Effect of urbanization on extreme temperature events in Liaoning Province, China, from a spatiotemporal perspective

Abstract

Understanding the role of urbanization in extreme temperature events can help mitigate their negative impacts. This study aimed to comprehensively analyze the effect of urbanization on extreme temperature events in Liaoning Province, China, from a spatiotemporal perspective. First, eight extreme temperature indices were selected from the temperature data for the period 1959–2018. Climatic regions corresponding to 24 meteorological stations were divided, and land use data were used to classify urban and rural areas. Then, the dynamic “urban minus rural” method was improved and used to quantify the urbanization effect (UE) and temporal variation trend of extreme temperature events. Furthermore, landscape indices were used to quantify the impact of the spatial layout of urban landscapes on extreme temperatures. The results showed that the UE in the northern region of Liaoning Province was reflected by most indices (minimum urbanization contribution, UC = 9.61%), while that in the southern region was mainly observed at night (maximum UC = 75.00% observed during frost days). The area and fragmentation of the urban landscape were the main spatial factors affecting extreme temperatures, primarily extremely high temperatures at night. Further, the highest correlation coefficient (-0.74) was between the contagion index and tropical nights index.