What are the factors that contribute to the formation of the Qiantang River tide

Cause: From the 16th to the 18th day of the eighth month of the lunar calendar every year, the sun, the moon and the earth are almost in a straight line, so the gravitational force of the sea is the largest on this day, and the tide is much larger than usual.

Geographical advantage: The horn terrain of the Qiantang River Estuary, the tide is easy to enter and not easy to get out, so that the back waves of the tide push the front waves, layer upon layer.

Wind: The wind blows from the sea to the mouth of the Qiantang River, helping to raise the tide.

The beginning of the lunar calendar every month.

Two or three days after the fifteenth day, the moon, the sun, and the earth are arranged in a straight line, so the tides around the world are generally higher than usual these days. Especially the two or three days after the Mid-Autumn Festival is the time of the year when the earth is closest to the sun, so the autumn tide at this time is the largest of the year.

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. Every year on the eighteenth day of the eighth month of the lunar calendar, the tide of the Qianjiang River is the largest, and the tide head can reach several meters. When the tide comes, the sound is like thunder, the mountains and the sea are overwhelmed, like ten thousand horses galloping, it is magnificent.

Southeasterly winds often blow along the coast, and the direction of the wind is roughly the same as that of the tide, which contributes to the tide.

Celestial time: 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 tidal gravitational force on the sea water on this day (the difference between the gravitational attraction of the moon, the sun or other celestial bodies on the earth's unit mass object and the gravitational force of the earth's centrium on the earth's centroid (sun), or the resultant force of the inertial centrifugal force generated by the earth's movement around the earth-moon (sun) center of mass and the moon's (sun) gravity. Maximum.

Geographical advantage: It is related to the trumpet-shaped shape of the Qiantang River estuary. Nearly 500,000 acres of reclamation land to the east of Zheshan on the south bank of the Qiantang River block the estuary like a peninsula, so that the Qiantang River Zheshan to the outer 12th section resembles a bottle with a big mouth and a small mouth, the tide is easy to enter and difficult to retreat, the outer mouth of Hangzhou Bay is as wide as 100 kilometers, only a few kilometers wide to the outer 12th section, 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 to the front wave, 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 catching up with the front wave, and the wave on top of each other. Winds: Southeasterly winds often blow along the coast, and the direction of the wind is roughly the same as the direction of the tide, which contributes to 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.

There are three reasons for the formation of the tide of the Qiantang River: the right time, the right place and the strong wind.

1. Time of day. The formation of tides is mainly affected by the rotation of the earth and the gravitational pull of the sun and moon, and the greater the gravitational force, the greater the tide. Therefore, on the first and fifteenth days of each month, the gravitational pull increases, and the tides also increase.

On the eighteenth day of the eighth month of the lunar calendar every year, the sun, moon and earth are almost in a straight line, and the influence of the gravitational force reaches its peak at this time, and the tide on this day is the largest.

2. Geographical advantage. The shape of the Qiantang River Estuary is a trumpet-like shape, just like a bottle with a big belly and a small mouth, when the tide pours into the Qiantang River Estuary, the river channel suddenly narrows, and the huge waves suddenly narrow, and it will definitely form a turbulent tide. When the Kaichan tide that entered the Qiantang River estuary wanted to retreat, it was stopped by the huge sand kan at the mouth of the river, and it was impossible to enter and exit to stare at Qingchen, and then the front wave would be blocked, and the back wave would follow, and the spectacular scene of wave after wave was produced.

3. Strong winds. On August 18, a strong wind struck, and the wind swept up the big waves, and the big waves moved forward by the wind, how could they not be turbulent. The above three points have created a magnificent tide of the Qiantang River, which makes people have to sigh at the magic of nature's creation.

Qiantang River introduced.

1. On the fifteenth day of August of the lunar calendar every year, the tide of the Qiantang River is the largest, and the tide head can reach several meters. On August 18 of the lunar calendar, the navy was inspected on the Qiantang River, and then it was followed by the Xi Festival. In addition to the tide watching festival three days before and after August 18 of the lunar calendar, there are high tides at the beginning and middle of each month of the lunar calendar, and you can do one tide and three times to see the "tide chasing tour".

Around the Mid-Autumn Festival, guests from all over the world flocked to see the wonders of the Qianjiang tide, which was unprecedented.

2. When the tide is big at the beginning of the year, it pours up to the river bank and injures the tide watchers. The literature contains the poem "Zaijingtang Collection, Jiangnan Jingshi Poems, and Watching the Qiantang Tide": "At first glance, the thunder is suspected of rain, and the sea is suddenly overturned and wants to float the mountain.

Ten thousand people retreated like a rout, and the turbid waves were higher than the viewing altar. "Haining Yanguan Scenic Area, which is 50 kilometers away from Hangzhou, is the best place to watch the tide.

3. Watching the autumn tide in Qiantang has become a trend as early as the Han, Wei and Six Dynasties, and this wind is more prosperous in the Tang and Song dynasties. According to legend, August 18 of the lunar calendar is the birthday of the tide god, so the tide peak is the highest. The court of the Southern Song Dynasty once stipulated that on this day, the colonel of the Qiantang River will read the water division, and then it will become a habit along the way, and August 18 will gradually become the tide watching festival.

The Northern Song Dynasty poet Pan Lang wrote in "Jiuquanzi":

4. In ancient times, Hangzhou watched the tide, with Phoenix Mountain and Jianggan as the best place. Due to the change of geographical location, from the Ming Dynasty, Haining Yanguan was the first resort to watch the tide, so it is also called"Haining tide watching"。

5、"Qianjiang Qiutao"It is well-known at home and abroad, and it has been prevalent as early as the Tang and Song dynasties. On the day of watching the tide, especially a few days before and after the 18th day of the eighth month of the lunar calendar, the cars on the road are like water and the people are surging. Overlooking the bell mouth of the Qiantang River out of the sea, the tide forms a turbulent wave, like a thousand horses galloping, encountering the riverbed near the Lupu sand is blocked, the tide is three to five meters high, and the tidal difference is up to nine to ten meters, indeed"The monstrous turbidity waves are emptied, and the rivers and mountains can be destroyed"momentum.

Different locations can enjoy different tide views: watch from the tower"A line of tide", Eight Castles look"Confluence tides", the old salt warehouse can be appreciated"Turning back"。

1. 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. When you reach the area of Yanguan Town in Haining, 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. In the vicinity of Dajia Mountain, we encountered a huge barrage sand bar under water, and the tide swarmed up, setting off a towering and amazing huge wave, and the draft began to form a steep water wall, causing the initial tide peak.

2. The southeast wind often blows in summer and autumn along the coastal area of Zhejiang, and the wind direction is roughly the same as the direction of the tide, which promotes the tide. On the eighteenth day of the eighth month of the lunar calendar, the sun, the moon, and the earth are almost in a straight line, so the gravitational pull of the sea is the greatest on this day. Under the action of the moon's gravity, when the tide of the long drive reaches the vicinity of Yanguan in Haining, the tide head can reach more than 3 meters at a maximum of more than 3 meters, and the speed difference of 5-7 meters per second imitates the mighty upstream and advances upstream, which is like a bamboo, and it is magnificent.

Qiantang River tide form:

1. Qiantang River tide: cross tide.

2. Qiantang River tide: a first-line tide.

3. Qiantang River Tide: Turning Back Tide.