meters per year, forming the great tide we see.

The Qiantang River is the largest river in Zhejiang Province, the name of the Liangzhejiang Road in the Song Dynasty, and the name of the province when Zhejiang Province was established in the early Ming Dynasty. Calculated from the Xin'an River in the north, the river is thousands of kilometers long; Counting from the Majin River in the upper reaches of the South Source Blind Buqu River, the river is thousands of kilometers long. From its source, it flows through the southern part of present-day Anhui Province and Zhejiang Province, with a basin area of 55,058 square kilometers, and flows into the East China Sea through Hangzhou Bay.

The Qiantang River tide is known as "the first tide in the world" and is a natural wonder of the world, which is caused by the centrifugal action of celestial gravity and the rotation of the earth, coupled with the special topography of the horn mouth of Hangzhou Bay.

The tide of the Qiantang River.

There are three main reasons for the formation: time, location and wind, and the specific causes are as follows:

Time: The eighteenth day of the eighth month of the lunar calendar, the sun and the moon.

The Earth is almost in a straight line, so the gravitational pull of the sea is greatest on this day.

Geographical advantage: It is related to the trumpet-shaped shape of the Qiantang River estuary. Nearly 500,000 acres of land to the east of Zheshan on the south bank of the Qiantang River block the river mouth like a peninsula, so that the 12th section of the Qiantang River from Zheshan to the outer 12 sections is like a bottle with a big belly and a small mouth, and the tide is easy to advance and difficult to retreat, Hangzhou Bay.

The width of the outer mouth is up to 100 kilometers, and it is only a few kilometers wide to the outer 12th section, and the riverbed in the eastern section of the estuary rises suddenly, the beach is high and the water is shallow, when a large amount of tide water pours in from the Qiantang estuary, because the river surface shrinks rapidly, the tide does not have time to rise evenly, so it has to go back to the waves.

Push the front wave, the front wave is not fast, the back wave chases Wu Bi, layer upon layer. Secondly, it is also related to the sedimentation of the Qiantang River, which blocks and rubs the tide, making the front slope of the tide steeper and the speed slowing down, thus forming the back wave to catch up with the front wave, one wave on top of the other, one wave high and one surge.

Tide. Winds: Southeasterly winds often blow along the coast of Zhejiang in summer and autumn, and the wind direction is roughly the same as the direction of the tide, which promotes the tide.

Hangzhou Bay outside the Qiantang River, wide on the outside and narrow on the inside, deep on the outside and shallow on the inside, is a very typical trumpet-shaped bay. The river at the mouth of the sea is 100 kilometers wide, and to the west to Pengpu, the river shrinks to 20 kilometers. To Haining Yanguan Town.

In one area, the river is only 3 kilometers wide. At the beginning of the tide, the wide and deep mouth of the bay swallows a large amount of seawater at once, and because the river surface shrinks rapidly, it narrows and becomes shallow, and the tide that rises on the road does not have time to rise evenly, so the back wave pushes the front wave, and the wave is higher than the other. When we go to the vicinity of Dajia Mountain, we encounter a huge barrage sand bar under water, and the tide rushes up, setting off a towering and amazing huge wave, forming a steep water wall, and causing the initial tide peak.

It is about to be the best time to watch the tide, although the tide is spectacular, but it is also dangerous, about the precautions when watching the tide and the best place to watch the tide, you can refer to: the cause of the tide of the Qiantang River Precautions for tide watching the tide of the Qiantang River.