西南地区干旱时空变化特征研究

干旱是一种严重的自然灾害，西南地区是我国受干旱影响比较严重的地区。分析干旱的时空变化特征，可以为 应对气候变化和抗旱减灾提供科学的决策依据。本文利用西南地区 31 个气象站 1951—2010 年的月降水量数据，计算尺度分别为 1 个月、3 个月和 1 年的标准化降水指数（SPI），分析了 60 年西南地区月、季和年干旱的时空变化特征。西南地 区干旱发生频率具有空间差异性，四川大部、云南南部发生干旱的频率高，而四川中部和广西东南部发生重旱的频率高。 60 年中西南地区降水量总体没有发生显著性变化，但是阶段性变化显著。年干旱、秋季的站次比具有明显增加的趋势，给西南地区抗旱带来更大的挑战。

Study on the temporal and spatial variation characteristics of drought in Southwest China

Drought is a serious natural disaster, and the southwest region of my country is seriously affected by drought. Analyzing the temporal and spatial variation characteristics of drought can provide scientific decision-making basis for addressing climate change and reducing drought and disasters. This paper uses the monthly precipitation data of 31 meteorological stations in Southwest China from 1951 to 2010, calculates the standardized precipitation index with the scale of 1 month, 3 months, and 1 year respectively, and analyzes the monthly, the spatial and temporal variation characteristics of seasonal and annual droughts. The frequency of droughts in Southwest China is spatially different. The frequency of droughts in most of Sichuan and southern Yunnan is high, while the frequency of severe droughts in central Sichuan and southeastern Guangxi is high. There was no significant change in precipitation as a whole, but there were significant periodic changes. The station-time ratio of annual drought and autumn showed an obvious increasing trend, which brought greater challenges to drought resistance in Southwest China.