Revealing the contribution of urban green spaces to improving the thermal environment under realistic stressors and their interactions

• The cooling effect of urban green spaces (UGS) is affected by multiple stressors. • Stressor interactions contributed more to the cooling effect in the GAM model. • Building density × building height had a dominant impact on the UGS cooling. • Individual stressors show a threshold effect on the cooling by UGS at the grid scale. Extreme temperatures in cities have become even more dramatic, making urban heat island (UHI) mitigation strategies difficult to implement. To understand the contribution of urban green spaces (UGS) to improving the thermal environment under realistic stressor interactions, six stressors – road density (RD), building density (BD), building height (BH), percentage of impervious surface (P_IS), percentage of green space (P_GS) and sky view factor (SVF) – were selected in this study to identify their impact on the cooling intensity of UGS (DLST) in summer using a generalized additive model (GAM) method. The results demonstrated that: (1) individual stressors RD, BD, BH, P_IS, and P_GS had a significant impact on DLST and showed threshold effect on DLST at grid scale; (2) stressor interactions BD × SVF, BD × P_IS, BD × BH and SVF × P_IS had significant impacts on DLST; and (3) stressor interactions contributed 54.07 % to DLST in GAM model, the individual stressors contributed 39.81 % to DLST, while in between BD × BH showed the dominant interactive impact on the cooling effect of UGS. These findings will assist with regulating urban stressors to enhance the cooling effects of UGS, thereby improving the urban thermal environment.