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Kosmos
Astronomia Astrofizyka
Inne

Kultura
Sztuka dawna i współczesna, muzea i kolekcje

Metoda
Metodologia nauk, Matematyka, Filozofia, Miary i wagi, Pomiary

Materia
Substancje, reakcje, energia
Fizyka, chemia i inżynieria materiałowa

Człowiek
Antropologia kulturowa Socjologia Psychologia Zdrowie i medycyna

Wizje
Przewidywania Kosmologia Religie Ideologia Polityka

Ziemia
Geologia, geofizyka, geochemia, środowisko przyrodnicze

Życie
Biologia, biologia molekularna i genetyka

Cyberprzestrzeń
Technologia cyberprzestrzeni, cyberkultura, media i komunikacja

Działalność
Wiadomości | Gospodarka, biznes, zarządzanie, ekonomia

Technologie
Budownictwo, energetyka, transport, wytwarzanie, technologie informacyjne

Natural Hazards and Earth System Sciences (NHESS)

Relationship between seismicity and water level in the Enguri high dam area (Georgia) using the singular spectrum analysisNatural Hazards and Earth System Science, 12, 2479-2485, 2012Author(s): L. Telesca, T. Matcharasvili, T. Chelidze, and N. ZhukovaThe declustered seismic catalog from 1965 to 2010 around the Enguri high dam
reservoir in western Georgia was analyzed using the singular spectrum
analysis (SSA) technique in order to investigate the relationship of local
seismicity with the reservoir water variations. In particular, the seismic
activity was analyzed in two periods: a "reference" period, from 1965 to
1970, before the start of dam building in 1971; and an "active" period,
from 1978 to 2010, in which the influence of the reservoir was significantly
effective on the seismic activity (since the first flooding of the dam
occurred in 1978). The SSA was applied to both the monthly number of
earthquakes and the time series of the monthly mean of the water level. The
first four reconstructed components explained most of the total variance in
both seismicity and water level. Clear signatures of the annual oscillation
linked with the loading/unloading operations of the dam are present in the
periodogram of the second and the third reconstructed components of the
seismic activity during the "active" period. Such annual cycle is absent
in the periodogram of the reconstructed components of the seismic activity
during the "reference" period. This is a clear indication of the
reservoir-induced character of the seismicity around the Enguri dam.

http://www.nat-hazards-earth-syst-sci.net/12/2479/2012/ 2012/08/08 - 11:14

Recurring features of extreme autumnall rainfall events on the Veneto coastal areaNatural Hazards and Earth System Science, 12, 2463-2477, 2012Author(s): A. Barbi, M. Monai, R. Racca, and A. M. RossaRecent recurring episodes of heavy flash flood-producing rainfall events on
the Veneto coastal area have renewed the interest in documenting the
frequency and key dynamical ingredients of such events. A climatological
analysis of the precipitation in Veneto reveals that, in comparison with the
rest of the region, the coastal area is characterized by fewer rain days,
lower rainfall accumulations, yet more days with heavy precipitation. If set
in relation to the yearly rainfall, daily accumulation can reach values as
high as 40% of the yearly total rainfall, more regularly between 15%
and 30%, often in periods of 12 h or less.

Four such heavy rainfall events were analyzed and synthetically described to
highlight key ingredients which appear instrumental in producing the high
rainfall accumulations. These comprise an upper-level trough elongating or
cutting off into the Western Mediterranean basin after a period of one to
two weeks of anticyclonic fair weather conditions with temperatures above
normal. The moisture supply over the Adriatic onto north-eastern Italy is
favoured by above normal sea surface temperatures, enhanced advection by a
surface low in the Gulf of Genoa, and in three of the four cases, an
additional surface low over southern Italy. The air flows associated with
the upper-level trough for the cases discussed were of moderate to weak
intensity, and convectively conditionally unstable. The flow intensity was
such that the lower tropospheric portion was blocked by and forced to flow
around the Alpine barrier, i.e. manifesting as a north-easterly, low-level
flow over much of the north-eastern Italian plains. This blocked flow seemed
to interact with the larger-scale synoptic flow to form a distinct and
persistent low-level convergence in the area of the Veneto coast.

It is suggested that these low-level convergence patterns are key in
releasing the convective instability present in the larger-scale flow just
on the Veneto coastal area. Hereby, it is the synoptic rather than the
convective setting which dictated the observed timescales of intense
rainfall. Therefore, the convective rainfall rates paired with the synoptic
durations combine to produce the exceptionally high rainfall accumulations
observed. Cases like these are significant contributors to forming the
coastal precipitation climatology, which for this area is found to be
distinctly different than for the rest of the region in terms of
precipitation concentration.

http://www.nat-hazards-earth-syst-sci.net/12/2463/2012/ 2012/08/08 - 11:14

Verification of ensemble forecasts of Mediterranean high-impact weather events against satellite observationsNatural Hazards and Earth System Science, 12, 2449-2462, 2012Author(s): J.-P. Chaboureau, O. Nuissier, and C. ClaudEnsemble forecasts at kilometre scale of two severe storms over the
Mediterranean region are verified against satellite observations. In
complement to assessing the forecasts against ground-based measurements,
brightness temperature (BT) images are computed from forecast fields and
directly compared to BTs observed from satellite. The so-called
model-to-satellite approach is very effective in identifying systematic
errors in the prediction of cloud cover for BTs in the infrared window and in
verifying the forecasted convective activity with BTs in the microwave range.
This approach is combined with the calculation of meteorological scores for
an objective evaluation of ensemble forecasts. The application of the
approach is shown in the context of two Mediterranean case studies, a
tropical-like storm and a heavy precipitating event. Assessment of cloud
cover and convective activity using satellite observations in the infrared
(10.8 μm) and microwave regions (183–191 GHz) provides results
consistent with other traditional methods using rainfall measurements. In
addition, for the tropical-like storm, differences among forecasts occur much
earlier in terms of cloud cover and deep convective activity than they do in
terms of deepening and track. Further, the underdispersion of the ensemble
forecasts of the two high-impact weather events is easily identified with
satellite diagnostics. This suggests that such an approach could be a useful
method for verifying ensemble forecasts, particularly in data-sparse regions.

http://www.nat-hazards-earth-syst-sci.net/12/2449/2012/ 2012/08/03 - 16:15

Uncertainty propagation for flood forecasting in the Alps: different views and impacts from MAP D-PHASENatural Hazards and Earth System Science, 12, 2439-2448, 2012Author(s): M. W. Rotach, M. Arpagaus, M. Dorninger, C. Hegg, A. Montani, and R. RanziD-PHASE was a Forecast Demonstration Project of the World Weather Research
Programme (WWRP) related to the Mesoscale Alpine Programme (MAP). Its goal
was to demonstrate the reliability and quality of operational forecasting of
orographically influenced (determined) precipitation in the Alps and its
consequences on the distribution of run-off characteristics. A special focus
was, of course, on heavy-precipitation events.

The D-PHASE Operations Period (DOP) ran from June to November~2007,
during which an end-to-end forecasting system was operated covering many
individual catchments in the Alps, with their water authorities, civil
protection organizations or other end users. The forecasting system's core
piece was a Visualization Platform where precipitation and flood warnings from some 30 atmospheric
and 7 hydrological models (both deterministic and probabilistic) and
corresponding model fields were displayed in uniform and comparable formats.
Also, meteograms, nowcasting information and end user communication was made
available to all the forecasters, users and end users. D-PHASE information
was assessed and used by some 50 different groups ranging from atmospheric
forecasters to civil protection authorities or water management bodies.

In the present contribution, D-PHASE is briefly presented along with its
outstanding scientific results and, in particular, the lessons learnt with
respect to uncertainty propagation. A focus is thereby on the transfer of
ensemble prediction information into the hydrological community and its use
with respect to other aspects of societal impact. Objective verification of
forecast quality is contrasted to subjective quality assessments during the
project (end user workshops, questionnaires) and some general conclusions
concerning forecast demonstration projects are drawn.

http://www.nat-hazards-earth-syst-sci.net/12/2439/2012/ 2012/08/03 - 16:15

A method to characterize the different extreme waves for islands exposed to various wave regimes: a case study devoted to Reunion IslandNatural Hazards and Earth System Science, 12, 2425-2437, 2012Author(s): S. Lecacheux, R. Pedreros, G. Le Cozannet, J. Thiébot, Y. De La Torre, and T. BulteauThis paper outlines a new approach devoted to the analysis of extreme waves
in presence of several wave regimes. It entails discriminating the
different wave regimes from offshore wave data using classification
algorithms, before conducting the extreme wave analysis for each regime
separately. The concept is applied to the pilot site of Reunion Island which
is affected by three main wave regimes: southern waves, trade-wind waves and
cyclonic waves. Several extreme wave scenarios are determined for each
regime, based on real historical cases (for cyclonic waves) and extreme
value analysis (for non-cyclonic waves). For each scenario, the nearshore
wave characteristics are modelled all around Reunion Island and the linear
theory equations are used to back calculate the equivalent deep-water wave
characteristics for each portion of the coast. The relative exposure of the
coastline to the extreme waves of each regime is determined by comparing the
equivalent deep-water wave characteristics.

This method provides a practical framework to perform an analysis of
extremes within a complex environment presenting several sources of extreme
waves. First, at a particular coastal location, it allows for
inter-comparison between various kinds of extreme waves that are generated
by different processes and that may occur at different periods of the year.
Then, it enables us to analyse the alongshore variability in wave exposition,
which is a good indicator of potential runup extreme values. For the case of
Reunion Island, cyclonic waves are dominant offshore around the island, with
equivalent deep-water wave heights up to 18 m for the northern part.
Nevertheless, due to nearshore wave refraction, southern waves may become as
energetic as cyclonic waves on the western part of the island and induce
similar impacts in terms of runup and submersion. This method can be easily
transposed to other case studies and can be adapted, depending on the data
availability.

http://www.nat-hazards-earth-syst-sci.net/12/2425/2012/ 2012/08/01 - 02:36

Grid based calibration of SWAT hydrological modelsNatural Hazards and Earth System Science, 12, 2411-2423, 2012Author(s): D. Gorgan, V. Bacu, D. Mihon, D. Rodila, K. Abbaspour, and E. RouholahnejadThe calibration and execution of large hydrological models, such as SWAT
(soil and water assessment tool), developed for large areas, high resolution,
and huge input data, need not only quite a long execution time but also high
computation resources. SWAT hydrological model supports studies and
predictions of the impact of land management practices on water, sediment,
and agricultural chemical yields in complex watersheds. The paper presents
the gSWAT application as a web practical solution for environmental
specialists to calibrate extensive hydrological models and to run scenarios,
by hiding the complex control of processes and heterogeneous resources across
the grid based high computation infrastructure. The paper highlights the
basic functionalities of the gSWAT platform, and the features of the
graphical user interface. The presentation is concerned with the development of
working sessions, interactive control of calibration, direct and basic
editing of parameters, process monitoring, and graphical and interactive
visualization of the results. The experiments performed on different SWAT
models and the obtained results argue the benefits brought by the grid
parallel and distributed environment as a solution for the processing
platform. All the instances of SWAT models used in the reported experiments
have been developed through the enviroGRIDS project, targeting the Black Sea
catchment area.

http://www.nat-hazards-earth-syst-sci.net/12/2411/2012/ 2012/08/01 - 02:36

Storm surge and wave simulations in the Gulf of Mexico using a consistent drag relation for atmospheric and storm surge modelsNatural Hazards and Earth System Science, 12, 2399-2410, 2012Author(s): D. Vatvani, N. C. Zweers, M. van Ormondt, A. J. Smale, H. de Vries, and V. K. MakinTo simulate winds and water levels, numerical weather prediction (NWP) and
storm surge models generally use the traditional bulk relation for wind
stress, which is characterized by a wind drag coefficient. A still commonly
used drag coefficient in those models, some of them were developed in the
past, is based on a relation, according to which the magnitude of the
coefficient is either constant or increases monotonically with increasing
surface wind speed (Bender, 2007; Kim et al., 2008; Kohno and Higaki, 2006). The NWP and surge
models are often tuned independently from each other in order to obtain good
results. Observations have indicated that the magnitude of the drag
coefficient levels off at a wind speed of about 30 m s−1, and then decreases
with further increase of the wind speed. Above a wind speed of approximately
30 m s−1, the stress above the air-sea interface starts to saturate. To
represent the reducing and levelling off of the drag coefficient, the
original Charnock drag formulation has been extended with a correction term.

In line with the above, the Delft3D storm surge model is tested using both
Charnock's and improved Makin's wind drag parameterization to evaluate the
improvements on the storm surge model results, with and without inclusion of
the wave effects. The effect of waves on storm surge is included by
simultaneously simulating waves with the SWAN model on identical model grids
in a coupled mode. However, the results presented here will focus on the
storm surge results that include the wave effects.

The runs were carried out in the Gulf of Mexico for Katrina and Ivan
hurricane events. The storm surge model was initially forced with H*wind
data (Powell et al., 2010) to test the effect of the Makin's wind drag
parameterization on the storm surge model separately. The computed wind,
water levels and waves are subsequently compared with observation data.
Based on the good results obtained, we conclude that, for a good reproduction
of the storm surges under hurricane conditions, Makin's new drag
parameterization is favourable above the traditional Charnock relation.
Furthermore, we are encouraged by these results to continue the studies and
establish the effect of improved Makin's wind drag parameterization in the
wave model.

The results from this study will be used to evaluate the relevance of
extending the present towards implementation of a similar wind drag
parameterization in the SWAN wave model, in line with our aim to apply a
consistent wind drag formulation throughout the entire storm surge modelling
approach.

http://www.nat-hazards-earth-syst-sci.net/12/2399/2012/ 2012/07/27 - 14:49

Seasonal forecast of French Mediterranean heavy precipitating events linked to weather regimesNatural Hazards and Earth System Science, 12, 2389-2398, 2012Author(s): J.-F. Guérémy, N. Laanaia, and J.-P. CéronSeasonal predictability of local precipitation is rather weak in the
mid-latitudes. This is the case when assessing the skill of the seasonal
forecast of Heavy Precipitating Event (HPE) extreme occurrence over the
French Mediterranean coast during the fall season. Tropics to extra-tropics
teleconnection patterns do appear when averaging analyzed fields over the
years characterised by a frequency of HPE occurrence in the upper
17% of the distribution. A methodology taking weather regime occurrence
into account as an intermediate step to forecast HPE extreme occurrence is
presented. For the period 1960 to 2001 and four different sets of seasonal
forecast, the Economical Value is doubled, compared to the score
obtained with the simulated local precipitation data, when using a linear
model (Linear Discriminant Analysis in this case) taking simulated 200 hPa
velocity potential–stream function regime occurrences as predictors.
Interestingly, larger scores are shown for this couple of fields
over a large-scale domain including the tropics than for the 500 hPa
geopotential height over an Euro–Atlantic domain, despite a tighter link of
the latter field to the local precipitation.

http://www.nat-hazards-earth-syst-sci.net/12/2389/2012/ 2012/07/25 - 20:16

Three-dimensional earthquake analysis of roller-compacted concrete damsNatural Hazards and Earth System Science, 12, 2369-2388, 2012Author(s): M. E. KartalGround motion effect on a roller-compacted concrete (RCC) dams in the
earthquake zone should be taken into account for the most critical
conditions. This study presents three-dimensional earthquake response of a
RCC dam considering geometrical non-linearity. Besides, material and
connection non-linearity are also taken into consideration in the
time-history analyses. Bilinear and multilinear kinematic hardening
material models are utilized in the materially non-linear analyses for
concrete and foundation rock respectively. The contraction joints inside the
dam blocks and dam–foundation–reservoir interaction are modeled by the
contact elements. The hydrostatic and hydrodynamic pressures of the
reservoir water are modeled with the fluid finite elements based on the
Lagrangian approach. The gravity and hydrostatic pressure effects are
employed as initial condition before the strong ground motion. In the
earthquake analyses, viscous dampers are defined in the finite element model
to represent infinite boundary conditions. According to numerical solutions,
horizontal displacements increase under hydrodynamic pressure. Besides,
those also increase in the materially non-linear analyses of the dam. In
addition, while the principle stress components by the hydrodynamic pressure
effect the reservoir water, those decrease in the materially non-linear
time-history analyses.

http://www.nat-hazards-earth-syst-sci.net/12/2369/2012/ 2012/07/24 - 22:59

Assessment of coastal vulnerability to climate change hazards at the regional scale: the case study of the North Adriatic SeaNatural Hazards and Earth System Science, 12, 2347-2368, 2012Author(s): S. Torresan, A. Critto, J. Rizzi, and A. MarcominiSea level rise, changes in storms and wave climate as a consequence of
global climate change are expected to increase the size and magnitude of
flooded and eroding coastal areas, thus having profound impacts on
coastal communities and ecosystems. River deltas, beaches, estuaries and
lagoons are considered particularly vulnerable to the adverse effects of
climate change, which should be studied at the regional/local scale. This
paper presents a regional vulnerability assessment (RVA) methodology
developed to analyse site-specific spatial information on coastal
vulnerability to the envisaged effects of global climate change, and assist
coastal communities in operational coastal management and conservation. The
main aim of the RVA is to identify key vulnerable receptors (i.e. natural
and human ecosystems) in the considered region and localize vulnerable hot
spot areas, which could be considered as homogeneous geographic sites for the
definition of adaptation strategies. The application of the RVA methodology
is based on a heterogeneous subset of bio-geophysical and socio-economic
vulnerability indicators (e.g. coastal topography, geomorphology, presence
and distribution of vegetation cover, location of artificial protection),
which are a measure of the potential harm from a range of
climate-related impacts (e.g. sea level rise inundation, storm surge
flooding, coastal erosion). Based on a system of numerical weights and
scores, the RVA provides relative vulnerability maps that allow to
prioritize more vulnerable areas and targets of different climate-related
impacts in the examined region and to support the identification of suitable
areas for human settlements, infrastructures and economic activities,
providing a basis for coastal zoning and land use planning. The
implementation, performance and results of the methodology for the coastal
area of the North Adriatic Sea (Italy) are fully described in the paper.

http://www.nat-hazards-earth-syst-sci.net/12/2347/2012/ 2012/07/24 - 22:59

Uncorrected land-use planning highlighted by flooding: the Alba case study (Piedmont, Italy)Natural Hazards and Earth System Science, 12, 2329-2346, 2012Author(s): F. Luino, L. Turconi, C. Petrea, and G. NigrelliAlba is a town of over 30 000 inhabitants located along the Tanaro River
(Piedmont, northwestern Italy) and is famous for its wine and white
truffles. Many important industries and companies are based in Alba,
including the famous confectionery group Ferrero.

The town suffered considerably from a flood that occurred on 5–6 November 1994.
Forty-eight percent of the urban area was inundated, causing severe
damage and killing nine people. After the flood, the Alba area was analysed
in detail to determine the reasons for its vulnerability.

Information on serious floods in this area since 1800 was gathered from
official records, state technical office reports, unpublished documents in
the municipal archives, and articles published in local and national
newspapers. Maps, plans and aerial photographs (since 1954) were examined to
reconstruct Alba's urban development over the last two centuries and the
planform changes of the Tanaro River.

The results were compared with the effects of the November 1994 flood, which
was mapped from aerial photographs taken immediately after the flood, field
surveys and eyewitness reports.

The territory of Alba was subdivided into six categories: residential;
public service; industrial, commercial and hotels; sports areas, utilities
and standards (public gardens, parks, athletics grounds, private and public
sport clubs); aggregate plants and dumps; and agriculture and riverine
strip. The six categories were then grouped into three classes with
different flooding-vulnerability levels according to various parameters.
Using GIS, the three river corridors along the Tanaro identified by the
Autorità di Bacino del Fiume Po were overlaid on the three classes to
produce a final map of the risk areas.

This study shows that the historic floods and their dynamics have not been
duly considered in the land-use planning of Alba. The zones that were most
heavily damaged in the 1994 flood were those that were frequently affected in
the past and sites of more recent urbanisation. Despite recurrent severe
flooding of the Tanaro River and its tributaries, areas along the riverbed
and its paleochannels have been increasingly used for infrastructure and
building (e.g., roads, a municipal dump, a prison, natural aggregate plants,
a nomad camp), which has often interfered with the natural spread of the
floodwaters. Since the 1994 flood, many remedial projects have been completed
along the Tanaro and its tributaries, including levees, bank protection,
concrete walls and floodway channels. In spite of these costly projects, some
areas remain at high risk for flooding.

The method used, which considered historical data, river corridors
identified by hydraulic calculations, geomorphological aspects and land-use
planning, can indicate with good accuracy flood-prone areas and in
consequence to be an useful tool for the coherent planning of urban
expansion and the mitigation of flood risk.

http://www.nat-hazards-earth-syst-sci.net/12/2329/2012/ 2012/07/24 - 22:59

Active faults and historical earthquakes in the Messina Straits area (Ionian Sea)Natural Hazards and Earth System Science, 12, 2311-2328, 2012Author(s): A. Polonia, L. Torelli, L. Gasperini, and P. MussoniThe Calabrian Arc (CA) subduction complex is located at the toe of the
Eurasian Plate in the Ionian Sea, where sediments resting on the lower plate
have been scraped off and piled up in the accretionary wedge due to the
African/Eurasian plate convergence and back arc extension. The CA has been
struck repeatedly by destructive historical earthquakes, but knowledge of
active faults and source parameters is relatively poor, particularly for
seismogenic structures extending offshore. We analysed the fine structure of
major tectonic features likely to have been sources of past earthquakes:
(i) the NNW–SSE trending Malta STEP (Slab Transfer Edge
Propagator) fault system, representing a lateral tear of the subduction
system; (ii) the out-of-sequence thrusts (splay faults) at the rear of the
salt-bearing Messinian accretionary wedge; and (iii) the Messina Straits
fault system, part of the wide deformation zone separating the western and
eastern lobes of the accretionary wedge.

Our findings have implications for seismic hazard in southern Italy, as we
compile an inventory of first order active faults that may have produced
past seismic events such as the 1908, 1693 and 1169 earthquakes. These
faults are likely to be source regions for future large magnitude events as
they are long, deep and bound sectors of the margin characterized by
different deformation and coupling rates on the plate interface.

http://www.nat-hazards-earth-syst-sci.net/12/2311/2012/ 2012/07/24 - 22:59

Risk perception – issues for flood management in EuropeNatural Hazards and Earth System Science, 12, 2299-2309, 2012Author(s): R. A. Bradford, J. J. O'Sullivan, I. M. van der Craats, J. Krywkow, P. Rotko, J. Aaltonen, M. Bonaiuto, S. De Dominicis, K. Waylen, and K. SchelfautPublic perception of flood risk and flood risk information is often
overlooked when developing flood risk management plans. As scientists and
the public at large perceive risk in very different ways, flood risk
management strategies are known to have failed in the past due to this
disconnect between authorities and the public. This paper uses a novel
approach in exploring the role of public perception in developing flood risk
communication strategies in Europe. Results are presented of extensive
quantitative research of 1375 questionnaire responses from thirteen
communities at risk across six European countries. The research forms part
of two research projects funded under the 2nd ERA-Net CRUE Funding
Initiative: URFlood and FREEMAN. Risk perception is conceptualised as a
pillar of social resilience, representing an innovative approach to the
issue. From this process recommendations are identified for improving flood
risk management plans through public participation.

http://www.nat-hazards-earth-syst-sci.net/12/2299/2012/ 2012/07/21 - 07:44

Analysis of microseismic signals and temperature recordings for rock slope stability investigations in high mountain areasNatural Hazards and Earth System Science, 12, 2283-2298, 2012Author(s): C. Occhiena, V. Coviello, M. Arattano, M. Chiarle, U. Morra di Cella, M. Pirulli, P. Pogliotti, and C. ScaviaThe permafrost degradation is a probable cause for the
increase of rock instabilities and rock falls observed in recent years in
high mountain areas, particularly in the Alpine region. The phenomenon
causes the thaw of the ice filling rock discontinuities; the water deriving
from it subsequently freezes again inducing stresses in the rock mass that
may lead, in the long term, to rock falls. To investigate these processes, a
monitoring system composed by geophones and thermometers was installed in
2007 at the Carrel hut (3829 m a.s.l., Matterhorn, NW Alps). In 2010, in the
framework of the Interreg 2007–2013 Alcotra project no. 56 MASSA, the
monitoring system has been empowered and renovated in order to meet project
needs.

In this paper, the data recorded by this renewed system between 6
October 2010 and 5 October 2011 are presented and 329 selected microseismic events
are analysed. The data processing has concerned the classification of the
recorded signals, the analysis of their distribution in time and the
identification of the most important trace characteristics in time and
frequency domain. The interpretation of the results has evidenced a possible
correlation between the temperature trend and the event occurrence.

The research is still in progress and the data recording and interpretation
are planned for a longer period to better investigate the spatial-temporal
distribution of microseismic activity in the rock mass, with specific
attention to the relation of microseismic activity with temperatures. The
overall goal is to verify the possibility to set up an effective monitoring
system for investigating the stability of a rock mass under permafrost
conditions, in order to supply the researchers with useful data to better
understand the relationship between temperature and rock mass stability and,
possibly, the technicians with a valid tool for decision-making.

http://www.nat-hazards-earth-syst-sci.net/12/2283/2012/ 2012/07/21 - 07:44

Enhancing flood resilience through improved risk communicationsNatural Hazards and Earth System Science, 12, 2271-2282, 2012Author(s): J. J. O'Sullivan, R. A. Bradford, M. Bonaiuto, S. De Dominicis, P. Rotko, J. Aaltonen, K. Waylen, and S. J. LanganA framework of guiding recommendations for effective pre-flood and flood
warning communications derived from the URFlood project (2nd ERA-Net
CRUE Research Funding Initiative) from extensive quantitative and
qualitative research in Finland, Ireland, Italy and Scotland is presented.
Eleven case studies in fluvial, pluvial, coastal, residual and "new" flood
risk locations were undertaken. The recommendations were developed from
questionnaire surveys by exploring statistical correlations of actions and
understandings of individuals in flood risk situations to low, moderate and
high resilience groupings. Groupings were based on a conceptual relationship
of self-assessed levels of awareness, preparedness and worry. Focus groups
and structured interviews were used to discuss barriers in flood
communications, explore implementation of the recommendations and to rank
the recommendations in order of perceived importance. Results indicate that
the information deficit model for flood communications that relies on the
provision of more and better information to mitigate risk in flood-prone
areas is insufficient, and that the communications process is very much
multi-dimensional. The recommendations are aimed at addressing this
complexity and their careful implementation is likely to improve the
penetration of flood communications. The recommendations are applicable to
other risks and are transferrable to jurisdictions beyond the project
countries.

http://www.nat-hazards-earth-syst-sci.net/12/2271/2012/ 2012/07/20 - 11:28

Multi-parametric investigation of the volcano-hydrothermal system at Tatun Volcano Group, Northern TaiwanNatural Hazards and Earth System Science, 12, 2259-2270, 2012Author(s): S. Rontogianni, K. I. Konstantinou, and C.-H. LinThe Tatun Volcano Group (TVG) is located in northern Taiwan near the capital
Taipei. In this study we selected and analyzed almost four years (2004–2007)
of its seismic activity. The seismic network established around TVG
initially consisted of eight three-component seismic stations with this
number increasing to twelve by 2007. Local seismicity mainly involved high
frequency (HF) earthquakes occurring as isolated events or as part of
spasmodic bursts. Mixed and low frequency (LF) events were observed during
the same period but more rarely. During the analysis we estimated duration
magnitudes for the HF earthquakes and used a probabilistic non-linear method
to accurately locate all these events. The complex frequencies of LF events
were also analyzed with the Sompi method indicating fluid compositions
consistent with a misty or dusty gas. We juxtaposed these results with
geochemical/temperature anomalies extracted from fumarole gas and rainfall
levels covering a similar period. This comparison is interpreted in the
context of a model proposed earlier for the volcano-hydrothermal system of
TVG where fluids and magmatic gases ascend from a magma body that lies at
around 7–8 km depth. Most HF earthquakes occur as a response to stresses
induced by fluid circulation within a dense network of cracks pervading the
upper crust at TVG. The largest (ML ~ 3.1) HF event that occurred
on 24 April 2006 at a depth of 5–6 km had source characteristics compatible
with that of a tensile crack. It was followed by an enrichment in magmatic
components of the fumarole gases as well as a fumarole temperature increase,
and provides evidence for ascending fluids from a magma body into the
shallow hydrothermal system. This detailed analysis and previous physical
volcanology observations at TVG suggest that the region is volcanically
active and that measures to mitigate potential hazards have to be considered
by the local authorities.

http://www.nat-hazards-earth-syst-sci.net/12/2259/2012/ 2012/07/19 - 14:40

Strengths and strain energies of volcanic edifices: implications for eruptions, collapse calderas, and landslidesNatural Hazards and Earth System Science, 12, 2241-2258, 2012Author(s): A. GudmundssonNatural hazards associated with volcanic edifices depend partly on how
fracture resistant the edifices are, i.e. on their strengths.
Observations worldwide indicate that large fluid-driven extension fractures
(dikes, inclined sheets), shear fractures (landslides), and mixed-mode fractures (ring dikes and ring faults) normally propagate more easily in a
basaltic edifice (shield volcano) than in a stratovolcano. For example,
dike-fed eruptions occur once every few years in many basaltic edifices but
once every 102-3 yr in many stratovolcanoes. Large landslides and
caldera collapses also appear to be more common in a typical basaltic
edifice/shield volcano than in a typical stratovolcano. In contrast to a
basaltic edifice, a stratovolcano is composed of mechanically dissimilar
rock layers, i.e. layers with mismatching elastic properties (primarily
Young's modulus). Elastic mismatch encourages fracture deflection and arrest
at contacts and increases the amount of energy needed for a large-scale
edifice failure. Fracture-related hazards depend on the potential energy
available to propagate the fractures which, in turn, depends on the boundary
conditions during fracture propagation. Here there are two possible
scenarios: one in which the outer boundary of the volcanic edifice or rift
zone does not move during the fracture propagation (constant displacement);
the other in which the boundary moves (constant load). In the former, the
total potential energy is the strain energy stored in the volcano before
fracture formation; in the latter, the total potential energy is the strain
energy plus the work done by the forces moving the boundary.
Constant-displacement boundary conditions favor small eruptions, landslides,
and caldera collapses, whereas constant-load conditions favor comparatively
large eruptions, landslides, and collapses. For a typical magma chamber
(sill-like with a diameter of 8 km), the strain energy change due to
magma-chamber inflation is estimated at the order of 1014 J (0.1 PJ).
For comparison, the surface energy needed to form a typical feeder dike is
of the same order of magnitude, or 1014 J. There are several processes
besides magma-chamber inflation that may increase the strain energy in a
volcano before eruption. Thus, during a typical unrest period with
magma-chamber inflation, the added strain energy in the volcano is large
enough for a typical feeder dike to form. An injected dike, however, only
reaches the surface and becomes a feeder if it is able to propagate
through the numerous layers and contacts that tend to deflect or arrest
dikes. The strong elastic mismatch between layers that constitute
stratovolcanoes not only encourages fracture arrest, but also the storage of
more strain energy (than in a typical basaltic edifice/shield volcano)
before fracture formation and failure. It is thus through producing
materials of widely different mechanical properties that stratovolcanoes
become strong and resilient.

http://www.nat-hazards-earth-syst-sci.net/12/2241/2012/ 2012/07/19 - 14:40

Analysis of intense rainfall events on Madeira Island during the 2009/2010 winterNatural Hazards and Earth System Science, 12, 2225-2240, 2012Author(s): F. T. Couto, R. Salgado, and M. J. CostaThis paper constitutes a step towards the understanding of some
characteristics associated with high rainfall amounts and flooding on
Madeira Island. The high precipitation events that occurred during the
winter of 2009/2010 have been considered with three main goals: to analyze the
main atmospheric characteristics associated with the events; to expand the
understanding of the interaction between the island and the atmospheric
circulations, mainly the effects of the island on the generation or
intensification of orographic precipitation; and to evaluate the performance of
high resolution numerical modeling in simulating and forecasting heavy
precipitation events over the island. The MESO-NH model with a horizontal
resolution of 1 km is used, as well as rain gauge data, synoptic charts and
measurements of precipitable water obtained from the Atmospheric InfraRed
Sounder (AIRS). The results confirm the influence of the orographic effects
on precipitation over Madeira as well as the tropical–extratropical
interaction, since atmospheric rivers were detected in six out of the seven
cases analyzed, acting as a low level moisture supplier, which together with
the orographic lifting induced the high rainfall amounts. Only in one of the
cases the presence of a low pressure system was identified over the
archipelago.

http://www.nat-hazards-earth-syst-sci.net/12/2225/2012/ 2012/07/19 - 14:40

Brief communication "An auto-diagnosis tool to highlight interdependencies between urban technical networks"Natural Hazards and Earth System Science, 12, 2219-2224, 2012Author(s): M. Toubin, D. Serre, Y. Diab, and R. LaganierNatural hazards threaten the urban system and its components that are likely
to fail. With their high degree of interdependency, urban networks and
services are critical issues for the resilience of a city. And yet, network
managers are scarcely aware of their flaws and dependencies and they are
reluctant to take them into account. In order to develop an operational tool
to improve urban resilience, we propose here an auto-diagnosis method to be
completed by network managers. The subsequent confrontation of all diagnoses
is the basis of collaborative research for problem identification and
solution design. The tool is experimented with the Parisian urban transport
society.

http://www.nat-hazards-earth-syst-sci.net/12/2219/2012/ 2012/07/19 - 14:40

Characteristics of damage to buildings by debris flows on 7 August 2010 in Zhouqu, Western ChinaNatural Hazards and Earth System Science, 12, 2209-2217, 2012Author(s): K. H. Hu, P. Cui, and J. Q. ZhangA debris-flow catastrophe hit the city of Zhouqu, Gansu Province, western
China, at midnight on 7 August 2010 following a local extreme rainfall of
77.3 mm h−1 in the Sanyanyu and Luojiayu ravines, which are located to the
north of the urban area. Eight buildings damaged in the event were
investigated in detail to study the characteristics and patterns of damage
to buildings by debris flows. It was found that major structural damage was
caused by the frontal impact of proximal debris flows, while non-structural
damage was caused by lateral accumulation and abrasion of sediment. The
impact had a boundary decreasing effect when debris flows encountered a
series of obstacles, and the inter-positioning of buildings produced
so-called back shielding effects on the damage. Impact, accumulation, and
abrasion were the three main patterns of damage to buildings in this event.
The damage scale depended not only on the flow properties, such as density,
velocity, and depth, but also on the structural strength of buildings,
material, orientation, and geometry. Reinforced concrete-framed structures
can effectively resist a much higher debris-flow impact than brick-concrete
structures. With respect to the two typical types of structure, a
classification scheme to assess building damage is proposed by referring to
the Chinese Classification System of Earthquake Damage to Buildings.
Furthermore, three damage scales (major structural, minor structural, and
non-structural damage) are defined by critical values of impact pressure.
Finally, five countermeasures for effectively mitigating the damage are
proposed according to the on-site investigation.

http://www.nat-hazards-earth-syst-sci.net/12/2209/2012/ 2012/07/18 - 16:02

Analysis of the cross-correlation between seismicity and water level in the Aswan area (Egypt) from 1982 to 2010Natural Hazards and Earth System Science, 12, 2203-2207, 2012Author(s): L. Telesca, R. ElShafey Fat ElBary, A. El-Ela Amin Mohamed, and M. ElGabryIn this study the correlation between the monthly fluctuations of the water
level of the Aswan High Dam and monthly number of earthquakes from 1982 to
2010, which occurred in the surrounding area, was investigated. Our findings
reveal that significant correlation is present during the period 1982–1993
between water level and shallow seismicity (depth less than 15 km). The deep
seismicity (depth larger than 15 km) is significantly correlated with the
water level between January and April 1989. The time lag of the significant
maximal cross-correlation varies from 2–8~months for the shallow
seismicity, while it is around 7–8 months for the deep seismicity. These values
of the time lags could be in favour of the presence of two distinct
triggering mechanisms: one due to pore pressure diffusion and the other due
to fracture compaction (undrained response).

http://www.nat-hazards-earth-syst-sci.net/12/2203/2012/ 2012/07/12 - 14:59

Effect of tidal triggering on seismicity in Taiwan revealed by the empirical mode decomposition methodNatural Hazards and Earth System Science, 12, 2193-2202, 2012Author(s): H.-J. Chen, C.-C. Chen, C.-Y. Tseng, and J.-H. WangThe effect of tidal triggering on earthquake occurrence has
been controversial for many years. This study considered earthquakes that
occurred near Taiwan between 1973 and 2008. Because earthquake data are
nonlinear and non-stationary, we applied the empirical mode decomposition
(EMD) method to analyze the temporal variations in the number of daily
earthquakes to investigate the effect of tidal triggering. We compared the
results obtained from the non-declustered catalog with those from two kinds
of declustered catalogs and discuss the aftershock effect on the EMD-based
analysis. We also investigated stacking the data based on in-phase phenomena
of theoretical Earth tides with statistical significance tests. Our results
show that the effects of tidal triggering, particularly the lunar tidal
effect, can be extracted from the raw seismicity data using the approach
proposed here. Our results suggest that the lunar tidal force is likely a
factor in the triggering of earthquakes.

http://www.nat-hazards-earth-syst-sci.net/12/2193/2012/ 2012/07/12 - 14:59

Local inundation distances and regional tsunami recurrence in the Indian Ocean inferred from luminescence dating of sandy deposits in ThailandNatural Hazards and Earth System Science, 12, 2177-2192, 2012Author(s): D. Brill, N. Klasen, K. Jankaew, H. Brückner, D. Kelletat, A. Scheffers, and S. ScheffersThe Holocene beach-ridge plain of Phra Thong Island (Ko Phra Thong, SW
Thailand) provides sedimentary evidence of several palaeotsunamis, in
addition to the deposit of the 2004 Indian Ocean tsunami. Due to poor preservation
conditions, these palaeoevent layers are restricted to swales. Correlation across beach ridges,
which is important e.g. to reconstruct inundation distances, remains a major challenge. A primary tool
for establishing a precisely confined correlation of the sand sheets is the
use of chronological data. Since the application of radiocarbon dating is
limited by the scarcity of appropriate material, this study utilised optically
stimulated luminescence (OSL) dating of tsunamigenic quartz grains.
Generally, the sediments showed favourable luminescence properties regarding
signal intensity, dose recovery and thermal stability. Disturbances of the
OSL signal due to partial bleaching were corrected using the minimum age
model. At least three palaeoevents – being 490–550, 925–1035 and 1740–2000 yr old – were distinguished by dating the discontinuous sand sheets at
four different sites. Besides this chronological framework, the OSL data
provide the opportunity to correlate the discontinuous sand sheets between
spatially separated sites within the same swale as well as across ridges.
This allows for first estimates of inundation distances for the
palaeotsunamis documented on Phra Thong Island. Furthermore, the two younger
events overlap in age with contemporaneous tsunami and earthquake evidence from
other coasts bordering the Indian Ocean.

http://www.nat-hazards-earth-syst-sci.net/12/2177/2012/ 2012/07/12 - 14:59

Corrigendum to "Probabilistic sensitivity analysis of two suspension bridges in Istanbul, Turkey to near- and far-fault ground motion" published in Nat. Hazards Earth Syst. Sci., 12, 459–473, 2012Natural Hazards and Earth System Science, 12, 2173-2175, 2012Author(s): Ö. ÇavdarNo abstract available.

http://www.nat-hazards-earth-syst-sci.net/12/2173/2012/ 2012/07/11 - 17:11

Searching for the seafloor signature of the 21 May 2003 Boumerdès earthquake offshore central AlgeriaNatural Hazards and Earth System Science, 12, 2159-2172, 2012Author(s): A. Cattaneo, N. Babonneau, G. Ratzov, G. Dan-Unterseh, K. Yelles, R. Bracène, B. Mercier de Lépinay, A. Boudiaf, and J. DéverchèreShaking by moderate to large earthquakes in the Mediterranean Sea has proved
in the past to potentially trigger catastrophic sediment collapse and flow.
On 21 May 2003, a magnitude 6.8 earthquake located near Boumerdès
(central Algerian coast) triggered large turbidity currents responsible
for 29 submarine cable breaks at the foot of the continental slope over
~150 km from west to east. Seafloor bathymetry and backscatter imagery
show the potential imprints of the 2003 event and of previous events. Large
slope scarps resulting from active deformation may locally enhance sediment
instabilities, although faults are not directly visible at the seafloor.
Erosion is evident at the foot of the margin and along the paths of the
numerous canyons and valleys. Cable breaks are located at the outlets of
submarine valleys and in areas of turbiditic levee overspilling and
demonstrate the multi-source and multi-path character of the 2003 turbiditic
event. Rough estimates of turbidity flow velocity are not straightforward
because of the multiple breaks along the same cable, but seem compatible
with those measured in other submarine cable break studies elsewhere.

While the signature of the turbidity currents is mostly erosional on the
continental slope, turbidite beds alternating with hemipelagites accumulate
in the distal reaches of sediment dispersal systems. In perspective, more
chronological work on distal turbidite successions offshore Algeria offers
promising perspectives for paleoseismology reconstructions based on
turbidite dating, if synchronous turbidites along independent sedimentary
dispersal systems are found to support triggering by major earthquakes.
Preliminary results on sediment core PSM-KS23 off Boumerdès typically
show a 800-yr interval between turbidites during the Holocene, in
accordance with the estimated mean seismic cycle on land, even if at this
stage it is not yet possible to prove the earthquake origin of all the
turbidites.

http://www.nat-hazards-earth-syst-sci.net/12/2159/2012/ 2012/07/10 - 20:33

Review article "Remarks on factors influencing shear wave velocities and their role in evaluating susceptibilities to earthquake-triggered slope instability: case study for the Campania area (Italy)"Natural Hazards and Earth System Science, 12, 2147-2158, 2012Author(s): V. PaolettiShear wave velocities have a fundamental role in connection with the
mitigation of seismic hazards, as their low values are the main causes of
site amplification phenomena and can significantly influence the
susceptibility of a territory to seismic-induced landslides. The shear wave
velocity (Vs) and modulus (G) of each lithological unit are influenced by factors
such as the degree of fracturing and faulting, the porosity, the clay amount
and the precipitation, with the latter two influencing the unit water
content. In this paper we discuss how these factors can affect the Vs
values and report the results of different analyses that quantify the
reduction in the rock Vs and shear modulus values connected to the
presence of clay and water. We also show that significant results in
assessing seismic-induced slope failure susceptibility for land planning
targets could be achieved through a careful evaluation, based only on
literature studies, of the geo-lithological and geo-seismic features of the
study area.

http://www.nat-hazards-earth-syst-sci.net/12/2147/2012/ 2012/07/10 - 20:33

The identity approach for assessing socio-technical resilience to climate change: example of flood risk management for the Island of DordrechtNatural Hazards and Earth System Science, 12, 2139-2146, 2012Author(s): B. Gersonius, R. Ashley, and C. ZevenbergenRecent EU guidance on adaptation calls for the enhancement of
socio-technical resilience to climate change. However, socio-technical
resilience is relatively poorly defined and this makes it difficult to apply
in practice. This paper uses the concept of identity as a vehicle to advance
the definition and assessment of socio-technical resilience. Identity
comprises four aspects (components, relationships, innovation, and
continuity) that constitute the minimum of what has to be identified and
specified if resilience is to be assessed. Characterising the identity of a
socio-technical system requires the conceptualisation of these four aspects
in relation to the particular function provided by the system (e.g. flood
risk management) and also the identification of the specific variables and
thresholds that reflect changes in identity. We have demonstrated the
utility of the identity approach, using the example of flood risk management
for the Island of Dordrecht, the Netherlands. Based on the results,
socio-technical resilience has been redefined as the ability of the system
to continue to function as expected in the face of change. This definition
implies that a system is resilient when it can deliver performance without a
change of identity by continuing compliance with standards and expectations.

http://www.nat-hazards-earth-syst-sci.net/12/2139/2012/ 2012/07/10 - 20:33

Change of extreme rainfall indexes at Ebro River BasinNatural Hazards and Earth System Science, 12, 2127-2137, 2012Author(s): J. L. Valencia, A. M. Tarquis, A. Saá-Requejo, and J. M. GascóExtreme rainfall events are a serious concern for regional hydrology and
agriculture in the Ebro River Basin. Repeated anomalous rainfall in recent
decades has had a devastating impact on this region, both socially and
economically. Some studies developed in Italy and USA have shown that there
is a change in seasonal patterns and an increasing frequency of extreme
rainfall events, whereas other studies have pointed out that no global
behaviour could be observed in monthly trends due to high climatic
variability. The aim of this work is to test which of these scenarios is the
case for the Ebro River Basin.

For this purpose, 14 meteorological stations were selected based on
the length of the rainfall series and the climatic classification to obtain
a representative untreated dataset from the river basin. Daily rainfall
series from 1957 to 2002 were obtained from each meteorological station.
First, classical climatic indexes were analysed with an autoregressive test
to study possible trends in rainfall. The results can be explained following
the evolution of the NAO and WeMO indexes, which indicate that the initial
period should be subdivided in two periods (1957–1979 and 1980–2002) to
assume stationarity and to analyse the rainfall distribution functions.

The general results obtained in this study for both sub-periods, through the
generalised Pareto distribution (GPD) parameters and the maximum expected
return values, do not support the results previously obtained by other
authors that affirm a positive trend in extreme rainfall indexes and point
to a slight reduction indicated by others. Three extreme precipitation
indexes show negative statistical significant trends. GPD-scale parameters
decrease except for only one rain gauge, although this decrease is only
statistically significant for two rain gauges. Another two locations show
statistical significance decreased for maximum expected return values.

http://www.nat-hazards-earth-syst-sci.net/12/2127/2012/ 2012/07/06 - 06:42

Potential of remote sensing techniques for tsunami hazard and vulnerability analysis – a case study from Phang-Nga province, ThailandNatural Hazards and Earth System Science, 12, 2103-2126, 2012Author(s): H. Römer, P. Willroth, G. Kaiser, A. T. Vafeidis, R. Ludwig, H. Sterr, and J. Revilla DiezRecent tsunami disasters, such as the 2004 Indian Ocean tsunami or the 2011
Japan earthquake and tsunami, have highlighted the need for effective risk
management. Remote sensing is a relatively new method for risk analysis,
which shows significant potential in conducting spatially explicit risk and
vulnerability assessments. In order to explore and discuss the potential and
limitations of remote sensing techniques, this paper presents a case study
from the tsunami-affected Andaman Sea coast of Thailand. It focuses on a
local assessment of tsunami hazard and vulnerability, including the
socio-economic and ecological components. High resolution optical data,
including IKONOS data and aerial imagery (MFC-3 camera) as well as different
digital elevation models, were employed to create basic geo-data including
land use and land cover (LULC), building polygons and topographic data sets
and to provide input data for the hazard and vulnerability assessment.
Results show that the main potential of applying remote sensing techniques
and data derives from a synergistic combination with other types of data. In
the case of hazard analysis, detailed LULC information and the correction of
digital surface models (DSMs) significantly improved the results of
inundation modeling. The vulnerability assessment showed that remote sensing
can be used to spatially extrapolate field data on socio-economic or
ecological vulnerability collected in the field, to regionalize exposure
elements and assets and to predict vulnerable areas. Limitations and
inaccuracies became evident regarding the assessment of ecological resilience
and the statistical prediction of vulnerability components, based on
variables derived from remote sensing data.

http://www.nat-hazards-earth-syst-sci.net/12/2103/2012/ 2012/06/28 - 12:35

Building an 18 000-year-long paleo-earthquake record from detailed deep-sea turbidite characterisation in Poverty Bay, New ZealandNatural Hazards and Earth System Science, 12, 2077-2101, 2012Author(s): H. Pouderoux, G. Lamarche, and J.-N. ProustTwo ~20 m-long sedimentary cores collected in two neighbouring
mid-slope basins of the Paritu Turbidite System in Poverty Bay, east of New
Zealand, show a high concentration of turbidites (5 to 6 turbidites per
meter), interlaid with hemipelagites, tephras and a few debrites. Turbidites
occur as both stacked and single, and exhibit a range of facies from muddy
to sandy turbidites. The age of each turbidite is estimated using the
statistical approach developed in the OxCal software from an exceptionally
dense set of tephrochronology and radiocarbon ages (~1 age per meter).
The age, together with the facies and the petrophysical properties of the
sediment (density, magnetic susceptibility and P-wave velocity), allows the
correlation of turbidites across the continental slope (1400–2300 m water
depth). We identify 73 synchronous turbidites, named basin events, across
the two cores between 819 ± 191 and 17 729 ± 701 yr BP. Compositional,
foraminiferal and geochemical signatures of the turbidites are used to
characterise the source area of the sediment, the origin of the turbidity
currents, and their triggering mechanism. Sixty-seven basin events are
interpreted as originated from slope failures on the upper continental slope
in water depth ranging from 150 to 1200 m. Their earthquake trigger is
inferred from the heavily gullied morphology of the source area and the
water depth at which slope failures originated. We derive an earthquake mean
return time of ~230 yr, with a 90% probability range from 10 to
570 yr. The earthquake chronology indicates cycles of progressive
decrease of earthquake return times from ~400 yr to ~150 yr at 0–7 kyr, 8.2–13.5 kyr,
14.7–18 kyr. The two 1.2 kyr-long intervals
in between (7–8.2 kyr and 13.5–14.7 kyr) correspond to basin-wide
reorganisations with anomalous turbidite deposition (finer deposits and/or
non deposition) reflecting the emplacement of two large mass transport
deposits much more voluminous than the "classical" earthquake-triggered
turbidites. Our results show that the progressive characterisation of a
turbidite record from a single sedimentary system can provide a continuous
paleo-earthquake history in regions of short historical record and
incomplete onland paleo-earthquake evidences. The systematic description of
each turbidite enables us to infer the triggering mechanism.

http://www.nat-hazards-earth-syst-sci.net/12/2077/2012/ 2012/06/28 - 12:35

Wave climate of the Adriatic Sea: a future scenario simulationNatural Hazards and Earth System Science, 12, 2065-2076, 2012Author(s): A. Benetazzo, F. Fedele, S. Carniel, A. Ricchi, E. Bucchignani, and M. SclavoWe present a study on expected wind wave severity changes in the Adriatic
Sea for the period 2070–2099 and their impact on extremes. To do so, the
phase-averaged spectral wave model SWAN is forced using wind fields computed
by the high-resolution regional climate model COSMO-CLM, the climate version
of the COSMO meteorological model downscaled from a global climate model
running under the IPCC-A1B emission scenario. Namely, the adopted wind
fields are given with a horizontal resolution of 14 km and 40 vertical
levels, and they are prepared by the Italian Aerospace Research Centre (CIRA). Firstly, in order to infer the wave model accuracy in predicting
seasonal variability and extreme events, SWAN results are validated against
a control simulation, which covers the period 1965–1994. In particular,
numerical predictions of the significant wave height Hs are compared
against available in-situ data. Further, a statistical analysis is carried
out to estimate changes on wave storms and extremes during the simulated
periods (control and future scenario simulations). In particular, the
generalized Pareto distribution is used to predict changes of storm peak
Hs for frequent and rare storms in the Adriatic Sea. Finally,
Borgman's theory is applied to estimate the spatial pattern of the expected maximum
wave height Hmax during a storm, both for the present climate and that
of the future scenario. Results show a future wave climate in the Adriatic
Sea milder than the present climate, even though increases of wave severity
can occur locally.

http://www.nat-hazards-earth-syst-sci.net/12/2065/2012/ 2012/06/26 - 15:35

Late Holocene landscape change history related to the Alpine Fault determined from drowned forests in Lake Poerua, Westland, New ZealandNatural Hazards and Earth System Science, 12, 2051-2064, 2012Author(s): R. M. Langridge, R. Basili, L. Basher, and A. P. WellsLake Poerua is a small, shallow lake that abuts the scarp of the Alpine
Fault on the West Coast of New Zealand's South Island. Radiocarbon dates
from drowned podocarp trees on the lake floor, a sediment core from a
rangefront alluvial fan, and living tree ring ages have been used to deduce
the late Holocene history of the lake. Remnant drowned stumps of kahikatea
(Dacrycarpus dacrydioides) at 1.7–1.9 m water depth yield a preferred time-of-death age at
1766–1807 AD, while a dryland podocarp and kahikatea stumps at 2.4–2.6 m yield
preferred time-of-death ages of ca. 1459–1626 AD. These age ranges are
matched to, but offset from, the timings of Alpine Fault rupture events at
ca. 1717 AD, and either ca. 1615 or 1430 AD. Alluvial fan detritus dated from
a core into the toe of a rangefront alluvial fan, at an equivalent depth to
the maximum depth of the modern lake (6.7 m), yields a calibrated age of AD
1223–1413. This age is similar to the timing of an earlier Alpine Fault
rupture event at ca. 1230 AD ± 50 yr. Kahikatea trees growing on
rangefront fans give ages of up to 270 yr, which is consistent with alluvial
fan aggradation following the 1717 AD earthquake. The elevation levels of
the lake and fan imply a causal and chronological link between lake-level
rise and Alpine Fault rupture. The results of this study suggest that the
growth of large, coalescing alluvial fans (Dry and Evans Creek fans)
originating from landslides within the rangefront of the Alpine Fault and
the rise in the level of Lake Poerua may occur within a decade or so of
large Alpine Fault earthquakes that rupture adjacent to this area. These
rises have in turn drowned lowland forests that fringed the lake.
Radiocarbon chronologies built using OxCal show that a series of massive
landscape changes beginning with fault rupture, followed by landsliding, fan
sedimentation and lake expansion. However, drowned Kahikatea trees may be
poor candidates for intimately dating these events, as they may be able to
tolerate water for several decades after metre-scale lake level rises have
occurred.

http://www.nat-hazards-earth-syst-sci.net/12/2051/2012/ 2012/06/26 - 15:35

Influence of the soil-atmosphere exchange on the hydric profile induced in soil-structure systemNatural Hazards and Earth System Science, 12, 2039-2049, 2012Author(s): A. Al Qadad, I. Shahrour, and M. RouainiaSoil-atmosphere exchange leads to a moisture change in the soil. This can
cause major damage to engineering structures due to the soil expansion and
shrinkage. The soil-atmosphere exchange is related to several parameters,
in particular the soil characteristics and climate conditions. The presence of an engineering structure causes a variation of the hydraulic
profile in the soil, which can lead to heterogeneous soil movement and
consequently to structural damage. This paper presents a coupled numerical
model based on the consideration of both water flow in unsaturated soils and
soil-atmosphere exchange. After the validation of the model, the paper
presents its use for the analysis of the influence of the presence of
structures on moisture change induced under climatic conditions recorded
in a semi-arid region. Analysis shows that the presence of the structure
leads to important change in the moisture distribution, in particular in the
vicinity of the structure.

http://www.nat-hazards-earth-syst-sci.net/12/2039/2012/ 2012/06/26 - 15:35

Estimation of seismic ground motions using deterministic approach for major cities of GujaratNatural Hazards and Earth System Science, 12, 2019-2037, 2012Author(s): J. Shukla and D. ChoudhuryA deterministic seismic hazard analysis has been carried out for various sites of
the major cities (Ahmedabad, Surat, Bhuj, Jamnagar and Junagadh) of the Gujarat
region in India to compute the seismic hazard exceeding a certain level in terms
of peak ground acceleration (PGA) and to estimate maximum possible PGA at
each site at bed rock level. The seismic sources in Gujarat are very
uncertain and recurrence intervals of regional large earthquakes are not
well defined. Because the instrumental records of India specifically in the
Gujarat region are far from being satisfactory for modeling the seismic
hazard using the probabilistic approach, an attempt has been made in this
study to accomplish it through the deterministic approach. In this regard,
all small and large faults of the Gujarat region were evaluated to
obtain major fault systems. The empirical relations suggested by earlier
researchers for the estimation of maximum magnitude of earthquake motion with
various properties of faults like length, surface area, slip rate, etc. have been
applied to those faults to obtain the maximum earthquake magnitude. For the
analysis, seven different ground motion attenuation relations (GMARs) of
strong ground motion have been utilized to calculate the maximum horizontal ground
accelerations for each major city of Gujarat. Epistemic uncertainties in the
hazard computations are accounted for within a logic-tree framework by
considering the controlling parameters like b-value, maximum magnitude and
ground motion attenuation relations (GMARs). The corresponding deterministic
spectra have been prepared for each major city for the 50th and 84th
percentiles of ground motion occurrence. These deterministic spectra are
further compared with the specified spectra of Indian design code
IS:1893-Part I (2002) to validate them for further practical use. Close
examination of the developed spectra reveals that the expected ground motion
values become high for the Kachchh region i.e. Bhuj city and moderate in the
Mainland Gujarat, i.e. cities of Surat and Ahmedabad. The seismic ground motion
level in the Saurashtra is moderate but marginally differs from that as
presently specified in IS:1893-Part I (2002). Based on the present study, the
recommended PGA values for the cities studied are 0.13 g, 0.15 g, 0.64 g,
0.14 g and 0.2 g for Ahmedabad city, Surat City, Bhuj City, Jamnagar City and
Junagadh city, respectively. The prepared spectra can be further used for
seismic resistant design of structures within the above major city
boundaries of Gujarat to quantify seismic loading on structures.

http://www.nat-hazards-earth-syst-sci.net/12/2019/2012/ 2012/06/26 - 15:35

Statistical emulation of a tsunami model for sensitivity analysis and uncertainty quantificationNatural Hazards and Earth System Science, 12, 2003-2018, 2012Author(s): A. Sarri, S. Guillas, and F. DiasDue to the catastrophic consequences of tsunamis, early warnings need to be
issued quickly in order to mitigate the hazard. Additionally, there is a need
to represent the uncertainty in the predictions of tsunami characteristics
corresponding to the uncertain trigger features (e.g. either position, shape
and speed of a landslide, or sea floor deformation associated with an
earthquake). Unfortunately, computer models are expensive to run. This leads
to significant delays in predictions and makes the uncertainty quantification
impractical. Statistical emulators run almost instantaneously and may
represent well the outputs of the computer model. In this paper, we use the
outer product emulator to build a fast statistical surrogate of a
landslide-generated tsunami computer model. This Bayesian framework enables
us to build the emulator by combining prior knowledge of the computer model
properties with a few carefully chosen model evaluations. The good
performance of the emulator is validated using the leave-one-out method.

http://www.nat-hazards-earth-syst-sci.net/12/2003/2012/ 2012/06/25 - 19:05

Quantifying human vulnerability in rural areas: case study of Tutova Hills (Eastern Romania)Natural Hazards and Earth System Science, 12, 1987-2001, 2012Author(s): I. C. Stângă and A. GrozavuThis paper aims to assess the vulnerability at regional level, the model and
the proposed indicators being explicitly intended for an essentially rural
region, in this case–Tutova Hills (Eastern Romania). Five categories of
variables were taken into account to define the vulnerability components:
rural habitat, demographic features, agriculture, environmental quality and
emergency situations. For each one, five variables were analyzed and ranked
based on the level of determination or subordination. In order to ensure the
flexibility of the model and to avoid the criteria duplication in assessing
vulnerability, only a single indicator of each category was retained and
included in analysis: total number of inhabitants, dependency ratio, weight
of arable land on slope categories, weight of land under forestry and road
accessibility of villages. The selected indicators were mathematically
processed in order to maximize their relevance and to unitary express the
results in the spread 0–1. Also, values of each indicator were grouped
into four classes, corresponding to the level of vulnerability: low, medium,
high and very high. A general index was obtained through the integration of
vulnerability factors in an equation based on the geometric mean. Spatial
analysis was based on features of the MicroImages TNTmips 7.3. software,
which allow the vulnerability mapping. This approach argues and states that
vulnerability assessment through indicator-based methods can be made only
according to the level and scale of analysis and related to natural or human
conditions of a region.

http://www.nat-hazards-earth-syst-sci.net/12/1987/2012/ 2012/06/25 - 19:05

The educational and awareness purposes of the Paideia approach for heritage managementNatural Hazards and Earth System Science, 12, 1983-1986, 2012Author(s): F. Carbone, L. Oosterbeek, and C. CostaThe need to raise awareness among the communities about the challenge of
resource use – and, more generally, about the principles of sustainability – is
the reason why the United Nations General Assembly proclaimed, in December 2002,
the United Nations Decade of Education for Sustainable Development,
2005–2014 (DESD). For operators and managers of cultural and natural
heritage, it represents a profound challenge to their ability to transmit
the content of scientific knowledge to the general public in order to
empower everyone on the preservation of cultural and natural resources, and
to raise awareness about the potential that mankind has at its disposal. In
this context, the application of the PAIDEIA APPROACH for the management of cultural
heritage is the key to the recovery of socio-economic values intrinsic to
these resources. This approach to management is based on the enhancement of
cultural (namely archaeological) and natural heritage for social benefit and
it involves the tourist trade as a vehicle of knowledge transmission,
intercultural dialogue and socio-economic sustainable development.

http://www.nat-hazards-earth-syst-sci.net/12/1983/2012/ 2012/06/25 - 19:05

Severe wind gust thresholds for Meteoalarm derived from uniform return periods in ECA&DNatural Hazards and Earth System Science, 12, 1969-1981, 2012Author(s): A. Stepek, I. L. Wijnant, G. van der Schrier, E. J. M. van den Besselaar, and A. M. G. Klein TankIn this study we present an alternative wind gust warning guideline for
Meteoalarm, the severe weather warning website for Europe. There are
unrealistically large differences in levels and issuing frequencies of all
warning levels currently in use between neighbouring Meteoalarm countries.
This study provides a guide for the Meteoalarm community to review their wind
gust warning thresholds. A more uniform warning system is achieved by using
one pan-European return period per warning level. The associated return
values will be different throughout Europe because they depend on local
climate conditions, but they will not change abruptly at country borders as
is currently the case for the thresholds. As return values are a measure of
the possible danger of an event and its impact on society, they form an ideal
basis for a warning system. Validated wind gust measurements from the
European Climate Assessment and Dataset (ECA&D, http://www.ecad.eu)
were used to calculate return values of the annual maximum wind gust. The
current thresholds are compared with return values for 3 different return
periods: 10 times a year return periods for yellow warnings, 2 yr periods
for orange and 5 yr periods for red warnings. So far 10 countries provide
wind gust data to ECA&D. Due to the ECA&D completeness requirements and the
fact that some countries provided too few stations to be representative for
that country, medians of the return values of annual maximum wind gust could
be calculated for 6 of the 10 countries. Alternative guideline thresholds are
presented for Norway, Ireland, The Netherlands, Germany, the Czech Republic
and Spain and the need to distinguish between coastal, inland and mountainous
regions is demonstrated. The new thresholds based on uniform return periods
differ significantly from the current ones, particularly for coastal and
mountainous areas.

We are aware of other, sometimes binding factors (e.g. laws) that prevent
participating counties from implementing this climatology based warning
system.

http://www.nat-hazards-earth-syst-sci.net/12/1969/2012/ 2012/06/25 - 19:05

ICT approaches to integrating institutional and non-institutional data services for better understanding of hydro-meteorological phenomenaNatural Hazards and Earth System Science, 12, 1961-1968, 2012Author(s): T. Bedrina, A. Parodi, A. Quarati, and A. ClematisIt is widely recognised that an effective exploitation of Information and
Communication Technologies (ICT) is an enabling factor to achieve major
advancements in Hydro-Meteorological Research (HMR). Recently, a
lot of attention has been devoted to the use of ICT in HMR activities, e.g.
in order to facilitate data exchange and integration, to improve
computational capabilities and consequently model resolution and quality.
Nowadays, ICT technologies have demonstrated that it is possible to extend
monitoring networks by integrating sensors and other sources of data managed
by volunteer's communities. These networks are constituted by peers that
span a wide portion of the territory in many countries. The peers are
"location aware" in the sense that they provide information strictly
related with their geospatial location. The coverage of these networks, in
general, is not uniform and the location of peers may follow random
distribution. The ICT features used to set up the network are lightweight
and user friendly, thus, permitting the peers to join the network without the
necessity of specialised ICT knowledge. In this perspective it is of increasing interest for HMR activities to elaborate of Personal Weather Station (PWS)
networks, capable to provide almost real-time, location aware, weather data.

Moreover, different big players of the web arena are now providing world-wide
backbones, suitable to present on detailed map location aware information,
obtained by mashing up data from different sources. This is the case, for
example, with Google Earth and Google Maps.

This paper presents the design of a mashup application aimed at aggregating,
refining and visualizing near real-time hydro-meteorological datasets. In
particular, we focused on the integration of instant precipitation depths,
registered either by widespread semi-professional weather stations and
official ones. This sort of information has high importance and usefulness
in decision support systems and Civil Protection applications. As a
significant case study, we analysed the rainfall data observed during the
severe flash-flood event of 4 November 2011 over Liguria region,
Italy. The joint use of official observation network with PWS networks and
meteorological radar allowed for the making of evident finger-like convection
structure.

http://www.nat-hazards-earth-syst-sci.net/12/1961/2012/ 2012/06/18 - 13:46

Using an integrated method to estimate watershed sediment yield during heavy rain period: a case study in Hualien County, TaiwanNatural Hazards and Earth System Science, 12, 1949-1960, 2012Author(s): S. M. Hsu, H. Y. Wen, N. C. Chen, S. Y. Hsu, and S. Y. ChiA comprehensive approach estimating sediment yield from a watershed is
needed to develop better measures for mitigating sediment disasters and
assessing downstream impacts. In the present study, an attempt has been made
to develop an integrated method, considering sediment supplies associated
with soil erosion, shallow landslide and debris flow to estimate sediment
yield from a debris-flow-prone watershed on a storm event basis. The
integrated method is based on the HSPF and TRIGRS models for predicting soil
erosion and shallow landslide sediment yield, and the FLO-2D model for
calculating debris flow sediment yield. The proposed method was applied to
potential debris-flow watersheds located in the Sioulin Township of Hualien
County. The available data such as hourly rainfall data, historical
streamflow and sediment records as well as event-based landslide inventory
maps have been used for model calibration and validation. Results for
simulating sediment yield have been confirmed by comparisons of observed
data from several typhoon events. The verified method employed a 24-h
design hyetograph with the 100-yr return period to simulate sediment yield
within the study area. The results revealed that the influence of shallow
landslides on sediment supply as compared with soil erosion was significant.
The estimate of landslide transport capacity into a main channel indicated the
sediment delivery ratio on a typhoon event basis was approximately 38.4%.
In addition, a comparison of sediment yields computed from occurrence and
non-occurrence of debris flow scenarios showed that the sediment yield from
an occurrence condition was found to be increasing at about 14.2 times more than
estimated under a non-occurrence condition. This implied watershed sediment
hazard induced by debris flow may cause severe consequences.

http://www.nat-hazards-earth-syst-sci.net/12/1949/2012/ 2012/06/18 - 13:46