云南气象灾害特征及成因分析

用1950～1999年气象灾害资料,分析云南气象灾害的主要特征,具有种类多、频率高、重叠交错;分布广、季节性、区域性突出;成灾面积小、累积损失大的特征.指出地理环境、气候、人类活动是形成云南气象灾害的主要原因.特殊的低纬高原、邻近热带海洋、地形地貌复杂、山高坡陡、植被少、降雨集中、地质构造复杂、断裂活动强烈是形成云南气象灾害的地理环境因素.季风强弱与冬夏大气环流差异是决定云南气象灾害的主要气候背景.人口剧增,垦植过度,滥伐森林,水土流失严重指出是加剧云南气象灾害频繁发生和损失严重的主要人为因素,提出了云南气象灾害的防灾减灾对策.

Characteristics and Formation Mechanism of Weather Disasters in Yunnan Province

The major characteristics of weather disasters in Yunnan Province is analyzed by using weather disasters data in the period of 1950-1999, weather disasters in Yunnan Province have characteristics of multi-kinds,high frequence,overlapping,wide distribution,obvious seasonality and regionalization,few disaster formation area and serious accumulated losses. The formation mechanism and occurrence background of weather disasters in Yunnan Province has also discussed. The results show that geographical environment,climate and human activities are main factors to form weather disasters in Yunnan Province. The geographical environment elements to form weather disasters in yunnan include low latitude plateau,approaching tropical oceans,complicated topographical features,cliffy mountain,few vegetation,concentrated rainfall,complicated geological structure and strong fault actions. The strong or weak monsoon activities and the difference of general atmospheric circulation in winter and summer over Yunnan are the climatic background to form weather disasters. Population increase,excessive wasteland reclamation,denudation forest,serious water and soil erosion are main human factors to intensify weather disasters occurrence frequently and loss seriousness in yunnan. At last countermeasure of weather disasters prevention and reduction were put forward.