研究了西双版纳地区夜雨及雾雨的天气气候特征及时空分布规律,分析了夜雨、雾雨的形成机制及其农业气候意义。结果表明,本区降水呈夜雨与昼雨相均衡的状况,夜雨率达５４５％～５７７％,尤其是雾季和干热季可分别达７１４％、７０６％。夜雨形成多是山风环流造成的地形雨,雨强小,雨时长,因而对作物的有效性高。夜间雾雨则在作物生态环境中起着至关重要的作用,可部分缓解干旱季节作物需水的不足。因此,深入探讨夜雨和雾雨资源是制定有效防御干旱对策的重要依据。

n this paper, the weather climate features and the laws of spatial and temporal distribution of night rain and fog rain in the Xishuangbanna area are studied. The formation mechanism of night rain and fog rain and their agroclimatic significance are analysed. The results show that the precipitation in Xishuangbanna presents a proportional state between the night rainfall and the daytime rainfall, in which the rate of night rain reaches 54.5%～57.7%. Especially during the foggy season and the hot dry season the night rain may reach 71.4% and 70.6% respectively. The formation of the night rain is mostly due to the orographic rain caused by mountainous wind circulation. Its rainfall intensity is weak and its rainfall hours is long. So it is highly efficient for the tropical crops. The night fog rain plays a very important role in the eco environment of crops, for it can partly relax the insufficiency of crops water requirement during the drought season. For this reason, the night rain and fog rain resources will become the important basis in making the drought prevention countermeasures in Xishuangbanna.