摘要：In studying indigenous climate knowledge, two approaches can be envisioned. In the first, traditional knowledgeis a cultural built-in object; conceived as a whole, its relevance can be assessed by referring to other cultural, economic, ortechnical components at work within an indigenous society. In the second, the accuracy of indigenous climate knowledge isassessed with western science knowledge used as an external reference. However, assessing the accuracy of indigenous climateknowledge remains a largely untapped area. We aim to show how accurate the culturally built indigenous climate knowledgeof extreme climatic events is, and how amenable it is to fuzzy logic. A retrospective survey was carried out individually andrandomly among 195 Eastern African farmers on climatic reasons for loss of on-farm crop diversity from 1961 to 2006. Morethan 3000 crop loss events were recorded, and reasons given by farmers were mainly related to droughts or heavy rainfall. Chi-square statistics computed by Monte Carlo simulations based on 999 replicates clearly rejected independence between indigenousknowledge of drought and heavy rainfall that occurred in the past and rainfall records. The fuzzy logic nature of indigenousclimatic knowledge appears in the clear association of drought or heavy rainfall events, as perceived by farmers, withcorresponding extreme rainfall values, contrasting with a fuzzy picture in the intermediate climatic situations. We discuss howthe cultural built-in knowledge helps farmers in perceiving and remembering past climate variations, considering the specificityof the contexts where extreme climatic events were experienced. The integration of indigenous and scientific climate knowledgecould allow development of drought monitoring that considers both climatic and contextual data
