1426—1949年腾格里沙漠边缘区旱涝灾害初探

通过对腾格里沙漠边缘区相关气候灾害的史料和文献进行搜集整理与归纳分析，利用统计分组、时间数列、滑动平均、旱涝等级划分等方法对研究区1426—1949年旱涝灾害的时空变化特征和干湿变化特征进行了研究。结果表明：1426—1949年，腾格里沙漠边缘区共发生旱灾149次（平均每3.52年1次）、涝灾98次（平均每5.35年1次）；因各县、区的地貌和建置时间不同，旱涝灾害具有明显的时空差异，在时间尺度上，清朝发生旱涝的频率最高，分别为51%、78.6%，在空间尺度上，沙坡头区发生旱涝灾害次数最多，分别为旱灾110次、涝灾78次；腾格里沙漠边缘区在明朝时期相对干旱，清朝、民国时期湿度增加，这与小冰期全球性的降温、西风强盛导致相对湿度增加和西风带位置南移导致降水增多有关。

Drought and flood disasters on the edge of Tengger Desert during 1426-1949 AD

We collected historical documents about climatic disasters in the Tengger Desert, located in northwest China. Statistical categorization, time-series analysis, moving average, and rank of climatic disasters were the main means to analyze these information and data we organized. The changes between wet and dry and spatial-temporal characteristics of climatic disasters in the study area during 1426-1949 AD were researched. This study shows that droughts occurred every 3.52 years, and floods occurred every 5.35 years during the study period on the southern and western edges of the Tengger Desert. Apparent spatial-temporal differences were invited by various landforms, and historic construction of counties and districts. At the time scale, both the droughts (51%) and flood disasters (78.6%) had the highest frequency in Qing dynasty. As for space scale, Shapotou district experienced the most amount of climatic disasters with 110 droughts and 78 floods, respectively. The climate in Qing dynasty or the Republican period was wetter than that in Ming dynasty. This was due to global cooling during Little Ice Age, strong westerly and southward of westerlies, leading increasing precipitation in the study area.