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River as an important link between the terrestrial and marine carbon pool carbon cycle behavior is to resolve an important part of the global carbon cycle. The river carbon transport characteristics reflect a variety of natural processes in the watershed and the impact of human activities on the river, not only record the history and current status of watershed erosion, also have a major impact on the offshore sedimentary processes and aquatic ecological environment and, therefore, a correct understanding of the river carbon transport for the study of the global carbon cycle is important. The Yangtze River is the third longest river in the world, its huge land-based sources of carbon input to the East China Sea ecosystem effects can not be ignored. Located in the upper reaches of the Yangtze River Three Gorges Project is by far the world's largest water control project, river damming water will change the river's original material field, the energy field, chemical field and biological field, may significantly affect the rivers biogenic elements biological Geochemical behavior. Therefore, a correct understanding of the the Yangtze carbon transport characteristics and the Three Gorges Project, its impact, for an accurate assessment of the Yangtze River into the sea flux of carbon and maintaining the ecosystem of the East China Sea and healthy has a very important significance. Based on April 2006 (Three Gorges Reservoir 135m-156m water storage period), April-May 2008 (Three Gorges Reservoir 156m ~~ 175m water storage period) the Yangtze mainstream sampling survey, combined with Wu et al (2007) in May 1997 (Three Gorges Dam interception before) and April 2003 (the Three Gorges Reservoir 135m before impoundment) along the survey results and other literature data, summed up the Yangtze mainstream dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and particulate organic along the distribution law and reason, the transport characteristics of the water phase of the Three Gorges Project on the Yangtze mainstream three forms of carbon into the sea flux of carbon (POC) in the downstream; based on the May 2006 - May 2007 Chase explore Yangtze the season organic carbon transport law stand sentinel observations twice a month, and estimates of the Odori Station May 2007, May 2006 and 2008 the three forms of carbon flux. Specific research results are as follows: (1) the top of a the Yangtze mainstream DIC concentration gradually reduce high values ??appear in the headwaters and the Jinsha river, all the way into the mainstream with the tributaries along DIC concentration lower, middle and lower reaches of Dongting Lake, Poyang Lake the different effects of the dilution effect of the DIC along distribution showed obvious three steps; Yangtze DIC concentration with the increased flow of negative logarithmic decline, reflecting the dilution effect of runoff; inflow size, and precipitation in the upper reaches of the Jinsha River and tributaries mainstream DIC concentration changes, is the main reason of the of each voyage DIC concentration differences. (2) Yangtze DOC by man-made pollution affected significantly, with no significant correlation between the flow, the lower concentration of Yibin more sparsely populated section of the river to the estuary in Chongqing along the Yangtze River industrial and agricultural waste discharge, living sewage, shipping impact and higher The rate of organic matter degradation DOC showed high values. POC and total suspended solids (TSM) along the distribution trend is broadly consistent with the POC% (POC / TSM] × 100%) increase in negative exponential relationship decline after impoundment reservoir area is very low with TSM TSM, POC and the high POC% with water due to sediment in the reservoir area, a large number of settlement are closely related. (3) Chase Station annual variation of DIC, DOC, POC concentration pronounced seasonal pattern. DIC highest values ??appear at the end of May, early June reservoir water runoff, the winter, the lowest value in more rainfall, flow summer; DOC concentration of high values ??appear in the fall, the carrier tape runoff, dilution and human impact. DOC and flow is more complicated; POC and TSM changes showed good consistency, summer flood season than in other seasons, reflecting basin mechanical erosion intensity variation with the seasons. (4) June 2006 - May 2007 Chase Station DIC, DOC, POC fluxes were 12.9 × 106tC, 1.17 × 106tC, 1.88 × 106tC, 2008 Odori Station DIC, DOC and POC flux 15.0- 16.6 × 106tC ,1.31-1 .62 × 106tC and 4.1-6.9 × 106tC, the organic carbon transport to particulate. (5) 2003, the Three Gorges Reservoir 135m water and water role of the upstream high DIC runoff interception 156m in 2006, has an important impact into the sea runoff and DIC flux reduction of water a year Odori Station. The the reservoir storing clear muddy \period, the dam on the the high DIC upstream water intercept the downstream section of the river DIC concentration and flux compared with low natural state. After the impoundment of the dam water level rises, the flow slowed caused upstream sediment in the reservoir area, a large number of settlement, on the one hand, lead to the reservoir surface the TSM, POC concentration decreased water transparency increased surface suspended solids particle size decreases, and phytoplankton authigenic POC increased so that the reservoir area POC% compared with water increased rapidly; On the other hand, the reduction of the amount of the discharged sediment makes the middle and lower reaches of the surface TSM decreased, decreasing particle size of the particulate matter, POC% significantly higher than before impoundment. The reservoir sediment interception led to the decrease in the amount of sediment into the sea, led to the sharp drop in carrier POC flux is also reduced. Term observations from four cruises in 1997-2008, the DOC concentration in the reservoir area and did not show significant increasing trend.
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