Abstract:

One of the most persistent and damaging natural hazards is the migratory locust plague in China,which is the most widespread locust species,and poses a threat to agricultural production and,subsequently,livelihoods and food security.In this study,based on the data on the history reported occurrence data of locust disasters,we applied MaxEnt niche models to predict and analyze the distribution area of the locust outbreak risk for three main species of migratory locust in China.It consists of a geographical information system,the spatial distribution of the locust outbreak risk for the Asian migratory locust (Locusta migratoria migratoria (Linnaeus)),the Oriental Migratory Locust（Locusta migratoria manilensis (Meyen) ) and the Tibetan migratory locust (Locusta migratoria tibetensis Chen) were mapped at 3 km×3 km resolution ,and the degree of outbreak risk is evaluated.The results of the migratory locust plague probability modelling displays a heterogeneous distribution of locust disasters risk probability in China.The area of low to high risk for three species of locust infestation is 3 158 667 km2,3 958 002 km2 and 1 250 037 km2 respectively,accounted for 33.43%,41.96% and 13.25% of China’s total land area respectively.The disaster risk areas of L.migratoria migratoria and L.migratoria manilensis have a spatial overlap of 757 890 km2,mainly distributed in the farmingpastoral ecotone and the south region of China.The geographic patterns of the spatial distribution of the locust outbreak for three species along latitudinal and longitudinal gradients are highly consistent with the three major natural geographical areas in China.The predicted results were then tested by ROC curves using suitability indexes (AUC),the mean AUC across eight different spatial scales is ranged from 0.924 to 0.987.The Jackknife test analysis reveals the linkages between locust infestation risk and main environmental factors and the results show that the difference of the dominant influence factors of the three species of migratory locust disasters leads to the significant differences and heterogeneity of geographical distribution pattern in China.The results show that the probability of locust disaster outbreak is simultaneously restricted by the adaptability of different migratory locust species to the climate environment and their geographical space isolation.The study will provide vital information to help manage and control the outbreak risk of the migratory locust disaster.

Key words: migratory locust plague, disaster outbreak risk, geographical distribution, suitability, MaxEnt