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Conditions and morphogenetic role of the 2018 and 2021 debris flows in Starorobociański Cirque, Western Tatra Mts.

Siemek Dawid, Gorczyca Elżbieta

Landform Analysis

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2023

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Vol. 42

63--73

EN

In this study we used geomorphologic mapping, precipitation analysis and archival photomaps to study debris flows in the Starorobociański Cirque, which were renewed in 2018 and 2021. Debris flow in 2021 was most likely the largest single flow recorded in the Polish Western Tatras in the twenty first century. It reached a length of about 870 m and it covered an area of 0.62 to 0.65 ha. We set July 14, 2021, as the date of debris flow initiation and 52.1 mm·d−1 as its threshold value. This is one of the lowest values provided in the literature for such flows in the Western Tatra Mts. On the contrary, debris flow which occurred July 18, 2018 was linked to threshold value of 150.5 mm·d−1. On the basis of former debris flow occurrence as well as precipitation analysis we interpret the appearance of debris flow in 2021 as an effect of short and intense rainfall.

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Rainfall Threshold for Landslide Warning in Southern Thailand – An Integrated Landslide Susceptibility Map with Rainfall Event – Duration Threshold

Salee Rattana, Chinkulkijniwat Avirut, Yubonchit Somjai, Bui Van Duc

Journal of Ecological Engineering

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2022

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Vol. 23, nr 12

124--133

EN

Southern Thailand is one of hotspots for landslides. So far, the rainfall triggered landslides in this region caused many sufferers and fatalities. On the basis of the rainfall data that triggered ninety-two landslide events during 1988–2018 and the landslide susceptibility maps published by the Department of Mineral Resources (DMR), this study introduced rainfall event-duration (ED) thresholds, namely EDm and EDh thresholds, for the places classified as the modest and the huge susceptibility levels, respectively. The modest susceptibility is a combination of very low, low, and moderate landslide susceptibility levels indicated in DMR maps. The huge susceptibility is a combination of high and very high landslide susceptibility levels indicated in DMR maps. Indicated by an area under the receiver operating characteristic curve (AUC), the EDm and EDh thresholds yielded the significantly better predictability than the original threshold did. Furthermore, the EDm threshold yielded the perfect prediction with AUC of 1.00.

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Rainfall-Induced Landslide Thresholds Development by Considering Different Rainfall Parameters: A Review

Mansor Maturidi Abdul Muaz Abu, Kasim Norhidayu, Abu Taib Kamaruddin, Wan Azahar Wan Nur Aifa

Journal of Ecological Engineering

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2021

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Vol. 22, nr 10

85--97

EN

This paper reviews the development of landslide thresholds from the perspective of rainfall and climate patterns. For certain, geology, morphology, lithology, etc., contribute to the initiation of the mass movement. However, the role of rainfall as the triggering mechanism of the landslide is vital as well. It has been proven by many researchers from various studies worldwide that have proposed the rainfall thresholds by utilising different rainfall parameters. The outcome of their studies is interesting, since different regions have diversified patterns of rainfall that produce a variety of threshold models. Therefore, from various published papers on rainfall thresholds, this paper studied the variety of rainfall parameters that have been utilised in establishing the rainfall threshold for landslide prediction. Instead of providing a better understanding regarding the application, this review aimed to cultivate the following study for deriving rigorous parameters for the purpose of sustainable findings.

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Rainfall thresholds for the occurrence of shallow landslides determined for slopes in the Nowy Wiśnicz Foothills (Polish Flysch Carpathians)

Demczuk Piotr, Zydroń Tymoteusz, Siłuch Marcin

Geological Quarterly

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2019

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Vol. 63, No. 4

822--838

EN

Values of rainfall thresholds on selected shallow landslide slopes (Dział, Gwoździec) located in the Nowy Wiśnicz Foothills are determined using a physically-based slope stability model considering a long-term period of analysis (GeoSlope Inc. software). Slope stability analysis included determination of the impact of rainfall on changes of stress state within the soil substrate and their influence on estimation of mass movement risk. The slope stability calculation results have shown that the rainfall threshold values are a function of many variables, primarily the hydraulic properties of soil and rock substratum, temporal distribution of precipitation, and soil moisture content conditions in the period proceeding rainfall. The results of the calculations indicate that, in extreme cases, accumulated rainfall threshold values for the same slope can range from ~100 to 500 mm. Estimated rainfall threshold values were lower than those values reported in the literature for the Polish Carpathians, but are similar to those determined by Guzetti et al. (2007) for Central and Southern Europe.