Yangtze River Delta With The Fine Cope With The Effects Of The Numerical Simulation Of Atmospheric Sulfur Nitrogen Settlement Estimation And The Ecosystem

The atmospheric deposition has great influence on the terrestrial and aquatic ecosystem. Since China has a large comsumption of coal and petroleum energy, the deposition of nitrogen and sulfur compounds deserves attention. Studying the amount and space-time variation of atmospheric deposition on various ecosystem could be a useful tool to estimate the maximum loads, so as to instruct the industry distribution. In this study, the deposition on different ecosystems (urban, forest, grass, wetland, farmland, freshwater and sea) in the Yangtze Delta Region has been studied by field measurements and numerical modeling, in which the meteorological conditions and pollutants concentrations have been simulated by the mesoscale meteorological model WRF and chemical transport model CMAQ. The major conclusions are:Through the modification of land-use data in meterological model, the modeled results have been improved for meterological parameters, in which surface temperature and wind speed are the two with the most improvements. The improved description of meterological conditions also results in better description of pollutants concentrations. These set up a good foundation for the modeling of atmospheric depostition. The modeling difference of wind speed from original land-use data and modified data ranges from-2～1.5m/s, and the difference of surface temperature ranges from-4～4℃. The model ing difference of NOx, HNO3、NH3、NO3-、NH4+、 SO42-and SO2concentrations ranges from-1000～1000,-15-40,-20-20,-80～80,-20～20,-10～10,-500～500n mol/m3.Atmospheric aerosol at the Qingcaosha Reservoir and Changxing Island, in the Yangtze Estuary, were collected in August2009and May2010. Concentrations of PM10were from109to197μg/m3. The average ion concentrations of NO3-and NH4+reached12.9μg/m3和12.4μg/m3. Sulfur was greatly enriched. The average daily deposition fluxes of nitrogen and sulfer were2.36mg/m2/d and2.47mg/m2/d, respectively.After the land-use modification, the annual deposition on forest, grass, wetland, farmland, urban, freshwater and sea was7.6,6.8,5.3,7.0,7.4,5.6and2.9g/m2for nitrogen, and7.7,2.9,2.9,23.0,8.6,6.5and6.0g/m2for sulphur. The nitrogen deposition fluxes have similar temporal variation, with high fluxes in summer, the second highest in spring, low fluxes in autumn and winter. The deposition from different ecosystems follow the order of terrestrial>wetland>aquatic. N-NO3-and N-HNO3are the top two compounds in nitrogen deposition. The sulphur deposition fluxes have different temporal variation with nitrogen deposition fluxes. The maximum fluxes are in spring, and the minimum in autumn. The sulphur deposition on farmland ecosystem is higher than the other ecosystem, with the monthly average deposition of22.98g/m2. S-SO42-accounts for most sulphur inputs into grass and wetland, while S-SO2accounts for most sulphur inputs into forest, urban area, farmland and water bodies.The deposition of sulphur and nitrogen generally exceeds the critical loads in the Yangtze Delta Region, especially for the sulphur inputs into farmland.