Prediction of Drought in Summer and Autumn in Hebei Province Based on SPEI Index
In order to obtain drought prediction models for summer and autumn in Hebei Province,in this paper,based on standardized rainfall Evapotranspiration Index(SPEI)and extreme learning Machine model(ELM),five optimization algorithms,namely sparrow search algorithm(SSA),bee colony algorithm(ABC),bat algorithm(BA),particle swarm optimization algorithm(PSO)and genetic algorithm(GA),were used to construct an optimized ELM model for establishing a regional SPEI index estimation model.The results showed that:SSA-ELM model had the highest precision and good portability among all models,and can be used as a drought prediction model in summer and autumn of Hebei Province.