Research Of Early-warning System Of Water Environment Security And The Key Technology For Nansihu Lake

The East-Route of the South-to-North Water Diversion Project is a large infrastructure projects which can alleviate unevenly distributed in space of water resources in China. As an important channel and flood storage lake of Diversion Project, water quality of Nansihu lake relationship to water safety in Shandong Province and the north. In recent years, After focusing on governance, the water quality has been significantly improved in Nansihu lake. However, the construction of prevention and control system has been close to perfect, but the sudden water pollution accidents and uncertainty is still difficulty prevention work, while water pollution accident, there are still some response lag, the early warning system of water environment is emergence and development in this context. While early warning system ensures predictable accident, it can alse make the original emergency system fully play its functions, it is effective guarantee and convergence means of accident prevention and emergency treatment. Research on early warning system Nansihu lake enormous environmental has great research value and far-reaching impact.On the basis of analysis of existing data induction, comprehensive domestic and foreign related research results, with the help of mathematical methods and modern computer technology, through research and analysis, initially established Nansihu lake early warning system of water environment. The system covers create early warning indicators system, water quality simulation, model of early warning, optimization for early warning and monitoring network. This thesis has been working in the following areas:(1) Proposed the construction of the framework Nansihu lake early warning system of water environment. Analysis of the constituent elements of early warning systems, including police sources, police intelligence, warning signs, warning limitand warning degrees; Implementation process to determine the early-warning, including warning intelligence identified, warning source identification, determine the degree and risk of exclusion; Based on Nasihu basin environmental characteristic, proposed the Nasihu lake overall frame for early warning system of water environment, mainly including the early warning index system, early warning model selection and early-warning monitoring system optimization, etc.(2) Build a index system for Nansihu early-warning of water environment.①Based on characteristics of environmental events, and identify the inducements of the water environmental events, analyzes the interaction between socio-economic, production, environmental water, natural ecosystems, prevention and control of five areas of the river, on the basis of these, built the structural model early warning system of water environmental;②Using the Delphi method, SPSS principal component analysis, were screened qualitative indicators and quantitative indicators, constructed Nansihu water warning indicator system includes four hierarchy environment based on AHP;③Using water warning indicator system has been built environment, take the form of a comprehensive early warning scores, establishing early warning indicators of water environment model to calculate warning index I, to identify early warning alarm limit values by defining the range of early warning index in order to determine the degree of police this study will alert police of the Chinese Communist Party is divided into red, orange, yellow, blue four levels, and each level gives the corresponding event description.(3) The aquatic environment simulated by use EFDC on Nansihu lake, successfully simulate the temporal and spatial migration process with the flow of pollutants. First introduces the principles and key analog multi-parameter equation finite difference model EFDC to EFDC_Explorer of Nansihu Lake subordinate regional mesh, on this basis, to build a dynamic model of the lower lake and water quality mode.①When hydrodynamic modeling, using the December2011measured daily flow, water level drawn boundary conditions, the conclusion that the micro-level analog values hill station after repeated calibration and comparison with the measured values, hydrodynamic model was successfully;②The basis of hydrodynamic model parameter set to build on the water quality model of permanganate, ammonia, dissolved oxygen to simulate the three parameters, the output water quality parameters Weishan station analog value and the measured values compared to the generated error of attribution analysis showed that these three substances with the water EFDC migration of simulation results and actual good fitting effect.③Based on the success of the hydrodynamic and water quality model building, simulation of migration process of pollutants with flow, determine the migration of pollutants with flow space-time distribution rule, and then make a detailed and accurate warning, provide theoretical support for emergency plan and optimize.(4) Summed optimization for Nansihu Lake early-warning and monitoring systems of water environment in two ways. The distribution of the original application of advanced water quality monitoring network automatic online technology, data collection, transmission and management techniques to optimize the improvements, the new setting monitoring sites should strictly abide by the principle of distribution; respectively, from enhanced monitoring network functions and role, as well as improve the overall capacity of the organization and training of personnel analyze the data presented Nansihu Lake early warning and monitoring system of water environmen improvements.