High tide in the river

Will the river rise and fall? I will! It may be clearer to say this:

Not only rivers, but also solids such as the earth's crust are called solid tides. Interested in cutting, come to Baidu Encyclopedia to see: baike.baidu/view/403542.

However, the water level of rivers changes in a day, not necessarily because of the "ebb and flow" like the sea, but because of other reasons. For example, the tide of Qiantang River belongs to the tide of seawater intrusion; For example, people upstairs say that there is a sluice upstream, and when the sluice is opened and closed, it causes "tides"; In addition, it is also related to agricultural water use, urban water use and rainfall, which is very complicated.

PS: Snow and ice melt?

How to calculate the time of river high tide? The fluctuation of sea water is a geographical phenomenon influenced by the gravity of the moon, so there are rules to follow, and it comes back every 15 days. The climax of the next day was 0.8 hours (48 minutes) later than that of the first day. The daily high tide time can be calculated according to the lunar calendar date. The specific calculation method is: according to the lunar calendar, if the number of days is less than 15, directly multiply the number by 0.8, and the obtained number is the most * * * time of the day; If the number of days is greater than 15. You must subtract the number of days from 15, and then multiply it by 0.8 to get the most * * * time of the day.

Calculation formula:

The first to fifteenth day of the lunar calendar: high tide time = date ×0.8.

Lunar calendar 16 to 30: high tide time = (date 15)×0.8 for example, the lunar calendar date is the sixth day, and 6×0.8=4.8, that is, the high tide time is 4: 48 in the morning and evening; If the lunar calendar date is eighteen, (18 15)×0 work 8=2.4, which means the high tide is at 2: 24 in the morning and afternoon. Generally, the interval between high tide and low tide is 6 hours, and the high tide and low tide are twice a day. * * * Generally speaking, the ebb tide can last for more than an hour.

Why do oceans and rivers have high tides and low tides? Tides rise and fall, so-called tides, are related to the moon. Generally speaking, the opposite side of the earth is attracted by the moon, so the sea will surge, while the side facing the moon will surge, because the moon has the least attraction to the center of the earth. This is the climax; The place perpendicular to the line between the moon and the center of the earth has the lowest water level, which is low tide. In addition, sunlight also has a certain influence on it. When the sun, the moon and the earth are approximately in a straight line, the force is the greatest, which usually occurs on the first or fifteenth day of the lunar calendar, and in some places it is called spring tide; When they are at right angles, the tidal fluctuation amplitude is the smallest, which is a small tide.

Calculation method:

Because the high tide and low tide of seawater are geographical phenomena influenced by the gravity of the moon, they can follow regularly, with a period of 65,438+05 days. Therefore, the next day's high tide is 0.8 hours (48 minutes) later than the previous day, and the daily high tide time can be calculated according to the lunar calendar date. The specific calculation method is as follows: according to the lunar calendar, if the number of days is less than 65,438+05, if the number of days is greater than 15. You must subtract the number of days from 15, and then multiply it by 0.8 to get the most * * * time of the day. At the same time, the interval between high tide and low tide is generally 6 hours, which means that high tide and low tide are twice a day. * * * Generally, the ebb tide can last for more than one hour, and the lowest ebb tide time is between two * * *.

Where does this river come from at high tide? At sea, the Yangtze River leads to the sea and the river leads to the Yangtze River.

Will the river rise and fall? I thought you had a sluice over there. The sluice will rise when it is boiled, but it will not rise when it is closed. If you don't believe me, go and see! Yes, it is influenced by the ocean, because rivers and oceans are connected. The river will not rise, will it? It will go up and down. There is a lot of water in the ocean, and there are obvious high tides and low tides. There are few rivers, and the ebb and flow are not obvious and invisible to the naked eye.

How can you tell the rising tide of the river in the rain? Author: Zheng Gu is from Lotus Leaf written by Zheng Gu in Tang Dynasty. The water splashed on the boat is pitiful green, and the hand is fragrant against the sill wind. (Wind swings: Wind shakes) Thank you, Huansha people, for staying in the rain. Appreciate Zheng Gu's Lotus Leaf, with beautiful artistic conception and picturesque sentences. The whole poem consists of a picture of a boat and a lotus pond, a picture of a lotus leaf fluttering in the wind, a picture of a lotus pond washing yarn and a picture of a Yuanyang playing lotus, which gives people endless beauty enjoyment. This little poem is about the lotus leaf. There is not a word "lotus" throughout, but every sentence does not leave the lotus leaf. The poem not only describes the color, fragrance and image of lotus leaves, but also describes the dynamic beauty of lotus leaves in the wind. When the boat went forward, the river splashed, and the uneven green lotus flowers rippled, leaning against the railing beside the boat, and the wind blew in waves, shaking a lotus leaf with a handle and emitting a faint fragrance. This poem not only describes people's love for lotus leaves from the side, but also expresses the subtle emotional changes in the heart of "Huansha people".

Who defines a year as two river basins according to the change of river tides? People compiled a solar calendar on the basis of observing the laws of the moon. There are no specific figures.

Where did the high tide water come from and where did the low tide water go? Tidal energy is ocean energy in the form of potential energy, which refers to the potential energy of water formed by the rise and fall of seawater. The tidal phenomenon of seawater fluctuation is caused by the movement and interaction between the earth and celestial bodies. In the ocean, the gravity of the moon makes the water level on the surface facing the moon and the surface facing the moon rise. Due to the earth's rotation, this water level rise propagates from east to west in the form of deep-sea waves, with a period of 12 hours and 25 minutes and an amplitude less than1m. The effect of solar gravity is similar, but the force is small, and its period is 12 hours. When the sun, the moon and the earth are in a straight line, spring tide); Happen; When they are at right angles, there will be a small tide. In addition to the semidiurnal tide and the monthly periodic tide, the rotation of the earth and the moon also produces many other periodic cycles, which range from a few days to several years. At the same time, the seawater on the surface is influenced by the centrifugal force of the earth's motion, and the resultant force of the moon's gravity and centrifugal force is the tidal force that causes seawater fluctuation. Besides the moon and the sun, other celestial bodies will also produce tidal force on the earth. Although the mass of the sun is much larger than that of the moon, the distance between the sun and the earth is also much larger than that between the moon and the earth, so its tidal force is less than half that of the moon. The tidal force of other celestial bodies can be ignored, because they are far away from the earth, or because their mass is too small. According to the theory of balanced tides, if the earth is completely covered by sea water with equal depth, the maximum tidal force produced by the moon can raise the sea level by 0.563m, and the tidal force of the sun is 0.246m.. The tidal range observed in Hawaii and other oceans is about 65,438+0 meters, which is close to the equilibrium tidal theory, but the actual tidal range near the ocean is much larger than the above calculated value. For example, the maximum tidal range of Hangzhou Bay in China is 8.93m, and that of Fendi Bay in North America and Canada is19.6m. At present, there is no exact explanation for this difference between reality and calculation. It is generally believed that when ocean tidal waves impact the continental shelf and coastline, the tidal range will increase through movements such as rising, gathering and resonance. The energy of tidal energy is directly proportional to tidal volume and tidal range. In other words, it is proportional to the square of tidal range and the area of reservoir. Compared with hydropower, the energy density of tidal energy is very low, which is equivalent to the level of micro-head power generation. The large tidal range in the world is about 13 ~ 15m, but generally speaking, the average tidal range above 3m has practical application value.

Tides vary from place to place, and different regions often have different tidal systems. They all get energy from deep-sea tidal waves, but they have their own unique characteristics. Although the tides are complex, they can be accurately predicted anywhere. Ocean tides get energy from the rotation of the earth and slow it down in the process of absorbing energy. However, this slowdown of the earth's rotation is almost imperceptible in people's life, and it will not be accelerated by the development and utilization of tidal energy. This energy is dissipated at the rate of 1.7TW through the friction between the shallow sea area and the coastal area. Only when there is a spring tide and the energy is concentrated, and the geographical conditions are suitable for the construction of tidal power stations, it is possible to extract energy from the tide. Although such places are not everywhere, countries all over the world have chosen quite a few places suitable for developing tidal energy. According to the latest estimate, the tidal energy with development potential is about 200 MW per year. h .

The theoretical reserve of tidal energy in the world is about 3 × 109kw. The coastline of China is tortuous, with a total length of about 1.8× 104 km, and there are more than 6,000 islands along the coast, forming a coastline of 1.4× 104 km. The long coastline contains abundant tidal energy resources. The theoretical reserves of tidal energy in China are 1. 1× 108kw, of which Zhejiang and Fujian provinces have the largest reserves, accounting for about 80.9% of the whole country, but these are theoretical estimates, and the actual available ones are far less than the above figures.