2000年以来内蒙古生长季旱情变化遥感监测及其影响因素分析

为探讨内蒙古旱情状况及其影响因素,利用MODIS 16 d合成的植被指数产品数据MOD13A2和8 d合成的地表温度产品数据MOD11A2构建Ts-NDVI特征空间,计算温度植被干旱指数（TVDI）,基于内蒙古2000—2017年生长季每16 d的TVDI分析了近18年来内蒙古生长季旱情时空分布特征,结合气温和降水资料初步探讨了旱情变化的影响因素。结果表明：（1）2000—2017年内蒙古生长季TVDI平均值为0.6,重旱和中旱所占面积最大,其中2007年、2010年为旱情最为严重的年份。内蒙古干旱空间分异明显,西南部以轻旱为主,中部地区以中旱为主,大兴安岭以西的呼伦贝尔草原等地旱情严重。（2）近18年内蒙古生长季干旱程度呈现轻微加重趋势,年际变化值θ_slope介于-0.07~0.7之间,阿鲁科尔沁旗东北部至霍林河一带旱情加重趋势最为严重,阿荣旗和扎兰屯等农业生产地区旱情有轻微加重趋势。（3）2017年内蒙古生长季以区域性和局域性干旱为主,6月和9月干旱最为严重,呼伦贝尔草原和鄂尔多斯高原西部干旱发生频率高且程度重。（4）内蒙古干旱影响因子分析结果表明,TVDI值与气温呈正相关、与降水和坡度呈负相关、与小于1300 m的高程呈正相关、与大于1300 m的高程呈负相关关系。内蒙古生长季TVDI与气温和降水偏相关分析结果表明,锡林郭勒盟苏尼特左旗北部、呼伦贝尔鄂伦春自治旗和呼伦贝尔草原等地旱情与气温正相关关系较为显著（P<0.01）,锡林郭勒盟东北部干旱情况与降水负相关关系较为显著（P<0.01）,其中,气温对旱情的影响强于降水。

Remote sensing monitoring and analysis of influencing factors of drought in Inner Mongolia growing season since 2000

This article takes Inner Mongolia Autonomous Region as the research area. The TsNDVI space is created by using MODIS 16 d synthetic vegetation index product data MOD13 A2 and 8 d synthetic surface temperature product data MOD11 A2. Additionally, based on the temperature vegetation dryness index(TVDI) in Inner Mongolia during 2000-2017 growing season, the spatiotemporal characteristics of drought in the study area are analyzed,and the influencing factors of drought are discussed by using air temperature and precipitation data. The results show that:(1) The average TVDI of Inner Mongolia was 0.6 in the growing season from 2000 to 2017, and the area of heavy and moderate drought was the largest, during which 2007 and 2010 are the years with the most severe drought. The spatial differentiation of drought was obvious. The moderate and slight drought mainly occurred in the central and southwest parts, respectively, and severe drought was observed in the Hulun Buir grassland to the west of Da Higgan Mountains.(2) In the past 18 years, the drought degree in Inner Mongolia showed a slight increase trend, and the interannual variation θsloperanged from-0.07 to 0.7.(3) In the growing season of 2017, drought was most serious in June and September, and drought occurred frequently and severely in the Hulun Buir grassland and western Ordos Plateau.(4) TVDI is positively correlated with the average temperature, negatively correlated with the cumulative precipitation and slightly negatively correlated with the slope, positively correlated with the elevation of less than 1300 m, and negatively correlated with the elevation of greater than 1300 m. The analysis of partial correlation between TVDI and climatic factors in Inner Mongolia growing season shows that the drought in northern Sonid Left Banner of Xilin Gol League, Oroqen Autonomous Banner and Hulun Buir grassland has a significant positive correlation with temperature(P<0.01), and that in northeastern Xilin Gol League has a significant negative correlation with precipitation(P<0.01);among the climatic factors, the average temperature has a stronger impact on drought than cumulative precipitation does.