城市化对重庆市主城区局地气候的影响

Effects of Urbanization on the Local Climatein the Main Urban Area of Chongqing

利用气温、降水量、相对湿度、日照时数等气象资料,以及土地利用资料和空气质量资料,分析了重庆市主城区1970—2019年各气象因子的变化趋势,以及城市化进程对局地气候变化的影响。结果表明:气候变化背景下,重庆市主城区呈温暖化、干燥化趋势,城市化加剧了这一趋势,并导致降水波动性增大,极端降水事件增多。主城区的城市化气候效应强度均呈上升趋势,夏季上升趋势最明显,其中热岛强度和雨岛强度变化显著,市区气候受城市化影响高于近郊。热岛效应、干岛效应的出现主要由热排放和土地利用面积的增加导致,气温的上升与建设用地的扩张对雨岛强度的增加作用明显,空气质量的改善及气温升高有效削弱了市区的暗岛强度。为减缓城市化带来的气候风险,应进一步优化城市能源、产业结构,保护水体、绿地等自然下垫面,建设海绵城市与地下水库工程。

Based on the meteorological data such as temperature,precipitation,relative humidity,and sunshine hours,as well as land use and air quality data,the variations of the meteorological factors in the main urban area of Chongqing from 1970 to 2019 and the impact of urbanization on local climate changes were analyzed.The results showed that under the background of climate change,the main urban area of Chongqing presented a warming and drying trend,and urbanization intensified this trend,leading to increased precipitation volatility and extreme precipitation events.The climate effect intensity of urbanization in the main urban area exhibited an increased trend,with the most obvious upward trend in summer,as well as significant changes in heat island intensity and rain island intensity.The influence of urbanization on the urban climate was higher than that on the suburbs.The emergence of the heat island effect and dry island effect was mainly caused by the increase of heat emissions and land use area.The expansion of temperature and construction land showed a significant effect on the increase of rain island intensity,while the improvement of air quality and the increase of temperature effectively weakened the intensity of the dark island in the urban area.In order to mitigate the climate risks brought by urbanization,it is necessary to further optimize the urban energy and industrial structure,protect natural underlying surfaces such as water bodies and green spaces,and build sponge cities and underground reservoir projects.