Abstract: In order to understand the degree of drought and impact on potato yield of main potato producing areas in central Inner Mongolia, the precipitation concentration degree (PCD), precipitation concentration period (PCP), standardized precipitation index (SPI), and standardized precipitation evapotranspiration index (SPEI) were calculated using precipitation data from 23 weather stations of the potato growing area in central of Inner Mongolia from 1961 to 2017. The indices were used to analyze the distribution of precipitation resources and the characteristics of drought in these regions, and establish correlations with yield reduction of potato. The results showed that the PCP in the study area had a negative correlation with the precipitation during the growing season and showed a significantly downward trend, and the PCD in the east was earlier than that in the west. The areas with severe drought were mainly located in the middle of the study area. Drought levels were eased in the northwest and increased in the southeast. Yield of potato might be reduced in the year with PCD>0.37, PCP>39, SPI<0.13, or SPEI<0.34; and  the year with PCD> 0.48, PCP> 41, SPI<-0.54 or SPEI<-0.29 might be a disaster.

Key words: potato, drought index, spatio-temporal characteristics, yield reduction

摘要： 为了解内蒙古中部马铃薯主产区干旱发生程度对马铃薯产量的影响，选用内蒙古中部马铃薯主产区23个气象站1961—2017年逐日降水量数据，统计分析了近50年的降水集中度（PCD）、降水集中期（PCP）、标准化降水指数（SPI）和标准化降水蒸散指数（SPEI）的时空特征及其与马铃薯产量变化的响应关系。结果表明，从年际变化来看，PCD呈下降趋势，突变年份为1998年，表明研究区区域降水量年度内的分配更趋近于均匀；PCP、SPI和SPEI无明显趋势变化。从区域变化来看，PCD与马铃薯生长季的降水量呈负相关关系，即降水越少的地区降水越集中；东部的PCP要早于西部，平均值出现在6月25—30日之间；SPI和SPEI低值区主要位于中部。SPI和SPEI气候倾向率的空间分布表征西北部地区干旱程度有所缓解，东南部地区有所增强。PCD>0.37、PCP>39 候、SPI<0.13或SPEI指<0.34的年景马铃薯产量可能因干旱出现减产；PCD>0.48、PCP>41 候、SPI<-0.54或SPEI<-0.29的年份可能因干旱成灾。研究结果为内蒙古马铃薯干旱的防灾减灾提供了科学的决策依据。

关键词: 马铃薯, 干旱指数, 时空特征, 减产率