Inner Mongolia, Monsoon marginal zone, Climate changes,Drought index, Time-space evolution
Inner Mongolia (97 ° 12'E -126 ° 04 'E, 37 ° 24' N-53 ° 23 'N) in the hinterland of Eurasia, which spans large from north to south and extends long from east to west is a typical monsoon’s boundary area. Winter climate here, under the influence of Siberia -Mongolia high, is characterized by dry and cold. while in summerits hot and rainy, rain in hot season, by the effect of East Asian summer monsoon. And the amount of precipitation in this region is controlled by the outbreak of the time intensity and duration of the summer monsoon. Therefore, the inter-annual changes in precipitation is intense, regional difference is obviously, and the spatial and temporal distribution is very uneven. And under the great background of global warming, Inner Mongolia has become the region where the droughts have the most frequent occurred, the most widely distribute and the greatest influenced, receives great concern to all levels of government and academia. Drought induced shortage of water resources and lead to serious ecological and environmental problems, resulting in huge economic losses and the constraint and limitations of regional economic and social sustainable development in the region. In order to make a deeper understanding of the dynamic process of aridity in Inner Mongolia, the monthly observations of 94 meteorological stations in this region and its surrounding were used and five Drought Index were selected, the drought conditions of 60a in the study area were comprehensively analyzed, and combined with the comparative analysis and empirical analysis of various drought index, evaluated the sensitivity of the drought index, indicated the applicability of drought index in the area, and thus accurate understanding of the Inner Mongolia arid characteristics, regular cycle, then providing a scientific basis for our region and drought relief work ultimately.