Use of sustainability index and cellular automata-Markov model to determine and predict long-term spatio-temporal variation of drought in China

Abstract Drought threatens both social and economic development, and it is necessary to develop a comprehensive drought index and a method of predicting future drought occurrence to enable effective associated management and warnings. However, barring a few, current drought indexes are not comprehensive; for example, they ignore the ability to recover from drought, and drought prediction does not consider spatial and temporal characteristics. In this study, the Sustainability Index (SI), which considers reliability, resilience, and vulnerability, was used to identify agricultural drought, and the Cellular Automata-Markov (CA-Markov) was used in drought prediction. In order to reflect the characteristics of crop water deficit in agricultural drought, this paper uses the Permanent Wilting Point (PWP) as the threshold; droughts are defined as soil moisture