now we are on the way to three gorges dam, I will offer you some basic information about this giant project in advance. Speaking of three gorges dam, it is goes without saying that the three gorges dam is virtually subtlety associated with the number 3,why?I will give you the explanation .Because many of information about three gorges dam contains the number 3.Firstly, three gorges dam is located at sandouping town,38km away from Gezhouba dam which is situated at downstream.Secondly, it is esteemed that 2039 billion has been invested in construction. Thirdly,the project had experienced 17 years which divided into 3 phases. from 1993 to 1997 is the first period and this period is regarded as preparation period;from 1998 to 20__ is the second period and the last period indicates the year from 20__ to 20__.After the project completed,the normal water lever has gone up to 175 meters and the strong capacity of reservoir amount to 393billion cubic meter. Due to the water level rises, 430 thousand arable land has been submerge and 1.75 million immigrations have to search for new land to inhabit.
As i have mentioned,in order to construct three gorges dam, considerable number of immigrant quit their home and arable land also is deserved.Apart from this, the dam will brings other negative effect, for social aspect, on one hand, millions of people will be displaced, the government will take great pains to solve the problem that settle down the immigrant and assit them to find a new job.On the other hand,some culture heritage will disappear and under the water forever since the water lever rises,for natural aspect,building dam will alter the envirment,also does harm to precious animal such as Chinese sturgeon.
Every coin has two sides, it must be paid price for the negative influences of three gorges dam, but the national congress insist maintain the decision of building three gorges dam because the advantage of building three gorges dam outweighs the disadvantage of building three gorges dam. three gorges dam, not only bring us significant economic effect but also is beneficial for environment and society because it will play vital role in many fields, for instance, flood control,electricity navigation,tourism,south to north water diversion,irragation,development-oriented resettlement.especially, three gorges dam demonstrates remarkable contribution in 3 fields:
First field is power generation:the annual average power of three gorges dam accounts up to 84.7 TWH. campared to the coal-fired power station with equivalent electricity generation,hyroelectric power is renewable and exhasible.besides that hydroelectric power is clean energy.three gorges power plant will decrease emission of 100 million tons of CO2,2 million tons of SO2.
Second field is navigation,the annual one-way navigation capacity of Yangtze at the dam will be upgraded from 10 million tons to 50 million tons.
third field is flood control,the effective flood control capacity reaches 22.15 billion cubic metres.the rare catastrophe of flood will be withstood by the dam thus 15million people and 1.5million hectare of farmland will be relieved from flood threaten.
OK!we are approaching the scenic spot.today we will view three spots in total,at first steep(tangziling platform) we will get the chance to have a glimpse of the panorama of three gorges dam.second stop-the platform of 185 meters height,it offers us golden opportunity to witness the shiplift and zigui immgrant town.the third stop.memorial gardern supply vidio and photoes about three gorges dam that you may interested in.
Now we are arriving at first stop-tangziling,please bring you valuables and get off the bus
preliminarly,please follow me to three gorges project model house.In front of us,there is the layout of three gorges dam's model with the scale of 1:850.Look at main body of three gorges dam which has been painted white colour.The main body can be divided into 3 parts:spillway structures,powerhouse and building for navigation.The axial length of the dam is 2309.47meters and the height of the dam is 185meters,the spillway structures,consisting 22 overflow and 23deep overflow,is in the middle of the main body with the length of 483meters.The spillway world drain the sludge and coordinate the flood when needed.There are 32 turbine-generator units installed on the right and left hand of the spillway structure,each with installed capacity of 700mw.
the navigation building consis of double-line five stage shiplock and ship elevator.double-line five stage shiplock is 6442m in length and 300m in width,with two way and five stages.And it is diveded into 10 rooms,each room is 280 in length and 34m in width.the fall between upstream and downstream is 113m,suitable for 10 thousand tonnages ships and it will take almost 3 hour to pass through the lock.Therefore the ship elevator is designed for fast navigation for medium and small ship below 3000 tonnages.The elevator container is 120m in length and 18m in width and it only need 40 minutes for those ships to pass through the dam.the elevator near the platform 185 will be finished in 20__.
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