Accounting for satellite rainfall uncertainty in rainfall-triggered landslide forecasting

Binru Zhao, Qiang Dai*, Lu Zhuo, Jingqiao Mao, Shaonan Zhu, Dawei Han

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

With an increasing spatial/temporal resolution and accuracy of satellite rainfall products, their potential in landslide forecasting has gradually been recognized. Despite this, few studies have evaluated the effect of satellite rainfall uncertainty on landslide forecasting. In this study, a specific procedure is developed to account for the satellite rainfall uncertainty in rainfall-triggered landslide forecasting. We select the Emilia-Romagna region in northern Italy as the study area, and the NASA GPM-based IMERG Early Run product as the representative of satellite rainfall estimates. An error model for satellite rainfall is first constructed based on the distribution of GR|SR (gauge rainfall | satellite rainfall), which consists of a deterministic distortion component and a stochastic component. With the error model, the satellite rainfall uncertainty is characterized by generating the ensemble of probable “true rainfall” for each rainfall condition responsible for landslides. Then the generated rainfall ensembles are applied to the definition of rainfall thresholds using the bootstrap technique. Finally, the landslide forecasting performance of rainfall thresholds is evaluated with the criteria of hit rate, false alarm rate and the Euclidean distance to the perfect point. Results show that the simulated uncertainty band of the IMERG product encompasses most of the rain gauge measurements. The IMERG uncertainty also propagates to the rainfall thresholds, especially when rainfall events have long durations, the cumulated event rainfall that is likely to trigger landslides has a larger variation range. Besides, the landslide forecasting performance for thresholds that account for IMERG uncertainty varies a lot in terms of false alarm rate from 0.50 to 0.75, demonstrating that it is necessary to take into account the uncertainty associated with the IMERG Early Run product when using it to construct rainfall thresholds for landslide forecasting.

Original languageEnglish
Article number108051
JournalGeomorphology
Volume398
Early online date27 Nov 2021
DOIs
Publication statusPublished - 1 Feb 2022

Bibliographical note

Funding Information:
The authors acknowledge Dr. Matteo Berti for providing landslide data and Arpae Emilia-Romagna organization for providing rain gauge measurements. This study is supported by the National Natural Science Foundation of China (Nos. 42101078 ), Project funded by China Postdoctoral Science Foundation (Nos. 2020M681660 ) and the National Natural Science Foundation of China (Nos. 41871299 ).

Publisher Copyright:
© 2021 Elsevier B.V.

Keywords

  • Landslide forecasting
  • Rainfall threshold
  • Satellite rainfall uncertainty

Fingerprint

Dive into the research topics of 'Accounting for satellite rainfall uncertainty in rainfall-triggered landslide forecasting'. Together they form a unique fingerprint.

Cite this