Drought dynamics and impacts on vegetation in China from 1982 to 2011

We investigated the drought dynamics and their impacts on vegetation change in China from 1982 to 2011 using the standard precipitation index (SPI) and the normalized difference vegetation index (NDVI) anomaly, which were calculated from meteorological and satellite-derived NDVI data, respectively. The trends in the change of SPI and vegetation were explored based on the non-parametric Mann-Kendall (MK) test and Sen's slope test, and the relationship between these trends was examined. The results were as follows: (1) For China as a whole, although the long term trend of drought-impacted areas changed little (−0.045% ⁄10 a) over the past 30 years, Dry trends were identified in northeastern and southwestern China. (2) The annual vegetation growth at the national scale showed an increasing trend, with a rate of 0.008%⁄10 a from 1982 to 2011; cropland vegetation presented the largest increase in NDVI (p < 0.05). (3) Droughts that occurred during the growing season and pre-growing season both had large negative impacts on vegetation growth, and significant influences were found in northern China, especially in the northwestern area. Compared to the northern areas, the NDVI in southern China appeared to benefit from warming temperatures.