A statistical framework for tree‐ring reconstruction of high‐magnitude mass movements: case study of snow avalanches in eastern canada

2016 ◽  
Vol 98 (4) ◽  
pp. 303-311 ◽  
Author(s):  
Daniel Germain
Keyword(s):  
Tree Ring ◽  
Mass Movements ◽  
Snow Avalanches ◽  
Eastern Canada ◽  
Statistical Framework ◽  
High Magnitude ◽  
Tree Ring Reconstruction

scholarly journals Dendrogeomorphology and high-magnitude snow avalanches: a review and case study

2008 ◽  
Vol 8 (2) ◽  
pp. 303-309 ◽  
Author(s):  
D. R. Butler ◽  
C. F. Sawyer
Keyword(s):  
Tree Ring ◽  
Index Number ◽  
Snow Avalanches ◽  
High Magnitude ◽  
Tree Ring Data ◽  
Critical Choice ◽  
Minimum Number ◽  
Size Type ◽  
Ring Analysis

Abstract. The application of the principles of dendrogeomorphology for the dating of high-magnitude snow avalanches is well established in the natural hazards literature. A variety of methodologies are employed by different authors, however, and no standardization currently exists for appropriate sample sizes, the issue of "weighting" certain tree-ring responses as more important than others, or the minimum number of responding trees required in order to infer an avalanche event. We review the literature of dendrogeomorphology as it applies to snow avalanches, and examine the questions of sample size, type of ring reactions dated and weighted, and minimum responses. We present tree-ring data from two avalanche paths in the Rocky Mountains of Montana, USA, from trees uprooted by major snow avalanches in the winter of 2002. These data provide distinct chronologies of past avalanche events, and also illustrate how the critical choice of a minimum Index Number can affect the number of avalanche events in a final chronology based on tree-ring analysis.

Tree-ring reconstruction of snow avalanches in Şureanu Mountains (Southern Carpathians, Romania)

2021 ◽  
Author(s):  
Corina Todea ◽  
Olimpiu Pop
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Spatial Extent ◽  
Snow Avalanches ◽  
Historical Archives ◽  
Hazard Zoning ◽  
Tree Ring Reconstruction ◽  
Natural Archive ◽  
Callus Tissues ◽  
Southern Carpathians

<p>Snow avalanches (SAs) are a widespread natural hazard in the Carpathians, damaging forests and threatening properties, tourism infrastructures and people. In Şureanu Mountains (Southern Carpathians), SA activity is not documented in the historical archives and consequently information regarding the SA frequency and their spatial extent is lacking. Along the forested avalanche paths, disturbed trees record selectively in their annual rings evidence of past events. Tree rings represent therefore a natural archive which can provide valuable information about the past SA activity. The aim of the present study is to reconstruct the occurrence and spatial extent of past SA activity with tree rings in Şureanu Mts. For this purpose, two avalanche paths adjacent to a ski area located in the central part of Şureanu Mts., have been investigated. Samples (cores and discs) collected from 121 and 141 Norway spruce (Picea abies (L.) Karst.) trees damaged by SAs along both paths have been analyzed. Tree-growth anomalies (e.g. scars, callus tissues, onset sequences of tangential rows of traumatic resin ducts, compression wood and growth suppression sequences) associated with the mechanical impact produced by SAs on trees were identified and used to reconstruct the SA history. Within the investigated paths, the reconstructed SA chronology spans the period of the last century. The minimum SA frequency and maximum extent reconstructed served to define the return periods within the two paths investigated. Tree-ring derived records provided the most consistent SA chronology in the study area, and can further be integrated in the avalanche hazard zoning assessment.</p>

Tree-ring-based reconstruction of high-magnitude snow avalanches in Piatra Craiului Mountains (Southern Carpathians, Romania)

2017 ◽  
Vol 100 (2) ◽  
pp. 99-115 ◽  
Author(s):  
Olimpiu Traian Pop ◽  
Anca Munteanu ◽  
Meseşan Flaviu ◽  
Ionela-Georgiana Gavrilă ◽  
Cosmin Timofte ◽  
...  
Keyword(s):  
Tree Ring ◽  
Snow Avalanches ◽  
High Magnitude ◽  
Southern Carpathians

scholarly journals Assessing the Response of Snow Avalanche Runout Altitudes to Climate Fluctuations Using Hierarchical Modeling: Application to 61 Winters of Data in France

2010 ◽  
Vol 23 (12) ◽  
pp. 3157-3180 ◽  
Author(s):  
N. Eckert ◽  
H. Baya ◽  
M. Deschatres
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Hierarchical Modeling ◽  
Control Measures ◽  
Level Shift ◽  
Snow Avalanches ◽  
Winter Climate ◽  
Climate Fluctuations ◽  
High Magnitude ◽  
Proposed Model

Abstract Snow avalanches are natural hazards strongly controlled by the mountain winter climate, but their recent response to climate change has thus far been poorly documented. In this paper, hierarchical modeling is used to obtain robust indexes of the annual fluctuations of runout altitudes. The proposed model includes a possible level shift, and distinguishes common large-scale signals in both mean- and high-magnitude events from the interannual variability. Application to the data available in France over the last 61 winters shows that the mean runout altitude is not different now than it was 60 yr ago, but that snow avalanches have been retreating since 1977. This trend is of particular note for high-magnitude events, which have seen their probability rates halved, a crucial result in terms of hazard assessment. Avalanche control measures, observation errors, and model limitations are insufficient explanations for these trends. On the other hand, strong similarities in the pattern of behavior of the proposed runout indexes and several climate datasets are shown, as well as a consistent evolution of the preferred flow regime. The proposed runout indexes may therefore be usable as indicators of climate change at high altitudes.

scholarly journals Soil Erosion Caused by Snow Avalanches: a Case Study in the Aosta Valley (NW Italy)

2010 ◽  
Vol 42 (4) ◽  
pp. 412-421 ◽  
Author(s):  
Michele Freppaz ◽  
Danilo Godone ◽  
Gianluca Filippa ◽  
Margherita Maggioni ◽  
Stefano Lunardi ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Snow Avalanches ◽  
Nw Italy

scholarly journals URBAN SPRAWL IN SMALL CITIES, ANALYSIS OF THE MUNICIPALITY OF SÃO PEDRO (SP): POTENTIALS AND CONSTRAINS

2013 ◽  
pp. 64-73 ◽  
Author(s):  
Priscila Carrara Fracassi ◽  
José Augusto Lollo
Keyword(s):  
Data Collection ◽  
Present Article ◽  
Urban Sprawl ◽  
Field Work ◽  
Limiting Factors ◽  
Soil Conditions ◽  
Mass Movements ◽  
Small Cities ◽  
Natural Factors

Urban sprawl in small cities has led to the occupation of unsuitable areas, resulting in peripheralization and in the occupation of fragile environments. In these occupations, the physical characteristics of the environment are often disrespected. In this context, the present article reports on a case study in the municipality of São Pedro, state of São Paulo, Brazil, which presents and discuss a set of natural factors (geological and geomorphological) conditioning the occurrence of erosion and gravitational mass movements, which are limiting factors for urban sprawl. The methodology employed in this study was based on field work, bibliographic research, and data collection, analysis and GIS-based systematization, which allowed for a spatial reading of the urban sprawl to indicate, from different perspectives, how the phenomenon is manifested. Thus, it was possible to draw up a chart highlighting the areas with the greatest potential for occupation and those with restrictions due to their greater susceptibility to erosion and mass movements. The main identified natural factors of restriction were steepness and soil conditions and law enforced restrictions (environmental protection areas).

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