Landslide inventories and water table response due to rainfall events in a tephra slope, Omokoroa Peninsula, New Zealand

Fuente: PANGAEA
Saved in:
Bibliographic Details
Main Authors: Kluger, Max Oke, Jorat, Ehsan M, Moon, Vicki G, Kreiter, Stefan, de Lange, Willem P, Mörz, Tobias, Robertson, Thomas, Lowe, David J
Format: Dataset Open Access
Language:en
Published: PANGAEA 2020
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867171374028554240
author Kluger, Max Oke
Jorat, Ehsan M
Moon, Vicki G
Kreiter, Stefan
de Lange, Willem P
Mörz, Tobias
Robertson, Thomas
Lowe, David J
author_facet Kluger, Max Oke
Jorat, Ehsan M
Moon, Vicki G
Kreiter, Stefan
de Lange, Willem P
Mörz, Tobias
Robertson, Thomas
Lowe, David J
collection Datos científicos de ciencias marinas y ambientales
contents Rainfall is one of the most important triggers of slope failure. Weathered pyroclastic (tephra) deposits are especially vulnerable to slope failure because they commonly form slopes of high porosity and high clay content. Empirically derived thresholds for the triggering of landslides are commonly based on rainfall conditions and have been widely applied in volcanic soils. However, so far only few researchers utilized pore water pressure in the slope as additional variable for the threshold calibration. Here, we derived a new rainfall threshold for initiating the decrease in effective stress in the slope by analyzing a long-term record of rainfall and piezometer data from a slide-prone coastal area in northern New Zealand that consists of clayey, halloysitic tephra deposits. The level of effective stress decrease increased with rainfall intensity and duration. We observed highest effective stress decrease of up to 36% during rainfall events that triggered landslides in our study area. The effective stress threshold exhibits a satisfactory predictive capability. The probability of correctly predicting a decrease in effective stress is 53%. The effective stress threshold contributes towards the implementation of the decrease in effective stress into rainfall thresholds for the occurrence of landslides.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_910781
institution PANGAEA
language en
publishDate 2020
publisher PANGAEA
record_format pangaea
spellingShingle Landslide inventories and water table response due to rainfall events in a tephra slope, Omokoroa Peninsula, New Zealand
Kluger, Max Oke
Jorat, Ehsan M
Moon, Vicki G
Kreiter, Stefan
de Lange, Willem P
Mörz, Tobias
Robertson, Thomas
Lowe, David J
New Zealand; Slope; Tephra; water table
Rainfall is one of the most important triggers of slope failure. Weathered pyroclastic (tephra) deposits are especially vulnerable to slope failure because they commonly form slopes of high porosity and high clay content. Empirically derived thresholds for the triggering of landslides are commonly based on rainfall conditions and have been widely applied in volcanic soils. However, so far only few researchers utilized pore water pressure in the slope as additional variable for the threshold calibration. Here, we derived a new rainfall threshold for initiating the decrease in effective stress in the slope by analyzing a long-term record of rainfall and piezometer data from a slide-prone coastal area in northern New Zealand that consists of clayey, halloysitic tephra deposits. The level of effective stress decrease increased with rainfall intensity and duration. We observed highest effective stress decrease of up to 36% during rainfall events that triggered landslides in our study area. The effective stress threshold exhibits a satisfactory predictive capability. The probability of correctly predicting a decrease in effective stress is 53%. The effective stress threshold contributes towards the implementation of the decrease in effective stress into rainfall thresholds for the occurrence of landslides.
title Landslide inventories and water table response due to rainfall events in a tephra slope, Omokoroa Peninsula, New Zealand
topic New Zealand; Slope; Tephra; water table
url https://doi.org/10.1594/PANGAEA.910781