用积云二维时变模式模拟长沙夏秋季积云并合过程，结果表明：系统性天气积云丛生，常产生自然并合，降水量很大；有些可播度大于零的天，积云散在发生，几无自然并合，降水量少，若在附近有一扰动产生积云，并合将使其发展强盛，降水量增加；可播度为零的天气，即使积云相距很近也不合并，而是先后消散，无作业价值 The two-dimensional time-varying model of cumulus was used to simulate the cumulus coalescence process in summer and autumn in Changsha. The results showed that: the systematic weathering of cumulonimbus often produces natural coalescence with large amount of precipitation; some can sow more than zero days, In the event of a few natural unification, less precipitation, if there is a disturbance in the vicinity of the cumulus clouds, the merger will make it strong growth, precipitation increased; zero sowing of the weather, even if the cumulus clouds are very close Merger, but has dissipated, no operating value