An Analysis of the Spatial-Temporal Characteristics of Drought in Guangdong Based on Vegetation Condition Index from 2003 to 2017

The temporal and spatial changes of drought in Guangdong Province in recent years were studied. The vegetation condition index (VCI) was calculated using MODIS surface reflectance data of 8 days and 250m resolution. The spatial and temporal characteristics and trend of drought in Guangdong were analyzed using trend analysis, frequency analysis and the Mann-Kenddall trend test. The results show that the average VCI of Guangdong has been rising significantly from 2003 to 2017, and the trend rate of VCI change in more than 80.3% of the whole area is positive, indicating that the drought in most regions of the province is alleviated in the study period. The frequency of drought in most regions of the province is between 0.2 and 0.6, the main drought is moderate drought(frequency: 0.2-0.4), and the severe drought is rare (frequency: 0-0.2). The proportion of drought-affected area in Guangdong has also been decreasing gradually, and the proportions of moderate and severe drought-affected areas show the same trend. Compared with 2003, the proportion of drought-affected area in 2017 decreased by 39.5%. In gene-ral, the severity of drought in Guangdong is decreasing year by year.