Contribution of Suburban Land Use Landscape Characteristics to Urban Heat Island Intensity at Varying Gradients in Shenyang

The intensification of the urban heat island (UHI) effect poses a serious threat to public health, particularly in cities. Effectively mitigating UHI has been a focus of national and international academic research over the last decades. However, most contemporary research has focused on land use mitigation measures within urban areas, with less emphasis on suburban land use. To address this research gap and explore spatial characteristics, we analyzed the driving mechanism of suburban land use patterns on UHI intensity (UHII) within the main urban area of Shenyang City based on high spatial resolution raster data, such as Landsat remote sensing images and land use, combined with extreme gradient boosting and SHapley Additive exPlanations models. The landscape fragmentation index of overall suburban land use provided a stronger contribution to the UHII in urban areas than the aggregation index. Increased cropland fragmentation and aggregation enhance UHII mitigation, whereas increased aggregation of impervious surfaces intensifies UHII. No significant difference was observed between the effects of various suburban gradient landscapes on UHII; however, the effects on different gradients in urban areas increased with decreasing distance from the countryside, with a minimal effect observed on the extreme center of the city (U1). The study provides a theoretical reference for mitigating land use pressure and reducing the UHI in urban areas based on suburban land use.