TGP service: flood flow reduction 40% Three Gorges flood-IT information

In 1998, the Yangtze River, the nenjiang River and songhuajiang River Valley flood, flooding was still fresh. This year, is also a strong El Nino events the following year, into early flood, heavy rain, widespread flooding nationwide. At 14 o'clock, hydrology Bureau of water resources issued a document saying, the Taihu lake water level fluctuations, super police 1.04 m, Super-0.19 m, around 20 Ultra. Many people doubt this summer after rufu, flood will be as it was in 1998 struck again? Wuhan was "flooded", is associated with TGP's flood releasing? Weather forecast than in 1998 whether there be progress? On the above issues, the China Meteorological Administration, Ministry of water resources, authority and expert answers.

Weather comparison

Climatic background similar to the 1998

This year has not yet formed a basin-wide flood

Reporters learned from the National Meteorological Centre, climate background before entering the flood season this year similar to 1998. 1998 and 2016 is ultra strong El Nino events the following year. Effect of precipitation in flood season in China this year was mainly from the Pacific and India oceans warm air and cold air from the North.

National Climate Center climate monitoring and research-level senior engineer, Chief expert Zhou bing said earlier that El Nino events the summer of the following year, due to the equatorial Pacific sea surface temperature is too high in the Middle East, leading to Western Pacific subtropical high enhancement, while East Asian summer monsoon rain belt South of the junction of cold and warm air, resulting in the middle and lower reaches of the Yangtze River and rainy, and less rainfall, drought along the Yellow River in North China.

Notable at the moment is, atmospheric response to strong El Nino event will continue, the response in the main flood season, especially from June to July rains further amplification.

Meanwhile, Zhou Bing emphasized that today the peak intensity of El Ni?o events, intensity, duration, monthly mean sea surface temperatures of more than 2 degrees centigrade since 1951, the strongest, or the longest, which not only further increases the likelihood of extreme weather and climate events, also increased the difficulty of climate prediction.

China Meteorological Administration Zheng guoguang said at a news conference several days ago, and this year into the longest duration since the flood season rainfall than the same period in 1998. June 12, 1998 to 27th of a rainstorm weather process lasted 16 days, long a storm so far this year only lasts for 7 days. From now, the degree of summer floods in China this year is weaker in 1998.

China Institute of water conservancy and hydropower and flood control experts in the field, the National Committee for disaster reduction expert Committee member Cheng Xiaotao said, so far, this year's flood and 1998 are very different. 1998 belongs to the whole basin flooding, widespread heavy rain continued, and this storm is one after another, but relatively sparse, not as concentrated as 1998, it has yet to form a basin-wide flood.

Ability to forecast

"3 day" to "the next 20 days"

Early 90 's of the last century, forecasting emerging. When the 1998 floods, China's weather forecasting technology is in the transition from traditional to modern human-computer interaction.

According to the Central Meteorological Observatory chief forecaster He Lifu introduction, forecasters were able to get 250-kilometre resolution from the European Centre for medium-range forecasts numerical model, Japan numerical model of precipitation from in the form of facsimile image, and at that time the best T106, poor, aging, less forecast elements are not all.

Now the situation is very different, the forecaster would sit in front of the computer, access to real-time data, all kinds of advanced forecast numerical models at home and abroad, through real-time communication system and forecast video TV consultation at all levels.

"Draw a circle 100 mm of rain before, takes a lot of courage, in particular how to depend on numerical weather prediction. "Today, rainfall forecasting more refined, objective forecast technique to improve the precipitation forecast ability, Ensemble Prediction System enhances the predictability of extreme weather in the past" circle "model is changed, attunement quantitative precipitation forecasting techniques to forecast rainfall within a 5 km radius.

"In 1998, the city where people usually know the next 3 days forecast. Now, the 3-day forecast of the city continue to be subdivided, and people can get around 3 hours, 6 hours, 12 hours, 24 hours of rainfall information. "The Central Meteorological Station forecast short-term Guerlain introduced section breaks. Issued by the Central Meteorological Observatory in 2015, the daily "forecasts within the next 20 days, 10 days level forecast and the precipitation in the area."

He Lifu said that flood control and drought relief, is forecast to be the most important decision a decision support. Fried dam flood discharge, or the baodi, in 1998, still today, are a great test.

Hot FAQ

Peak reduction of the three gorges of the Yangtze River flood control pressure in?

Avoid the upper and the middle and lower reaches of the flood overlay

Run according to the three gorges construction and operation of Administration Hub Wang Hai, Deputy Director of the Department to introduce, by the upper reaches of the Yangtze River and the Wujiang river water and storm floods combined effect of the three gorges, as of June 30, the three Gorges reservoir inflow rose rapidly. July 1, at 14 o'clock, the three Gorges reservoir in 2016 ", 1th of Yangtze River" flood, this year's first since the flood season to reach peak of 50,000 cubic meters per second.

According to the overall arrangements for the flood control of the Yangtze River, after a reservoir regulation and storage, the flood, to 31,000 cubic meters per second of flow discharged at a constant speed, maximum peak 19,000 cubic meters per second, almost 40% of the flood being cut. In addition, 21 reservoirs in the upper reaches of three gorges project played an effective role, the Yangtze River flood control to control it, further burdens the middle and lower reaches of.

"The peak to avoid flooding in the upper reaches of the Yangtze River and the middle and lower reaches of the flood overlay, reduce the pressure of the middle and lower reaches of the Yangtze River flood control. "Wang said without the impoundment of three Gorges reservoir, this round of heavy rains, Wuhan, or face greater flood pressure.

Super Typhoon "nepartak" landing will have implications on the subtropical high and water vapor channels in recent days, rain in middle reaches of the Yangtze River into the intermission. "Nepartak" after landing, leading to heavy rain in the western part of Sichuan basin, impact on the upper reaches of the Yangtze River, the three gorges will increase storage capacity.

"While there are some risks, but the main stream of the Yangtze River flood control and now in control of the situation. "The Ministry of Defense Office said Chen Guiya, Deputy Director of the Yangtze River, past no libraries are available for flood control of the Yangtze River, after 1998, the dyke reinforcement around the stem of thickening, formation of 34,000 km Dyke system, improved quality of embankments.

Cheng Xiaotao pointed out that, when the construction of the three gorges project's first task is to flood control, to prevent the Jingjiang Dyke collapse levees. The Jingjiang levees upstream in Wuhan, zhicheng downstream, about 8 million more than the life and property security of the masses. Therefore, there is a saying in the past, called "Yangtze insurance in the Jingjiang River". Therefore, the three Gorges Dam, a flood control feature, there is no alternative to other measures.

Wuhan was "flooded" with TGP's flood releasing relevant?

Continuous heavy rains caused by the three gorges, Wuhan no worse

According to the Meteorological Department data, from June 30 to July 6, 560 mm of rainfall in Wuhan, the equivalent of a week for half a year of rain the next.

Ding Liuqian, Director of flood control and drought prevention and disaster reduction of water resources Research Center, said some urban waterlogging, and part of the small river exceeded flood pressure. Integrated urban drainage of storm water drainage capacity low rain "see the sea" phenomenon is still going on. Although the proposed new standards on construction of urban drainage in recent years, but it will take years of sustained development. In addition, modern urban drainage of storm water drainage system, not only to improve sewer and drainage and River drainage capacity, should also strengthen the lowland Lakes, underground water storage and infiltration measures such as planning and construction, a difficult task.

Cheng Xiaotao, Wuhan was "flooded city" Three Gorges by no means gets in the way. Wuhan was "flooded" is because of the continuing heavy rain does not come from the upper reaches of the flood, reduced discharge of the three gorges, creating conditions to speed up the drainage. Current flood is the Yangtze River local rainfall, not within the control of the three gorges. If there is no project in the upper reaches of the third peak, face greater flood pressure downstream, chenglingji of Yangtze River water levels are likely to exceed guaranteed levels.

Industry experts say that, the medium and small rivers flood control capacity is not high, some reservoir and dam is also weak. Wide in China small and medium river flow, flood control standard is low, generally 10-20 year, some not. Add dike quality is not high, excess flood standard, prone to danger, or even burst events. In addition, inappropriate human activity will aggravate flooding, such as excessive space diverted rivers and lakes, needs further strengthening and speeding up, strict legislation, binding human wrongdoing.

In addition, mountain torrents disaster prevention difficult, causing the flood's death toll above 70%. National Defense Office spokesman Zhang Jiatuan said, focused on prevention and control of mountain flood disaster in China, about 970,000 square kilometers, involving 130 million people, mountain rains flood the last short, fast, defense is not easy. Current flood control and entered a critical stage that we must take, based on the anti-flood, grab the big risks, from the most adverse situations prepared, in order to minimize flood damage and protect people's life and property safety.

7 August, such as reproduction of the Yangtze River floods do?

The role played by the three Gorges dam will be more significant

New problems for the next flood will occur, said Cheng Xiaotao, antecedent precipitation have to soil saturation from surface reservoirs, followed by rainfall runoff in 90% or 100%, it is easy to form flooding, followed by rains are more dangerous. Meanwhile, 7 August rainfall areas to move upstream, there is a high probability of big floods in the upper reaches.

"Appear not to judge how much flood now can only be made against flood preparations. But thanks to the three gorges project, if there is flooding in the upper reaches, compared with 1998, flood prevention in downstream pressure will ease. "Cheng Xiaotao said.

"According to the law in the past, upper reaches of the Yangtze River flood situation than earlier. "Analysis of Wang Hai, from late July to early August, or face more severe situation of flood control of the Yangtze River, to the late, the role played by the three Gorges dam will be more significant.

When the flood comes, often hears "a century", "ten year" argument. Experts say that met no more than "a century" (peak flow 83700 cubic metres per second) flood, zhicheng maximum flow can be controlled in three gorges project not more than 56,700 cubic meters per second, do not enable flood diversion project, Jingjiang River to safety in flood.

If you are experiencing "thousand year" flood, after the three Gorges reservoir, by zhicheng of the appropriate flow rate no more than 80,000 cubic meters per second, with the application of Jingjiang river flood diversion project and other flood diversion measures, so that you can avoid Jingjiang River North and South sides of the Dongting Lake plain and jianghan plain devastating disasters that may occur.

Wang Hai-an example, pop into the "ten-year" flood, flood of 66,600 cubic meters per second in Yichang, relying on the Jingjiang levees can defend. After the three gorges project, "a century" flood peak of of 83700 per second cubic metres by impoundment of three Gorges reservoir, corresponding to the control range can be reduced, reduced to "ten year" level, without diversion. Meet "thousand year" flood, Yichang 98800 per second cubic metres of peak flow, you can enable the Jingjiang diversion area, after impoundment of three Gorges reservoir, but does not exceed the guaranteed level, avoiding of Jingjiang River Dyke burst.

Flood force

The people's Liberation Army has 19 Professional emergency flood force

Into the flood since a 24 regional rainstorm process in the South, 321 Super police force more than floods in river.

"Overall current river flood control, tributary of the Yangtze River embankment all kinds of danger have been effectively controlled. "Zhang Jia recently made it clear that.

According to Ding Liuqian introduction, flood control is a complex system. Flood control, you can use the "reservoirs, dikes, waterways, flood diversion" projects such as "weapons", "barriers, separation, storage, time-delay, anti-" five tricks. Flood, first play levee, river flood when flood Super safety relief amount and use reservoir impoundment flood; if you're still not able to control floods, enable flood diversion area at the right time. "The current urban waterlogging highlight, some heavy pressure from smaller rivers, rivers did not appear big. ”

It is understood that China's flood control and drought relief head of administrative accountability. State was always the main decision-making bodies, seven established basin agencies against total, do, responsible for river basin flood management; the provinces, cities and counties have set up flood control and drought relief headquarters. From the central to the local, responsibility step by step clear. "In accordance with the flood control plans at all levels, when to start the appropriate level of response, scheduling, how the defense, are regulated and orderly response. "Ding Liuqian said.

In emergency, "hat, to warfare" of the people's Liberation Army is the backbone of. At present, the national flood control teams of 470,000 people, PLA 19 flood-professional emergency forces, armed police hydropower force 3 9 Corps detachment, 1389 flood and mobile rescue teams in place. Since June 30, the middle and lower reaches of the Yangtze River today put in flood human 2.87 million passengers.

三峡工程立功：削减近四成洪水流量 - 三峡,洪水 - IT资讯

1998年，长江、嫩江、松花江等流域出现特大洪水，洪涝灾害之重，令人记忆犹新。今年，同样是超强厄尔尼诺事件次年，入汛早、暴雨多，全国发生大面积洪涝灾害。昨日14时，水利部水文局又发文称，太湖水位持续波动，超警1.04米，超保0.19米，周边20站超保。不少民众由此疑惑，今夏入伏后，特大洪水是否还会像1998年一样再次来袭？武汉被“淹城”，又是否与三峡泄洪有关？气象预警比起1998年是否有进步？就以上问题，中国气象局、水利部等权威部门及相关专家做出了解答。

气象对比

气候背景与1998年相似

今年尚未形成流域性大洪水

记者从国家气象中心了解到，今年入汛前的气候背景与1998年相似。1998年和2016年都是超强厄尔尼诺事件的次年。今年影响我国汛期降雨的主要是来自太平洋和印度洋的暖湿气流以及来自北方的冷空气。

国家气候中心气候监测室正研级高级工程师、首席专家周兵此前表示，在厄尔尼诺事件次年的夏季，由于赤道中东太平洋海温偏高，导致西太平洋副高增强、同时东亚夏季冷暖空气交汇产生的季风雨带偏南，从而导致长江中下游多雨，华北和黄河一带少雨、易干旱。

目前值得注意的是，大气对超强厄尔尼诺事件的响应还会持续，这种响应在主汛期，尤其是6月至7月梅雨季进一步显现放大。

同时，周兵强调，此次厄尔尼诺事件的峰值强度、累计强度、持续时间、月平均海表温度高于2℃的时间均为1951年以来最强或最长，这不仅进一步增加极端天气气候事件出现的可能性，还加大了气候预测的难度。

中国气象局局长郑国光在日前的新闻发布会上也表示，今年入汛以来暴雨过程的最长持续时间不如1998年同期。1998年6月12日至27日的一场暴雨天气过程持续了16天，而今年到目前为止最长一场暴雨持续时间仅为7天。从目前来看，今年我国夏季洪涝灾害程度要弱于1998年。

中国水利水电科学研究院防洪领域专家、国家减灾委专家委员会委员程晓陶也表示，从目前来看，今年的洪水与1998年有很大差别。1998年属于全流域洪水，大范围暴雨不停地下，而今年暴雨是一场接一场，但相对分散，不像1998年那样集中，所以至今尚未形成流域性大洪水。

预报能力

从“未来3天”至“未来20天”

上世纪90年代初，数值预报刚刚兴起。1998年发大水时，我国天气预报技术正处于由传统经验型向现代人机交互型的过渡期。

据中央气象台首席预报员何立富介绍，当时预报员能够收到欧洲中期数值预报中心提供的250公里分辨率的形势场数值模式，日本以传真图形式发来的降水数值模式，以及当时我国最好的T106模式，产品少、时效差、预报要素也不全。

如今的情况则大为不同，预报员会坐在电脑前，查阅实时数据资料、国内外各类先进天气预报数值模式，通过实时通信系统和各级预报员视频会商。

“以前画出一个100毫米的大暴雨圈，都需要极大勇气，具体会下多大，需要借助数值预报。”如今，降雨预报更精细化，客观预报技术提高了降水预报能力，集合预报系统增强了极端天气的可预报性，以往“画圈”的预报模式被改变，格点化定量降水预报技术能够预报5公里范围内的降水。

“1998年，人们通常只能知道所在城市未来3天的预报。而今，城市3天预报被不断细分，人们可以获取周边3小时、6小时、12小时、24小时的降雨信息。”中央气象台天气预报室短期科科长符娇兰介绍。中央气象台在2015年实现了逐日发布“未来20天内的过程预报，10天内降水的落区及量级预报”。

何立富指出，在防汛抗旱中，最为重要的是预报必须成为决策拍板的支撑。泄洪、炸坝，还是保堤，无论在1998年，还是在今天，都是巨大考验。

热点问答

三峡削峰是否减轻了长江中下游防洪压力？

避免了上游与中下游的洪水叠加

据三峡枢纽建设运行管理局枢纽运行部副主任王海介绍，受长江上游干流、乌江来水及三峡区间暴雨洪水共同影响，6月30日起，三峡水库入库流量迅速上涨。7月1日14时，三峡水库迎来2016年“长江1号”洪峰，这也是今年入汛以来首个达到每秒5万立方米的洪峰。

根据长江防总的统筹安排，洪水经三峡水库调度调蓄后，以3.1万立方米每秒的流量匀速下泄，最大削峰每秒1.9万立方米，近四成的洪水流量被削减。此外，三峡工程上游21座水库起到有效保障作用，长江防总对其进行统一调度，中下游得以进一步减负。

“此次削峰，避免了长江上游的洪水与中下游洪水叠加，减轻了长江中下游的防洪压力。”王海称，如果没有三峡水库的拦蓄，本轮强降雨，武汉或将面临更大的抗洪压力。

超强台风“尼伯特”的登陆，将对最近一段时间的副高及水汽通道带来影响，长江中游降雨将进入间歇期。“尼伯特”登陆后，导致四川盆地西部有大到暴雨，对长江上游带来影响，三峡入库量将增大。

“尽管存在一定的风险，但长江干流防汛形势目前处于可控状态。”水利部长江委防办副主任陈桂亚表示，过去长江防洪无库可用，1998年以后，各地对干流堤防加固加厚，形成3.4万公里的堤防体系，堤防质量明显提高。

程晓陶指出，当年建设三峡工程的首要任务是为防洪、为防止荆江大堤垮堤。荆江大堤位于武汉上游、枝城下游，关系到800万以上群众的生命财产安全。所以，过去有一种说法，叫“万里长江险在荆江”。因此，三峡大坝这一防洪功能，没有任何其他措施能够替代。

武汉被“淹城”与三峡泄洪有关？

武汉持续强降雨所致三峡没帮倒忙

据气象部门数据，从6月30日到7月6日，武汉降雨达到560毫米，相当于一周下了半年的雨。

水利部防洪抗旱减灾技术研究中心主任丁留谦称，目前一些城市内涝突出，部分中小河流遇超标洪水压力大。城市排水防涝的综合能力偏低，下雨“看海”现象还在上演。尽管近年对城市排涝的建设提出新标准，但这需要多年持续建设。另外，现代化的城市排水防涝体系，不仅要提高城市管网排水和城市河道的排涝能力，还应加强洼地湖泊、地下蓄水和下渗等措施的规划建设，任务很艰巨。

程晓陶表示，武汉被“淹城”，三峡绝没有帮倒忙。武汉被“淹城”是因为本身的持续强降雨，并非来自上游的洪水，三峡减少下泄流量，为加快排水创造了条件。目前洪涝主要是长江中下游本地降雨造成，不在三峡的控制范围内。如果没有三峡工程在上游的拦蓄削峰，下游地区面临的防洪压力更大，长江干流城陵矶水位极有可能超过保证水位。

业内专家指出，我国中小河流防洪能力不高，一些小型水库、塘坝也是薄弱环节。我国中小河流量多面广，防洪标准低，一般为10—20年一遇，有的还达不到。加上堤防质量不高，遇超标准洪水，易发生险情甚至溃决事件。另外，不当的人类活动也会加重洪涝灾害，比如过度挤占河湖空间，需要进一步加强、加快、从严立法，约束人类不当行为。

此外，山洪灾害防御难度大，其造成的死亡人数占到洪灾70%以上。国家防办新闻发言人张家团说，我国山洪灾害重点防治区约97万平方公里，涉及1.3亿人，山区强降雨，历时短、成灾快，防御不易。当前防汛进入关键阶段，不可掉以轻心，立足防大汛、抢大险，从最不利情况准备，才能最大程度减少洪涝灾害损失，保护人民群众生命财产安全。

长江7、8月如再现大洪水怎么办？

三峡大坝发挥的作用将更显著

针对下一步汛情是否会出现新的问题，程晓陶表示，前期降雨已经让地表水塘土壤都饱和了，后面的降雨几乎90%甚至100%都会产流，易于形成洪涝，后面再降雨的危害性更大。同时，7、8月降雨区要向上游移动，上游出现大洪水的可能性很大。

“具体出现多大的洪水现在无法判断，只能说要做好迎战大洪水的准备。但由于有了三峡，如果出现上游大洪水，相比于1998年，下游的防汛压力会减轻。”程晓陶说。

“根据以往规律，长江中下游汛情一般来得比上游早。”王海分析，到7月中下旬至8月上旬，长江或面临更严峻防汛形势，到后期，三峡大坝发挥的作用将更显著。

每当洪水来临，常听到“百年一遇”“十年一遇”等说法。专家称，遇到不大于“百年一遇”(洪峰流量超过8.37万立方米每秒)的洪水，三峡工程可控制枝城站最大流量不超过每秒5.67万立方米，不启用分洪工程，荆江河段可安全行洪。

如果遇到“千年一遇”的洪水，经三峡水库调蓄，通过枝城的相应流量不超过每秒8万立方米，配合荆江分洪工程和其他分蓄洪措施的运用，从而可避免荆江南北两岸的洞庭湖平原和江汉平原地区可能发生的毁灭性灾难。

王海举了个例子，通俗来讲，碰上“十年一遇”的洪水，宜昌的洪峰是每秒6.66万立方米，依靠荆江大堤可以防御。有了三峡工程后，“百年一遇”的洪水洪峰是每秒8.37万立方米，通过三峡水库拦蓄，可以减小到堤防可控的范围内，减小到“十年一遇”的水平，可不用分洪。遇上“千年一遇”的洪水，宜昌洪峰流量为每秒9.88万立方米，则通过启用荆江分洪区，三峡水库拦蓄后，可不超过保证水位，避免荆江河段干堤的溃决。

防洪力量

解放军已有19支抗洪专业应急部队

入汛以来，南方出现24次区域性暴雨过程，全国321条河流发生超警以上洪水。

“当前大江大河汛情总体可控，长江干支流堤防的各类险情均得到有效控制。”张家团近日明确表示。

另据丁留谦介绍，防洪调度是一项复杂的系统工程。防御洪水，可以使用“水库、堤防、河道、分蓄洪区”等工程“武器”，使出“拦、分、蓄、滞、排”五种招数。发生洪水，首先发挥堤防作用，利用河道泄洪；当洪水超安全泄量时，再运用水库拦蓄洪水；如果仍不能够控制洪水，再适时启用分蓄洪区。“当前一些城市内涝突出，部分中小河流压力大，但大江大河没出现大问题。”

据了解，我国防汛抗旱实行行政首长责任制。国家防总是主要指挥决策机构，七大流域机构设立防总、防办，负责流域内防洪管理；各省、市、县均设立防汛抗旱指挥部。从中央到地方，责任逐级明晰。“按照各级防汛预案，什么时候启动相应级别响应，如何调度，怎么防御，都有章可循、有序应对。”丁留谦说。

在应急抢险中，“召之即来、来之能战”的人民子弟兵是骨干力量。目前，全国防汛抢险队伍47万人，其中解放军19支抗洪抢险专业应急部队，武警水电部队3个总队9个支队，1389支地方防汛机动抢险队。6月30日以来，长江中下游累计投入抗洪抢险人力287万人次。