Natural Hazards and Earth System Science 

About: Natural Hazards and Earth System Science is an academic journal. The journal publishes majorly in the area(s): Terrain & Reinforced solid. Over the lifetime, 9 publications have been published receiving 105 citations.

Performance based design of reinforced concrete beams under impact

Abstract: . The purpose of this research is to collect fundamental data and to establish a performance-based design method for reinforced concrete beams under perpendicular impact load. Series of low speed impact experiments using reinforced concrete beams were performed varying span length, cross section and main reinforcement. The experimental results are evaluated focusing on the impact load characteristics and the impact behaviours of reinforced concrete beams. Various characteristic values and their relationships are investigated such as the collision energy, the impact force duration, the energy absorbed by the beams and the beam response values. Also the bending performance of the reinforced concrete beams against perpendicular impact is evaluated. An equation is proposed to estimate the maximum displacement of the beam based on the collision energy and the static ultimate bending strength. The validity of the proposed equation is confirmed by comparison with experimental results obtained by other researchers as well as numerical results obtained by FEM simulations. The proposed equation allows for a performance based design of the structure accounting for the actual deformation due to the expected impact action.

Reliability of regional climate model simulations of extremes and of long-term climate

Abstract: . We present two case studies that demonstrate how a common evaluation methodology can be used to assess the reliability of regional climate model simulations from different fields of research. In Case I, we focused on the agricultural yield loss risk for maize in Northeastern Brazil during a drought linked to an El-Nino event. In Case II, the present-day regional climatic conditions in Europe for a 10-year period are simulated. To comprehensively evaluate the model results for both kinds of investigations, we developed a general methodology. On its basis, we elaborated and implemented modules to assess the quality of model results using both advanced visualization techniques and statistical algorithms. Besides univariate approaches for individual near-surface parameters, we used multivariate statistics to investigate multiple near-surface parameters of interest together. For the latter case, we defined generalized quality measures to quantify the model's accuracy. Furthermore, we elaborated a diagnosis tool applicable for atmospheric variables to assess the model's accuracy in representing the physical processes above the surface under various aspects. By means of this evaluation approach, it could be demonstrated in Case Study I that the accuracy of the applied regional climate model resides at the same level as that we found for another regional model and a global model. Excessive precipitation during the rainy season in coastal regions could be identified as a major contribution leading to this result. In Case Study II, we also identified the accuracy of the investigated mean characteristics for near-surface temperature and precipitation to be comparable to another regional model. In this case, an artificial modulation of the used initial and boundary data during preprocessing could be identified as the major source of error in the simulation. Altogether, the achieved results for the presented investigations indicate the potential of our methodology to be applied as a common test bed to different fields of research in regional climate modeling.

Preface "Landslide hazard and risk assessment at different scales"

Abstract: Department of Geography and Regional Research, Vienna, AustriaCorrespondence to: P. Reichenbach (paola.reichenbach@irpi.cnr.it)The special issue of Natural Hazards and Earth SystemSciences entitled “Landslide hazard and risk assessment atdifferent scales” contains 6 of more than 20 oral and postercontributions originally presented in the session NH3.9 –“Landslide risk assessment methods and strategies” held atthe General Assembly of the European Geosciences Union,in Vienna, Austria, on 7 May 2010. Topics discussed in thesession included the following: (i) heuristic, statistical, deter-ministic, and physically based methods and models to eval-uate landslide susceptibility and hazard, and (ii) evaluationof qualitative and quantitative vulnerability and risk assess-ments based on different data. During the session, variouscontributions were discussed dealing with landslide hazardand risk assessment at local, regional or national scales, indifferent physiographic, climatic and geological settings.The meeting proved a valuable opportunity to discuss andcompare methods, techniques, and tools for the identifica-tion, evaluation, and mitigation of landslide hazards and theassociated risks. Despite the large number of contributionspresenting case study applications to evaluate landslide haz-ards and risk, information on the quality, the reliability andthe limitations of the applied models was not analyzed indetail and should be considered a major issue for future re-search. In the following, we summarize the content and themain results of the papers originally presented and discussedat the meeting that are published in this special issue.Floris et al. (2011) exploit spatial data available in Ital-ian WebGIS portals to evaluate landslide susceptibility ofthe Euganean Hills Regional Park, located SW of Padua, NEItaly. In the paper, quality, applicability and possible analysisscales of the online data were investigated and a susceptibil-ity analysis of the study area was completed using a prob-abilistic approach that compared landslide distribution andthe influencing factors. The input factors used in the analysisinclude landslide distribution, morphometric data (i.e., ele-vation, slope, curvature, profile and plan curvature) and non-morphometric data (i.e., land use, distance to roads and dis-tance to rivers). Attention was paid to data pre-processing, inparticular to the re-classification of continuous data that wasperformed following objective, geologic, and geomorpholog-ical criteria. The results show that the simple probabilisticapproach used for the susceptibility evaluation was accurateand precise (repeatability). Heuristic, statistical, or determin-istic methods could be applied to the online data to improvethe prediction. The data available online for Italy allow forthe assessment of landslide susceptibility at medium to smallscales. Morphometric factors, including terrain elevation andslope angle, provide significant information where lithologi-cal and structural data are not available. The main drawbackof the online data sources was the lack of information on thetemporal frequency of landslides. For this reason, a completehazard analysis is not possible.Pereira et al. (2012) use a bivariate statistical model toidentify a combination of landslide predisposing factors thatbest predicted landslide susceptibility in the Santa Marta dePenagui˜ao study area (70km

Quantification of basal friction for glide-snow avalanche mitigation measures in forested and non-forested terrain

Abstract: This manuscript describes the quantification of basal friction for glide-snow avalanches in non-forested terrain (’No avalanches were observed in forested terrain. (2952, 5)’). A mechanical stauchwall model is used to estimate the basal friction of 67 observed glide snow avalanches. Additionally model results and field observations are compared to different European guidelines for mitigation measures (also in forested terrain). Topic and content of this paper fit well to the audience of NHESS.