气候变化领域集成服务门户

This study endeavoured to accurately estimate the effects of urbanization on changes in temperatures during 1977-2014 throughout China. To this end, we (a) classified the stations using improved standards, (b) homogenized the mean minimum (Tmin), mean maximum (Tmax), and mean temperature (Tm) data series, (c) identified regions with different temperature trends based on the modified methodology, and analysed the regional changes in the background rural temperatures, (d) explored the relationships between the temperature trend effects of urbanization and the three indices of the urbanization intensity, and (a) calculated the contribution from urbanization on the regional scale. The results indicated the following: (a) After homogenization, several adjustment amplitudes were larger than 1 degrees C, the maximum value of which reached 7.84 degrees C. (b) China was divided into six regions with different rural temperature trends. Rural temperatures significantly increased throughout China with annual Tmin, Tmax and Tm changing rates of 0.424, 0.339, and 0.352 degrees C/decade, respectively. Throughout all of China, the maximum rates for Tmax, Tmin, and Tm occurred during the spring and the minimum rates for Tmax and Tm occurred during the summer, while that for Tmin was slightly lower in the winter than during the summer. (c) Significant correlations did not always exist between the urbanization-contributed temperature-changing rates and the indices of urbanization intensity, and the correlation coefficients varied under different conditions. These values were both positive and negative. The changes in the areas of the built-up regions constituted the best correlation factors. (d) The percentages of the contributions of urbanization to the mean annual Tmin, Tmax, and Tm were -0.08, 0.21, and -0.09%, respectively. These results are beneficial for understanding the effects of urbanization on regional or global climate change to some extent.