Why is the lake green Why is the lake green?

The reason is that the river water contains a large number of algae, which are mostly green, such as green algae, etc., and some river water is seriously polluted, resulting in eutrophication, and the number of algae has increased greatly, and it has become more and more green.

The combination of these two causes causes the river to be green!

In fact, if the river is very clear, the water should be very light blue. Or it's transparent

That's because eutrophication of water bodies leads to wild growth of plants such as cyanobacteria.

Nowadays, the sewage used daily often contains high phosphorus and other elements, which is the most needed nutrients for aquatic plants, especially algae plants, to make them multiply and grow quickly, because the color of the plants is green, so the water is green.

Copper sulfate is currently the most widely used algaecide, mostly used in water source water to kill algae. Lv Qizhong et al. from Zhengzhou Water Supply Company conducted an experimental study on the algae removal of the polluted surface raw water of the Yellow River by using copper sulfate and changing the pH value of the water, and the results showed that the effective dose of copper sulfate algagicide in the water body was5. The removal rate of algae in water can reach 70-90%.

Yin Qingqing et al. found that after using iron salts and aluminum salts as synergists in the enclosure, copper ions can control the growth of microcystis blooms. It has been reported that the removal rate of diatoms can reach 90% when copper sulfate is added to the horn in the production experiment. However, copper sulphate often does not destroy the odor-causing substances released by algae.

Excessive use of copper sulphate can lead to an increase in the concentration of copper salts in water, which is harmful to human health. Moreover, copper sulfate will destroy algal cells, so that most of the algal toxins in the cells will seep into the water body, increasing the background concentration of algal toxins in the water body.

In addition, when the algaecide is used in combination with the flocculant, it can accelerate the accumulation and precipitation of algae. In the open waters of Caohai outside Dianchi Lake, the chemical agent BC-655 has been used to carry out cyanobacteria removal experiments. The one-month water quality monitoring showed that the transparency of the experimental waters increased from the highest before the administration, and the EHLA decreased from the lowest before the administration, and the water quality of the experimental waters was generally better than that of the reference points in the non-dosed waters, and the bloom phenomenon was basically eliminated.

It is worth noting that chemical algaecides have a certain amount of *** and should be used cautiously according to the functional requirements of the water body.

Calcium hypochlorite produced by sodium process is a high-efficiency broad-spectrum sterilization drug with no residual toxicity and no secondary pollution, which can effectively kill green algae, cyanobacteria and diatoms that cause blooms. >available chlorine content) for 96 hours, the mortality rate of 4 species of algae can reach 92% to 100%. At 500 ppm, green algae, cyanobacteria and diatoms all died within a few minutes and 1 hour, respectively.

This is due to the wave-particle ditropy of light and the ability of water to absorb red wavelength light. Water absorbs the long-wave portion of the light (red) and the rest is the short-wave portion (green).

A certain beautiful color of the lake water, such as green, is due to the dissolution of certain minerals, and this color is only possible in a lake with high transparency. The color of the lake is also limited by the depth of the water, because it is only at a depth of more than 5 meters that the lake water is likely to absorb light from other color spectrums and reflect only blue light.

The formation of lakes can be divided into the following main types:

1. Due to the movement of the earth's crust, deep valleys appear on the ground, and lakes are formed after water accumulation, which is called tectonic lakes;

2. The erosion of glaciers causes depressions on the ground to appear and accumulate water into lakes, which are called glacial erosion lakes;

3. After the end of the glacier melts, the rocks and sediment carried by the glacier are piled up into a dam, and the lake formed by the accumulation of water above the dam is called a glacial lake;

4. The former bay has evolved into a lake;

5. When a volcano erupts, magma flows into the river, and after cooling and solidifying, it will form a dam that cuts off the river, and the water above the dam is stored into a lake, which is called a volcanic dammed lake;

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The color of seawater is mainly caused by the optical properties of seawater, that is, the absorption, reflection and scattering of the sun's rays by seawater. We know that sunlight is composed of red, orange, yellow, green, cyan, blue, and violet light, and the wavelength of the seven-color light varies from red light to violet light, and the wavelength gradually shortens from the length, among which the red light, orange light, and yellow light with long wavelength have strong penetrating ability and are most easily absorbed by water molecules.

Blue light and violet light with short wavelengths have weak penetrating ability, and are most easily scattered and reflected when encountering pure seawater. And because people's eyes are very insensitive to violet light, they often turn a blind eye and are more sensitive to blue light. As a result, the ocean we see takes on a blue or deep blue color.

If you beat a bucket of seawater and put it in a bowl, the seawater is colorless and transparent like ordinary water. In fact, the sea does not look all blue, but there are red, yellow, white, black, etc., which are colorful. Because in addition to the above factors, the color of seawater will also be affected by other factors such as suspended matter in seawater, the depth of seawater, and clouds.

For example, the Yellow Sea in China looks yellow-green, because the large amount of sediment carried by the Yellow River in ancient times "dyed yellow" the seawater. Although the Yellow River is now diverted to flow into the Bohai Sea, the northern part of the Yellow Sea is connected to it by the wide Bohai Strait, and it is also fed by the Huai River and other rivers, so the sea surface is still light yellow.

The ocean is wide, and the sunlight is reflected blue by the sea when it enters the sea surface, because the blue light is short-waved, which is easily reflected by the seawater, and the lake is a freshwater lake, which is small in area, and some of the growth is mostly green aquatic plants, plus the surroundings.

When daylight enters the lake, the speed slows down, Raman frequency conversion scattering occurs, and the light frequency shifts to high frequencies. The density of the water in the depths becomes larger, and the deeper it goes, the more it slows down, the more it shifts, and then through the Tyndall effect, what you see is green. The depth of the sea is more variable frequency, so it appears blue.

There are algae plants at the bottom of the lake, and after photosynthesis, when the sun shines, it looks green!

Now the sewage of daily water often contains high phosphorus and other elements, and this is the nutrients that aquatic plants, especially algae plants need most, can make them reproduce and grow rapidly, because the color of the plant is green, so the water is green, which generally appears in the river channel and lake water with low flow rate, and the place with a large drop can not grow regularly because the water flows too fast, so there is no phenomenon of water color turning green.

When sunlight hits the surface of the water, part of the light is reflected back and the other part is refracted into the water. The light that enters the water is absorbed by the water during its propagation. The absorption of light by water is related to the wavelength of the light, i.e., water has selective absorption.

Water absorbs light with longer wavelengths significantly, but not with shorter wavelengths. Red, orange and yellow light are all absorbed at different depths, and the green light is reflected back, making the lake appear green. As the depth deepens, the green light is also absorbed.

Blue and violet light, which have shorter wavelengths, scatter or reflect back on water molecules or other particles when they encounter them, so the sea looks blue.

In addition, due to the presence of algae, the river water will also take on a green color.

The scattering effect of water molecules on various wavelengths of light (referring to red, orange, yellow, green, cyan, blue, violet) in visible light (refers to the phenomenon that part of the light rays disperses and propagates from the original direction when the beam advances in the medium), and its scattering effect on short wavelengths (such as green, cyan, blue, etc.) is much stronger than that of light with long wavelengths (such as red and orange). In addition, the strength of the scattering effect is also related to the length of the optical path. When the water layer is shallow, almost all wavelengths of light in the visible light can be transmitted, and the scattering effect is not significant.

Therefore, water is colorless and transparent. When the water is deep, the water appears pale blue-green due to significant scattering. The more air dissolved in the water, the greener it is.

When the water is deeper, it will appear dark blue or even black. This is why the water is blue when it is deeper.

The green color of the lake is mainly caused by the optical properties of the water, i.e. the absorption, reflection and scattering of the sun's rays by the seawater. Due to the increase of suspended matter, the particles are larger, the absorption of green light is weak, and the scattering is stronger, so the lake is mostly light blue or green. Sunlight is composed of seven colors: red, orange, yellow, green, cyan, blue, and violet, and its wavelengths vary, ranging from red to violet, with wavelengths gradually getting shorter.

The lake area refers to the area within the boundaries of the lake. When the water level of the lake increases, the area of the lake increases, and when the water level decreases, the area of the lake decreases, and the two are a functional relationship. In order to calculate the volume of the lake, it is necessary to know the area enclosed by each depth contour, i.e., the area of the water surface at each depth at different isobaths.

The method of accurately measuring the area of the lake is usually the plotter method. If there are islands in the lake, the total area of the lake and the area of each island must be measured, and the difference between the two is the lake area. In square kilometers.

Because there is a large amount of brine in the lake, which contains various minerals, it will turn green when refracted by sunlight.

For example, the Zarhan Salt Lake, with the change of the sun's irradiation angle, the green lake water is sometimes blue, and the blue lake water is sometimes green, especially on a sunny day, the surrounding scenery, sky and white clouds are reflected in the lake, making the best place for photography. If there's one word to describe the beauty of the salt lake, it's the mirror of the sky.

Here, nature is no longer a magical topographer, and man, with his own powers, has inadvertently changed all this. This area is devoid of grass, perhaps because there are no birds, insects, fish, flowers and trees, and the Zarkhan Salt Lake reveals a lonely beauty all year round.

The salt lake is breathtakingly beautiful, but the words "nice weather" are very important. Some scenes must be at a specific moment to capture its most beautiful moments, and it is best to pick a sunny day when you come to the salt lake, although it is very sunny, but the best beauty of the shot.

Shanxi Yuncheng Salt Lake:

When there are many brine worms in salt lakes, the water will also appear red, and there are also rotifers, which will appear a purplish-red color if the rotifers are very dense. And then there is a kind of salt algae, salt algae with the increase of light and the increase of temperature, if the salinity is relatively low, it is basically green, if the salinity is high, the lead group, there is an orange to red transition.

Especially in the summer, the higher the temperature, the more the water in the salt lake evaporates, the more concentrated it becomes, and the darker the color of each pond. Yuncheng Salt Lake has a history of salt production and mining for thousands of years, with a total area of about 130 square meters.

In recent years, with the continuous enrichment of salt lake microbial species such as salt insects, the ecological circle of the salt lake is also changing, and more and more birds come here to feed, such as anti-billed sandpipers, mandarin ducks, and flamingos.