基于RS和GIS的兰州市城区NO_2时空分布特征研究

摘要

以1986和2006年四期Landsat/TM为数据源,利用NO2在蓝光波段存在吸收峰谷结构这一光谱特征,采用回归分析方法,借助ERDAS空间建模功能,反演了兰州市NO2的空间分布,得到不同时期NO2分布图.将同时期统计观测数据与反演结果进行对比,分析了兰州市NO2分布特征,探讨了NO2分布的成因.结果表明,兰州市NO2浓度分布情况与LANDSAT卫星蓝光波段象元灰度值（DN）存在负相关关系;兰州市西固区、安宁区和城关区雁滩乡NO2污染严重,城关区其他地区和七里河区污染较轻;两山夹一盆地的地形和盆地气候特征,以及不合理的城市空间结构及布局是造成NO2污染的主要原因.所得结论可为兰州市城区优化布点和环境污染治理提供一定的参考.%Taking 1986 and 2006 Landsat/TM images as the data source,and using the negative-correlativity characteristics between the concentration of NO2 and DN,regression-analysis is also employed to make model.Because of the absorb-apex-paddy-structure of NO2 is blue-light-wave,it has applied the model-maker of ERDAS to the studies of spatial model and the spatial-temporal distribution of atmospheric NO2 in Lanzhou City of Gansu Province.By making the spatial-temporal distribution of NO2 maps,the retrieved results are compared with monitor datas.The results show that the relationship between the distrution of NO2 and DN is inverse correlation.There is severity pollution of NO2 in the regions of Xigu,Anning and Yantan.Relatively,there is light pollution in Chengguan and Qilihe region.The special terrain and basin climatic features,as well as the unreasonable layout of urban spatial structure are the main reason that cause of NO2 pollution.The conclusions provide some references for optimal placement and environmental pollution control of Lanzhou City.