| 29 Apr 2026
Review article: Rainfall-Induced Landslide Early Warning System: Advances, Gaps, and Perspectives
Abstract. This review is necessary at this time to provide a comprehensive evaluation of the rainfall-induced landslide early warning system (LEWS) through the lens of the United Nations ‘Early Warnings for All’ (EW4All) framework. This study integrates EW4All pillars, incorporates overlooked literature, examines information sharing in academic publications, and evaluates the global feasibility of implementing EW4All for LEWS. Of 61 rainfall-induced LEWS identified in the literature covering 23 countries, 14 are considered operational, meaning they are currently implemented and actively used for warning purposes, across only 10 countries. Among local, regional, and national systems, local LEWS is often less scalable and more resource-intensive. Most operational systems target debris flows and shallow landslides and rely mainly on rainfall thresholds. While some include susceptibility maps, risk maps are largely absent. Real-time sensor data are used in some systems; however, high maintenance costs limit scalability. Reliability is further constrained by data scarcity, limited forecast verification, suboptimal use of AI, and the lack of standardised forecasting approaches. Community engagement and multi-hazard integration remain limited. Although EW4All is transformative, implementing effective LEWS in rainfall-induced landslide-prone areas worldwide by 2027 remains impractical without localised approaches, sufficient funds, and resources.
Competing interests: At least one of the (co-)authors is a member of the editorial board of Natural Hazards and Earth System Sciences.
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This manuscript deals with an important topic, namely rainfall-induced landslide early warning systems (LEWS) framed within the United Nations “Early Warnings for All” (EW4All) initiative. The subject is highly appropriate for NHESS, as it combines physical hazard forecasting with operational, institutional, and governance aspects related to risk reduction that are often neglected. The international perspective adopted is valuable, as it allows the reader to appreciate the heterogeneity of LEWSs implementation. The paper reflects the effort in reviewing a lot of literature. A clear added value is the attempt to interpret LEWS literature through the EW4All framework, which provides a wide perspective compared to more conventional reviews focused mainly on rainfall thresholds or modeling approaches. The manuscript brings attention to several important operational issues, including data limitations, the warning dissemination, and the role of community involvement. At the same time, a recurring aspect is the repeated emphasis on a limited number of concepts, EW4All, the scarcity of operational systems, data constraints, and the use of artificial intelligence. These are central themes, but they tend to reappear too frequently across sections, sometimes without adding new insight. A clearer structuring of these ideas, with less repetition and more cross-referencing, would make the argument better. I recommend a major revision before that the manuscript can be reconsidered for publication. My comments are provided in the attached file.