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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)

Submarine mass wasting and associated tsunami risk offshore western Thailand, Andaman Sea, Indian OceanNatural Hazards and Earth System Science, 12, 2609-2630, 2012Author(s): J. M. Schwab, S. Krastel, M. Grün, F. Gross, P. Pananont, P. Jintasaeranee, S. Bunsomboonsakul, W. Weinrebe, and D. Winkelmann2-D seismic data from the top and the western slope of Mergui Ridge in water
depths between 300 and 2200 m off the Thai west coast have been investigated
in order to identify mass transport deposits (MTDs) and evaluate the
tsunamigenic potential of submarine landslides in this outer shelf area.
Based on our newly collected data, 17 mass transport deposits have been
identified. Minimum volumes of individual MTDs range between 0.3 km3
and 14 km3. Landslide deposits have been identified in three different
settings: (i) stacked MTDs within disturbed and faulted basin sediments at
the transition of the East Andaman Basin to the Mergui Ridge; (ii) MTDs within
a pile of drift sediments at the basin-ridge transition; and (iii) MTDs
near the edge of/on top of Mergui Ridge in relatively shallow water depths
(< 1000 m). Our data indicate that the Mergui Ridge slope area seems to have
been generally unstable with repeated occurrence of slide events. We find
that the most likely causes for slope instabilities may be the presence of
unstable drift sediments, excess pore pressure, and active tectonics. Most
MTDs are located in large water depths (> 1000 m) and/or comprise small
volumes suggesting a small tsunami potential. Moreover, the recurrence rates
of failure events seem to be low. Some MTDs with tsunami potential, however,
have been identified on top of Mergui Ridge. Mass-wasting events that may
occur in the future at similar locations may trigger tsunamis if they
comprise sufficient volumes. Landslide tsunamis, emerging from slope
failures in the working area and affecting western Thailand coastal areas
therefore cannot be excluded, though the probability is very small compared
to the probability of earthquake-triggered tsunamis, arising from the Sunda
Trench.

http://www.nat-hazards-earth-syst-sci.net/12/2609/2012/ 2012/08/17 - 13:51

Testing the critical exponent in the relation between stress drop of earthquake and lead time of seismic electric signalNatural Hazards and Earth System Science, 12, 2603-2607, 2012Author(s): E. DologlouThe application of new data in the power law relation between the stress
drop of the earthquake and the lead time of the precursory seismic electric
signal led to an exponent which falls in the range of the values of
critical exponents for fracture and it is in excellent agreement with a
previous one found by (Dologlou, 2012). In addition, this exponent is very
close to the one reported by Varotsos and Alexopoulos (1984a), which
interconnects the amplitude of the precursory seismic electric signals (SES)
and the magnitude of the impending earthquake. Hence, the hypothesis that
underlying dynamic processes evolving to criticality prevail in the pre-focal area when the SES is emitted is significantly supported.

http://www.nat-hazards-earth-syst-sci.net/12/2603/2012/ 2012/08/16 - 16:45

Long-term temporal changes in the occurrence of a high forest fire danger in FinlandNatural Hazards and Earth System Science, 12, 2591-2601, 2012Author(s): H. M. Mäkelä, M. Laapas, and A. VenäläinenClimate variation and change influence several ecosystem components
including forest fires. To examine long-term temporal variations of forest
fire danger, a fire danger day (FDD) model was developed. Using mean
temperature and total precipitation of the Finnish wildfire season
(June–August), the model describes the climatological preconditions of fire
occurrence and gives the number of fire danger days during the same time
period. The performance of the model varied between different regions in
Finland being best in south and west. In the study period 1908–2011, the
year-to-year variation of FDD was large and no significant increasing or
decreasing tendencies could be found. Negative slopes of linear regression
lines for FDD could be explained by the simultaneous, mostly not significant
increases in precipitation. Years with the largest wildfires did not stand
out from the FDD time series. This indicates that intra-seasonal variations
of FDD enable occurrence of large-scale fires, despite the whole season's
fire danger is on an average level. Based on available monthly climate data,
it is possible to estimate the general fire conditions of a summer. However,
more detailed input data about weather conditions, land use, prevailing
forestry conventions and socio-economical factors would be needed to gain
more specific information about a season's fire risk.

http://www.nat-hazards-earth-syst-sci.net/12/2591/2012/ 2012/08/16 - 16:45

Measurement frequency and sampling spatial domains required to characterize turbidity and salinity events in the Guadalquivir estuary (Spain)Natural Hazards and Earth System Science, 12, 2581-2589, 2012Author(s): E. Contreras and M. J. PoloEstuaries are complex systems in which long water quality data series are
not always available at the proper scale. Data proceeding from several water
quality networks, with different measuring frequencies (monthly, weekly and
15 min) and different numbers of sampling points, were compared throughout
the main channel of the Guadalquivir estuary. Higher frequency of turbidity
sampling in the upper estuary is required. In the lower estuary, sampling
points help to find out the ETM, and higher frequency sampling of EC is
required because of the effect of the tidal and river components. This could
be a feedback for the implementation of monitoring networks in estuaries.

http://www.nat-hazards-earth-syst-sci.net/12/2581/2012/ 2012/08/14 - 22:25

Geological evidence for paleotsunamis along eastern Sicily (Italy): an overviewNatural Hazards and Earth System Science, 12, 2569-2580, 2012Author(s): P. M. De Martini, M. S. Barbano, D. Pantosti, A. Smedile, C. Pirrotta, P. Del Carlo, and S. PinziWe present geological evidence for paleotsunamis along the ~230 km-long
coast of eastern Sicily (Italy); combining this information
with historical data, we reconstruct a unique history of tsunami inundations.
We integrate data on 38 paleotsunami deposits (from fine sand layers to
boulders) collected at 11 sites (one offshore). The geological data record
traces of large tsunamis which have occurred during the past 4 millennia. Chronological
constrains include 14C, 210Pb and 137Cs, OSL and
tephrochronology. When compatible, the age of the paleotsunami deposits is
associated to historical events, but it is also used to highlight unknown
tsunamis. Average tsunami recurrence interval (between 320 and 840 yr) and
minimum inland tsunami ingressions (often greater than the historical ones)
were estimated at several sites. On the basis of this work, the tsunami
catalogue is implemented by two unknown tsunamis which occurred during the first
millennium BC and by one unknown regional tsunami, which occurred in 650–770 AD.
By including this latter event in the eastern Sicily catalogue, we estimate
an average recurrence interval for strong tsunamis of ca. 385 yr.

Comparison and merging of historical and geological data can definitely
contribute to a better understanding of regional and local tsunami potential
and provides robust parameters to be used in tsunami hazard estimates.

http://www.nat-hazards-earth-syst-sci.net/12/2569/2012/ 2012/08/14 - 22:25

Combining inland and offshore paleotsunamis evidence: the Augusta Bay (eastern Sicily, Italy) case studyNatural Hazards and Earth System Science, 12, 2557-2567, 2012Author(s): A. Smedile, P. M. De Martini, and D. PantostiOffshore and inland geological evidence for multiple tsunami inundations was
found in the Augusta Bay area: (1) the main local historical
tsunamis (1908, 1693, 1169), (2) two far-generated tsunamis (i.e. Crete
365 AD and Santorini, 3600 BP), and (3) seven unknown tsunamis). Average
tsunami recurrence intervals from inland and offshore investigations of
about 550 and 320 yr, respectively were obtained for the past 4 ka. The
history of paleotsunamis from the marine record appears to be as complete as
the historical one for the past millennium, yielding an average tsunami
recurrence interval of 250 yr for the Augusta Bay. Geological data allow
also estimating a minimum tsunami inundation distance of 530 m and a
minimum run-up of 5 m. The marine record contains evidence for more
paleotsunamis with respect to the inland one because of continuous
sedimentation and better preservation of stratigraphy in the offshore with
respect to coastal areas, which are commonly affected by intermittent-erosion and
sedimentation and anthropic activities.

This work shows that the integration of geological and historical data can
provide critical information regarding the extent and age of tsunamis of the
past (e.g. inundation distance, age, and frequency), which is of immediate relevance
for tsunami hazard assessment.

http://www.nat-hazards-earth-syst-sci.net/12/2557/2012/ 2012/08/14 - 22:25

Relationships between magnetic parameters, chemical composition and clay minerals of topsoils near Coimbra, central PortugalNatural Hazards and Earth System Science, 12, 2545-2555, 2012Author(s): A. M. Lourenço, F. Rocha, and C. R. GomesMagnetic measurements, mineralogical and geochemical studies were carried
out on surface soil samples in order to find possible relationships and to
obtain environmental implications. The samples were taken over a square grid
(500 × 500 m) near the city of Coimbra, in central Portugal. Mass specific
magnetic susceptibility ranges between 12.50 and 710.11 × 10−8 m3 kg−1
and isothermal magnetic remanence at 1 tesla values range
between 253 and 18 174 × 10−3 Am−1. Chemical analysis by atomic
absorption spectrometry shows that the concentration of various toxic
elements was higher than the mean background values for world soils. Higher
values of susceptibility and toxic elements content were reported near roads
and rivers. Urban pollution and road traffic emission seem to be the main
influence for these values. A semi-quantitative X-ray diffraction study has
been carried out on a representative set of subsamples, using peak areas.
Illite (average 52%), kaolinite (average 55%), chlorite (average 6%)
and irregular illite-smectite mixed-layers (average 9%) are the
major clay minerals groups identified. Mineral composition of total fraction
confirms the presence of magnetite/maghemite. The clay minerals results
point to a contrast in the behavior of the main clay minerals: illite,
chlorite, and kaolinite (also, smectite in some samples), which are
generally in agreement with the magnetic and geochemical data. The results
showed that magnetic measurements are a sensitive, fast, inexpensive and
robust method, which can be advantageously applied for studying soils
affected by urban and road pollution.

http://www.nat-hazards-earth-syst-sci.net/12/2545/2012/ 2012/08/14 - 22:25

Continuous multi-criteria methods for crop and soil conservation planning on La Colacha (Río Cuarto, Province of Córdoba, Argentina)Natural Hazards and Earth System Science, 12, 2529-2543, 2012Author(s): J. M. Antón, J. B. Grau, J. M. Cisneros, F. V. Laguna, P. L. Aguado, J. J. Cantero, D. Andina, and E. SánchezAgro-areas of Arroyos Menores (La Colacha) west and south of Río
Cuarto (Prov. of Córdoba, Argentina) basins are very fertile but have
high soil loses. Extreme rain events, inundations and other severe erosions
forming gullies demand urgently actions in this area to avoid soil
degradation and erosion supporting good levels of agro production. The authors
first improved hydrologic data on La Colacha, evaluated the systems of
soil uses and actions that could be recommended considering the relevant
aspects of the study area and applied decision support systems (DSS)
with mathematic tools for planning of defences and uses of soils in these
areas. These were conducted here using multi-criteria models, in multi-criteria decision making (MCDM); first of discrete MCDM to
chose among global types of use of soils, and then of continuous MCDM to evaluate and optimize combined actions, including repartition of
soil use and the necessary levels of works for soil conservation and for hydraulic management to conserve against erosion these basins.
Relatively global solutions for La Colacha area have been defined and were
optimised by Linear Programming in Goal Programming forms that are
presented as Weighted or Lexicographic Goal Programming and as Compromise
Programming. The decision methods used are described, indicating algorithms
used, and examples for some representative scenarios on La Colacha area are given.

http://www.nat-hazards-earth-syst-sci.net/12/2529/2012/ 2012/08/14 - 00:23

Decadal trends in beach morphology on the east coast of South Africa and likely causative factorsNatural Hazards and Earth System Science, 12, 2515-2527, 2012Author(s): S. Corbella and D. D. StretchSandy shorelines are dynamic with constant changes that can cause hazards in
developed areas. The causes of change may be either natural or anthropogenic.
This paper evaluates evidence for shoreline changes and their causative
factors using a case study on the east coast of South Africa. Beach
morphology trends were found to be location-specific, but overall the beaches
show a receding trend. It was hypothesized that wave, tide, sea level and
wind trends as well as anthropogenic influences are causative factors, and
their contributions to shoreline changes were evaluated. Maximum significant
wave heights, average wave direction, peak period and storm event frequencies
all show weak increasing trends, but only the increases in peak period and
wave direction are statistically significant. The chronic beach erosion
cannot be attributed to wave climate changes since they are still too small
to explain the observations. Instead, the impacts of sea level rise and
reductions in the supply of beach sediments are suggested as the main
causative factors. The analysis also identifies a trend in the frequency of
severe erosion events due to storms that coincide with a 4.5-yr extreme tide
cycle, which demonstrates the potential impact of future sea level rise.

http://www.nat-hazards-earth-syst-sci.net/12/2515/2012/ 2012/08/14 - 00:23

Preface "New Developments in Tsunami Science: from Hazard to Risk"Natural Hazards and Earth System Science, 12, 2507-2514, 2012Author(s): I. Didenkulova, S. Monserrat, and S. Tinti

http://www.nat-hazards-earth-syst-sci.net/12/2507/2012/ 2012/08/14 - 00:23

Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channelNatural Hazards and Earth System Science, 12, 2499-2505, 2012Author(s): N. HottaMeasuring the interstitial water pressure of debris flows under various
conditions gives essential information on the flow stress structure. This
study measured the basal interstitial water pressure during debris flow
routing experiments in a laboratory flume. Because a sensitive pressure
gauge is required to measure the interstitial water pressure in shallow
laboratory debris flows, a differential gas pressure gauge with an attached
diaphragm was used. Although this system required calibration before and
after each experiment, it showed a linear behavior and a sufficiently high
temporal resolution for measuring the interstitial water pressure of debris
flows. The values of the interstitial water pressure were low. However, an
excess of pressure beyond the hydrostatic pressure was observed with
increasing sediment particle size. The measured excess pressure corresponded
to the theoretical excess interstitial water pressure, derived as a Reynolds
stress in the interstitial water of boulder debris flows. Turbulence was
thought to induce a strong shear in the interstitial space of sediment
particles. The interstitial water pressure in boulder debris flows should be
affected by the fine sediment concentration and the phase transition from
laminar to turbulent debris flow; this should be the subject of future
studies.

http://www.nat-hazards-earth-syst-sci.net/12/2499/2012/ 2012/08/11 - 06:13

Glacial lake mapping with very high resolution satellite SAR dataNatural Hazards and Earth System Science, 12, 2487-2498, 2012Author(s): T. Strozzi, A. Wiesmann, A. Kääb, S. Joshi, and P. MoolFloods resulting from the outbursts of glacial lakes are among the most
far-reaching disasters in high mountain regions. Glacial lakes are typically
located in remote areas and space-borne remote sensing data are an important
source of information about the occurrence and development of such lakes.
Here we show that very high resolution satellite Synthetic Aperture Radar
(SAR) data can be employed for reliably mapping glacial lakes. Results in
the Alps, Pamir and Himalaya using TerraSAR-X and Radarsat-2 data are
discussed in comparison to in-situ information, and high-resolution
satellite optical and radar imagery. The performance of the satellite SAR
data is best during the snow- and ice-free season. In the broader
perspective of hazard management, the detection of glacial lakes and the
monitoring of their changes from very high-resolution satellite SAR
intensity images contributes to the initial assessment of hazards related to
glacial lakes, but a more integrated, multi-level approach needs also to
include other relevant information such as glacier outlines and outline
changes or the identification of unstable slopes above the lake and the
surrounding area, information types to which SAR analysis techniques can also
contribute.

http://www.nat-hazards-earth-syst-sci.net/12/2487/2012/ 2012/08/08 - 11:14

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