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针对2011年长江中下游湖北、湖南、江西、安徽、江苏5省春、夏旱的发展过程和空间演变态势,利用2011年4～8月中分辨率MODIS每16d合成产品MOD13A2-NDVI数据,构建植被状态指数距平(AVCI)进行干旱监测及分级。结果表明:AVCI指数能监测出长江中下游5省春、夏季干旱的发展变化,在整个监测期内,长江中下游湖北、湖南、江西、安徽、江苏5省大部分地区AVCI值偏低,出现大范围干旱持续的现象,并且表现出明显的旱情加重—旱情减轻—旱情再加重的变化趋势。前期春季干旱主要分布在湖北中东部、安徽中南部、江苏南部、湖南东北部、江西北部地区,后期伏旱则在5省大范围发展。春旱干旱程度比伏旱更甚,其中春季旱情在平原地区更为严重。
According to the development process and spatial evolution of spring and summer drought in Hubei, Hunan, Jiangxi, Anhui and Jiangsu provinces in the middle and lower reaches of the Yangtze River in 2011, MOD13A2-NDVI data of synthetic products were analyzed every 16 days from April to August in 2011, Vegetation status index anomaly (AVCI) for drought monitoring and grading. The results show that the AVCI index can monitor the development of spring and summer drought in five provinces in the middle and lower reaches of the Yangtze River. During the whole monitoring period, the AVCI values of most areas of Hubei, Hunan, Jiangxi, Anhui and Jiangsu provinces in the middle and lower reaches of the Yangtze River are low, A wide range of drought continued phenomenon, and showed a clear increase in the drought - reduce the drought situation - the trend of increasing drought again. Early spring droughts are mainly distributed in the central and eastern Hubei, central and southern Anhui, southern Jiangsu, northeastern Hunan, northern Jiangxi, the latter part of the drought in a large-scale development in five provinces. Spring drought is even worse than drought, with spring drought in the plains more serious.