Spatial-temporal distribution and driving mechanism of drought predictability in the Loess Plateau
Under the changing environment,global drought occurs frequently,which has a great impact on social economy and ecology.Current researches focus on the research and development of drought forecasting technology,but pay little attention to the theory of drought forecasting,such as the temporal and spatial distribution and driving mechanism of drought predictability.This work took the Loess Plateau as the research object,constructed a support vector machine model to forecast regional drought from 2008 to 2019,and quantified drought predictability with Kling-Gupta Efficiency(KGE).Then the spatial distribution characteristics of drought predictability at different time scales were investigated,and the key factors influencing changes in the distribution of drought predictability were identified.The results showed that the drought predictability of the Loess Plateau showed an upward trend with the increase of the time scale.The KGE average of SPEI12 was 73.8%higher than that of SPEI1.The predictability of seasonal drought is the highest in autumn,followed by summer,spring and winter.The drought predictability showed spatial heterogeneity,showing a high distribution pattern in the north and low distribution pattern in the south,and the drought predictability in the central Loess Plateau in spring and in the northwest desert region of the Loess Plateau in winter was extremely low.There were differences in the main factors affecting the predictability of inter-seasonal drought.The highest explanatory power in autumn was temperature,summer and spring was aridity index(AI),and winter was the coupling of air-sea PRE_AMO.Meanwhile,the influence of both variable factors on drought predictability of the Loess Plateau was significantly higher than that of single factor.This study provided a new insight into the predictability of drought and was helpful to further improve the ability of drought forecasting and early warning in the Loess Plateau.
the Loess Plateaudrought forecastgeographic detectorSPEIpredictability
NETL
NSTL
万方数据
