Impact of land use change on the urban-rural temperature disparity in Eastern China.

Unprecedented land use and land cover change (LULCC) has occurred across China over the past two decades. While urban heat island effects have been well documented, few studies identified the LULCC-induced temperature disparity within cities and nearby rurual areas. Through an integrated analysis of satellite observations and regional model simulations, this study quantifies LULCC effect on summer temperature in old urban areas (existed in 2003), new urban areas (developed after 2003) and rural areas (non-urban areas) over Eastern China in 2003–2019. The results show that LULCC causes urban areas to become warmer, with the effect being more pronounced in new urban areas than in old urban areas. Air temperature (2 m, T 2) and surface temperature (TSK) in new urban areas increase respectively by 1.69 °C and 3.40 °C, while in old urban areas, T 2 (TSK) increases by 0.10 °C (0.13 °C). Significant vegetation degradation is observed in new urban areas, whereas vegetation restoration occurs in old urban areas in recent years as a result of urban renewal. In contrast, LULCC cools and greens rural areas, with a 0.02 °C (0.03 °C) decrease in T 2 (TSK). Urbanization warming can spread to the suburbs, along with vegetation degradation. The analysis of surface energy budget reveals that the reduction in latent heat plays a dominant role in urban warming. Our study underscores that a much larger greenspace fraction and albedo management in urban areas are suggested as an inherent part of future LULCC policy to alleviate urban-rural temperature disparity. • WRF model with satellite-based land parameters is developed to quantify the impact of land use change on temperature. • New urban areas become warmer and less green, vegetation restoration occurs in old urban areas due to urban renewal. • A much larger greenspace fraction and albedo management are suggested in urban areas to alleviate urban warming. [ABSTRACT FROM AUTHOR]