Affiliation:
1. School of Environment, The University of Auckland, Private Bag 92019, Auckland 1010, New Zealand
2. Gisborne District Council, 15 Fitzherbert Street, Gisborne 4010, New Zealand
Abstract
Recently uplifted, soft Pleistocene sediments in northern New Zealand are particularly vulnerable to landsliding because they are often underlain by less permeable, clay-rich Neogene mudstone–siltstone rocks. Typically, instability is rainfall-induced, often owing to a high-intensity rainfall event from extra-tropical cyclones, following wetter months when antecedent soil moisture has increased. Using remote sensing, field surveys and laboratory testing, we report on some emerging slope instability hazards in the eastern suburbs of the coastal city of Gisborne, on the North Island. Retrogressive failure of the main landslide (at Wallis Road) is continuing and has already led to the abandonment of one dwelling, and an adjacent landslide (at Titirangi Drive) appears to be in an incipient phase of failure. The Wallis Road landslide has been particularly active from mid-2017, with slumping of the headscarp area changing to a constrained mudflow downslope, which then descends a cliff before terminating on the beach. In contrast, the incipient Titirangi Drive landslide at present displays much more subtle effects of deformation. Although activity at both landslides appears to be linked to rainfall-induced increases in soil moisture, this is due to the effects of prolonged periods of rainfall rather than the passage of high-intensity cyclonic storms.
Publisher
Geological Society of London
Subject
Earth and Planetary Sciences (miscellaneous),Geology,Geotechnical Engineering and Engineering Geology
Reference51 articles.
1. AS 1289.3.8.1:2006. Methods of testing soils for engineering purposes – soil classification tests – dispersion – determination of Emerson class number of a soil. Standards Australia, Sydney, NSW.
2. Landslides and stratigraphy in the coastal outcrop of the Barton Clay
3. Estimating the timing and location of shallow rainfall-induced landslides using a model for transient, unsaturated infiltration;Baum R.L.;Journal of Geophysical Research: Earth Surfaces,2010
4. A simple ring-shear apparatus;Bromhead E.N.;Ground Engineering,1979
5. Bedding-controlled coastal landslides in Southeast Britain between Axmouth and the Thames Estuary
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献