Detailed data of artificial lake

Artificial lake is generally a kind of lake excavated by people in a planned and purposeful way, which is produced in an unnatural environment, including landscape lakes and large reservoirs, such as Hongze Lake.

Chinese name: artificial lake mbth: artificial lake properties: a kind of lake example: Hongze Lake formation reason: dam impoundment and artificial excavation, also known as: reservoir introduction, formation reason, characteristics, influence, influence of artificial lake on microclimate, influence of artificial lake leakage on environment, existing problems, problems caused by circular filtration method, problems caused by extensive ecological method, ignoring the efficacy of micro-ecosystem, control methods, controlling mosquito and fly breeding, and supplementing landscape. In some places, artificial lakes exist in the form of landscapes and beautiful scenery. Generally, it is a kind of lake excavated by people in a planned and purposeful way, which is produced in an unnatural environment, that is, a reservoir that is often said in daily life. Reservoir is a hydraulic engineering building used for flood control and water storage and regulating water flow, which can be used for irrigation, power generation and fish farming. For example, in the Weiming Lake of Peking University, the reservoir is a hydraulic engineering building for flood interception, water storage and water flow regulation, which can be used for irrigation, power generation and fish farming. Very large reservoirs may also have a negative impact on local ecology. In some places, the artificial lake is a kind of architecture that exists for the purpose of landscape, such as the unnamed lake in Peking University. Some large artificial lakes, such as reservoirs, have a negative impact on local ecology. The reason is 1. At a certain section of the river, a dam was built for people's needs. 2. The dam stopped the incoming water and the flowing water was accumulated. 3. The accumulated water constitutes an artificial lake reservoir. Different from natural lakes, "artificial lakes" reflect the wisdom of human beings to use and transform nature. Reservoirs are developed with the appearance of human beings, which are used to solve floods and store water for later use. More than 4000 years ago, people in ancient Egypt and Mesopotamia began to build the world's first reservoir for flood control and irrigation. The people of China built the less-skin irrigation project in the 6th century BC, which is still playing a role today. According to statistics, the total storage capacity of reservoirs in the world is 5.5 trillion cubic meters, and the water surface area exceeds 350,000 square kilometers. At the beginning of the People's Republic of China, Guanting Reservoir, the first comprehensive project with flood control and water supply as the main utilization goal, was built. By the end of 1950, 86,852 reservoirs of various types had been built in China, with the total storage capacity accounting for 59% of that of natural lakes and nearly twice that of freshwater lakes. In addition to the famous ancient reservoirs-Shaopi and Jianhu, there is also a reservoir-shaped lake-Hongze Lake. A number of reservoirs have been built in the middle and upper reaches of major rivers in China, which not only have the function of storing water, but also have the function of generating electricity and shipping, such as Liujiaxia, Yanguo Gorge, Bapan Gorge, Qingtongxia, Sanmenxia and Longyang Gorge in the middle and upper reaches of the Yellow River. There are Danjiangkou, Zhexi, Wujiang and Ertan reservoirs in the middle and upper reaches of the Yangtze River. Xin 'anjiang Reservoir, Qiandao Lake in Chun 'an, Hangzhou, Zhejiang, is a famous tourist area in China and a national 5A scenic spot. Wang Ying Reservoir is Yangxin Xiandao Lake in Huangshi, Hubei Province, one of the three Qiandao Lake in the world and a national 4A-level scenic spot. There is also the world-famous Three Gorges Project. The dam is as high as 1.85 meters, with a total storage capacity of 20 billion cubic meters, the installed capacity of hydropower stations of 22.5 million kilowatts, and the annual power generation of 90 billion kwh, which is the highest in the world. Influence of artificial lake on microclimate During the technical exchange of artificial lake landscaping, the consulting experts of German Architectural Design Institute cautiously proposed to conduct a two-month environmental assessment-by fully collecting meteorological and geological data, investigating the influence of lake digging and water storage on the surrounding microclimate, and stressed that this assessment is the standard process of German industry. German consulting experts suggested that the impact of artificial lake landscaping in Hunnan New District of Shenyang, where water resources are relatively poor, on the microclimate of the project plot should not be underestimated. The artificial lake diffuses water vapor to the lakeside through water evaporation, which not only causes water loss, but also changes the air humidity of the lakeside, and its influence range is within 100 meters. The beautification of artificial lake will also reduce the ambient temperature around the lake. Studies have shown that its influence range is about 300 meters, and the closer it is to the center of the lake, the more obvious the microclimate effect is. Lakes gain heat after absorbing solar energy, and then lose heat through evaporation, scattering and convection between water surface and atmosphere. Lake water can reduce the daily average temperature of the surrounding environment by 1-2 degrees, and the ground temperature by 2-3 degrees, especially when the temperature exceeds 30 degrees Celsius. The bigger the lake, the deeper the lake, and the more obvious the adjustment effect on climate. On the one hand, artificial lake landscaping can reduce the temperature of the surrounding environment, increase air humidity, increase human comfort and improve the microclimate of the surrounding environment; On the other hand, in the process of utilizing and transforming nature, it will cause various negative feedback effects on the ecological environment, and reducing this effect is a problem that needs to be deeply considered in the design of artificial lakes. The impact of artificial lake leakage on the environment, the water loss of artificial lake, one is through evaporation, the other is through leakage, the former can not be avoided, the latter needs to be solved by formulating corresponding technical means. Some artificial lakes try to solve the problem of water leakage by laying impervious membranes, and the seepage control project in Yuanmingyuan is a famous example. After the implementation of this special rectification project, the disadvantages are prominent. The impervious membrane hinders the natural infiltration process of lake water, and rich nutrients appear in the sediments on the impervious membrane, which increases the risk of water quality deterioration. For the ecological environment, the artificial lake water system and the external natural water system (rainwater, natural rivers, etc.) are interconnected. ) and groundwater system are beneficial to ecological balance. An artificial lake water system without water exchange will lead to a sharp deterioration of the overall water environment, and even produce a large number of methane toxic gases, leading to the destruction of the ecosystem composed of aquatic microorganisms, animals and plants and coastal plants. At present, the design of artificial lake basically considers the connection between the upper part of water body and the external natural water system, but for the lake bottom of artificial lake, waterproof layers such as HDPE geomembrane, SBS modified asphalt waterproofing membrane, bentonite waterproof blanket and composite geomembrane are often used to completely block infiltration. Technically, some waterproof engineering methods are simply and mechanically adopted, which leads to problems such as eutrophication of lake water quality and silt accumulation at the bottom of lake. Therefore, artificial lakes in some real estate projects, contrary to the original design concept, have become the main pollution source of living environment. The natural leakage of artificial lakes is beneficial to ecological balance. The application of clay can greatly reduce natural leakage, but it can not completely block natural leakage, and the two-way regulation of surface water and groundwater is guaranteed. In addition, clay also has strong filtration and purification ability, and can adsorb inorganic phosphide in water. These two characteristics of clay make natural clay seepage control widely used in traditional buildings in China. For example, some wells in mountainous rural areas rely on clay layers to keep water. Clay seepage control technology is a modern upgraded version of the above natural clay seepage control technology. Simply put, it is to directly inject multi-chemical substances with soil-loving properties into deep soil, thus forming an effective vertical or horizontal anti-seepage barrier. This technology can artificially determine the soil leakage rate, control soil erosion more effectively, and is extremely beneficial to ecological balance. The artificial lake in Ziegeleipark Park in Heilbronn -B-ckingen, Germany, was reconstructed with the anti-hydrophobic system, which changed the rapid water loss caused by the natural leakage speed of the lake water much faster than the inflow speed of external streams. After the transformation, the lake can basically replenish and maintain the water balance through the inflow of streams, thus improving the ecological environment of artificial lakes and protecting biodiversity, which shows that the system has a positive impact on the ecological environment. There is a problem with the circulating filtration method. Circulating filtration is called forced water treatment in the process of water treatment, and the following problems usually occur: (1) Because the filtration system is a discontinuous equipment, it stopped for more than 10 days because it did not backwash in time, and the effluent was colored and blurred when it started. (2) Generally, the landscape water will be slightly eutrophic, and a certain amount of algae will appear in the water. If the filter is used for more than 8 months, there will be different degrees of ship blocking and short flow, which will reduce the treatment effect. (3) The filter involves a lot of machinery, electric power and other equipment, which needs professional maintenance and management. General property companies do not have this condition. In other words, the service life of such a system is less than 5 years. (4) Improper design of circulating purification quantity and circulating route leads to water treatment cost accounting for 1/4 or even exceeding 1/3 of property management cost. Problems caused by extensive ecological methods At present, landscape water is treated by ecological methods in many places, and the treatment method is to eat or absorb pollutants in water according to the natural habits of animals and plants. Thereby degrading substances harmful to the environment. Aquatic ecosystem is highly respected because of its low investment, low operating cost and closest to natural ecology. However, in the process of implementation, most designers and users focus on the macro-ecosystem, ignoring the micro-ecosystem, resulting in the phenomenon of excessive planting of aquatic plants and flooding of aquatic animals. This not only failed to achieve the expected therapeutic effect, but also caused many negative problems. The areas where aquatic plants are concentrated are often the areas where pests such as mosquitoes and flies are most concentrated. Because planting immortal plants affects the water flow, it is easy to form a dead water area. In addition, some dark and humid stagnant water areas have become the best places for mosquitoes and flies to breed because of the shade of plants. At present, due to seepage control and other problems, the bottom of most artificial lakes is very hard. There are many restrictions on the cultivation and growth of aquatic plants that need soil to grow. First of all, it is necessary to dig out an area at the hard bottom of the lake and fill it with planting soil in order to plant aquatic plants. Planting soil is generally difficult to control. On the one hand, plants need certain nutrients, on the other hand, nutrients in the soil will also have an impact on water bodies. This creates a contradiction. In addition, the quality of impervious layer in many waters is not up to standard, which leads to the rapid loss of artificial lake water, or the water is not replenished in time during management. Aquatic plants do not grow well or even die because of drying, which neither plays a role in purifying water quality nor destroys the ornamental effect. Ignoring the efficacy of microecosystem, the role of microecosystem is fully recognized by many designers. Microorganisms in water are the key link of water ecological balance. Through the decomposition and enrichment of microorganisms, pollutants are transformed into carbon dioxide, nitrogen and their own biomass, which are further utilized by the next level of organisms. In order to achieve the purpose of establishing micro-ecology. Many designs focus on the use of exotic biological resources or the establishment of micro-ecology through simple natural culture of water bodies. This practice not only increases the cost and difficulty of operation and management, but also fails to give full play to the water purification function of microecology. Treatment is naturally a very complicated system. To build a clear and natural artificial lake, we can't adopt a single method mechanically, but should consider it comprehensively. We should not only make full use of the advantages of the ecosystem, but also forcibly treat the water beyond its self-purification function. To control the breeding of mosquitoes and flies, it is necessary to ensure the flow of water and certain dissolved oxygen. The elimination of dead water area is mainly to set up push flow and aeration devices in the dead corner of artificial lake, especially in the area with dense aquatic plants, so as to turn dead water into living water. The data showed that when the water velocity reached 0.09 m/s and the dissolved oxygen was greater than 4.5mg/L, mosquito and fly larvae could not grow in the water, so there was no problem of mosquito and fly breeding. In addition, the planting area of aquatic plants should be larger than 1/4 and 1/3 of the water area to play its role in purifying water quality, and a certain proportion of fish and shellfish can also control the growth of mosquitoes. The cultivation and management of aquatic plants should be carried out in captivity and planting ponds. It must be submerged above 15ml, and it needs live water for exchange. Supplementary landscape water For landscape water that uses reclaimed water or water below Class IV (surface water standard) as supplementary water, it is suggested to increase compulsory treatment measures. In Europe, America and Japan, air flotation water treatment is generally adopted as compulsory measures. Air flotation is also widely used in algae-bearing water treatment. Only 50% of algae-bearing water can be removed by filter treatment, while 85% of algae and suspended matter can be completely removed by air flotation. In addition, the air flotation equipment can work intermittently, that is, it can be used immediately. At present, most landscape water bodies in self-purification state are closed and stagnant water. The water is easy to rot and stink. In addition, algae are more likely to grow wildly in still water. In order to purify water, it is necessary to create a stream of water in the water to turn stagnant water into living water, thus strengthening the self-purification ability of water. Oxygenating water supply and increasing dissolved oxygen in water can effectively eliminate the anoxic (anaerobic) state of water and avoid the occurrence of black odor. It is reported abroad that when the dissolved oxygen content is above 4.5mg/L, the water body is in a good aerobic environment. It can not only stimulate the micro-ecological function in water, but also control the breeding of mosquitoes and flies. Therefore, the reasonable setting of flow-making aeration device in artificial lake has obvious effect on water purification and mosquito and fly control Hongze Lake is the youngest of the five freshwater lakes in China. On the basis of some small lakes in the lower reaches of Huaihe River before Tang and Song Dynasties, it was a reservoir-type lake formed by the long-term southward migration of the Yellow River and the damming of water. Hongze Lake is shaped like an eagle spreading its wings and flying. The east coast is straight, and the rest of the coastline is tortuous. The lake area belongs to the transitional climate between the north subtropical zone and the warm temperate zone. In the plane distribution of the whole lake, there are obvious differences in the color and transparency of the lake. Generally, in the open area of the main estuary, the water body is green and yellow due to the influence of sediment and wind waves carried by the river.