基于多种干旱指数的长江中下游五省干旱监测与对比

Monitoring and Comparison of Drought in Five Provinces of the Middle and Lower Reaches of the Yangtze River Based on the Multiple Drought Indices

利用多源遥感数据和稻谷产量资料,采用降水条件指数(PCI)、植被状态指数(VCI)、土壤湿度条件指数(SMCI)、温度条件指数(TCI)以及优化植被干旱指数(OVDI)5种干旱指数,对2012、2013年长江中下游五省的干旱状况进行监测。在此基础上,以标准化降水指数(SPI)和作物减产率为参考指标,对上述5种干旱指数在该区域的适用性进行比较分析。结果表明:PCI、SMCI更适用于长江中下游五省的干旱监测,而TCI、VCI不适合单独用于该地区的干旱监测。在2012、2013年,长江中下游五省发生了不同程度的干旱,其中2013年的干旱更严重(波及范围更广、发生频次更高)。2012年的干旱主要集中在1—2月和6—8月两个时段,旱区集中在北部地区,大致呈东北—西南向的条带状分布;而2013年的干旱主要集中在1—2月和6—10月两个时段,旱区覆盖了整个研究区域,且各省旱情不同步。

Based on the multiple remote sensing data from satellite and rice yield, the temporal and spatial distribution of drought was monitored in five provinces of the middle and lower reaches of the Yangtze River (MLRYR) in 2012 and 2013 by using the multiple drought indexes including precipitation condition index (PCI), vegetation condition index (VCI), soil moisture condition index (SMCI), temperature condition index (TCI) and optimized vegetation drought index (OVDI). And on this basis the applicability of five drought indexes in this area was contrasted by taking standardized precipitation index (SPI) and reduction rate of crop as reference. The results show that PCI and SMCI were more suitable to monitor the drought, while TCI and VCI weren’t suitable to monitor the drought alone in five provinces of the MLRYR. The drought with different levels occurred in five provinces of the MLRYR in 2012 and 2013, and the drought in 2013 was more serious (the range of drought was wide and the frequency was high) than that in 2012. The drought mainly occurred from January to February and June to August of 2012, and the drought region with NE-SW strip distribution concentrated in the north of five provinces of the MLRYR. However, the drought was mainly occurred from January to February and June to October of 2013, and the drought covered the whole area, but the drought situation in each province wasn’t synchronous.