4.6 Article

Post-seismic aggradation history of the West Coast, South Island, Aotearoa/New Zealand; dendrogeomorphological evidence and disaster recovery implications

期刊

NATURAL HAZARDS
卷 114, 期 3, 页码 2545-2570

出版社

SPRINGER
DOI: 10.1007/s11069-022-05479-5

关键词

Westland; New Zealand; Great earthquakes; Coseismic landslides; Dendrochronology; River aggradation and flooding; Societal impacts; Disaster recovery

资金

  1. University of Canterbury PhD scholarship
  2. NZ National Science Challenge Resilience to Nature's Challenges [GNS-RNC011]
  3. New Zealand Vice-Chancellors' Committee National Science Challenge Resilience to Nature's Challenges [GNS-RNC011]
  4. CAUL

向作者/读者索取更多资源

This study examines the impacts of large earthquakes on the floodplains of Westland, New Zealand, using dendrochronological data and tree-ring analyses. The results show that major prehistoric reforestation episodes on the floodplains correspond well with known dates of large earthquakes, indicating the sediment deliveries resulting from coseismic landsliding and their reworking by rivers. This regional aggradation picture is important for understanding the potential societal impacts of future major West Coast earthquakes.
In the active tectonic setting of Aotearoa/New Zealand, large earthquakes are a relatively frequent occurrence and pose particular threats to infrastructure and society in Westland, on the west coast of South Island. In order to better define the medium- and long-term (annual to decadal) implications of these threats, existing dendrochronological data were supplemented by several hundred tree-ring analyses from 14 hitherto unstudied living tree stands in five catchments; these were combined to compile a regional picture of the location, extent, and timing of major prehistoric reforestation episodes on the floodplains of the area. These episodes correspond well with known dates of large earthquakes in the area (ca. 1400, ca. 1620, 1717 and 1826 AD), and their extents are thus interpreted to reflect the sediment deliveries resulting from coseismic landsliding into mountain valleys, and their reworking by rivers to generate widespread avulsion, aggradation, floodplain inundation and forest death. This regional aggradation picture can underpin anticipation of, and planning for, the medium- to long-term societal impacts of future major West Coast earthquakes. The source location of the next major earthquake in the region is unknown, so any of the Westland floodplains could be affected by extensive, up to metre-scale river aggradation, together with avulsion and flooding, in its aftermath, and these could continue for decades. Re-establishment and maintenance of a functioning economy under these conditions will be challenging because roads, settlements and agriculture are mostly located on the floodplains. The differences in floodplain vegetation between prehistoric and future episodes will affect the rapidity and distribution of aggradation; response and recovery planning will need to consider this, together with the impacts of climate changes on river flows.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据