A critical review on rainfall induced landslide occurrences and early warning systems
Kuntal Ghosh, Rajib Saha
Abstract
Mitigating landslide risks involves a multifaceted approach, and one effective strategy is the implementation of early warning systems. These systems serve as a vital tool for alerting authorities and the public to potential landslide events, thereby enabling proactive risk management and reduction. Numerous studies have outlined the essential components and skills required for the effective design and implementation of landslide early warning systems (LEWS), emphasising the importance of interdisciplinary collaboration and stakeholder engagement. This review examines 11 operational LEWSs worldwide, specifically designed to reduce the impacts of rainfall-induced landslides. These systems generally adhere to a four-stage model comprising: setting, modelling, warning and response. Typically, governments oversee these systems, which can result in limited and incomplete information availability. This review synthesises data from scientific literature and websites to provide a comprehensive overview. The examined early warning systems primarily rely on rainfall monitoring, utilising rain gauges as the primary instrument. Thresholds are established to trigger warnings, and meteorological models are employed to predict rainfall intensity. When predicted rainfall exceeds these thresholds, warnings are issued to prepare both the public and relevant agencies for potential landslide events.