Exploring the influence of geographic proximity on the urban thermal environment and its boundary effects

Urban form's impact on the thermal environment is well studied, but a gap remains in understanding the boundary effect of natural geographic proximity on urban thermal conditions. For plateau cities' unique environment, the urban block distance to Dianchi Lake (UB-DDL) and the urban block distance to forested mountain areas (UB-DFMA) were incorporated as natural factors influencing land surface temperature (LST). The results of the XGBoost model analysis revealed that while urban form, such as the normalized difference built-up index, building density, and vegetation cover, predominantly contributes to the LST, the influences of UB-DDL and UB-DFMA should not be overlooked. Furthermore, urban blocks within 5 km of Dianchi Lake and within 6.7 km of the forested mountain area are classified as effective cooling zones. This study combines local climate zone classification with boundary effects to provide unique insights for effectively mitigating the urban heat environment in plateau cities.