Fusing Damage Proxy Maps with Geospatial Models for Bayesian Updating of Seismic Ground Failure Estimations: A Case Study in Central Italy

Author(s):  
Susu Xu ◽  
Joshua Dimasaka ◽  
David J. Wald ◽  
Hae Young Noh

<p>On August 24, 2016, a magnitude-6.2 earthquake in Central Italy resulted in at least 290 deaths, significant ground failure (including landslides and liquefaction), and building damage. After the event, the NASA Advanced Rapid Imaging and Analysis team produced Damage Proxy Maps (DPM) that reflect earthquake-induced surficial changes using synthetic aperture data from the COSMO-SkyMed satellite. However, exact causes of these surface changes, e.g., ground failure, building damage, or other environmental changes, are difficult to directly differentiate from the satellite images alone. For example, changes could reflect building damage, landslides, the co-occurrence of both, or numerous other processes that are not related to the earthquake. Alternatively, existing ground failures models are useful in locating areas of higher likelihoods but suffer from high false alarm rates due to inaccurate or incomplete geospatial proxies and complex physical interdependencies between shaking and specific sites of ground failure. In this work, we present a joint Bayesian updating framework using a causal graph strategy. The Bayesian causal graph models physical interdependencies among ground shaking, ground failures, building damage, and remote sensing observations. Based on the graph, a variational inference approach is designed to jointly update the estimates of ground failure and building damage through fusing traditional geospatial models and the remotely sensed data. As a case study, the DPMs in Central Italy are input to the model for jointly calibrating and updating the probability of ground failure estimations as well as for estimating building damage probabilities. The results showed that by incorporating high-resolution imagery, our model significantly reduces the false alarm rate of ground failure estimates and improves the spatial accuracy and resolution of ground failure and building damage inferences.</p>

Author(s):  
Nikifor Ostanin ◽  
Nikifor Ostanin

Coastal zone of the Eastern Gulf of Finland is subjected to essential natural and anthropogenic impact. The processes of abrasion and accumulation are predominant. While some coastal protection structures are old and ruined the problem of monitoring and coastal management is actual. Remotely sensed data is important component of geospatial information for coastal environment research. Rapid development of modern satellite remote sensing techniques and data processing algorithms made this data essential for monitoring and management. Multispectral imagers of modern high resolution satellites make it possible to produce advanced image processing, such as relative water depths estimation, sea-bottom classification and detection of changes in shallow water environment. In the framework of the project of development of new coast protection plan for the Kurortny District of St.-Petersburg a series of archival and modern satellite images were collected and analyzed. As a result several schemes of underwater parts of coastal zone and schemes of relative bathymetry for the key areas were produced. The comparative analysis of multi-temporal images allow us to reveal trends of environmental changes in the study areas. This information, compared with field observations, shows that remotely sensed data is useful and efficient for geospatial planning and development of new coast protection scheme.


Food Control ◽  
2021 ◽  
Vol 125 ◽  
pp. 107964
Author(s):  
Daniele Castiglione ◽  
Lisa Guardone ◽  
Francesca Susini ◽  
Federica Alimonti ◽  
Valeria Paternoster ◽  
...  

Author(s):  
Iunio Iervolino ◽  
Pasquale Cito ◽  
Chiara Felicetta ◽  
Giovanni Lanzano ◽  
Antonio Vitale

AbstractShakeMap is the tool to evaluate the ground motion effect of earthquakes in vast areas. It is useful to delimit the zones where the shaking is expected to have been most significant, for civil defense rapid response. From the earthquake engineering point of view, it can be used to infer the seismic actions on the built environment to calibrate vulnerability models or to define the reconstruction policies based on observed damage vs shaking. In the case of long-lasting seismic sequences, it can be useful to develop ShakeMap envelopes, that is, maps of the largest ground intensity among those from the ShakeMap of (selected) events of a seismic sequence, to delimit areas where the effects of the whole sequence have been of structural engineering relevance. This study introduces ShakeMap envelopes and discusses them for the central Italy 2016–2017 seismic sequence. The specific goals of the study are: (i) to compare the envelopes and the ShakeMap of the main events of the sequence to make the case for sequence-based maps; (ii) to quantify the exceedance of design seismic actions based on the envelopes; (iii) to make envelopes available for further studies and the reconstruction planning; (iv) to gather insights on the (repeated) exceedance of design seismic actions at some sites. Results, which include considerations of uncertainty in ShakeMap, show that the sequence caused exceedance of design hazard in thousands of square kilometers. The most relevant effects of the sequence are, as expected, due to the mainshock, yet seismic actions larger than those enforced by the code for structural design are found also around the epicenters of the smaller magnitude events. At some locations, the succession of ground-shaking that has excited structures, provides insights on structural damage accumulation that has likely taken place; something that is not accounted for explicitly in modern seismic design. The envelopes developed are available as supplemental material.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3982
Author(s):  
Giacomo Lazzeri ◽  
William Frodella ◽  
Guglielmo Rossi ◽  
Sandro Moretti

Wildfires have affected global forests and the Mediterranean area with increasing recurrency and intensity in the last years, with climate change resulting in reduced precipitations and higher temperatures. To assess the impact of wildfires on the environment, burned area mapping has become progressively more relevant. Initially carried out via field sketches, the advent of satellite remote sensing opened new possibilities, reducing the cost uncertainty and safety of the previous techniques. In the present study an experimental methodology was adopted to test the potential of advanced remote sensing techniques such as multispectral Sentinel-2, PRISMA hyperspectral satellite, and UAV (unmanned aerial vehicle) remotely-sensed data for the multitemporal mapping of burned areas by soil–vegetation recovery analysis in two test sites in Portugal and Italy. In case study one, innovative multiplatform data classification was performed with the correlation between Sentinel-2 RBR (relativized burn ratio) fire severity classes and the scene hyperspectral signature, performed with a pixel-by-pixel comparison leading to a converging classification. In the adopted methodology, RBR burned area analysis and vegetation recovery was tested for accordance with biophysical vegetation parameters (LAI, fCover, and fAPAR). In case study two, a UAV-sensed NDVI index was adopted for high-resolution mapping data collection. At a large scale, the Sentinel-2 RBR index proved to be efficient for burned area analysis, from both fire severity and vegetation recovery phenomena perspectives. Despite the elapsed time between the event and the acquisition, PRISMA hyperspectral converging classification based on Sentinel-2 was able to detect and discriminate different spectral signatures corresponding to different fire severity classes. At a slope scale, the UAV platform proved to be an effective tool for mapping and characterizing the burned area, giving clear advantage with respect to filed GPS mapping. Results highlighted that UAV platforms, if equipped with a hyperspectral sensor and used in a synergistic approach with PRISMA, would create a useful tool for satellite acquired data scene classification, allowing for the acquisition of a ground truth.


2011 ◽  
Vol 186 ◽  
pp. 499-504 ◽  
Author(s):  
Pan He ◽  
Jie Xu ◽  
Kai Gui Wu ◽  
Jun Hao Wen

Service-oriented workflows are the fundamental structures in service-oriented applications and changes in the workflow could cause dramatic changes in system reliability. In several ways to re-heal workflows in execution, re-sizing service pools in the workflow is practical and easy to implement. In order to quickly adjust to workflow or environmental changes, this paper presents a dynamic service pool size configuration mechanism from the point of view of maintaining workflow reliability. An architecture-based reliability model is used to evaluate the overall reliability of a workflow with service pools and an optimal method is proposed to get the combination of service pool size aiming at minimizing the sum of service pool size subject to the workflow reliability requirement. A case study is used to explain this method and experiment results show how to change service pool size to meet the workflow reliability requirements.


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