2002-2016年锡林郭勒草原干旱时空特征

随着气候变暖，干旱越发普遍，关于干旱的研究一直是国内外学者关注的热点。采用MODIS产品数据计算温度植被干旱指数TVDI，反演2002—2016年锡林郭勒草原植被生长期土壤干湿状况，对干旱的时空分布特征进行了研究。结果表明:锡林郭勒草原在各时相几乎都处于一种干旱的状态，但主要以轻旱和中旱为主，重旱现象较少。从时间上看，6月、8月和9月份易出现大规模干旱，中旱占较大比例，而7月、10月上旬容易发生大面积的轻旱。空间上，西部地区以轻旱为主，中旱及重旱现象较少；中东部、南部地区干旱事件的发生频率较高，且大面积的中旱及局部的重旱现象较为普遍；中部及北部地区也常常会发生不同等级的干旱现象，出现严重干旱的频率也较高。

Temporal and Spatial Characteristics of Drought in the Xilingol Grassland From 2002 to 2016

With the climate warming, drought is becoming more and more common. The study on the drought has been a hotspot for decades worldwide. The temperature and vegetation dryness index was calculated using the MODIS products to evaluate the temporal and spatial characteristics of drought in the Xilingol grassland from 2002 to 2016. The results showed that the Xilingol grassland was in drought at all phases, but mainly in light drought and moderate drought with less severe drought; temporally, the large-scale of moderate drought was prone to occur in June, August and September; the light drought occurred widely in July and the first half of October; spatially, the light drought mainly occurred in the western area, while large scale of moderate drought and regional severe drought were found in the middle of east and southern part of the study area. Different levels of drought were also occurred in the central and northern Xilingol, where severe drought was frequent.