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ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Geohazards and Georisks

This article is part of the Research TopicMonitoring, Early Warning and Mitigation of Natural and Engineered Slopes – Volume VView all 12 articles

A Rainfall-Based Flash Flood Warning Method Integrating Spatial Stratification and Multi-Mode Discrimination

Provisionally accepted
Xiangning  LiuXiangning Liu1,2Yanhong  DouYanhong Dou1,2*Tianyu  LiuTianyu Liu3Min  XieMin Xie1,2
  • 1China Institute of Water Resources and Hydropower Research, Beijing, China
  • 2Research Center on Flood & Drought Disaster Prevention and Reduction of the Ministry of Water Resources, Beijing, China
  • 3Shandong Jianzhu University, Jinan, China

The final, formatted version of the article will be published soon.

Rainfall -based methods are widely used for flash flood monitoring and warning. However, the conventional approach of issuing an alert based on any single associated station exceeding a threshold leads to frequent false alarms, hindering timely evacuations. This study proposes a method integrating spatial stratification and multi-mode discrimination. The method innovatively classifies rainfall stations associated with each village according to the spatial relationships among station–village, station–watershed, and station–station pairs. A multi-mode warning framework combining single-station, multi-station, and areal rainfall warnings is developed, with the appropriate warning mode determined by the station–village distance and the upstream watershed area of the village. Validation was conducted in six representative villages across Fujian Province. These villages were selected to encompass diverse watershed characteristics and varying rainfall gauge densities, thereby forming a systematic and representative testing framework. Results demonstrate that, compared to the traditional method, the proposed approach maintains high detection rates for actual disasters while significantly reducing the false alarm rate. The new method completely eliminated the three false alarms generated by the traditional approach, demonstrating a substantial improvement in warning precision. Specifically, using single-station warnings for nearby stations ensures rapid response to local heavy rainfall, while multi-station and areal rainfall warnings for more distant stations effectively capture regional events and reduce false alarms caused by gauge failures or localized convective storms. By integrating the sensitivity of point rainfall information with the stability of regional rainfall patterns, the proposed method substantially enhances the reliability and robustness of flash flood warnings, providing strong technical support for timely evacuation and disaster risk reduction in mountainous flash flood prone regions.

Keywords: areal rainfall warning, false alarm rate, Flash flood warning, multi-station warning, single-station warning, warningaccuracy

Received: 31 Oct 2025; Accepted: 29 Nov 2025.

Copyright: © 2025 Liu, Dou, Liu and Xie. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Yanhong Dou

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