代写范文

留学资讯

写作技巧

论文代写专题

服务承诺

资金托管
原创保证
实力保障
24小时客服
使命必达

51Due提供Essay,Paper,Report,Assignment等学科作业的代写与辅导,同时涵盖Personal Statement,转学申请等留学文书代写。

51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标

私人订制你的未来职场 世界名企,高端行业岗位等 在新的起点上实现更高水平的发展

积累工作经验
多元化文化交流
专业实操技能
建立人际资源圈

The Use of Hydropower in China

2015-06-21 来源: 51due教员组 类别: Report范文

 这是一篇水力发电对于生态环境和社会贡献的调查报告,报告中指出水力发电的生产设备是非常便宜的,但是建立一个新的大坝却很贵,总体上,建设大坝的优点大于缺点,但利用水力发电也需要考虑周围的环境。建造水坝可以减少由于暴雨径流和侵蚀带来的危害。因此,它们必须强大到足以对抗地震或风暴等自然灾害的冲击。
 For thousands of years, hydropower has been widely used by hardworking people in various fields such as grinding grain, sawing lumber, transporting goods and so on. In the recent centuries, hydropower is more and more utilized to produce electricity. Specifically, water behind the dam flows down to the power house through a large pipe called the penstock. In the power house, kinds of electric generators are placed. When the water comes through the generators, its elevation becomes lower and its speed is reduced. Wheels in the generator are turned around by the water flow and the gravitational potential energy can be converted to electrical energy according to the electromagnetic induction.
  Take China as an example. In 2013, the total amount of the electrical energy needs of the whole society is 5322.3 billion kWh. This is a very big number indeed. The Three Gorges Dam’s installed capacity is 22 thousand MW, and it can produce 84.7 billion kWh for one year. Taking the statistics above, we can see if we want to provide various fractions of the needed energy by hydropower alone, we need about 63 dams, which all have the same size like the Three Gorges Dam. While this biggest dam created a reservoir of 625 km long, 2000 meters the most wide. Its total area can be 10 thousand square kilometers. 63 dams like this one would take almost two-thirds area of China. It is almost an impossible mission, with the statistics above being taken. Compared to the 2.4% in 2008, this estimate is accurate because the total consumption of China rose from 3433.4 billion kWh to 5322.3 billion kWh. Only for 5 years, the total amount has gone up so quickly, which told to us that it is difficult to meet the need by hydropower output alone.
  Although the hydroelectric plants do not pollute the environment, they do influence the environment around a lot. First of all, the dam will result in a large area being flooded. Tens of thousands of residents have to move from what they have lived for dozens of years to a strange place. Maybe it means starting a new life for the youth, but this would really be sadness for the old.  Still take the Three Gorges Dam as an example. About 1.2 million people are displaced and hundreds of cultural treasures are inundated because of the Three Gorges project. This is a big damage to Chinese treasures. What's more, over 10 thousand square kilometers being flooded has, been a disaster to local animals and plants. On one hand, the water behind the dam provides a large recreational area, which is good for promoting the economic development. On the other hand, local habitat is eliminated for animals and plants. Birds fly away to search for trees; predators run farther to look for food; fishes are trapped in the reservoir with no freedom. Last but not least, still water is likely to cause health problems. Pollutants produced by the large cities upstream being trapped in the reservoir is the major incentive to some debilitating diseases.
  As we all know, production of electricity from hydro facilities is very inexpensive, but building a new dam really costs a lot. To stop the flow, it needs a large number of cement, steels and human resources. It will be a tough mission before the dam is built down. Also, offering new shelters to the original inhabitants will be a huge task for the government. Great energy is needed during this process. Overall, the advantages of building a dam outweigh the disadvantages. However, there are still   some limitations associated to hydropower development. A large output hydropower output is achieved using either a high head or a low head with a large volume of water flow. This is the most important thing because if the water flow cannot even push forward the wheel, electricity will never be produced. Making use of hydropower should also take the environment around into consideration. We mustn’t achieve the economic benefits at the cost of the destruction of the ecological environment. Building dams can reduce runoff and erosion due to torrential rains. However, they must be strong enough to fight against the pressure of water, earthquake or storm. If not, it would be another disaster to people.
  To meet electrical energy needs in China, we need to build 63 biggest dams. Not to mention whether there are enough rivers or lakes to provide hydropower, building so many dams will make great impacts on the environment nearby. Changing environment easily may cause some unknown effects. Moreover, with the development of economy, the total amount of electrical energy we need is rising year by year, which means we have to build more and more dams. It is impossible to rely on hydroelectric generation alone. Although the USA has more lakes or rivers, he does need more electricity, too. So it is in the same situation as China. In one word, hydropower cannot be expected to meet electrical energy needs in the US and in China in the coming decades.  

Note: Some data in the text come from the source in the given book. 
 51Due网站原创范文除特殊说明外一切图文著作权归51Due所有;未经51Due官方授权谢绝任何用途转载或刊发于媒体。如发生侵犯著作权现象,51Due保留一切法律追诉权。 

上一篇:Hope, the Bacon of Life 下一篇:Summary of THE Death of JOHN A