2015-2022年桂林市PM2.5外来输送特征及潜在源分析

Characterization of External Transport and Potential Source Analysis of PM2.5 in Guilin City, 2015-2022

关键词:  PM2.5  时空分布  后向轨迹聚类  浓度权重轨迹分析法

Key words:  PM2.5  Temporal and spatial distribution  Backward trajectory clustering  Concentration-weighted trajectory

摘要:

为了揭示桂林市PM2.5时空分布特征与潜在来源，利用2015-2022年PM2.5浓度数据，结合后向轨迹模型(HYSPLIT)模拟以桂林市为起点后向轨迹，并结合聚类轨迹分析法和浓度权重分析法(CWT)，探讨桂林市不同季节PM2.5潜在源区分布及其贡献。结果表明：桂林市PM2.5污染呈现逐年下降趋势，PM2.5输送途径的季节特征明显，是导致桂林市PM2.5月际变化“冬高夏低，春秋居中”一大因素。来自华中地区和两广地区的污染输送是桂林市城区PM2.5的主要外来贡献源，桂林独特的地理位置和地形因素对该地区污染物的输送和扩散起着重要作用。

Abstract:

To reveal the spatiotemporal distribution characteristics and potential sources of PM2.5 in Guilin City, this study utilized PM2.5 concentration data from 2015 to 2022, combined with backward trajectory modeling (HYSPLIT) simulations starting from Guilin City, and integrated cluster trajectory analysis and concentration weighted trajectory analysis (CWT) to explore the distribution of potential PM2.5 source areas and their contributions in different seasons in Guilin City. The results indicate that the PM2.5 pollution in Guilin City shows a decreasing trend year by year, with the seasonal characteristics of PM2.5 transport pathways being a significant factor leading to the "higher in winter, lower in summer, and moderate in spring and autumn" monthly variations of PM2.5 in Guilin City. The pollution transport from the Central China region and the Guangdong-Guangxi region is the main external contribution source of PM2.5 in the urban area of Guilin City. The unique geographical location and topographical factors of Guilin play a crucial role in the transport and diffusion of pollutants in this region.