Analysis Of Its Spatial And Temporal Characteristics Of Atmosphere And Precipitation Of Chongqing In Three Gorges Reservoir Area

Three Gorges Project is a remarkable large hydraulic engineering, environmental engineering impact is major concern at home and abroad, including the Three Gorges Reservoir water quality problems are the focus. As China’s Three Gorges reservoir water resource library strategy, which not only affect the water quality of life of residents of the Three Gorges reservoir area, the production of water safety, but also on the production and life of residents in the Yangtze River region, economic development and water diversion projects have an important impact on the success or failure. Now with the completion of the Three Gorges Project and operations, engineering gradual emergence ecological impact. The completion of the Three Gorges Project in flood control benefits and use of hydroelectric power generation, but also on the ecological environment has produced a number of adverse effects. After the completion of the Three Gorges reservoir water storage, water slows down, lower self-purification capacity of water bodies, reservoir water quality is affected, especially in some tributary river, water quality deterioration phenomenon is more obvious, water safety is a concern. Atmospheric pollution and precipitation pollution is deteriorating water quality of receiving water bodies is one of the important reasons, therefore, the Three Gorges reservoir area as soon as possible contamination of air pollution and precipitation has become essential. Three Gorges in Chongqing Three Gorges reservoir area as an important component of its total area of the Three Gorges Reservoir area accounted for85%of the water environment in Chongqing section of the Three Gorges Reservoir quality not only directly affects the water quality, but will affect the Yangtze downstream water security. Among them. the Three Gorges in Chongqing ambient air quality, acid rain precipitation composition and extent of the Three Gorges Reservoir will directly have an important impact on the ecological environment. Thus, the study of Chongqing ambient air quality and composition and spatial and temporal distribution of precipitation, propose appropriate measures feasible pollutant control Three Gorges Reservoir water quality protection is very important to the Three Gorges total pollutant control and water quality protection has important theoretical value and practical significance. In view of this, the scope of this study,39stations in Chongqing city’s long-term precipitation data for trend analysis, and select the Three Gorges reservoir area in Chongqing Banan, Fuling, Wanzhou three zones2000-2009observation station data were analyzed in detail comparison and analysis of the Three Gorges in Chongqing chemical composition of precipitation and pollutant concentration, from the industrial structure, atmospheric pollutants and climatic factors discussed several aspects of precipitation pollution partly different. Precipitation composed with other regions to compare, analyze and propose pollutant pollutant source control measures. Three points also studied atmospheric Nitrogen, sulfur wet deposition of long-term trends, and atmospheric nitrogen, sulfur wet deposition temporal and spatial. Then from the perspective of atmospheric chemical composition analysis of the "Eleventh Five-Year" period throughout the39counties of Chongqing main pollutant atmospheric conditions, variation summarize, analyze the causes, and then compared with the chemical composition of precipitation explore the chemical composition of the atmosphere and precipitation some linkages. The main contents are as follows:1. Chongqing section of the Three Gorges Reservoir area and the main city of nine30suburban county in the "Eleventh Five-Year" period of precipitation were analyzed, Banan Chongqing Three Gorges reservoir area, Fuling, Wanzhou District, represented by three of its pH, EC, F-, Cl-,NO3-,SO42-,Na+, NH4,K+, Mg2+, Ca2+, rainfall and other indicators of a consecutive10-year follow-up analysis, from2000to2009Three Gorges in Chongqing Pakistan South, Fuling and Wanzhou three main areas of precipitation chemical composition and temporal and spatial variation characteristics were analyzed. The study results showed that:(1) Acid-controlled areas (acid rain control zones, including the main city of nine areas and12suburban counties) precipitation pH mean the lowest in2007(4.58), then increased in2010to reach the maximum value (4.70); city average precipitation pH lowest in2007(4.70), followed by an increase in2010, reached the maximum (4.87). Compared with2005, in2010the city’s average precipitation pH rose by0.04; acid precipitation pH-controlled areas mean and2005unchanged."Eleventh Five-Year" period of acid precipitation pH-controlled areas and the city’s average annual variation were tested first decreased and then increased.(2) the "Eleventh Five-Year" during the city’s average rainfall of4.79pH, acid rain frequency was48.2%in precipitation sulfate and nitrate equivalent concentration ratio of6.3:1."Eleventh Five-Year" period of acid rain frequency-controlled areas was57.0%average precipitation pH was4.70, precipitation sulfate and nitrate equivalent concentration ratio of5.3:1."Eleventh Five-Year" period of the Three Gorges Reservoir in Chongqing acid precipitation SO42-controlled areas and the concentration of NO3-ion equivalent annualized interannual variability of the overall downward trend.2006maximum (as7.1:1), in2009the lowest (to4.8:1); city precipitation SO42-and NO3-ion equivalent concentration interannual variability over year for the first decreased and then increased. Gradual decline from2006to2009(5:1), in2010it rose to (6.6:1). Show sulfate precipitation for the city’s main cause acid substances, while the contribution of nitrate increases.(3) from2000to2009, the Three Gorges reservoir area Banan District precipitation pH range of3.57～7.40, with an average of5.76, rain frequency was37.9%; Fuling District precipitation pH range of4.13～7.98. with an average of6.03, acid rain frequency was27.5%; Wanzhou District, the average precipitation pH was5.52, the minimum value of3.86and a maximum of7.70, rain frequency was49.1%. Three stations were measured average conductivity117.3μS/cm,72.3μS/cm,63.1μS/cm, that is, its size order:Banan> Fuling> Wanzhou. With domestic Shenzhen, Beijing and other cities, the average is much higher conductivity, and far higher than the market at Mt precipitation background value, indicating that the area of atmospheric pollution is more serious. Precipitation tainted ingredient contained higher concentrations, would have been affected by the reservoir area.(4) three regional precipitation composition exhibits similar characteristics, precipitation SO42-is the most abundant ions, which accounts for77%of the proportion of the anion; cation of the highest concentrations of ions Ca+and NH4+, the two cations share the proportion is75%. And NO3-/SO42-were low, indicating that the local atmospheric pollution comes mainly from coal-based stationary sources, and accounted for an absolute advantage. Three Gorges reservoir area, there are still significant precipitation consisting of temporal and spatial variation, the time, the main ion concentration showed high summer and autumn, winter and spring and low, showing a clear "V" type distribution, which may change with the seasons and precipitation is about; space, the overall performance of the degree of pollution:Banan> Fuling> Wanzhou, there exists in space. On the one hand may be due to the high frequency of rainfall in summer and autumn, rainfall, atmospheric better scouring action, resulting in the chemical composition of rainfall relative reduction; autumn and winter, on the other hand is probably because the temperature is low, weather conditions are not conducive to the spread of pollutants and vegetation absorb purification, causing high levels of precipitation ion concentration.(5) Banan District precipitation SO42-and NO3-related higher, mainly with their similar chemical properties as well as its precursors SO2and NOx emissions in the atmosphere. F-and SO42-and NO3-has a good correlation was0.783(P<0.01) and0.825(P<0.01), described three homology, and mainly from coal combustion; Cl’and Na+poor correlation, which may be affected by human impact is more serious; as land-based sources of Ca2+and Mg2+, also shows a good correlation, suggesting both from surface soil; K+and Cl-significant correlation, indicating that two who have similar sources. In addition, the alkaline cation NH4+, Ca2+, Mg2+and ions SO42-、NO3-has a good correlation, suggesting that these ions in precipitation mainly in (NH4)2SO4, NH4HSO4, CaSO4, MgSO4, NH4NO3and other forms exist. Precipitation in these alkaline ions, to reduce acid rain damage, reduce the frequency of occurrence of acid rain plays a vital role.(6) the average annual precipitation at three observation points nitrogen wet deposition flux:Banan District209.2kg·hm-2, Fuling District,348.15kg·hm-2, Wanzhou District316kg·hm-2; annual wet sulfur deposition flux is:Banan District236.4kg·hm-2, Fuling District296.8kg·hm-2, Wanzhou District237.4kg·hm-2; wherein the total wet deposition of inorganic nitrogen, NH4+-N accounted for more than90%, is the main wet deposition of inorganic nitrogen forms.(7) Reasons:As the "Eleventh Five-Year" period, Chongqing increase desulfurization facilities renovation and efforts to eliminate backward production capacity, in-depth implementation of clean energy coal-fired facilities renovation project, this series of measures to make the city’s sulfur dioxide emissions of sulfur dioxide emissions overall gradually reduced, but the time has not yet Chongqing total control NOx emissions, power plant flue gas denitrification work has not yet carried out, resulting in the "Eleventh five-Year" period of precipitation SO42-and NO3-ratio change the overall downward trend, nitrogen oxides contribute to acid precipitation increasing role. Therefore, we should continue to promote the work of sulfur dioxide emissions, nitrogen oxide emissions to carry out the work, the establishment of regional joint prevention and control pollution of the coordination mechanism to strengthen motor vehicle exhaust pollution control, reasonable layout to promote green urban transport development.2. comprehensive and detailed analysis of the "Eleventh Five-Year" period of the Three Gorges Reservoir in Chongqing ambient air quality of the main city of Chongqing nine areas and30rural counties major pollutants in ambient air SO2, NO2, participate matter and dust analysis and analysis results were compared and evaluated from2005to2010Three Gorges in Chongqing comprehensive analysis of ambient air to conduct a detailed analysis of spatial and temporal characteristics of data, summarize variation and to make appropriate recommendations. The study results showed that:(1)’Eleventh Five-Year" period of Chongqing city air quality improved significantly, in2010the ratio of the number of days to meet good compared to2005increased by12.3percent, sulfur dioxide, nitrogen dioxide and respirable particulate matter concentrations, respectively, compared to2005decreased by34.2%,18.8%and15.0%, the air pollution index dropped23.5%. Although the main city air quality improved significantly, but the situation is still more severe. Respirable particulate matter concentration has decreased but still no standard; and respirable particulate matter load ratio share increased year by year, the main urban air quality impact of the growing role. The main city of the district, the daily average sulfur dioxide in the big crossing area, Banan District. Jiangbei District and Jiulongpo appear excessive, respirable particulate matter in addition to the daily average Beibei District, Yubei District and south zones compliance, the remaining districts were exceeded.(2) the "Eleventh Five-Year" period, Chongqing suburban counties overall air quality is better.2008sulfur dioxide, nitrogen dioxide and respirable particulate matter concentrations, respectively, compared to2005decreased by23.4%,8.0%and21.0%, the air pollution index dropped18.0percent. Although air quality is generally good suburban counties, but some counties are still polluting sulfur dioxide, sulfur dioxide, and in2010the share load ratio increased significantly, and respirable particulate matter in ambient air along a suburban county in the primary pollutant. The county town, Nanchuan District. Wansheng District and other nine counties appear daily average sulfur dioxide exceeded, Kaixian five counties inhalable particles appear excessive annual daily average. (3)"Eleventh Five-Year" period changes in ambient air quality in Chongqing main reasons are:a. Total emissions of sulfur dioxide, sulfur dioxide concentrations were significantly decreased implement the direct cause, b. increase in vehicle ownership is the main reason affecting the concentration of nitrogen dioxide, c. a series of dust pollution control measures undertaken so that the concentration of respirable particulate matter reduced year by year. d. terrain and peripheral sources have a certain influence on the concentration of sulfur dioxide. In addition, Wansheng, Nanchuan led some suburban counties sulfur dioxide pollution is more serious, mainly with the social and economic development and the industrial layout related. This area is the city’s main source of energy, building materials base, sulfur dioxide emissions from power plants and cement plants and other large distribution is more concentrated, resulting in these two regions concentration of sulfur dioxide in the "Eleventh Five-Year" period has been in the city’s highest value.(4) According to the findings raised:should further deepen the "Action Blue Sky" to raise the overall ambient air quality. Strengthen departmental interaction, further control dust pollution. Focus on strengthening the Qijiang-Wansheng-nanchuan Area sulfur dioxide pollution control. Strengthen the nitrogen oxide air pollution control:a. Promote Chongqing power plants, power plants, Kowloon environmental relocation, b. further enhance vehicle nitrogen oxide pollution control. Furthermore, it should further improve air pollution warning and response mechanism, establish a regional joint prevention and control system of the atmosphere.