山西春季旱情时空分布特征

基于2007—2018年春季TVDI干旱监测结果,利用趋势分析、偏度系数以及结构相似度分析方法,探讨山西省春季旱情时空分布特征及影响因子。结果表明：（1）受到水资源（降水、地表水、地下水）分布差异的影响,2007—2018年山西省春季西南地区TVDI呈减少趋势,春旱发生概率减小,东北地区TVDI增加趋势明显,旱情趋于严重;（2）2007—2018年TVDI偏度系数分布在-1~-1.7,与累积降水量呈负相关。同时作物在不同生育时期对水分胁迫敏感程度存在差异,非水分胁迫敏感期内的集中降水无法有效缓解作物因水分胁迫敏感时期缺水而造成的干旱;（3）在空间上,地形起伏程度越大且土壤类型（通气孔隙度和保水性）差异性越显著,TVDI结构相似度越小,空间差异性越大,反之则越小。

Spatial and Temporal Characteristics of Spring Droughts in Shanxi

Based on the drought monitoring results of TVDI in spring from 2007 to 2018, the spatial and temporal characteristics of spring droughts in Shanxi Province and the influencing factors were analyzed by trend analysis, skewness coefficient and structural similarity. The results showed that (1) affected by the spatial distribution of water resources (precipitation, surface water and ground water), the trend of TVDI decreased in southwest Shanxi from 2007 to 2018, which indicated that the probability of spring drought decreased, the trend of TVDI increased in northeast Shanxi and spring drought became serious; (2) the skewness coefficient of TVDI varied from -1 to -1.7 from 2007 to 2018 and was negatively correlated to cumulative precipitation on the time scale, moreover, precipitation at non water stress sensitive stages could not alleviate the drought caused by water shortage at the water stress sensitive stages, as the sensitivity of water stress was different at different growth stages; (3) with the increase of terrain complexity and the difference in soil types (ventilation porosity and water retention capacity), the SSIM of TVDI decreased, which indicated that the spatial difference increased, and vice versa.