The response of Vegetation Index to Drought: Taking the extreme drought disaster between 2009 and 2010 in Southwest China as an example
Based on the 10-year (2001-2010) time series of Moderate-resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) products and meteorological station data in the area of Southwest China, we extracted the NDVI values for the footprint of meteorological measurements and calculated the percentage of precipitation anomaly (Pa) and D index (difference between precipitation and potential evapotranspiration) as two drought indices. We then involved the information on vegetation types (Vegetation type map of China's landmass, 2000) conducted a compressive spatial-temporal regression analyses against these two meteorological drought indices and NDVI anomaly at seasonal time scales. The results showing that: (1) For most vegetation types, NDVI anomaly significantly corresponded to D index with a lag of about one month (R2>= 0.7, P<0.01); (2) These correlations were higher for the drought-sensitive vegetation types (i.e. dry land: R2= 0.83; grassland: R2=0.71) than other types; (3) The spatial distribution of NDVI anomaly was relatively consistent with that of D index especially in drought season while it was only consistent with Pa in very drought season or for drought sensitive vegetation types.
NDVIdroughtpercentage of precipitation anomalyD indexSouthwest China
NETL
NSTL
万方数据
维普
