文章基本信息

标题：A susceptibility-based rainfall threshold approach for landslide occurrence
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作者：Monsieurs, Elise ; Dewitte, Olivier ; Demoulin, Alain 等
期刊名称：Natural Hazards and Earth System Sciences
电子版ISSN：2195-9269
出版年度：2019
卷号：19
期号：4
页码：775-789
DOI：10.5194/nhess-19-775-2019
语种：English
出版社：Copernicus Publications
摘要：Rainfall threshold determination is a pressing issue inthe landslide scientific community. While major improvements have been made towards more reproducible techniques for the identification of triggeringconditions for landsliding, the now well-established rainfall intensity orevent-duration thresholds for landsliding suffer from severallimitations. Here, we propose a new approach of the frequentist method forthreshold definition based on satellite-derived antecedent rainfallestimates directly coupled with landslide susceptibility data. Adopting abootstrap statistical technique for the identification of thresholduncertainties at different exceedance probability levels, it results inthresholds expressed as AR = (α±Δα)⋅S(β±Δβ), where AR is antecedent rainfall (mm), S islandslide susceptibility, α and β are scaling parameters, andΔα and Δβ are their uncertainties. The mainimprovements of this approach consist in (1) using spatially continuoussatellite rainfall data, (2) giving equal weight to rainfall characteristicsand ground susceptibility factors in the definition of spatially varyingrainfall thresholds, (3) proposing an exponential antecedent rainfallfunction that involves past daily rainfall in the exponent to account forthe different lasting effect of large versus small rainfall,(4) quantitatively exploiting the lower parts of the cloud of data points, mostmeaningful for threshold estimation, and (5) merging the uncertainty onlandslide date with the fit uncertainty in a single error estimation. Weapply our approach in the western branch of the East African Rift based onlandslides that occurred between 2001 and 2018, satellite rainfall estimatesfrom the Tropical Rainfall Measurement Mission Multi-satellite PrecipitationAnalysis (TMPA 3B42 RT), and the continental-scale map of landslidesusceptibility of Broeckx et al. (2018) and provide the first regional rainfallthresholds for landsliding in tropical Africa.