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41.
Raffaele?GrassoEmail author Marco?Cococcioni Baptiste?Mourre Jacopo?Chiggiato Michel?Rixen 《Ocean Dynamics》2012,62(3):469-493
The aim of this work is to report on an activity carried out during the 2010 Recognized Environmental Picture experiment,
held in the Ligurian Sea during summer 2010. The activity was the first at-sea test of the recently developed decision support
system (DSS) for operation planning, which had previously been tested in an artificial experiment. The DSS assesses the impact
of both environmental conditions (meteorological and oceanographic) and non-environmental conditions (such as traffic density
maps) on people and assets involved in the operation and helps in deciding a course of action that allows safer operation.
More precisely, the environmental variables (such as wind speed, current speed and significant wave height) taken as input
by the DSS are the ones forecasted by a super-ensemble model, which fuses the forecasts provided by multiple forecasting centres.
The uncertainties associated with the DSS’s inputs (generally due to disagreement between forecasts) are propagated through
the DSS’s output by using the unscented transform. In this way, the system is not only able to provide a traffic light map
(run/not run the operation), but also to specify the confidence level associated with each action. This feature was tested on a particular
type of operation with underwater gliders: the glider surfacing for data transmission. It is also shown how the availability
of a glider path prediction tool provides surfacing options along the predicted path. The applicability to different operations
is demonstrated by applying the same system to support diver operations. 相似文献
42.
In this paper, we illustrate a Bayesian Event Tree to estimate Volcanic Hazard (BET_VH). The procedure enables us to calculate
the probability of any kind of long-term hazardous event for which we are interested, accounting for the intrinsic stochastic
nature of volcanic eruptions and our limited knowledge regarding related processes. For the input, the code incorporates results
from numerical models simulating the impact of hazardous volcanic phenomena on an area and data from the eruptive history.
For the output, the code provides a wide and exhaustive set of spatiotemporal probabilities of different events; these probabilities
are estimated by means of a Bayesian approach that allows all uncertainties to be properly accounted for. The code is able
to deal with many eruptive settings simultaneously, weighting each with its own probability of occurrence. In a companion
paper, we give a detailed example of application of this tool to the Campi Flegrei caldera, in order to estimate the hazard
from tephra fall. 相似文献
43.
Jan Lindsay Warner Marzocchi Gill Jolly Robert Constantinescu Jacopo Selva Laura Sandri 《Bulletin of Volcanology》2010,72(2):185-204
The Auckland Volcanic Field (AVF) is a young basaltic field that lies beneath the urban area of Auckland, New Zealand’s largest
city. Over the past 250,000 years the AVF has produced at least 49 basaltic centers; the last eruption was only 600 years
ago. In recognition of the high risk associated with a possible future eruption in Auckland, the New Zealand government ran
Exercise Ruaumoko in March 2008, a test of New Zealand’s nation-wide preparedness for responding to a major disaster resulting from a volcanic
eruption in Auckland City. The exercise scenario was developed in secret, and covered the period of precursory activity up
until the eruption. During Exercise Ruaumoko we adapted a recently developed statistical code for eruption forecasting, namely
BET_EF (Bayesian Event Tree for Eruption Forecasting), to independently track the unrest evolution and to forecast the most
likely onset time, location and style of the initial phase of the simulated eruption. The code was set up before the start
of the exercise by entering reliable information on the past history of the AVF as well as the monitoring signals expected
in the event of magmatic unrest and an impending eruption. The average probabilities calculated by BET_EF during Exercise
Ruaumoko corresponded well to the probabilities subjectively (and independently) estimated by the advising scientists (differences
of few percentage units), and provided a sound forecast of the timing (before the event, the eruption probability reached
90%) and location of the eruption. This application of BET_EF to a volcanic field that has experienced no historical activity
and for which otherwise limited prior information is available shows its versatility and potential usefulness as a tool to
aid decision-making for a wide range of volcano types. Our near real-time application of BET_EF during Exercise Ruaumoko highlighted
its potential to clarify and possibly optimize decision-making procedures in a future AVF eruption crisis, and as a rational
starting point for discussions in a scientific advisory group. It also stimulated valuable scientific discussion around how
a future AVF eruption might progress, and highlighted areas of future volcanological research that would reduce epistemic
uncertainties through the development of better input models. 相似文献
44.
Bayesian event tree for eruption forecasting (BET_EF) at Vesuvius,Italy: a retrospective forward application to the 1631 eruption 总被引：1，自引：0，他引：1
Laura Sandri Emanuela Guidoboni Warner Marzocchi Jacopo Selva 《Bulletin of Volcanology》2009,71(7):729-745
Reliable forecasting of the next eruption at Vesuvius is the main scientific factor in defining effective strategies to reduce
volcanic risk in one of the most dangerous volcanic areas of the world. In this paper, we apply a recently developed probabilistic
code for eruption forecasting to new and independent historical data related to the pre-eruptive phase of the 1631 eruption.
The results obtained point out three main issues: (1) the importance of “cold” historical data (according to Guidoboni 2008) related to pre-eruptive phases for evaluating forecasting tools and possibly refining them; (2) the BET_EF code implemented
for Vesuvius would have forecasted the 1631 eruption satisfactorily, marking different stages of the pre-eruptive phase; (3)
the code shows that pre-eruptive signals that significantly increase the probability of eruption were likely detected more
than 2 months before the event. 相似文献
45.
Hydrogeology Journal - This study aims to determine the groundwater flow in a large area of the Venice (northeast Italy) lagoon that is under great anthropogenic pressure, which is influencing the... 相似文献
46.
Fragility curves (FCs) constitute an emerging tool for the seismic risk assessment of all elements at risk. They express the probability of a structure being damaged beyond a specific damage state for a given seismic input motion parameter, incorporating the most important sources of uncertainties, that is, seismic demand, capacity and definition of damage states. Nevertheless, the implementation of FCs in loss/risk assessments introduces other important sources of uncertainty, related to the usually limited knowledge about the elements at risk (e.g., inventory, typology). In this paper, within a Bayesian framework, it is developed a general methodology to combine into a single model (Bayesian combined model, BCM) the information provided by multiple FC models, weighting them according to their credibility/applicability, and independent past data. This combination enables to efficiently capture inter-model variability (IMV) and to propagate it into risk/loss assessments, allowing the treatment of a large spectrum of vulnerability-related uncertainties, usually neglected. As case study, FCs for shallow tunnels in alluvial deposits, when subjected to transversal seismic loading, are developed with two conventional procedures, based on a quasi-static numerical approach. Noteworthy, loss/risk assessments resulting from such conventional methods show significant unexpected differences. Conventional fragilities are then combined in a Bayesian framework, in which also probability values are treated as random variables, characterized by their probability density functions. The results show that BCM efficiently projects the whole variability of input models into risk/loss estimations. This demonstrates that BCM is a suitable framework to treat IMV in vulnerability assessments, in a straightforward and explicit manner. 相似文献
47.
Enkhjargal Natsagdorj Martin Kappas Batchuluun Tseveen Chimgee Dari Oyunbileg Tsend 《地球空间信息科学学报》2017,20(1):46-55
Soil moisture (SM) content is one of the most important environmental variables in relation to land surface climatology, hydrology, and ecology. Long-term SM data-sets on a regional scale provide reasonable information about climate change and global warming specific regions. The aim of this research work is to develop an integrated methodology for SM of kastanozems soils using multispectral satellite data. The study area is Tuv (48°40′30″N and 106°15′55″E) province in the forest steppe zones in Mongolia. In addition to this, land surface temperature (LST) and normalized difference vegetation index (NDVI) from Landsat satellite images were integrated for the assessment. Furthermore, we used a digital elevation model (DEM) from ASTER satellite image with 30-m resolution. Aspect and slope maps were derived from this DEM. The soil moisture index (SMI) was obtained using spectral information from Landsat satellite data. We used regression analysis to develop the model. The model shows how SMI from satellite depends on LST, NDVI, DEM, Slope, and Aspect in the agricultural area. The results of the model were correlated with the ground SM data in Tuv province. The results indicate that there is a good agreement between output SM and SM of ground truth for agricultural area. Further research is focused on moisture mapping for different natural zones in Mongolia. The innovative part of this research is to estimate SM using drivers which are vegetation, land surface temperature, elevation, aspect, and slope in the forested steppe area. This integrative methodology can be applied for different regions with forest and desert steppe zones. 相似文献
48.
Perego Rodolfo Pera Sebastian Boaga Jacopo Bulgheroni Monica Dalla Santa Giorgia Galgaro Antonio 《Hydrogeology Journal》2021,29(6):2187-2210
The progressive electrification of the building conditioning sector in recent years has greatly contributed to reducing greenhouse gas emissions by using renewable energy sources, particularly shallow geothermal energy. This energy can be exploited through open and closed shallow geothermal systems (SGS), and their performances greatly depend on the ground/groundwater temperature, which can be affected by both natural and anthropogenic phenomena. The present study proposes an approach to characterize aquifers affected by high SGS exploitation (not simulated in this work). Characterization of the potential hydro/thermogeological natural state is necessary to understand the regional flow and heat transport, and to identify local thermal anomalies. Passive microseismic and groundwater monitoring were used to assess the shape and thermal status of the aquifer; numerical modeling in both steady-state and transient conditions allowed understanding of the flow and heat transport patterns. Two significant thermal anomalies were detected in a fluvio-glacial aquifer in southern Switzerland, one created by river water exfiltration and one of anthropogenic nature. A favorable time lag of 110 days between river and groundwater temperature and an urban hot plume produced by underground structures were observed. These thermal anomalies greatly affect the local thermal status of the aquifer and consequently the design and efficiency of current and future SGS. Results show that the correct characterization of the natural thermo-hydrogeological status of an aquifer is a fundamental basis for determining the impact of boundary conditions and to provide initial conditions required to perform reliable local thermal sustainability assessments, especially where high SGS exploitation occurs.
相似文献49.
Daniele Andronico Antonio Cristaldi Paola Del Carlo Jacopo Taddeucci 《Journal of Volcanology and Geothermal Research》2009,180(2-4):110
The 2002–03 flank eruption of Etna was characterized by two months of explosive activity that produced copious ash fallout, constituting a major source of hazard and damage over all eastern Sicily. Most of the tephra were erupted from vents at 2750 and 2800 m elevation on the S flank of the volcano, where different eruptive styles alternated. The dominant style of explosive activity consisted of discrete to pulsing magma jets mounted by wide ash plumes, which we refer to as ash-rich jets and plumes. Similarly, ash-rich explosive activity was also briefly observed during the 2001 flank eruption of Etna, but is otherwise fairly uncommon in the recent history of Etna. Here, we describe the features of the 2002–03 explosive activity and compare it with the 2001 eruption in order to characterize ash-rich jets and plumes and their transition with other eruptive styles, including Strombolian and ash explosions, mainly through chemical, componentry and morphology investigations of erupted ash. Past models explain the transition between different styles of basaltic explosive activity only in terms of flow conditions of gas and liquid. Our findings suggest that the abundant presence of a solid phase (microlites) may also control vent degassing and consequent magma fragmentation and eruptive style. In fact, in contrast with the Strombolian or Hawaiian microlite-poor, fluidal, sideromelane clasts, ash-rich jets and plumes produce crystal-rich tachylite clasts with evidence of brittle fragmentation, suggesting that high groundmass crystallinity of the very top part of the magma column may reduce bubble movement while increasing fragmentation efficiency. 相似文献
50.