全球气候变化环境下,内蒙古各气候区出现不同程度的干旱,可能会对当地农牧业带来一定的灾害损失。为了明确内蒙古地区主要作物生长季（5—9月）干旱特征及其对气候因子的响应,将内蒙古全区划分为5个气候区,选取1981—2012年内蒙古地区46个气象站点和2014—2020年20个气象站点逐月气象观测数据,计算了多尺度标准化降水蒸散指数（Standardized Precipitation Evaporation Index,SPEI）,揭示其干旱特征规律;以月尺度为例,探明了各气候区作物生育期干旱高发时间与地区,干旱的气象主导因子,验证回归模型的适用性。结果表明：（1） 从时间变化来看,1998—2008年干旱情况较为严重,其余年份干旱程度较轻;（2） 作物生长季内干旱面积和程度最大为5月;西部特干旱气候区发生中度干旱的概率比东部湿润半湿润气候区高37%,而特大干旱主要发生在东部湿润半湿润气候区;（3） 各气候区同一月份干旱气象主导因子各不相同,降水和最低温度是作物生长季干旱的最主要影响因子;（4） 各气候区估算模型精度较高,误差在合理范围内,因此,回归模型可以用于有限气象数据下估算月SPEI。研究结果可为科学评估内蒙古地区作物生长季干旱特征及其制定合理干旱应对措施提供科学依据。

With the foundation of global climate change in recent years, droughts in various climatic areas in Inner Mongolia may bring unpredictable disaster risks to local agricultural production. The whole region was divided into five climatic areas, and monthly data was received from 46 meteorological stations from 1981 to 2012. Twenty meteorological stations from 2014 to 2020 were selected to calculate the different time scales of the standardized precipitation evapotranspiration index (SPEI) using precipitation and reference evapotranspiration from the Penman-Monteith method to reveal the drought characteristics and its dominant meteorological factors during the crop growing season (May-September) in Inner Mongolia. A monthly drought during the crop growing season was revealed. The high-incidence month and region of drought in the growing season in various climatic areas were identified by the SPEI of a 1-month scale, and a stepwise linear regression method was selected and verified to extract the dominant meteorological factors driving the drought in each month and the whole growing season in various climatic areas. Results indicated that the following: (1) from the interannual changes, the drought from 1998 to 2008 was more serious, and the drought in other years was less serious. (2) The largest drought area and degree appeared in May during the crop growing season. The probability of moderate drought in the moist and semi-humid area was 37% higher compared to the hyper-arid area, while the extreme drought probably occurred in the moist and semi-humid area and dry and semi-humid area. (3) Dominant meteorological factors driving the drought varied in the crop growth period of various climatic areas in Inner Mongolia. Precipitation and a minimum temperature were the main impact factors for a drought in the crop growing season. (4) Using limited meteorological data, the regression models in each climate region performance well can be used to estimate the monthly SPEI. The results provide a theoretical basis for scientific evaluation of drought characteristics in the spring maize growing season and formulates reasonable measures of response to the drought.