Developing Real-Time Nowcasting System for Regional Landslide Hazard Assessment under Extreme Rainfall Events

Yuan-Chang Deng,Yu-Da Lyu,Jin-Hung Hwang

doi:10.3390/w13050732

Yuan-Chang Deng, Yu-Da Lyu + Show 1 more

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https://doi.org/10.3390/w13050732

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Abstract

In this research, a real-time nowcasting system for regional landslide-hazard assessment under extreme-rainfall conditions was established by integrating a real-time rainfall data retrieving system, a landslide-susceptibility analysis program (TRISHAL), and a real-time display system to show the stability of regional slopes in real time and provide an alert index under rainstorm conditions for disaster prevention and mitigation. The regional hydrogeological parameters were calibrated using a reverse-optimization analysis based on an RGA (Real-coded Genetic Algorithm) of the optimization techniques and an improved version of the TRIGRS (Transient Rainfall Infiltration and Grid-based Regional Slope-Stability) model. The 2009 landslide event in the Xiaolin area of Taiwan, associated with Typhoon Morakot, was used to test the real-time regional landslide-susceptibility system. The system-testing results showed that the system configuration was feasible for practical applications concerning disaster prevention and mitigation.

Highlights

During 7–10 August 2009, Typhoon Morakot brought strong southwesterly winds and extremely heavy rainfall
To execute the real-time TRIGRS analysis for the practical application of disaster prevention, we developed a real-time landslide-susceptibility analysis interface coded in Visual Basic programming language
Xiaolin is located in the Jiasian District, Kaohsiung City, southern Taiwan (Figure 3)

Summary

Introduction

During 7–10 August 2009, Typhoon Morakot brought strong southwesterly winds and extremely heavy rainfall. Rainfall exceeded 50 mm, with a cumulative total of more than 2500 mm. The extreme duration and intensity of the rainfall caused many landslides in the mountainous area near the village of Xiaolin. The village was destroyed and buried by debris from a deep-seated landslide, resulting in the loss of 500 lives. This was the most serious landslide tragedy in the history of Taiwan, which caused great public concern. A real-time regional landslide forecasting system for extreme-rainfall conditions would contribute to the development of a nation-wide early warning system to prevent such a landslide disaster

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