Abstract:

Studying the variation characteristics of regional drought in Shandong Province is of great significance for drought disaster prevention and mitigation. Using daily temperature and precipitation data from 123 national meteorological stations in Shandong Province, this study identified regional meteorological drought processes from 1961 to 2024 based on the MCI (Meteorological Drought Composite Index) and the monitoring and assessment method of regional drought process, and analyzed the spatio-temporal evolution features of these drought processes and their responses to climate warming. The results show that Shandong experienced 1-2 regional meteorological drought events annually with distinct seasonal patterns, predominantly concentrated in spring and summer, peaking from April to July. The frequency of consecutive spring-summer droughts reached 42%. Regional droughts exhibited clear geographical distribution: except for the eastern Jiaodong Peninsula and southeastern Linyi, the average drought duration exceeded 50 days in most remaining regions, with high-value zones concentrated in central Shandong and the southwestern side of Mount Tai. The northwestern Shandong regions showed a decreasing trend, with most areas experiencing a reduction of over 2 days per decade, while the southeastern regions demonstrated an increasing trend, particularly in the southern Jiaodong Peninsula and southeastern coastal areas, where the increase exceeded 2 days per decade. The frequency and affected extent of regional drought processes showed a slight upward trend, with the highest incidence observed from the 1980s to the early 21st century, followed by a marked decline and thereafter a renewed intensifying trend in recent years. Against the background of climate warming, precipitation across Shandong showed a decreasing-then-increasing trend, and the climate shifted from warm-dry to warm-wet conditions. Spatially, western Shandong tended toward warming-wetting, whereas eastern Shandong remained characterized by warming-drying. As warming accelerates, greater attention should be paid to guarding against more severe regional meteorological drought risks.

Key words: MCI, regional drought, spatio-temporal variation, climate warming, Shandong Province

摘要：

研究山东区域性干旱变化特征对干旱防灾减灾具有重要意义。利用山东省123个国家气象观测站逐日气温和降水资料，基于气象干旱综合指数（Meteorological Drought Composite Index，MCI）和区域性干旱过程监测评估方法，识别1961—2024年历次区域性气象干旱过程，并分析其时空演变特征及对气候增暖的响应。结果显示，山东平均每年发生1~2次区域性气象干旱过程，季节性特征明显，主要集中在春、夏季，4—7月为高发期，春夏连旱过程频繁，年发生频率高达42%；干旱过程地域分布差异大，除胶东半岛东部和临沂东南部外，其他大部分地区区域性气象干旱过程平均干旱日数在50 d以上，高值区分布在鲁中及泰山西南侧。山东西北部呈减少趋势，多数区域减少速率为2 d·（10 a）^-1以上，而东南部呈增加趋势，胶东半岛南部及东南沿海部分地区增加速率超过2 d·（10 a）^-1。干旱过程发生频次和影响范围略呈增加趋势，20世纪80年代至21世纪初期为高发期，之后明显减弱，近年来又呈增强趋势。在气候变暖背景下，山东降水呈“先减后增”变化趋势，气候从暖干化向暖湿化转变，呈现西部地区暖湿化、东部地区暖干化的分布态势；随着增暖加快需要注意防范更强的区域性气象干旱。

关键词: MCI, 区域性干旱, 时空变化, 气候增暖, 山东省