A 3D Copula Method for the Impact and Risk Assessment of Drought Disaster and an Example Application

Droughts have more impact on crops than any other natural disaster. Therefore, drought risk assessments, especially quantitative are significant in order to understand and reduce the negative impacts associated with droughts, a assessment includes estimating probability consequences of hazards. In achieve this goal, we built model based three-dimensional (3D) Copula function for proportion affected farmland areas (PAFA) idea internally combining duration, intensity, impact. This achieves “internal combination” characteristics rather an “external combination.” The results not only able provide at different levels that event (drought duration intensity) may cause, but also show occurrence each particular level. We took Huize County Mengzi Yunnan Province as application examples meteorological index (SPI), showed PAFAs obtained by method proposed paper were basically consistent actual two counties. Moreover, due always occurring before agricultural drought, can get SPI predictions next month or months further obtain abundant information warning its has values both theory practice.