###### Abstract
However, the sensitivity of PM\({}_{2.5}\) concentration in the receptor city to emissions from the source area is not necessarily the same as the contribution of transport, due to the non-linear relationships between emissions and concentrations [29]. A transport flux approach is usually applied to assess the large-scale transport of air pollutants, such as inter-continental and trans-boundary [30; 31; 32]. These approaches, based on air quality models, are effective only in the context of accurate emission inventories, reliable weather simulations, and comprehensive descriptions of chemical reactions since they are based on the simulated meteorology field and air pollutant concentrations. Despite the preceding methods, the quantity of external sources of straw burning in rural areas and the duration of burning may affect urban air quality, and have rarely been assessed quantitatively and systematically; our understanding of the influence of burning area, transport distance, and meteorological conditions along transport pathways are neither complete nor comprehensive. This is because it is difficult to identify the potential spatial scope of external straw burning sites associated with elevated PM\({}_{2.5}\) concentrations of the receptor city with a high temporal resolution, such as during ten to dozens of hours of a specific haze episode. The geographic origin, identified using trajectory statistical methods, is the probability that an external source is located at a point location with latitude and longitude, rather than the exact spatial scope. This is semi-quantitative, which is suitable for identifying long-term transport characteristics. For methods based on air quality models, the subdomains of emission scenarios should be arranged in advance, and the results should be limited to the pre-divided subdomains. However, straw burning associated with a specific haze episode of a receptor city is rather sporadic and transient [33], it may occur randomly anywhere on farmland in a rural area surrounding a city, and a single burning lasts only a few hours. This study constructs a GIS-based integrated method including multiple techniques and models with collaborative multi-source datasets to quantify the contribution of external SOB sources to the elevated urban PM\({}_{2.5}\) concentrations during specific haze episodes. The integrated model offers the possibility to link the spatial scope of external SOB sources, their transport pathways, and the pollution level of the receptor city at a high temporal resolution (1 h). Taking Jilin Province as the study area, and its capital Changchun as the pollution receptor city, SOB in province-wide farmland is examined, and its contribution to specific urban haze episodes during the SOB season of 2020-2021 is assessed quantitatively. Moreover, the impact of the area of SOB sources, their transport distance, average planetary boundary layer height (PBLH) along the transport pathway, urban PBLH, and urban wind speed are explored. The results will be beneficial to policymakers in developing refined management regulations on SOB to protect the atmospheric environment and to ensure agricultural production as well.