Relationship of drought severity index with climatic factors on the Tibetan Plateau

Abstract

It remains unclear how drought is varying under climatic change. Quantifying the relationship between drought and climatic factors is crucial for predicting future drought risk under global climatic change. Correlations of annual drought severity index (DSI) with climatic factors were examined from 2000 to 2011 on the Tibetan Plateau. Spatially averaged DSI increased with increasing precipitation and minimum relative humidity, but decreased with increasing sunshine. The degrees of correlation between DSI and climatic factors varied with vegetation types. The change magnitude of DSI decreased with increasing temperature, precipitation and vapor pressure, but increased with increasing wind speed and sunshine. Therefore, clarifying the correlation between drought and climatic change need consider ecosystem types and their local climate on the Tibetan Plateau.