沈阳城市CO_2通量的足迹分析

Footprint characteristics of CO_2 flux over the urban district of Shenyang

基于涡动法测量的沈阳市CO2通量资料,利用KM模型(Kormann-Meixner method)分析了沈阳市2008年供暖期前后CO2通量足迹及不同区域的贡献.同时,探讨了影响CO2通量的因子,并重点分析了交通和供暖对CO2通量的影响.结果表明,供暖对城市CO2体积分数有显著影响,较非供暖时期平均增加了102.54×10-6,CO2通量平均增加了10.74μmol.m-.2s-1.风向与源区也会显著影响CO2体积分数.CO2通量贡献率受风向、供暖、下垫面类型、交通和人口密集度等因素的影响.供暖期间住宅区的CO2通量贡献率夜晚大于白天,交通区的CO2通量贡献率白天大于夜晚.供暖期间交通区在白天和夜晚的单位面积CO2通量贡献率分别为住宅区的6.0和4.2倍.

Based on the CO2 flux data measured by eddy covariance（EC）and the KM model（Kormann-Meixner method）,we analyzed the footprint of the urban CO2 flux and the contributions from different regions before and after the 2008 heating period in Shenyang.The impact factors of carbon flux are discussed,including traffic and heating effects.The results indicated that CO2 concentration（volume fraction）was affected by the urban heating,increasing 102.54×10^-6 on average,and the CO2 flux increased by 10.74 μmol·m-2·s-1.CO2 concentration was significantly affected by wind direction and the source region.The flux contribution rate was affected obviously by wind direction,hot water heating and the property of land surfaces,city transportation and population density.The flux contribution rate was higher at night than during the daytime due to the heating in the residential district,and it was higher during the daytime than at night in the transportation district.The flux contribution rate from the city transportation area was 6.0 times in the daytime and 4.2 times at night from the residential areas in the heating period.