scholarly journals Visualization of radar-observed rainfall for hydrological risk assessment

2021 ◽  
Vol 18 ◽  
pp. 59-64
Author(s):  
Jonas Olsson ◽  
Peter Berg ◽  
Remco van de Beek
Keyword(s):  
Risk Assessment ◽  
Debris Flow ◽  
Return Period ◽  
Scale Space ◽  
Time Variability ◽  
Small Scale ◽  
Temporal Aggregation ◽  
Urban Flooding ◽  
Rainfall Extremes ◽  
Flood Analysis

Abstract. Short-duration high-intensity rainfall constitutes a major hydro-meteorological hazard, with impacts such as pluvial (urban) flooding and debris flow. There is a great demand in society for improved information on small-scale rainfall extremes, both in real time (e.g. for early warning) and historically (e.g. for post-flood analysis). Observing this type of events is notoriously difficult, because of their extreme small-scale space-time variability. However, owing to recent advances in weather radar technology as well as integration with ground-based sensors, observational products potentially applicable in this context are now available. In this paper we present a visualization prototype tailored for hydrological risk assessment by using sub-basins as spatial units, by allowing temporal aggregation over different durations (i.e. accumulation periods) and by expressing high rainfall intensities in terms of return period exceedance. The radar-based data is evaluated by comparison with gauge observations and the quality is deemed sufficient for the intended applications. Different stakeholders have shown great interest in the prototype, which is openly accessible online.

scholarly journals Community-based landslide hazard probability and risk assessment: A case in west Hubei, China

2019 ◽  
Author(s):  
Sheng Fu ◽  
Lixia Chen ◽  
Tsehaie Woldai ◽  
Kunlong Yin ◽  
Lei Gui ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Return Period ◽  
Probabilistic Method ◽  
Least Square Method ◽  
Landslide Hazard ◽  
Least Square ◽  
Small Scale ◽  
Power Law Distribution ◽  
Inverse Gamma ◽  
Landslide Volume

Abstract. Small communities living in high mountainous terrains, in Hubei Province are often impacted by landslide hazard. Past work by China Geology Survey focused only on hazard assessment at 1 : 100 000 scales. In this study, we conducted a more-detailed semiquantitative landslide and risk assessment at a community level and scale of 1 : 10 000. We applied the probabilistic method to assess the landslide spatial, temporal and size probabilities while the landslide hazard and risk assessment were considered for four return periods (5, 10, 20 and 50 years) and two size scenarios (landslide volume). The spatial probability by susceptibility mapping with an accuracy of 84 % indicates that Quaternary deposits and weathered eluvium from Ordovician limestone are the two major controlling factors. Most building areas in hazard maps are located at the foot of major slopes where hazard probabilities are very high. We computed the loss of lives and properties for each slope. The result shows that 1530 people and 126 million RMB economics were at risk of being affected by landslides with a 50-year return period and a landslide volume of fifty thousand cubic meters. Meanwhile, the longer the return period, the higher the hazard probability is. Compared with the function by ordinary least square method, classic inverse gamma and power law distribution of landslide magnitude and frequency are not suitable for landslide size probability analysis in the study area. The proposed procedure is proved to be more useful to complement risk assessment on the small scale of 100 000 in west Hubei, China.

On the effects of small scale space–time variability of rainfall on basin flood response

2014 ◽  
Vol 514 ◽  
pp. 313-327 ◽  
Author(s):  
Athanasios Paschalis ◽  
Simone Fatichi ◽  
Peter Molnar ◽  
Stefan Rimkus ◽  
Paolo Burlando
Keyword(s):  
Scale Space ◽  
Space Time ◽  
Time Variability ◽  
Small Scale ◽  
Flood Response

scholarly journals Movement Around Real and Virtual Cluttered Environments

2005 ◽  
Vol 14 (5) ◽  
pp. 580-596 ◽  
Author(s):  
Simon Lessels ◽  
Roy A. Ruddle
Keyword(s):  
Real World ◽  
Search Task ◽  
Scale Space ◽  
Visual Scene ◽  
Field Of View ◽  
Small Scale ◽  
High Fidelity ◽  
Cluttered Environments ◽  
The Real ◽  
Desktop Virtual Environment

Two experiments investigated participants' ability to search for targets in a cluttered small-scale space. The first experiment was conducted in the real world with two field of view conditions (full vs. restricted), and participants found the task trivial to perform in both. The second experiment used the same search task but was conducted in a desktop virtual environment (VE), and investigated two movement interfaces and two visual scene conditions. Participants restricted to forward only movement performed the search task quicker and more efficiently (visiting fewer targets) than those who used an interface that allowed more flexible movement (forward, backward, left, right, and diagonal). Also, participants using a high fidelity visual scene performed the task significantly quicker and more efficiently than those who used a low fidelity scene. The performance differences among all the conditions decreased with practice, but the performance of the best VE group approached that of the real-world participants. These results indicate the importance of using high fidelity scenes in VEs, and suggest that the use of a simple control system is sufficient for maintaining one's spatial orientation during searching.

Fuzzy Matter-Element Evaluation Method for Analysis of Debris Flow Risk Assessment

2012 ◽  
Vol 446-449 ◽  
pp. 3058-3061 ◽  
Author(s):  
Chun Tan ◽  
Jian Ping Chen ◽  
Yu Zhen Pan ◽  
Cen Cen Niu ◽  
Li Ming Xu
Keyword(s):  
Risk Assessment ◽  
Debris Flow ◽  
Information Entropy ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Practical Application ◽  
Element Analysis ◽  
Matter Element Analysis ◽  
Concept Of Information

Based on the principle of fuzzy matter-element analysis, the concept of information entropy is introduced to establish a fuzzy matter-element evaluation method. This method is utilized to comprehensively evaluate the degree of debris flow. The classifications of debris flow are regarded as the objects of matter-element and their indexes for evaluation as well as the corresponding fuzzy values are used to construct the composite fuzzy matter-elements. By calculating the relevancy the comprehensive evaluation of debris flow can be carried out. This model is applied to analyze the degree of debris flow in the practical application. The application shows that the model is effective and practical.

Post Wildfire Debris Flow and Flood Analysis of the September 2020 Badger Fire in the Trapper Creek and Rock Creek Watersheds, Idaho, USA.

2021 ◽  
Author(s):  
Stephen Turnbull ◽  
Nawa Pradhan ◽  
Ian Floyd
Keyword(s):  
Debris Flow ◽  
Finite Volume ◽  
Overland Flow ◽  
Frozen Ground ◽  
Channel Network ◽  
Hydrologic Analysis ◽  
Flood Analysis ◽  
Model Equations ◽  
Volume Method ◽  
Parameter Values

<p>There are several different infiltration, overland flow routing, and channel routing schemes that can be used in conjunction with recommended hydrodynamic and infiltration parameter values, which are found within the literature, to provide critical flooding assessments for stakeholders and decision makers.  We focus on post wildfire debris flow and flood analysis in two tributaries of the Snake River in Idaho, Trapper Creek and Rock Creek.  The Badger Fire started on September 12, 2020 in the Sawtooth National Forest in Idaho, USA, and burned sub-alpine fir, lodgepole pine, juniper, mountain brush and grass communities, in the upper part of both the Trapper Creek and Rock Creek watersheds.  Trapper Creek has a U.S. Geological Gaging station, and there are two snow gaging sites available.   The biggest concern for flooding and debris flow is the result of a wintertime rain-on-snow event, which resulted in the largest storm in the gaging record period.    </p><p>To estimate runoff in ungaged stream locations, existing process-based hydrodynamic models can be applied in a distributed form to solve the governing equations for mass, momentum and energy in a spatially explicit way. The purpose of this study is to predict potentially inundated land areas as a result of a rain-on-snow event, using the data in the gages basin to provide flood analysis information for both the gaged (Trapper Creek) and ungaged watershed (Rock Creek).  Rain-on-snow events are rainfall events that occur on the snowpack and frozen ground, resulting in a larger magnitude and volume of streamflow.  To predict these flows, Gridded Surface Subsurface Hydrologic Analysis (GSSHA) watershed models are prepared and calibrated to simulate rain-on-snow events in both watersheds.  The runoff generated from a two dimensional overland flow grid is transferred over land with a finite volume numerical method into a one dimensional channel network.  The channel network also uses a finite volume method.    The consistency in the identified range of the parametric values and their physical applicability make GSSHA an ideal candidate for this study, as the model equations provide a methods to evaluate a rain-on-snow event.</p>

Bending tests for the structural safety assessment of space truss members

2018 ◽  
Vol 33 (3-4) ◽  
pp. 138-149 ◽  
Author(s):  
Marco Bonopera ◽  
Kuo-Chun Chang ◽  
Chun-Chung Chen ◽  
Tzu-Kang Lin ◽  
Nerio Tullini
Keyword(s):  
Cross Sections ◽  
Flexural Rigidity ◽  
Compressive Force ◽  
Scale Space ◽  
Transverse Load ◽  
Structural Safety ◽  
Small Scale ◽  
Order Effects ◽  
Beam Columns ◽  
Space Truss

This article compares two nondestructive static methods used for the axial load assessment in prismatic beam-columns of space trusses. Examples include the struts and ties or the tension chords and diagonal braces of steel pipe racks or roof trusses. The first method requires knowledge of the beam-column’s flexural rigidity under investigation, whereas the second requires knowledge of the corresponding Euler buckling load. In both procedures, short-term flexural displacements must be measured at the given cross sections along the beam-column under examination and subjected to an additional transverse load. The proposed methods were verified by numerical and laboratory tests on beams of a small-scale space truss prototype made from aluminum alloy and rigid connections. In general, if the higher second-order effects are induced during testing and the corresponding total displacements are accurately measured, it would be easy to obtain tensile and compressive force estimations.

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