【摘要】 基于1982—2013年内蒙古地区41个站点的气象数据和GIMMS遥感数据,以标准化降水蒸散指数(SPEI)表征干旱状况,以归一化植被指数(NDVI)表征植被状况,对内蒙古地区干旱和植被的时空变化特征进行分析,探讨植被对干旱变化的响应。结果表明,(1)1982—2013年,内蒙古地区总体呈轻微干旱化趋势,东、中、西部对气候变化的响应具有明显的地域差异,蒙东地区的干旱化趋势较为显著,其次为蒙中地区,蒙西地区干旱有所缓解;32年间,林地和草地的SPEI均呈下降趋势,耕地的SPEI值变化不明显。(2)全区NDVI值在空间上呈东高西低的分布特征,东、中、西部的年均NDVI值均呈增长的趋势,其中蒙西地区增速较快;蒙中和蒙西地区NDVI值上升面积均超过50%,蒙东地区NDVI的下降面积超过50%;耕地NDVI上升面积达到77.77%,草地上升面积为56.74%,林地略有下降。(3)不同地区植被状况与干旱状况相关性存在差异,蒙中地区相关系数最大,蒙东次之,蒙西最小;不同时段植被对干旱的响应程度不同,三地植被均表现为对4～5月干旱响应较弱,对6～9月的干旱响应较强。更多还原

【Abstract】 The characteristics of drought evolution between 1982 and 2013 in Inner Mongolia were studied using standardized precipitation evapotranspiration index(SPEI) calculated based on daily meteorological data from 41 meteorological stations. What’s more, a time series data set(1982—2013) of normalized difference vegetation index(NDVI) was used to assess the spatial-temporal dynamics of vegetation. We also explored the relationship between drought and vegetation condition. The resultsof this study are:(1) During the period of 1982 and 2013, the entire Inner Mongolia had a slight drought trend, while the three sub-regions of Inner Mongolia showed different responses to climate change. The drought trend was relatively significant in the east of Inner Mongolia, and not obvious in the middle of Inner Mongolia, while drought condition in the west of Inner Mongolia was relieved. The SPEI value in forest and grassland had a decreasing trend, and the SPEI in farm land remained stable.(2) The distribution pattern of NDVI was high in the east and low in the west. The NDVI of three sub-regions in Inner Mongolia all had an increasing trend, while that in the west part increased the fastest. The area with increasing NDVI in the middle and west of Inner Mongolia exceeded 50%. The area with increasing NDVI of crop land made up 77.77%, and the grassland was 56.74%, while the forest showed a decreasing trend.(3) The relationship between vegetation and drought in different regions of Inner Mongolia was different. Correlation coefficient in the middle part was the highest, followed by that in the east part, while that in the west part was the lowest. The response of vegetation to drought in different periods was different, which was weak from April to May, and strong from June to September.更多还原