Spatial and Temporal Risk Assessment of Crops Induced by Natural Disasters in the Three Northeastern Provinces of China

[Purpose] Nowadays, risk assessment of crops induced by natural disasters just concerns on spatial variance of risk, which cannot meet the requirement that crop risk management would develop in the fine direction. Risk variance assessment in both space and time dimensions can help to enhance the results of risk assessment, and play an important role in risk management. [Contents] In this paper, the spatial and temporal risk assessment of crops induced by natural disaster including flood, draught, hail, freezing and typhoon was performed in the three northeastern provinces of China by using the disaster recording data and crops' planting area data. [Methods] In order to overcome the scarcity of disaster samples, information diffusion model was employed to calculate conditioned expected disaster affected ratio as risk measure. Furthermore, four types of spatial and temporal risk zonation models and two algorithms for recognizing the spatial-and-temporal risk clustering and outliers were proposed. [Results] Through the case study, risk variance rules in city-level and month-level was worked out to be used in enhancing high-risk zones recognition.