Study On Impact Of Three Gorges Reservoir Operation On Variation Characteristics Of Nitrogen And Phosphorus In Waters Of Poyang Lake

In this paper, on the basis of the director of the Ministry of Science and Technology Fund《The research of Poyang lake wetland changes and climate seasonal water of response》, as a case study of Poyang Lake, for the operation of the Three Gorges project in recent years has been on the hydrological situation in the lake area, nitrogen and phosphorus nutrient characteristics, the impact of nutrient level and water environmental capacity study reveals the concentration variation of the variation in water levels caused by nitrogen and phosphorus in the Poyang Lake, the Three Gorges Reservoir; analysis of the impact of Three Gorges Project on the Poyang Lake; explore the nitrogen and phosphorusthe source of the distribution of the characteristics of flux variation and eutrophication evaluation; Analysis Lakes water environmental capacity in the Three Gorges Reservoir, and feasible measures for the sustainable development of the Poyang Lake Basin. Obtaines follwing conclusions:(1) On the basis of Three Gorges Project with the Yangtze river standing water level of impact prediction towards, through the establishment Hukou station and the Poyang Lake Lakes water level on behalf of station with the relationship, and study the impact of Three Gorges Project on the Poyang Lake, in flood water storage reduction at the end of the vent flow1000-7653m3/s impact on the Poyang Lake water level is very obvious, the biggest drop of the Lakes region, the water level is1～2m; vacated during the growth vent1000-6500m3/s in the flood season, the stations of water level rise an average of at0.2-0.3m the water level affect the pattern of showing north to south, the vacated hours before the flood season high in the low water level increasing drain caused by the large range of water level changes, the major surface of the basic coverage of lakes.(2) Statistical processing of the hydrological and water quality data of hydrological stations in Poyang Lake in2006to2010, through Lakes nutrient loading, nutrient flux model of revenue and expenditure estimates, the results show that since the operation of Three Gorges Reservoir, Lakes average concentration of nitrogen and phosphorus than in the buildthe water in front of the same period increased by1.7times, the maximum and minimum difference of nutrients in the lake flux of NH4+469t, NO3"6413t, PO43"1181t, which small differences in changes of the NH4+, NO3" and PCVthe difference is even larger than before impoundment; the application of empirical frequency curve random evaluation method of lake eutrophication status in the Three Gorges Reservoir to evaluate the frequency of the Poyang Lake water quality experience for38.67%, the evaluation level of3.11, ineutrophication status of the Poyang Lake pollution by nitrogen and phosphorus substances.(3) Water environmengtal capacity in Poyang Lake went up and went down obviously, and the decrease was more obvious than the increase, which revealed that the self-purification capacity of Poyang Lake was weakened under the scheduling of Three Gorges Reservoir. After the completion of the Three Gorges Project as reservoir operation, the waterenvironmental capacity of COD> TN and TP in Poyang Lake decreased by14.0%,15.4%and15.4%compared with those before operation, while they increased by3.64%,4.88%and4.88%when reservoir discharged water to prevent flood.