摘要: 粤港澳大湾区近三十年城市规模迅速扩张，其形成的城市效应在现今和未来均会对当地天气气候产生一定影响。本研究基于区域气候模式WRF，采用1990年、2020年以及假设城市规模最大化的广东省土地利用数据，针对2021年6月22~23日粤港澳大湾区发生的一次强降水事件进行模拟。模拟结果表明：粤港澳大湾区近三十年来城市规模扩张形成的热岛效应激发了反气旋式偏差环流，更多水汽由珠江口和南海被输送到城市区域并形成辐合，大气处于湿对流不稳定状态，引起垂直上升运动增强，配合中高层增加的水汽，使得降水增多，增量甚至可达到暴雨级别；当城市规模未来进一步扩大后，城市热岛效应更为显著，激发的偏差环流将城市水汽带离城市，城市干岛效应明显，在干对流不稳定的作用下低层垂直上升运动有所增强，但由于水汽不足，部分城市降水有所增加但不明显。

Abstract: The rapid urban expansion of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in the past 30 years would have a certain impact on the local weather and climate today and in the future. Based on the regional climate model WRF, a heavy precipitation event in the GBA on June 22~23, 2021 was simulated by using the land use data of Guangdong Province in 1990, 2020 and with the maximized city size in the future. The simulation results show that: The heat island effect caused by urban expansion in the GBA in the past 30 years has motivated an anomalous anticyclonic circulation, and more water vapor is transported from the Pearl River Estuary and the South China Sea to the urban area and forms convergence. The atmosphere is in a state of wet convective instability, resulting in enhanced vertical upward movement. With the increase of water vapor in the middle and upper levels, the precipitation increases and the increment can even reach the level of rainstorm. When the urban scale is further expanded in the future, the urban heat island effect becomes more significant, the stimulated anomalous circulation carries urban water vapor away from the city, and the urban dry island effect is obvious. The vertical upward movement of the low layer is enhanced under the action of dry convection instability, but due to insufficient water vapor, the precipitation in some cities increases but is not obvious.