Choose you own scientific experiment: Triggering debris flows and flash floods

2016 ◽  
Author(s):  
Thea Turkington
Keyword(s):  
Debris Flows ◽  
Flash Floods ◽  
The Other ◽  
Background Information ◽  
Atmospheric Conditions ◽  
Scientific Experiment

Landslides and flash floods result in many fatalities around the globe. Understanding what triggers these events is therefore vital, although how to approach this problem is not straight forward. After background information for the experiment and some guidelines, two options are presented to learn more about the triggers of debris flows: (A) using rainfall or (B) the atmospheric conditions. You can then choose the option that appears more useful and interesting to you (you can always go back and read the other experiment afterwards). The article then ends with a reflection on the results.

scholarly journals Empirical atmospheric thresholds for debris flows and flash floods in the southern French Alps

2014 ◽  
Vol 14 (6) ◽  
pp. 1517-1530 ◽  
Author(s):  
T. Turkington ◽  
J. Ettema ◽  
C. J. van Westen ◽  
K. Breinl
Keyword(s):  
Debris Flows ◽  
Warning System ◽  
Flash Floods ◽  
Rain Gauge ◽  
Reanalysis Data ◽  
Specific Humidity ◽  
Atmospheric Conditions ◽  
Convective Rainfall ◽  
French Alps ◽  
Mountainous Regions

Abstract. Debris flows and flash floods are often preceded by intense, convective rainfall. The establishment of reliable rainfall thresholds is an important component for quantitative hazard and risk assessment, and for the development of an early warning system. Traditional empirical thresholds based on peak intensity, duration and antecedent rainfall can be difficult to verify due to the localized character of the rainfall and the absence of weather radar or sufficiently dense rain gauge networks in mountainous regions. However, convective rainfall can be strongly linked to regional atmospheric patterns and profiles. There is potential to employ this in empirical threshold analysis. This work develops a methodology to determine robust thresholds for flash floods and debris flows utilizing regional atmospheric conditions derived from ECMWF ERA-Interim reanalysis data, comparing the results with rain-gauge-derived thresholds. The method includes selecting the appropriate atmospheric indicators, categorizing the potential thresholds, determining and testing the thresholds. The method is tested in the Ubaye Valley in the southern French Alps (548 km2), which is known to have localized convection triggered debris flows and flash floods. This paper shows that instability of the atmosphere and specific humidity at 700 hPa are the most important atmospheric indicators for debris flows and flash floods in the study area. Furthermore, this paper demonstrates that atmospheric reanalysis data are an important asset, and could replace rainfall measurements in empirical exceedance thresholds for debris flows and flash floods.

scholarly journals Empirical atmospheric thresholds for debris flows and flash floods in the Southern French Alps

2014 ◽  
Vol 2 (1) ◽  
pp. 757-798 ◽  
Author(s):  
T. Turkington ◽  
J. Ettema ◽  
C. J. van Westen ◽  
K. Breinl
Keyword(s):  
Debris Flows ◽  
Warning System ◽  
Flash Floods ◽  
Rain Gauge ◽  
Reanalysis Data ◽  
Specific Humidity ◽  
Atmospheric Conditions ◽  
Convective Rainfall ◽  
French Alps ◽  
Mountainous Regions

Abstract. Debris flows and flash floods are often preceded by intense, convective rainfall. The establishment of reliable rainfall thresholds is an important component for quantitative hazard and risk assessment, and for the development of an early warning system. Traditional empirical thresholds based on peak intensity, duration and antecedent rainfall can be difficult to verify due to the localized character of the rainfall and the absence of weather radar or sufficiently dense rain gauge networks in mountainous regions. However, convective rainfall can be strongly linked to regional atmospheric patterns and profiles. There is potential to employ this in empirical threshold analysis. This work develops a methodology to determine robust thresholds for flash floods and debris flows utilizing regional atmospheric conditions derived from ECMWF ERA-Interim reanalysis data, comparing the results with rain gauge derived thresholds. The method includes selecting the appropriate atmospheric indicators, categorizing the potential thresholds, determining and testing the thresholds. The method is tested in the Ubaye Valley in the southern French Alps, which is known to have localized convection triggered debris flows and flash floods. This paper shows that instability of the atmosphere and specific humidity at 850 hPa are the most important atmospheric indicators for debris flows and flash floods in the study area. Furthermore, this paper demonstrates that atmospheric reanalysis data is an important asset, and could replace rainfall measurements in empirical exceedence thresholds for debris flows and flash floods.

Annual Variability in Summer Evapotranspiration and Water Balance at a Subarctic Forest Site

1994 ◽  
Vol 25 (5) ◽  
pp. 331-344 ◽  
Author(s):  
Peter M. Lafleur
Keyword(s):  
Water Balance ◽  
Daily Precipitation ◽  
The Other ◽  
Forest Site ◽  
Net Radiation ◽  
Atmospheric Conditions ◽  
Surface Moisture ◽  
Equilibrium Evaporation ◽  
Subarctic Forest ◽  
Single Regression

Evapotranspiration (ET) and precipitation were measured during five summers (1989-1993 inclusive) at a subarctic forest site near Churchill, Manitoba, Canada. Mean daily ET varied from 2.14-3.18 mm d−1 during the five summers, while mean daily precipitation (P) ranged from 1.46-3.15 mm d−1. Yearly variability in summer ET was most influenced by availability of surface moisture, then by atmospheric conditions (i.e. temperature), and least of all by net radiation. In four of the five years total summer ET exceeded P resulting in significant soil water deficits and in the other year summer ET and P were similar in magnitude. The use of equilibrium evaporation (EE) as a predictor of ET was explored. Separate relationships between ET and EE were computed for all five years. Three statistically dissimilar groups of equations were found: 1989/1990, 1991/ 1992, and 1993. A single regression equation describing all years is presented.

Observations and Analyses of the 9 January 2018 Debris-Flow Disaster, Santa Barbara County, California

2021 ◽  
Vol 27 (1) ◽  
pp. 3-27
Author(s):  
Jeremy T. Lancaster ◽  
Brian J. Swanson ◽  
Stefani G. Lukashov ◽  
Nina S. Oakley ◽  
Jacob B. Lee ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Extreme Rainfall ◽  
Atmospheric Conditions ◽  
Santa Barbara ◽  
Debris Removal ◽  
Fire Debris ◽  
Santa Barbara County ◽  
Coastal Land

ABSTRACT The post–Thomas Fire debris flows of 9 January 2018 killed 23 people, damaged 558 structures, and caused severe damage to infrastructure in Montecito and Carpinteria, CA. U.S. Highway 101 was closed for 13 days, significantly impacting transportation and commerce in the region. A narrow cold frontal rain band generated extreme rainfall rates within the western burn area, triggering runoff-driven debris flows that inundated 5.6 km2 of coastal land in eastern Santa Barbara County. Collectively, this series of debris flows is comparable in magnitude to the largest documented post-fire debris flows in the state and cost over a billion dollars in debris removal and damages to homes and infrastructure. This study summarizes observations and analyses on the extent and magnitude of inundation areas, debris-flow velocity and volume, and sources of debris-flow material on the south flank of the Santa Ynez Mountains. Additionally, we describe the atmospheric conditions that generated intense rainfall and use precipitation data to compare debris-flow source areas with spatially associated peak 15 minute rainfall amounts. We then couple the physical characterization of the event with a compilation of debris-flow damages to summarize economic impacts.

Modelling of debris flows and flash floods propagation: a case study from Italian Alps

2020 ◽  
pp. 1-24
Author(s):  
Leonardo Cascini ◽  
Sabatino Cuomo ◽  
Manuel Pastor ◽  
Ilaria Rendina
Keyword(s):  
Debris Flows ◽  
Flash Floods ◽  
Italian Alps

scholarly journals An experimental Investigation of the Impact of Personality Disorder Diagnosis on Clinicians: Can We See Past the Borderline?

2015 ◽  
Vol 44 (3) ◽  
pp. 361-373 ◽  
Author(s):  
Danny C.K. Lam ◽  
Elena V. Poplavskaya ◽  
Paul M. Salkovskis ◽  
Lorna I. Hogg ◽  
Holly Panting
Keyword(s):  
Personality Disorder ◽  
Mental Health Professionals ◽  
Health Professionals ◽  
Borderline Personality ◽  
The Other ◽  
Background Information ◽  
Descriptive Information ◽  
Diagnostic Labels ◽  
Diagnostic Label ◽  
The Impact

Background: There is concern that diagnostic labels for psychiatric disorders may invoke damaging stigma, stereotypes and misunderstanding. Aims: This study investigated clinicians’ reactions to diagnostic labelling by examining their positive and negative reactions to the label borderline personality disorder (BPD). Method: Mental health professionals (n = 265) viewed a videotape of a patient suffering from panic disorder and agoraphobia undergoing assessment. Prior to viewing the videotape, participants were randomly allocated to one of three conditions and were given the following information about the patient: (a) general background information; (b) additional descriptive information about behaviour corresponding to BPD; and (c) additional descriptive information about behaviour corresponding to BPD, but explicitly adding BPD as a possible comorbid diagnostic label. All participants were then asked to note things they had seen in the videotape that made them feel optimistic or pessimistic about treatment outcome. Results: Participants in the group that were explicitly informed that the patient had a BPD diagnostic label reported significantly fewer reasons to be optimistic than the other two groups. Conclusions: Diagnostic labels may negatively impact on clinicians’ judgments and perceptions of individuals and therefore clinicians should think carefully about whether, and how, they use diagnoses and efforts should be made to destigmatize diagnostic terms.

Q-Phenomena, I-Phenomena and Impliciture: Some Experimental Pragmatics

2009 ◽  
Vol 1 (1) ◽  
pp. 84-117 ◽  
Author(s):  
Robert Harnish ◽  
Merrill Garrett
Keyword(s):  
Frontal Lobe ◽  
Experimental Work ◽  
Background Knowledge ◽  
Generative Grammar ◽  
Linguistic Theory ◽  
The Other ◽  
Background Information ◽  
Experimental Pragmatics ◽  
Frontal Lobe Function ◽  
Initial Results

AbstractElements of communicative content that are not expressed by constituents of the sentence uttered, what we will call "unexpressed elements of content" (UECs), played an important role in the history and development of generative grammar. In the 80's and 90's, mostly inspired by the work of Grice, UECs and mechanisms for recovering them not contemplated by linguistic theory of the time, began to surface under a variety of labels. We will collectively refer to these phenomena as 'impliciture' (extending Bach: 1994). Impliciture phenomena raise some interesting questions, only some of which is the field in a position to say anything about at present. Levinson (2000) has taken the useful step of distinguishing what we call "Q-phenomena", mostly related to linguistic scales, from "I-phenomena", mostly related to stereotypical information. Starting in the late 80's, experimental work began on the nature of these unspoken contents and their attendant mechanisms. In a recent study, Garrett and Harnish (2007) looked at I-phenomena, that have been proposed to depend on stereotypical background information. We asked whether these contents really are delivered by such mechanisms as "default heuristics", operating on general background knowledge, or whether they might be more tied to language via something like the "standardization" of a form for a certain use. Initial results for the materials tested seem to favor standardization as a mechanism for delivering this content. Completed research by Orjada (2007) and Rybarova (2007) extends the study of impliciture to additional examples and new populations. One assesses performance in RH damaged populations. The other contrasts performance for populations with high and low frontal lobe function.

A clear and present danger: Ladakh's increasing vulnerability to flash floods and debris flows

2016 ◽  
Vol 30 (22) ◽  
pp. 4214-4223 ◽  
Author(s):  
Alan D. Ziegler ◽  
Sebastian I. Cantarero ◽  
Robert J. Wasson ◽  
Pradeep Srivastava ◽  
Sonam Spalzin ◽  
...  
Keyword(s):  
Debris Flows ◽  
Flash Floods ◽  
Clear And Present Danger

scholarly journals An experimental study on premixed CNG/H2/CO2 mixture flames

2018 ◽  
Vol 8 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Ilker Yilmaz ◽  
Harun Yilmaz ◽  
Omer Cam
Keyword(s):  
Experimental Study ◽  
Thermal Power ◽  
The Other ◽  
Gas Composition ◽  
Atmospheric Conditions ◽  
Swirl Number ◽  
Combustion Performance ◽  
Temperature Distributions ◽  
The City ◽  
Flame Behaviour

Abstract In this study, the effect of swirl number, gas composition and CO2 dilution on combustion and emission behaviour of CNG/H2/CO2 gas mixtures was experimentally investigated in a laboratory scale combustor. Irrespective of the gas composition, thermal power of the combustor was kept constant (5 kW). All experiments were conducted at or near stoichiometric and the local atmospheric conditions of the city of Kayseri, Turkey. During experiments, swirl number was varied and the combustion performance of this combustor was analysed by means of centreline temperature distributions. On the other hand, emission behaviour was examined with respect to emitted CO, CO2 and NOx levels. Dynamic flame behaviour was also evaluated by analysing instantaneous flame images. Results of this study revealed the great impact of swirl number and gas composition on combustion and emission behaviour of studied flames.

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