Effects of Urbanization on Regional Extreme-Temperature Change in China, 1960-2016

Fast urbanization is one of the aggrandizement factors to global warming, but the effects of urbanization on extreme temperature change is still not quantitatively assessed. Based on high-resolution land cover map, this study classified 613 meteorological stations in China into three classes, namely, urban station, suburban station and rural station to simulate the trends of extreme minimum temperature (TNN), mean temperature (Tavg) and extreme maximum temperature (TXX) of each meteorological station. The roles of urbanization in temperature change in the period 1960-2016 were then assessed. The results indicated that annual temperature increased significantly, but seasonal temperature increased with varied degrees. Temperature in high latitudes increased faster than that in low latitudes. Temperature in summer increased slower than that in other seasons. The effects of urbanization on TNN, Tavg and TXX were all statistically significant, but the effects on TNN and Tavg were more noticeable than TXX. The aggrandizement effects of urbanization presented by low-altitude meteorological stations are significant in South China and East China for all temperature indices, despite no statistical significance presented by high-altitude meteorological stations in Southwest China. This paper can provide a reference for understanding the regional temperature changes and the effects of urbanization on its changes in China.