The transformation of a steepland river valley following an earthquake-triggered landslide near Kaikōura, NZ

Author(s):  
Jon Tunnicliffe ◽  
Jamie Howarth ◽  
Chris Massey

<p>In the relatively short and steep catchments of New Zealand’s Alps and Front Range, river systems traverse several process domains, from steep boulder-bed cascades to shallower braided range-front streams. Headwater streams (slope gradient >0.1 m·m<sup>-1</sup>) typically operate in a state of ‘supply limited’ conditions, where the river’s ability to carry sediment far exceeds the supply of material from upstream. With the catastrophic delivery of 13M m<sup>3</sup> of landslide detritus following the 2016 7.8 Mw Kaikōura Earthquake, a tributary of the upper Hapuku River was filled to depths of up to 30 m, as debris spilled 1 km downstream from the delivery point. Nine airborne LiDAR surveys along the 12 km corridor have captured the transformation of the system from step-pool cascade to an unstable aggrading braidplain deposit to a vigorously incising channel, within four years of the event. With this rare window into disequilibrium conditions, we document the dramatic shifts in channel behaviour and dramatic reworking of the debris train following the landslide. There are two distinct phases: (1) a highly dynamic and unstable aggradation phase, with supply from upstream greatly exceeding river transport capacity and (2) exhaustion of supply from upstream and downcutting, maintaining high sediment transport rates through recruitment of material in the valley deposit. With a catchment area of only 3 km<sup>2</sup>, the upper river has transferred more than 4.2×10<sup>6</sup> m<sup>3</sup> of coarse-grained material in 9 storm events of relatively modest intensity. This sequence of surveys provides an unprecedented picture of dramatic changes to a steepland river system in the aggradation/degradation cycle, which are very seldom captured owing to both the remoteness of such sites and the relative rarity of such events. A temporal picture of the valley sediment budget demonstrates the remarkable capacity of alpine systems to absorb disturbance through storage in the upper reaches, modulating the timing and the sedimentary character of materials being transferred to the reaches downstream. The case study highlights the utility of repeat LiDAR surveys for large-scale process studies and provides insights for assessing residence times of major landslide deliveries following large earthquake events.</p>

2018 ◽  
Vol 75 (3) ◽  
pp. 755-774 ◽  
Author(s):  
Theodore W. Letcher ◽  
Justin R. Minder

Abstract The Front Range mountain–plain circulation (FRMC) is a large-scale diurnally driven wind system that occurs east of the Colorado Rocky Mountains in the United States and affects the weather both in the Rocky Mountains and Great Plains. As the climate warms, the snow albedo feedback will amplify the warming response in the Rocky Mountains during the spring, increasing the thermal contrast that drives the FRMC. In this study, the authors perform a 7-yr pseudo–global warming (PGW) regional climate change experiment along with an idealized PGW “fixed albedo” experiment to test the sensitivity of the FRMC to the snow albedo feedback (SAF). The authors find a mean increase in the springtime FRMC strength in the PGW experiment that is primarily driven by the snow albedo feedback. Furthermore, interannual variability of changes in FRMC strength is strongly influenced by interannual variability in the SAF. An additional case study experiment configured with a much higher resolution is performed to examine the finescale details of how the SAF and the FRMC interact. This experiment includes a passive tracer to investigate subsequent impacts on pollution transport. The case study reveals that loss of snow cover causes an increase in the strength of the FRMC. Advection by the strengthened FRMC increases the concentration of tracers emitted over the Great Plains in the boundary layer over the Front Range mountains.


Shore & Beach ◽  
2019 ◽  
pp. 31-40
Author(s):  
Eve Eisemann ◽  
Lauren Dunkin ◽  
M. Hartman ◽  
Jennifer Wozencraft

The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) deployed to support regional-scale post-storm damage assessments following Hurricanes Irma (2017), Maria (2017), and Michael (2018) for the Federal Emergency Management Agency (FEMA) and the U.S. Army Corps of Engineers (USACE) following Hurricanes Matthew (2016) and Florence (2018). The JALBTCX has a long history of providing regional coastal surveys after storm impacts in the United States. These high-resolution, regional datasets extend beyond project boundaries, providing critical data to quantify large-scale impacts associated with storm events. These regional datasets directly support missions within the USACE, other federal agencies, academia, and the broader coastal community.


1968 ◽  
Vol 49 (7) ◽  
pp. 690-714 ◽  
Author(s):  
Dean E. Mann

In December 1955 a severe tropical storm caused severe flooding throughout Northern California with damage exceeding $200,000,000. One area suffering large-scale flooding was at Yuba City, at the confluence of the Feather and Yuba Rivers. The levees broke and consequent damage was in the magnitude of $65 million. Property-owners sought recompense through suits brought in the Superior Court of Sutter County against the State of California, Pacific Gas and Electric Company (PG&E), and North American Weather Consultants (NAWC). PG&E, through its contracting agent, NAWC, had undertaken cloud seeding operations in three places in the high Sierras, one of which was in the Lake Almanor water-shed in the Feather River system. NAWC had interrupted seeding activities in that area three days before the levees broke at Yuba City. Plaintiffs charged that PG&E and NAWC were negligent in the operation of their generators, had contributed to the total quantity of water produced by the watershed and therefore were legally liable, and that cloud seeding was ultra-hazardous activity so that those engaged in such activities were strictly liable for damages. The suit was begun in 1958 and concluded in 1964. Trial before a judge only began in October 1963 and a decision was rendered in April 1964. The judge ruled that neither PG&E nor NAWC was liable. In accordance with an agreement among the parties no appeal was taken. Plaintiffs were successful, however, against the State, basing their claim for damages on the doctrine of inverse condemnation which holds that the State must recompense for damages incurred in the lawful exercise of its powers—in this case, the construction of levees. The litigation raises important questions of public policy with regard to weather modification and these are considered in the light of this case.


1996 ◽  
Vol 5 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Chris Halpin ◽  
Barbara Herrmann ◽  
Margaret Whearty

The family described in this article provides an unusual opportunity to relate findings from genetic, histological, electrophysiological, psychophysical, and rehabilitative investigation. Although the total number evaluated is large (49), the known, living affected population is smaller (14), and these are spread from age 20 to age 59. As a result, the findings described above are those of a large-scale case study. Clearly, more data will be available through longitudinal study of the individuals documented in the course of this investigation but, given the slow nature of the progression in this disease, such studies will be undertaken after an interval of several years. The general picture presented to the audiologist who must rehabilitate these cases is that of a progressive cochlear degeneration that affects only thresholds at first, and then rapidly diminishes speech intelligibility. The expected result is that, after normal language development, the patient may accept hearing aids well, encouraged by the support of the family. Performance and satisfaction with the hearing aids is good, until the onset of the speech intelligibility loss, at which time the patient will encounter serious difficulties and may reject hearing aids as unhelpful. As the histological and electrophysiological results indicate, however, the eighth nerve remains viable, especially in the younger affected members, and success with cochlear implantation may be expected. Audiologic counseling efforts are aided by the presence of role models and support from the other affected members of the family. Speech-language pathology services were not considered important by the members of this family since their speech production developed normally and has remained very good. Self-correction of speech was supported by hearing aids and cochlear implants (Case 5’s speech production was documented in Perkell, Lane, Svirsky, & Webster, 1992). These patients received genetic counseling and, due to the high penetrance of the disease, exhibited serious concerns regarding future generations and the hope of a cure.


2008 ◽  
Author(s):  
D. L. McMullin ◽  
A. R. Jacobsen ◽  
D. C. Carvan ◽  
R. J. Gardner ◽  
J. A. Goegan ◽  
...  

Author(s):  
Lori Stahlbrand

This paper traces the partnership between the University of Toronto and the non-profit Local Food Plus (LFP) to bring local sustainable food to its St. George campus. At its launch, the partnership represented the largest purchase of local sustainable food at a Canadian university, as well as LFP’s first foray into supporting institutional procurement of local sustainable food. LFP was founded in 2005 with a vision to foster sustainable local food economies. To this end, LFP developed a certification system and a marketing program that matched certified farmers and processors to buyers. LFP emphasized large-scale purchases by public institutions. Using information from in-depth semi-structured key informant interviews, this paper argues that the LFP project was a disruptive innovation that posed a challenge to many dimensions of the established food system. The LFP case study reveals structural obstacles to operationalizing a local and sustainable food system. These include a lack of mid-sized infrastructure serving local farmers, the domination of a rebate system of purchasing controlled by an oligopolistic foodservice sector, and embedded government support of export agriculture. This case study is an example of praxis, as the author was the founder of LFP, as well as an academic researcher and analyst.


2020 ◽  
Vol 86 (7) ◽  
pp. 12-19
Author(s):  
I. V. Plyushchenko ◽  
D. G. Shakhmatov ◽  
I. A. Rodin

A viral development of statistical data processing, computing capabilities, chromatography-mass spectrometry, and omics technologies (technologies based on the achievements of genomics, transcriptomics, proteomics, metabolomics) in recent decades has not led to formation of a unified protocol for untargeted profiling. Systematic errors reduce the reproducibility and reliability of the obtained results, and at the same time hinder consolidation and analysis of data gained in large-scale multi-day experiments. We propose an algorithm for conducting omics profiling to identify potential markers in the samples of complex composition and present the case study of urine samples obtained from different clinical groups of patients. Profiling was carried out by the method of liquid chromatography mass spectrometry. The markers were selected using methods of multivariate analysis including machine learning and feature selection. Testing of the approach was performed using an independent dataset by clustering and projection on principal components.


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