WEPS模型下天津郊区风蚀尘对城区空气质量的影响

Effect of wind-blown dust derived from Tianjin suburban on air quality of central district based on WEPS model

为了模拟天津市郊区地表风蚀起尘对城区空气质量影响,以美国风蚀预报系统(WEPS)为基础,并对其进行二次开发,本地化风文件、其他气象要素文件、土壤文件以及管理文件.循环计算每个起尘地块不同季节的蠕移质+跃移质平均损失量、悬移质平均损失量及PM10平均损失量.结果表明,2009年冬季,单位地块的起尘量与总起尘量均大于其他季节;冬季,指向中心城区蠕移+跃移量、悬浮量及PM10各区总起尘量较其他季节大.春季,总起尘量来自东方向最大;夏季,来自西方向最大;秋季,来自西方向最大;冬季,来自北方向最大.一年中,来自北方向的PM10最多,达9.67×104t,而冬季占81.7%.可见,位于城区北面的郊区尤其在冬季对城区空气质量的影响最大.

Based on U.S.wind erosion prediction system（WEPS）,secondary development of this model was done in order to estimate the effect of wind-blown dust came from suburban on air quality of central district.The database files of blocks were localized,including wind file,climate file,soil file and management file.The dust flux of each dusting block was estimated,including creep and saltation fluxes,suspension fluxes and PM10 fluxes.In 2009,the maximum emission fluxes per block and emission fluxes occurred in winter.In winter,the creep and saltation fluxes,suspension fluxes and PM10fluxes pointing to central district were the most comparing to other seasons.In spring,emission fluxes mainly came from east,in summer,mainly came from west;in autumn,mainly came from west,and in winter,mainly came from north.In 2009,PM10fluxes came from north was 9.67 104t,and accouted for 81.7% in winter.So,PM10 came from northern suburban districts in winter affected deeply on the air quality of central district.