气象参证站的选取对AERMOD模型结果的影响分析

选取南昌经济技术开发区规划大气环境影响预测工作为案例,分析了当选取不同气象参证站,输入同期两套不同的气象数据参数对AERMOD模型计算结果的影响,探究气象条件的差异对大气扩散的影响程度。分析结果表明,气象参证站的选取对大气环境影响预测的结果有较大的影响,使用两个距离相近的地面气象站进行预测,污染物浓度计算结果相差可达数倍以上。对比风速、风向、气温、湿度、压力、云量这些单个的气象因子,稳定边界层(SBL)湍流高度和莫宁-奥布霍夫长度这些边界层参数更能综合地反映当时的气象扩散条件,对污染扩散模型的响应更为直接。翔实的有代表性的气象数据是环境影响评价至关重要的基础。在日常的大气环境影响评价中,应全面调查了解项目周边的地面气象站的数量、类型、距离、地形特征,经过专业的气象分析,选取最能代表评价项目所在地气象条件的气象站作为气象参证站,用于该项目的环评和浓度预测。各地气象部门还应加强城市与郊区大气边界层垂直结构变化规律的观测与研究,从而为提高各地空气质量预报的精度,改善大气污染治理措施和优化城市布局提供更为科学的依据。

Influence Analysis of the Selection of Meteorological Reference Station on Results of AERMOD Model

This paper selected the atmospheric environmental impact prediction work of Nanchang Economic Technical Development Area Planning as a case, compared the different meteorological reference stations, analyzed the impact of two different meteorological parameters on the results of AERMOD modeling and investigated the influence of meteorological conditions on the atmospheric diffusion. The results show that the selection of meteorological reference stations has a great influence on the atmospheric environmental impact prediction. The calculated results from two adjacent ground meteorological station show great difference which can reach several times and above. By comparing those individual weather factors such as wind speed, wind direction, temperature, humidity, pressure and cloud cover, the boundary parameters like the turbulent height of the stable boundary layer (SBL) and Monin-Obukhov length reflect more comprehensively the meteorological dispersion conditions and affect more directly to pollution dispersion models. The precise and representative meteorological data is a critical fundament for the environmental impact assessment (EIA). In the routine work of EIA, it should be fully investigated number, type, distance, topographic features of ground meteorological stations around the project by professionally weather analyzing. The meteorological station which can most represent the project should be chosen for the EIA and concentration prediction of the project. Local meteorological departments should also strengthen the observation and research of the vertical structure variation of urban and suburban atmospheric boundary layer, so as to provide more scientific basis for enhancing local air quality forecast accuracy, improving the atmospheric pollution control measures and optimizing the urban layout.