关键词: 干旱, 时空特征, SPI, VHI, 长江中下游地区

Abstract: In the middle and lower reaches of the Yangtze River, drought has had serious impacts on economic development with increasing frequency, intensity, disaster scope and duration over the past six decades. In this study, 60-year historical precipitation dataset and 40-year remote sensing dataset were constructed to calculate the meteorological drought and agricultural drought indexes. The drought monitoring index series curves were established based on standardized precipitation index (SPI) and vegetation health index (VHI). The spatial distribution, seasonal distribution, occurrence frequency and other indicators of drought were analyzed to explore the drought’s spatial-temporal differentiation laws. The results show that drought events in the study area are notably season-dependent, with high frequency in spring and summer, and low frequency in autumn and winter. Droughts in the north and west part were more serious than those in the south and east part. Northern Hubei and southern Hunan were prone to suffer from droughts.

Key words: drought, spatial-temporal characteristics, SPI, VHI, middle and lower reaches of Yangtze River