基于WRF-Chem模拟的玉溪市大气环境容量精细估算

云南高原的清洁大气环境及其潜在变化是一个值得深入研究的大气环境问题.本文选择云南高原重要工业城市—玉溪作为研究区域,基于中尺度空气质量模式WRF-Chem,开展玉溪市的大气环境容量模拟估算.同时,以2015年冬、春、夏、秋季主要大气污染物模拟为基础,采用以我国环境空气质量标准(GB3095—2012)为约束目标的WRF-Chem模拟迭代大气环境容量算法,设置3 km的精细分辨率,计算得到2015年玉溪市一次PM_(10)、一次PM_(2.5)、SO_2、NO_x和CO的大气环境容量分别为1.284×10~4、0.854×10~4、1.917×10~4、1.796×10~4和51.556×10~4t·a~(-1).最后,研究了整个玉溪市区域和城区大气环境容量的季节变化特征,结果发现,各污染物冬季大气环境容量最小,除PM_(2.5)外的污染物均在春季大气环境容量最大.玉溪市城区剩余容量占全市的比例均在40%左右,反映了工业发展和城市化带来的大气环境的城乡差异及可能的环境变化效应.

An elaborative assessment of atmospheric environmental capacity in Yuxi based on WRF-Chem modeling

Clean air environment and its potential change over the Yunnan Plateau is an issue for further study on atmospheric environment. This study is focused on Yuxi, an important industrial area over the plateau. The estimation of atmospheric environmental capacity is conducted based on the meso-scale air quality model WRF-Chem in a fine resolution of 3 km. Based on the simulation of major air pollutants for winter, spring, summer and autumn in 2015, and by applying an iterative algorithm for assessing the atmospheric environmental capacity governed by air quality targets according to the national ambient air quality standards (GB3095-2012), the atmospheric environmental capacities of primary PM₁₀, primary PM_2.5, SO₂, NO_x and CO emissions in Yuxi are estimated with 1.284×10⁴ t·a^-1, 0.854×10⁴ t·a^-1, 1.917×10⁴ t·a^-1, 1.796×10⁴ t·a^-1 and 51.556×10⁴ t·a^-1, respectively. The seasonal variations of atmospheric environmental capacities in the entire and urban areas over Yuxi are characterized with troughs in winter and peaks in spring for the major air pollutants except for PM_2.5. The remaining atmospheric environmental capacity in the urban area accounts for 40% of that in entire Yuxi region, reflecting the regional differences in atmospheric environment and possible environmental change resulted from the industrial development and urbanization over this plateau region.