外文翻譯--黃河下游小浪底水庫(kù)運(yùn)行10年期間的水庫(kù)淤積和庫(kù)區(qū)演變（英文）

1、9142012,24(6):914-924 DOI: 10.1016/S1001-6058(11)60319-3 RESERVOIR SEDIMENTATION AND TRANSFORMATION OF MORPHO- LOGY IN THE LOWER YELLOW RIVER DURING 10 YEAR’S INITIAL OPERATION OF THE XIAOLANGDI RESERVOIR*CHEN Jian-gu

2、o International Research and Training Center on Erosion and Sedimentation (IRTCRS), Beijing 100048, China, E-mail: chenjg@iwhr.com ZHOU Wen-hao, CHEN Qiang China Institute of Water Resources and Hydropower Research

3、 (IWHR), Beijing 100048, China (Received June 1, 2012, Revised July 14, 2012) Abstract: The Xiaolangdi Hydro-Project is one of the large projects on the main stem of the Middle Yellow River. It has been operated for mor

4、e than 10 years, since its impoundment in October, 1999. The reservoir has trapped 2.833×109 m3 of sediment, and caused the total erosion of 1.891×109 t in the Lower Yellow River from October, 1999 through Oct

5、ober, 2010. Not only the serious atrophied situation of the Lower Yellow River (LYR) has been resuscitating, but also many new phenomena of sediment transport and behaviors of channel re-establishing are coming into be

6、ing. They are illustrated and discussed in detail in this paper.Key words: reservoir sedimentation, density current, water-sediment regulation, artificial flood, channel siltation and erosion, erosion efficiency, river

7、configuration Introduction?The Lower Yellow River (LYR) carrying an eno- rmous amount of sediment is notorious for its serious deposition. It has a channel composed of fine bed materials characterized by easy erosion,

8、 easy siltation and high speed of morphology changes. It has suffered two remarkable channel erosion processes in recent 50 years. The first continuous erosion along the river happened during 1960-1964 when the Sanme

9、nxia Reservoir (SMX) was impounded[1]. After two re-con- struction operations of the reservoir, due to its serious deposition, the LYR returned to the state of severe siltation. Especially, under the deteriorated cli

10、mate conditions, the rapid increases of water supply, and other human activities, the incoming runoff of the * Project supported by the National Basic Research and Development Program of China (973 Program, Grant No.

11、 2011CB409901), the “12th Five-Year Plan” to Support Science and Technology Project (Grant No. 2012BAB02B01) and the Special Funds for Public Welfare Project (Grant No. 200901014). Biography: CHEN Jian-guo (1962-), Ma

12、le, Master, Professor river was dramatically reduced, the deposition in the main channel of the LYR was seriously increased, and the flood-conveying capacity was amazingly declined, thus the safety against flood along

13、 the LYR became a challenging issue. Faced with these severe situations, the Xiaolangdi Hydro-Project was forced to be con- structed. Since the impoundment of the reservoir, the channel of the entire LYR has suffered

14、 a second conti- nuous erosion, and then its vigor of flood conveyance, water supply, and eco-environment has been gradually recovered. Meanwhile, a series of new phenomena of reservoir sedimentation and channel re-e

15、stablishing of the LYR have come into being, such as the patterns of reservoir deposition, the formation and the transport of density current, the characteristics and the efficie- ncies of erosion in the LYR, the imp

16、acts of bed sedi- ment armouring, the relationship between reservoir deposition and river channel erosion, and the compe- nsation index of reservoir deposition. All of them have enriched the connotations of the scien

17、ce of fluvial pro- cesses for the rivers with high sediment concentrations after the founding of large hydro-projects. 916Table 1 Density current in the Xiaolangdi Reservoir (2001-2009) Incoming conditions Outflow con

18、ditions Date Cause of formation Runoff (109 m3) Sediment load (109 t) Runoff (109 m3) Sediment load (109 t)Ratio of sediment delivering (%) Aug. 19-sept. 5, 2001 Incoming flood 1.404 0.2000 0.251 0.01300 6.500 Ju

19、ne 23-July 4, 2002 Water-sediment regulation 1.098 0.1060 0.861 0.00400 3.440 July 5-July 9, 2002 Incoming flood 0.646 0.1710 1.147 0.01900 11.10 Aug. 1-Aug. 9, 2003 Water-sediment regulation 0.724 0.0840 0.2

20、07 0.00020 0.240 Aug. 25-Sept. 16, 2003 Water-sediment regulation 4.479 0.3410 1.726 0.07000 20.56 July 6-July 13, 2004 Water-sediment regulation 0.628 0.0435 1.727 0.00440 10.11 Aug. 22-Aug. 31, 2004 Incoming

21、 flood 1.027 0.1710 1.383 0.14200 83.16 June 27-June 2, 2005 Water-sediment regulation 0.403 0.0450 1.109 0.00200 4.410 July 5-July 10, 2005 Incoming flood 0.416 0.0700 0.786 0.03100 44.29 June 25-June 29,

22、2006 Water-sediment regulation 0.540 0.0230 1.228 0.00700 30.97 July 22-July 29, 2006 Incoming flood 0.799 0.0127 0.810 0.00480 37.93Aug. 1-Aug. 6, 2006 Incoming flood 0.467 0.0379 0.770 0.01530 40.41Aug. 31-Sept

23、. 7, 2006 Incoming flood 1.079 0.0554 0.761 0.01210 21.77June 26-July 2, 2007 Water-sediment regulation 0.949 0.0613 1.960 0.02340 38.14July 29-Aug. 8, 2007 Incoming flood 1.301 0.0834 1.974 0.04260 51.03Oct. 6-Oct

24、. 19, 2007 Incoming flood 1.959 0.0712 1.215 0June 27-July 3, 2008 Water-sediment regulation 0.686 0.0741 0.04580 61.08June 30-July 3, 2009 Water-sediment regulation 0.492 0.0545 0.00360 6.610Aug. 23-Aug. 27, 2009

25、 Incoming flood 0.0144 0.00003 0.200only 67.1%. (2) The pattern of deposition takes a shape of delta or cone, depending on the water level fluctua- tion, as shown in Fig.2, in which D is the distance, e Z is the el

26、evations. The deposited delta can be easily eroded and then the eroded coarse sediment is easily settled down in front of the dam[4].1.3 Density current The density current is generated by the density difference betwee

27、n the incoming muddy flow and the water free of sediment in the reservoir[5]. To make a full use of the density current to drive fine sediment out of the reservoir is one of the major procedures to mitigate the depos

28、ition of large reservoirs in China. During 2001-2009, there were nineteen density curre- nts generated in the Xiaolangdi Reservoir. 1.3.1 Origin of density current In the initial operation stage, two kinds of density

29、 currents, the natural density current and the artificial density current, were generated according to their ori- gins. (1) Natural density current. The natural density current is formed by the incoming flood. When

30、the muddy flood enters the head part of the backwater, a strong sorting process takes place. The coarse sedi- ment is settled down, and the fine sediment is carried and plunged into the clear water to form the densit