Risk Assessment of Drought, Based on IDM-VFS in the Nanpan River Basin, Yunnan Province, China

A new model for risk assessment of agricultural drought based on information diffusion method and variable fuzzy sets (IDM-VFS) was proposed. In addition, an integrated index system of agricultural drought risk was established. In the proposed model, IDM was employed to calculate the agricultural drought risk level classification standards, and then the VFS was adopted to assess the dangerousness, sensitivity, vulnerability, and comprehensive risk of agricultural droughts. In the present study, Nanpan River Basin was employed to assess the agricultural drought risk with the proposed model. The results showed that KaiYuan, ShiZong, QiuBei, and ZhanYi have higher dangerousness, due to water shortage. GuangNan have higher sensitivity and vulnerability because of lower drought resistance level and higher crop planting proportion. The comprehensive agricultural drought risk shows apparent regional characteristics: the central, western and northwestern counties have lower risk than the eastern counties. Moreover, most areas of the Nanpan River Basin are of moderate agricultural drought risk grade. The results are consistent with the actual situation of Nanpan River Basin and verify the model’s effectiveness. The study can provide a scientific reference in drought risk management for local governmental agencies.