Development of a new rainfall‐triggering index of flash flood warning‐case study in Yunnan province, China

Relying upon rain gage data and official statistics of flash flood events with casualties, this study proposes a new rainfall triggering index, β, defined as the ratio of accumulated rainfall to intraday rainfall, which effectively divides floods into events triggered by heavy intraday rainfall (0 < β ≤ 5) and those triggered by high cumulative rainfall (β > 5). Then, historical disaster events were used to evaluate the performance of the proposed index. This paper stretches the thought of flash flood warning method and provides the reference for flood‐prone regions.