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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)

Post-earthquake ignition vulnerability assessment of Küçükçekmece DistrictNatural Hazards and Earth System Science, 13, 3357-3368, 2013Author(s): S. S. Yildiz and H. KaramanIn this study, a geographic information system (GIS)-based model was
developed to calculate the post-earthquake ignition probability of a
building, considering damage to the building's interior gas and electrical
distribution system and the overturning of appliances. In order to make our
model more reliable and realistic, a weighting factor was used to define the
possible existence of each appliance or other contents in the given
occupancy. A questionnaire was prepared to weigh the relevance of the
different components of post-earthquake ignitions using the analytical hierarchy
process (AHP). The questionnaire was evaluated by researchers who were
experienced in earthquake engineering and post-earthquake fires. The
developed model was implemented to HAZTURK's (Hazards Turkey) earthquake loss
assessment software, as developed by the Mid-America Earthquake Center with the
help of Istanbul Technical University. The developed post-earthquake
ignition tool was applied to Küçükçekmece, Istanbul, in
Turkey. The results were evaluated according to structure types, occupancy
types, the number of storeys, building codes and specified districts. The
evaluated results support the theory that post-earthquake ignition
probability is inversely proportional to the number of storeys and the
construction year, depending upon the building code.

http://www.nat-hazards-earth-syst-sci.net/13/3357/2013/ 2013/12/19 - 15:37

Assessing the spatial variability of coefficients of landslide predictors in different regions of Romania using logistic regressionNatural Hazards and Earth System Science, 13, 3339-3355, 2013Author(s): M. C. Mărgărint, A. Grozavu, and C. V. PatricheIn landslide susceptibility assessment, an important issue is the correct
identification of significant contributing factors, which leads to the
improvement of predictions regarding this type of geomorphologic processes.
In the scientific literature, different weightings are assigned to these
factors, but contain large variations. This study aims to identify the
spatial variability and range of variation for the coefficients of landslide
predictors in different geographical conditions. Four sectors of
15 km × 15 km (225 km2) were selected for analysis from
representative regions in Romania in terms of spatial extent of landslides,
situated both on the hilly areas (the Transylvanian Plateau and Moldavian
Plateau) and lower mountain region (Subcarpathians). The following factors
were taken into consideration: elevation, slope angle, slope height, terrain
curvature (mean, plan and profile), distance from drainage network, slope
aspect, land use, and lithology. For each sector, landslide inventory,
digital elevation model and thematic layers of the mentioned predictors were
achieved and integrated in a georeferenced environment. The logistic
regression was applied separately for the four study sectors as the statistical
method for assessing terrain landsliding susceptibility. Maps of landslide
susceptibility were produced, the values of which were classified by using
the natural breaks method (Jenks). The accuracy of the logistic regression
outcomes was evaluated using the ROC (receiver operating characteristic) curve and AUC (area under the curve) parameter, which show
values between 0.852 and 0.922 for training samples, and between 0.851 and
0.940 for validation samples. The values of coefficients are generally
confined within the limits specified by the scientific literature. In each
sector, landslide susceptibility is essentially related to some specific
predictors, such as the slope angle, land use, slope height, and lithology.
The study points out that the coefficients assigned to the landslide
predictors through logistic regression are capable to reveal some important
characteristics in landslide manifestation. The study also shows that the
logistic regression could be an alternative method to the current Romanian
methodology for landslide susceptibility and hazard mapping.

http://www.nat-hazards-earth-syst-sci.net/13/3339/2013/ 2013/12/19 - 15:37

A new-type flexible rock-shed under the impact of rock block: initial experimental insightsNatural Hazards and Earth System Science, 13, 3329-3338, 2013Author(s): S. Q. Shi, M. Wang, X. Q. Peng, and Y. K. YangA new concept of flexible rock-shed is proposed in this paper. The flexible
rock-shed is made of flexible nets held up by a specially designed, steel
vaulted structure. A 1:1 prototype is manufactured and tested for
functional evaluation with an impact experiment. It is shown that the structure
can stand for an impact energy of about 250 kJ without observable rupture of
the flexible nets or cables and can be put into service again with some
maintenances on the steel vaulted structure. Experimental data such as local
strains, peak loads and impact times are recorded by dynamic strain gauges,
load cells and a high-speed camera for structural analysis and some
complementary suggestions of improving and designing are offered with respect
to the joints and components. Finally, the advantages and limitations of the
flexible rock-shed are outlined and the limits of the present experimental
investigation and the future research for the flexible rock-shed are
proposed.

http://www.nat-hazards-earth-syst-sci.net/13/3329/2013/ 2013/12/18 - 11:53

Airborne geophysical mapping as an innovative methodology for landslide investigation: evaluation of results from the Gschliefgraben landslide, AustriaNatural Hazards and Earth System Science, 13, 3313-3328, 2013Author(s): R. Supper, I. Baroň, D. Ottowitz, K. Motschka, S. Gruber, E. Winkler, B. Jochum, and A. RömerIn September 2009, a complex airborne geophysical survey was performed in
the large landslide affected area of the Gschliefgraben valley, Upper
Austria, in order to evaluate the applicability of this method for landslide
detection and mapping. An evaluation of the results, including different
remote-sensing and ground-based methods, proved that airborne geophysics,
especially the airborne electromagnetic method, has a high potential for
landslide investigation. This is due to its sensitivity to fluid and clay
content and porosity, which are parameters showing characteristic values in
landslide prone structures. Resistivity distributions in different depth
levels as well as depth slices along selected profiles are presented and
compared with ground geoelectrical profiles for the test area of
Gschliefgraben.

Further interesting results can be derived from the radiometric survey,
whereas the naturally occurring radioisotopes 40K and 232Th, as
well as the man-made nuclide 137Cs have been considered. While the
content of potassium and thorium in the shallow subsurface layer is
expressively related to the lithological composition, the distribution of
caesium is mainly determined by mass wasting processes.

http://www.nat-hazards-earth-syst-sci.net/13/3313/2013/ 2013/12/18 - 11:53

Coastal vulnerability assessment of Puducherry coast, India, using the analytical hierarchical processNatural Hazards and Earth System Science, 13, 3291-3311, 2013Author(s): R. Mani Murali, M. Ankita, S. Amrita, and P. VethamonyAs a consequence of change in global climate, an increased frequency of natural hazards such as storm surges, tsunamis and cyclones, is predicted to have
dramatic affects on the coastal communities and ecosystems by virtue of the
devastation they cause during and after their occurrence. The tsunami of
December 2004 and the Thane cyclone of 2011 caused extensive human and
economic losses along the coastline of Puducherry and Tamil Nadu. The
devastation caused by these events highlighted the need for vulnerability
assessment to ensure better understanding of the elements causing different
hazards and to consequently minimize the after- effects of the future
events. This paper demonstrates an analytical hierarchical process (AHP)-based approach to coastal vulnerability studies as an improvement to the
existing methodologies for vulnerability assessment. The paper also
encourages the inclusion of socio-economic parameters along with the
physical parameters to calculate the coastal vulnerability index using AHP-derived weights. Seven physical–geological parameters (slope, geomorphology,
elevation, shoreline change, sea level rise, significant wave height and
tidal range) and four socio-economic factors (population,
land use/land cover (LU/LC), roads and location of tourist areas) are
considered to measure the physical vulnerability index (PVI) as well as the
socio-economic vulnerability index (SVI) of the Puducherry coast. Based on
the weights and scores derived using AHP, vulnerability maps are prepared to
demarcate areas with very low, medium and high vulnerability. A combination
of PVI and SVI values are further utilized to compute the coastal vulnerability index (CVI). Finally, the various coastal segments are grouped
into the 3 vulnerability classes to obtain the coastal vulnerability map.
The entire coastal extent between Muthiapet and Kirumampakkam as well as the
northern part of Kalapet is designated as the high vulnerability zone, which
constitutes 50% of the coastline. The region between the southern coastal
extent of Kalapet and Lawspet is the medium vulnerability zone and the remaining
25% is the low vulnerability zone. The results obtained enable the
identification and prioritization of the more vulnerable areas of the region in order to further
assist the government and the residing coastal communities in better coastal
management and conservation.

http://www.nat-hazards-earth-syst-sci.net/13/3291/2013/ 2013/12/17 - 08:02

Temporal and spatial analyses on seismo-electric anomalies associated with the 27 February 2010 M = 8.8 Chile earthquake observed by DEMETER satelliteNatural Hazards and Earth System Science, 13, 3281-3289, 2013Author(s): Y.-Y. Ho, J.-Y. Liu, M. Parrot, and J.-L. PinçonThis paper studies seismo-electromagnetic anomalies observed by the French
satellite DEMETER (Detection of Electro-Magnetic Emissions Transmitted from
Earthquake Regions) during the 27 February 2010 M = 8.8 Chile earthquake. The
nighttime electron density (Ne), electron temperature (Te), ion density
(Ni), ion temperature (Ti) and whistler counts (Cw) are investigated. A
statistical analysis of the box-and-whisker method is applied to see if data
of two or more groups under study are significantly different. A
cross-examination of temporal variations before and after shows that Ne and
Ni (Cw) increases (decreases) appear 10–20 days before the earthquake. A
comparison of data over the epicenter and those over its reference area can
be employed to discriminate the earthquake-related anomalies from global
effects. Results prove that anomalous enhancements of Ne, Ni, and Ti occur
specifically around the epicenter area. The intersection of the temporal and
spatial results confirms that Ne and Ni are useful and sensitive detecting
anomalous related to the 2010 M = 8.8 Chile earthquake.

http://www.nat-hazards-earth-syst-sci.net/13/3281/2013/ 2013/12/17 - 08:02

Climatic characteristics of summer human thermal discomfort in Athens and its connection to atmospheric circulationNatural Hazards and Earth System Science, 13, 3271-3279, 2013Author(s): A. Bartzokas, C. J. Lolis, P. A. Kassomenos, and G. R. McGregorThe climate characteristics of summer human thermal discomfort in Athens and
its connection to atmospheric circulation are studied for the period
1954–2012. The human thermal discomfort is examined in terms of the
Predicted Mean Vote (PMV) discomfort index for calm and light wind
(3 ms-1) conditions. Its inter-annual variability is characterised
by a significant increase from the middle 1980s to the end of the study
period. The onset and the cessation of the discomfort period are found to
take place around the beginning of July and the end of August respectively,
but from middle 1980s the dates of onset and cessation have slightly moved
earlier and later, respectively, leading to a longer summer discomfort
period. The connection between human thermal discomfort and atmospheric
circulation is studied by examining the distribution of discomfort cases
across six objectively defined circulation types over Europe, based on Athens
weather characteristics. High values of the PMV discomfort index are mainly
associated with two typical high-summer pressure patterns with the intensity
of discomfort depending on the pressure gradient over the Aegean Sea. On the
contrary, low PMV discomfort index values prevail mainly on days typified by
the other four circulation types, which are more frequent during May, June,
and September.

http://www.nat-hazards-earth-syst-sci.net/13/3271/2013/ 2013/12/17 - 08:02

Tsunami evacuation modelling as a tool for risk reduction: application to the coastal area of El SalvadorNatural Hazards and Earth System Science, 13, 3249-3270, 2013Author(s): P. González-Riancho, I. Aguirre-Ayerbe, I. Aniel-Quiroga, S. Abad, M. González, J. Larreynaga, F. Gavidia, O. Q. Gutiérrez, J. A. Álvarez-Gómez, and R. MedinaAdvances in the understanding and prediction of tsunami impacts allow the
development of risk reduction strategies for tsunami-prone areas. This paper
presents an integral framework for the formulation of tsunami evacuation
plans based on tsunami vulnerability assessment and evacuation modelling.
This framework considers (i) the hazard aspects (tsunami flooding
characteristics and arrival time), (ii) the characteristics of the exposed
area (people, shelters and road network), (iii) the current tsunami warning
procedures and timing, (iv) the time needed to evacuate the population, and
(v) the identification of measures to improve the evacuation process. The
proposed methodological framework aims to bridge between risk assessment and
risk management in terms of tsunami evacuation, as it allows for an
estimation of the degree of evacuation success of specific management
options, as well as for the classification and prioritization of the gathered
information, in order to formulate an optimal evacuation plan. The framework
has been applied to the El Salvador case study, demonstrating its
applicability to site-specific response times and population characteristics.

http://www.nat-hazards-earth-syst-sci.net/13/3249/2013/ 2013/12/14 - 12:07

Trends and variability in extreme precipitation indices over Maghreb countriesNatural Hazards and Earth System Science, 13, 3235-3248, 2013Author(s): Y. Tramblay, S. El Adlouni, and E. ServatMaghreb countries are highly vulnerable to extreme hydrological events, such
as floods and droughts, driven by the strong variability of precipitation.
While several studies have analyzed the presence of trends in precipitation
records for the Euro-Mediterranean basin, this study provides a regional
assessment of trends on its southernmost shores. A database of 22 stations
located in Algeria, Morocco and Tunisia with between 33 and 59 yr of daily
precipitation records is considered. The change points and trends are
analyzed for eleven climate indices, describing several features of the
precipitation regime. The issue of conducting multiple hypothesis tests is
addressed through the implementation of a false discovery rate procedure. The
spatial and interannual variability of the precipitation indices at the
different stations are analyzed and compared with large-scale atmospheric
circulation patterns, including the North Atlantic Oscillation (NAO), western
Mediterranean Oscillation (WEMO), Mediterranean Oscillation (MO) and El
Niño–Southern Oscillation (ENSO). Results show a strong tendency towards a
decrease of precipitation totals and wet days together with an increase in
the duration of dry periods, mainly for Morocco and western Algeria. On the
other hand, only a few significant trends are detected for heavy precipitation
indices. The NAO and MO patterns are well correlated with precipitation
indices describing precipitation amounts, the number of dry days and the
length of wet and dry periods, whereas heavy precipitation indices exhibit a
strong spatial variability and are only moderately correlated with large-scale atmospheric circulation patterns.

http://www.nat-hazards-earth-syst-sci.net/13/3235/2013/ 2013/12/14 - 12:07

Tephra hazard assessment at Mt. Etna (Italy)Natural Hazards and Earth System Science, 13, 3221-3233, 2013Author(s): S. Scollo, M. Coltelli, C. Bonadonna, and P. Del CarloIn this paper we present a probabilistic hazard assessment for tephra fallout
at Mt. Etna (Italy) associated with both short- and long-lived eruptions.
Eruptive scenarios and eruption source parameters were defined based on the
geological record, while an advection–diffusion–sedimentation model was
used to capture the variation in wind speed and direction with time after
calibration with the field data. Two different types of eruptions were
considered in our analysis: eruptions associated with strong short-lived
plumes and eruptions associated with weak long-lived plumes. Our
probabilistic approach was based on one eruption scenario for both types and
on an eruption range scenario for eruptions producing weak long-lived plumes.
Due to the prevailing wind direction, the eastern flanks are the most
affected by tephra deposition, with the 122 BC Plinian and 2002–2003
eruptions showing the highest impact both on infrastructures and agriculture.

http://www.nat-hazards-earth-syst-sci.net/13/3221/2013/ 2013/12/13 - 07:08

Novel method for hurricane trajectory prediction based on data miningNatural Hazards and Earth System Science, 13, 3211-3220, 2013Author(s): X. Dong and D. C. PiThis paper describes a novel method for hurricane trajectory prediction based
on data mining (HTPDM) according to the hurricane's motion characteristics.
Firstly, all frequent trajectories in the historical hurricane trajectory
database are mined by using association analysis technology and their
corresponding association rules are generated as motion patterns. Then, the
current hurricane trajectories are matched with the motion patterns for
predicting. If no association rule is found for matching, a predicted result
according to the hurricane current movement trend would be returned. All
experiments are conducted with the Atlantic weather Hurricane/Tropical Data
from 1900 to 2008. The experimental results show that if the matching failure
part is contained, the prediction accuracy is 57.5%. Whereas, the valve
would be to 65% provided all matches are successful.

http://www.nat-hazards-earth-syst-sci.net/13/3211/2013/ 2013/12/11 - 20:56

Collisions of two breathers at the surface of deep waterNatural Hazards and Earth System Science, 13, 3205-3210, 2013Author(s): A. I. Dyachenko, D. I. Kachulin, and V. E. ZakharovWe present results of numerical experiments on long-term evolution and
collisions of breathers (which correspond to envelope solitons in the NLSE
approximation) at the surface of deep ideal fluid. The collisions happen to
be nonelastic. In the numerical experiment it can be observed only after many
acts of interactions. This supports the hypothesis of "deep water
nonintegrability". The experiments were performed in the framework of the
new and refined version of the Zakharov equation free of nonessential terms
in the quartic Hamiltonian. Simplification is possible due to exact
cancellation of nonelastic four-wave interaction.

http://www.nat-hazards-earth-syst-sci.net/13/3205/2013/ 2013/12/09 - 20:39

Sea cliff instability susceptibility at regional scale: a statistically based assessment in the southern Algarve, PortugalNatural Hazards and Earth System Science, 13, 3185-3203, 2013Author(s): F. M. S. F. Marques, R. Matildes, and P. RedweikSea cliff evolution is dominated by the occurrence of slope mass movements of
different types and sizes, which are a considerable source of natural hazard,
making their assessment a relevant issue in terms of human loss prevention
and land use regulations. To address the assessment of the spatial component
of sea cliff hazards, i.e. the susceptibility, a statistically based study
was made to assess the capacity of a set of conditioning factors to express
the occurrence of sea cliff failures affecting areas located along their top.

The study was based on the application of the bivariate information value and
multivariate logistic regression statistical methods, using a set of
predisposing factors for cliff failures, mainly related to geology
(lithology, bedding dip, faults) and geomorphology (maximum and mean slope,
height, aspect, plan curvature, toe protection), which were correlated with a
photogrammetry-based inventory of cliff failures that occurred in a 60 yr
period (1947–2007). The susceptibility models were validated against the
inventory data using standard success rate and ROC curves, and provided
encouraging results, indicating that the proposed approaches are effective
for susceptibility assessment. The results obtained also stress the need for
improvement of the predisposing factors to be used in this type of study and
the need for detailed and systematic cliff failure inventories.

http://www.nat-hazards-earth-syst-sci.net/13/3185/2013/ 2013/12/09 - 20:39

Shallow landslide's stochastic risk modelling based on the precipitation event of August 2005 in Switzerland: results and implicationsNatural Hazards and Earth System Science, 13, 3169-3184, 2013Author(s): P. Nicolet, L. Foresti, O. Caspar, and M. JaboyedoffDue to their relatively unpredictable characteristics,
shallow landslides represent a risk for human
infrastructures. Multiple shallow landslides can be triggered by
widespread intense
precipitation events. The event of August 2005 in Switzerland
is used in order to propose a risk model to predict the expected
number of landslides based on the precipitation amounts and
lithological units. The spatial distribution of rainfall is
characterized by merging data coming from operational weather radars
and a dense network of rain gauges with an artificial neural
network. Lithologies are grouped into four main units, with similar
characteristics. Then, from a landslide inventory containing more than
5000 landslides, a probabilistic relation linking the precipitation
amount and the lithology to the number of landslides in
a 1 km2 cell, is derived. In a next step, this relation is
used to randomly redistribute the landslides using Monte Carlo
simulations. The probability for a landslide to reach a building is
assessed using stochastic geometry and the damage cost is assessed
from the estimated mean damage cost using an exponential distribution
to account for the variability. Although the model reproduces well
the number of landslides, the number of affected buildings is underestimated. This seems to result from the human
influence on landslide occurrence. Such a model might be useful to
characterize the risk resulting from shallow landslides and its
variability.

http://www.nat-hazards-earth-syst-sci.net/13/3169/2013/ 2013/12/09 - 20:39

Application and reliability of techniques for landslide site investigation, monitoring and early warning – outcomes from a questionnaire studyNatural Hazards and Earth System Science, 13, 3157-3168, 2013Author(s): I. Baroň and R. SupperThe presented questionnaire study summarizes an evaluation of approaches,
techniques and parameters of slope-instability investigation and monitoring
of their occurrence, reliability and the applicability of the monitoring
techniques for early warning. The study is based on information collected
from 86 monitored landslides in 14 European and Asian countries. Based on
the responses, lidar ALS (airborne laser scanners), geophysical logging, aerial photographs,
resistivity surveying, GB InSAR (ground-based synthetic aperture radar
interferometer) and the refraction seismic were considered
the most reliable methods for investigation of structure and character of
landslides. Especially lidar ALS and geophysical logging were ranked high
despite their application at relatively few landslides. Precipitation
amount, pore-water pressure and displacement monitored by wire
extensometers, dGPS and total stations, followed by air temperature and
EM-emissions monitoring and displacement monitored by the TM 71 crack gauge
were considered the most promising parameters for early warning.

http://www.nat-hazards-earth-syst-sci.net/13/3157/2013/ 2013/12/09 - 20:39

Assessment of flash floods taking into account climate change scenarios in the Llobregat River basinNatural Hazards and Earth System Science, 13, 3145-3156, 2013Author(s): M. Velasco, P. A. Versini, A. Cabello, and A. Barrera-EscodaGlobal change may imply important changes in the future occurrence and
intensity of extreme events. Climate scenarios characterizing these plausible
changes were previously obtained for the Llobregat River basin (NE Spain).
This paper presents the implementation of these scenarios in the HBV
(Hydrologiska Byråns Vattenbalansavdelning) hydrological model. Then, the
expected changes in terms of flash flood occurrence and intensity are
assessed for two different sub-basins: the Alt Llobregat and the Anoia
(Llobregat River basin).

The assessment of future flash floods has been done in terms of the
intensity and occurrence of extreme events, using a peak over threshold (POT) analysis. For these
two sub-basins, most of the simulated scenarios present an increase of the
intensity of the peak discharge values. On the other hand, the future
occurrence follows different trends in the two sub-basins: an increase is
observed in Alt Llobregat but a decrease occurs in Anoia. Despite the
uncertainties that appear in the whole process, the results obtained can
shed some light on how future flash floods events may occur.

http://www.nat-hazards-earth-syst-sci.net/13/3145/2013/ 2013/12/06 - 18:14

Calibration of a real-time tsunami detection algorithm for sites with no instrumental tsunami records: application to coastal tide-gauge stations in eastern Sicily, ItalyNatural Hazards and Earth System Science, 13, 3129-3144, 2013Author(s): L. Bressan, F. Zaniboni, and S. TintiCoastal tide gauges play a very important role in a tsunami warning system,
since sea-level data are needed for a correct evaluation of the tsunami
threat, and the tsunami arrival has to be recognized as early as possible.
Real-time tsunami detection algorithms serve this purpose. For an efficient
detection, they have to be calibrated and adapted to the specific local
characteristics of the site where they are installed, which is easily done
when the station has recorded a sufficiently large number of tsunamis. In
this case the recorded database can be used to select the best set of
parameters enhancing the discrimination power of the algorithm and minimizing
the detection time. This chance is however rare, since most of the coastal
tide-gauge stations, either historical or of new installation, have recorded
only a few tsunamis in their lifetimes, if any. In this case calibration must
be carried out by using synthetic tsunami signals, which poses the problem of
how to generate them and how to use them. This paper investigates this issue
and proposes a calibration approach by using as an example a specific case,
which is the calibration of a real-time detection algorithm called TEDA
(Tsunami Early Detection Algorithm) for two stations (namely Tremestieri and
Catania) in eastern Sicily, Italy, which were recently installed in the frame
of the Italian project TSUNET, aiming at improving the tsunami monitoring
capacity in a region that is one of the most hazardous tsunami areas of Italy
and of the Mediterranean.

http://www.nat-hazards-earth-syst-sci.net/13/3129/2013/ 2013/12/06 - 18:14

Sediment transport on the inner shelf off Khao Lak (Andaman Sea, Thailand) during the 2004 Indian Ocean tsunami and former storm events: evidence from foraminiferal transfer functionsNatural Hazards and Earth System Science, 13, 3113-3128, 2013Author(s): Y. Milker, M. Wilken, J. Schumann, D. Sakuna, P. Feldens, K. Schwarzer, and G. SchmiedlWe have investigated the benthic foraminiferal fauna from sediment event
layers associated with the 2004 Indian Ocean tsunami and former storms that
have been retrieved in short sediment cores from offshore environments of
the Andaman Sea, off Khao Lak, western Thailand. Species composition and
test preservation of the benthic foraminiferal faunas exhibit pronounced
changes across the studied sections and provide information on the
depositional history of the tsunami layer, particularly on the source water
depth of the displaced foraminiferal tests. In order to obtain accurate
bathymetric information on sediment provenance, we have mapped the
distribution of modern faunas in non-tsunamigenic surface sediments and
created a calibration data set for the development of a transfer function.
Our quantitative reconstructions revealed that the resuspension of sediment
particles by the tsunami wave was restricted to a maximum water depth of
approximately 20 m. Similar values were obtained for former storm events,
thus impeding an easy distinction of different high-energy events.

http://www.nat-hazards-earth-syst-sci.net/13/3113/2013/ 2013/12/06 - 18:14

Mapping tsunami impacts on land cover and related ecosystem service supply in Phang Nga, ThailandNatural Hazards and Earth System Science, 13, 3095-3111, 2013Author(s): G. Kaiser, B. Burkhard, H. Römer, S. Sangkaew, R. Graterol, T. Haitook, H. Sterr, and D. Sakuna-SchwartzThe 2004 Indian Ocean tsunami caused damages to coastal ecosystems and thus
affected the livelihoods of the coastal communities who depend on services
provided by these ecosystems. The paper presents a case study on evaluating
and mapping the spatial and temporal impacts of the tsunami on land use and
land cover (LULC) and related ecosystem service supply in the
Phang Nga province, Thailand. The method includes local stakeholder
interviews, field investigations, remote-sensing techniques, and GIS.
Results provide an ecosystem services matrix with capacity scores
for 18 LULC classes and 17 ecosystem functions and services as well as
pre-/post-tsunami and recovery maps indicating changes in the ecosystem
service supply capacities in the study area. Local stakeholder interviews
revealed that mangroves, casuarina forest, mixed beach forest, coral reefs, tidal inlets, as
well as wetlands (peat swamp forest) have the highest capacity to supply
ecosystem services, while e.g. plantations have a lower capacity. The
remote-sensing based damage and recovery analysis showed a loss of the
ecosystem service supply capacities in almost all LULC classes for most of
the services due to the tsunami. A fast recovery of LULC and related
ecosystem service supply capacities within one year could be observed for
e.g. beaches, while mangroves or casuarina forest needed several years to
recover. Applying multi-temporal mapping the spatial variations of
recovery
could be visualised. While some patches of coastal forest were fully
recovered after 3 yr, other patches were still affected and thus had
a reduced capacity to supply ecosystem services. The ecosystem services maps can
be used to quantify ecological values and their spatial distribution in the
framework of a tsunami risk assessment. Beyond that they are considered to
be a useful tool for spatial analysis in coastal risk management in Phang
Nga.

http://www.nat-hazards-earth-syst-sci.net/13/3095/2013/ 2013/12/06 - 18:14

Scale model for the confluent area of debris flow and main river: a case study of the Wenjia GullyNatural Hazards and Earth System Science, 13, 3083-3093, 2013Author(s): J. Zhang, Z. X. Guo, S. Y. Cao, and V. P. SinghWhen debris flow discharges into the main river, the deposition of debris
raises the river bed, occupies the path of water conveyance and damages or
even destroys buildings, resulting in considerable economic loss and
possibly fatalities. Mathematical models are normally employed to compute debris flow.
However, most of these models employ empirical formulae and coefficients and
their results are seldom reliable. On the other hand, scale model tests
associated with debris flow have seldom been conducted due to the lack of
corresponding similarity laws and the difficulty of achieving the grain
diameter scale. Focusing on pseudo-one-phase flow, this paper discusses the
laws of similarity for the confluence of debris flow and main river and
conducts a case study of the debris flow that occurred on 13 August 2010, in
the Wenjia Gully, China. After satisfying the roughness scale, the kinematic
viscosity coefficient scale, and the momentum ratio scale, it was found that
the deposition terrain in the model test is consistent with the one in the
prototype.

http://www.nat-hazards-earth-syst-sci.net/13/3083/2013/ 2013/12/02 - 14:04

Adaptability and transferability of flood loss functions in residential areasNatural Hazards and Earth System Science, 13, 3063-3081, 2013Author(s): H. Cammerer, A. H. Thieken, and J. LammelFlood loss modeling is an important component within flood risk assessments.
Traditionally, stage-damage functions are used for the estimation of direct
monetary damage to buildings. Although it is known that such functions are
governed by large uncertainties, they are commonly applied – even in
different geographical regions – without further validation, mainly due to
the lack of real damage data. Until now, little research has been done to
investigate the applicability and transferability of such damage models to
other regions. In this study, the last severe flood event in the Austrian
Lech Valley in 2005 was simulated to test the performance of various damage
functions from different geographical regions in Central Europe for the
residential sector. In addition to common stage-damage curves, new functions
were derived from empirical flood loss data collected in the aftermath of
recent flood events in neighboring Germany. Furthermore, a
multi-parameter flood loss model for the residential sector was adapted to
the study area and also evaluated with official damage data. The analysis
reveals that flood loss functions derived from related and more similar
regions perform considerably better than those from more heterogeneous
data sets of different regions and flood events. While former loss functions estimate the
observed damage well, the latter overestimate the reported loss clearly. To
illustrate the effect of model choice on the resulting uncertainty of damage
estimates, the current flood risk for residential areas was calculated. In
the
case of extreme events like the 300 yr flood, for example, the range of
losses to residential buildings between the highest and the lowest estimates
amounts to a factor of 18, in contrast to properly validated models with a
factor of 2.3. Even if the risk analysis is only performed for residential
areas, our results reveal evidently that a carefree model transfer in other
geographical regions might be critical. Therefore, we conclude that loss
models should at least be selected or derived from related regions with
similar flood and building characteristics, as far as no model validation is
possible. To further increase the general reliability of flood loss
assessment in the future, more loss data and more comprehensive loss data for model
development and validation are needed.

http://www.nat-hazards-earth-syst-sci.net/13/3063/2013/ 2013/11/30 - 19:36

Mapping wave set-up near a complex geometric urban coastlineNatural Hazards and Earth System Science, 13, 3049-3061, 2013Author(s): T. Soomere, K. Pindsoo, S. R. Bishop, A. Käärd, and A. ValdmannWave induced set-up is a process that leads to increased water levels in
coastal regions. When coupled with storm conditions, wave set-up – or, for
brevity, set-up – can significantly increase the risk of flooding or
structural damage and therefore is of particular importance when considering
coastal management or issues related to the planning of nearshore
infrastructures. Here, we investigate the effects of set-up in the coastal
region of the Gulf of Finland in the Baltic Sea, close to Tallinn, Estonia,
although the results will have wider relevance for many other areas. Due to
a lack of continuous wave data we employ modelling to provide input data
using a calculation scheme based on a high-resolution (470 m) spectral wave
model WAM to replicate spatial patterns of wave properties based on
high-quality, instrument-measured wind data from the neighbourhood of the
study site. The results indicate that for the specific geometry of coastline
under consideration, there is a variation in set-up which is strongly
affected by wind direction. The maximum set-up values are up to 70–80 cm in
selected locations. This is more than 50% of the all-time maximum water
level and thus may serve as a substantial source of marine hazard for
several low-lying regions around the city. Wind directions during storms
have changed in recent years and, with climate variability potentially
increasing, these results will encourage further tests which may be used
in a policy setting regarding defences or other structures in and around
coastlines. In particular, with urban development now taking place in many
coastal regions (including the one within this study) these results have
implications for local planners. They may also be incorporated into new
storm warning systems.

http://www.nat-hazards-earth-syst-sci.net/13/3049/2013/ 2013/11/30 - 19:36

Preface: Forecast and projection in climate scenario of Mediterranean intense events: uncertainties and propagation on environment (the MEDUP project)Natural Hazards and Earth System Science, 13, 3043-3047, 2013Author(s): V. Ducrocq, P. Drobinski, D. Lambert, G. Molinié, and C. Llasat

http://www.nat-hazards-earth-syst-sci.net/13/3043/2013/ 2013/11/30 - 19:36

QVAST: a new Quantum GIS plugin for estimating volcanic susceptibilityNatural Hazards and Earth System Science, 13, 3031-3042, 2013Author(s): S. Bartolini, A. Cappello, J. Martí, and C. Del NegroOne of the most important tasks of modern volcanology is the construction of
hazard maps simulating different eruptive scenarios that can be used in
risk-based decision making in land-use planning and emergency management. The
first step in the quantitative assessment of volcanic hazards is the
development of susceptibility maps (i.e., the spatial probability of a future
vent opening given the past eruptive activity of a volcano). This challenging
issue is generally tackled using probabilistic methods that use the
calculation of a kernel function at each data location to estimate
probability density functions (PDFs). The smoothness and the modeling ability
of the kernel function are controlled by the smoothing parameter, also known
as the bandwidth. Here we present a new tool, QVAST, part of the open-source
geographic information system Quantum GIS, which is designed to create
user-friendly quantitative assessments of volcanic susceptibility. QVAST
allows the selection of an appropriate method for evaluating the bandwidth for the
kernel function on the basis of the input parameters and the shapefile
geometry, and can also evaluate the PDF with the Gaussian kernel. When
different input data sets are available for the area, the total susceptibility
map is obtained by assigning different weights to each of the PDFs, which are
then combined via a weighted summation and modeled in a non-homogeneous
Poisson process. The potential of QVAST, developed in a free and
user-friendly environment, is here shown through its application in the
volcanic fields of Lanzarote (Canary Islands) and La Garrotxa (NE Spain).

http://www.nat-hazards-earth-syst-sci.net/13/3031/2013/ 2013/11/27 - 22:19

The role of risk perception in making flood risk management more effectiveNatural Hazards and Earth System Science, 13, 3013-3030, 2013Author(s): M. Buchecker, G. Salvini, G. Di Baldassarre, E. Semenzin, E. Maidl, and A. MarcominiOver the last few decades, Europe has suffered from a number of severe flood
events and, as a result, there has been a growing interest in probing
alternative approaches to managing flood risk via prevention measures. A
literature review reveals that, although in the last decades risk evaluation
has been recognized as key element of risk management, and risk assessment
methodologies (including risk analysis and evaluation) have been improved by
including social, economic, cultural, historical and political conditions,
the theoretical schemes are not yet applied in practice. One main reason for
this shortcoming is that risk perception literature is mainly of universal
and theoretical nature and cannot provide the necessary details to implement
a comprehensive risk evaluation. This paper therefore aims to explore a
procedure that allows the inclusion of stakeholders' perceptions of
prevention measures in risk assessment. It proposes to adopt methods of risk
communication (both one-way and two-way communication) in risk assessment
with the final aim of making flood risk management more effective. The
proposed procedure not only focuses on the effect of discursive risk
communication on risk perception, and on achieving a shared assessment of
the prevention alternatives, but also considers the effects of the
communication process on perceived uncertainties, accepted risk levels, and
trust in the managing institutions.

The effectiveness of this combined procedure has been studied and
illustrated using the example of the participatory flood prevention
assessment process on the Sihl River in Zurich, Switzerland. The main
findings of the case study suggest that the proposed procedure performed
well, but that it needs some adaptations for it to be applicable in
different contexts and to allow a (semi-) quantitative estimation of risk
perception to be used as an indicator of adaptive capacity.

http://www.nat-hazards-earth-syst-sci.net/13/3013/2013/ 2013/11/27 - 22:19

Corrigendum to "The UBO-TSUFD tsunami inundation model: validation and application to a tsunami case study focused on the city of Catania, Italy" published in Nat. Hazards Earth Syst. Sci., 13, 1795–1816, 2013Natural Hazards and Earth System Science, 13, 3011-3011, 2013Author(s): S. Tinti and R. ToniniNo abstract available.

http://www.nat-hazards-earth-syst-sci.net/13/3011/2013/ 2013/11/26 - 20:23

Reduction of maximum tsunami run-up due to the interaction with beachfront development – application of single sinusoidal wavesNatural Hazards and Earth System Science, 13, 2991-3010, 2013Author(s): N. GosebergExperiments are presented that focus on the interaction of single sinusoidal
long waves with beachfront development on the shore. A pump-driven
methodology is applied to generate the tested waves in the wave flume. The
approaching waves firstly propagate over a horizontal bottom, then climbing
up a 1 in 40 beach slope. The experiments reported here are confined to the
surf similarity parameter of the waves ranging from ξ =7.69–10.49. The
maximum run-up of the tested waves under undisturbed conditions agrees well
with analytical results of
of Madsen and Schäffer (2010).
Beachfront development is modelled with cubic concrete blocks
(macro-roughness (MR) elements). The obstruction ratio, the number of element
rows parallel to the shoreline as well as the way of arranging the MR
elements influences the overall reduction of maximum run-up compared to the
undisturbed run-up conditions. Staggered and aligned as well as rotated and
non-rotated arrangements are tested. As a result, nomograms are finally
compiled to depict the maximum run-up reduction over the surf similarity
parameter. In addition, some guidance on practical application of the
results to an example location is given.

http://www.nat-hazards-earth-syst-sci.net/13/2991/2013/ 2013/11/23 - 00:10

Mesoscale numerical analysis of the historical November 1982 heavy precipitation event over Andorra (Eastern Pyrenees)Natural Hazards and Earth System Science, 13, 2969-2990, 2013Author(s): L. Trapero, J. Bech, F. Duffourg, P. Esteban, and J. LorenteFrom 6 to 8 November 1982 one of the most catastrophic flash-flood
events was recorded in the Eastern Pyrenees affecting Andorra and also
France and Spain with rainfall accumulations exceeding 400 mm in 24 h, 44
fatalities and widespread damage. This paper aims to exhaustively document
this heavy precipitation event and examines mesoscale
simulations performed by the French Meso-NH non-hydrostatic atmospheric
model. Large-scale simulations show the slow-evolving synoptic environment
favourable for the development of a deep Atlantic cyclone which induced a
strong southerly flow over the Eastern Pyrenees. From the evolution of the
synoptic pattern four distinct phases have been identified during the event.
The mesoscale analysis presents the second and the third phase as the most
intense in terms of rainfall accumulations and highlights the interaction of
the moist and conditionally unstable flows with the mountains. The presence
of a SW low level jet (30 m s−1) around 1500 m also had a crucial role on
focusing the precipitation over the exposed south slopes of the Eastern Pyrenees. Backward trajectories based on Eulerian on-line passive tracers
indicate that the orographic uplift was the main forcing mechanism which
triggered and maintained the precipitating systems more than 30 h over
the Pyrenees. The moisture of the feeding flow mainly came from the Atlantic
Ocean (7–9 g kg−1) and the role of the Mediterranean as a local moisture
source was very limited (2–3 g kg−1) due to the high initial water vapour
content of the parcels and the rapid passage over the basin along the
Spanish Mediterranean coast (less than 12 h).

http://www.nat-hazards-earth-syst-sci.net/13/2969/2013/ 2013/11/23 - 00:10

Risk assessment of debris flow in Yushu seismic area in China: a perspective for the reconstructionNatural Hazards and Earth System Science, 13, 2957-2968, 2013Author(s): H. X. Lan, L. P. Li, Y. S. Zhang, X. Gao, and H. J. LiuThe 14 April 2010 Ms = 7.1 Yushu Earthquake (YE) had caused
severe damage in the Jiegu township, the residential centre of Yushu Tibetan
Autonomous Prefecture, Qinghai Province, China. In view of the fragile
geological conditions after YE, risk assessment of secondary geohazards
becomes an important concern for the reconstruction. A quantitative
methodology was developed to assess the risk of debris flow by taking into
account important intensity information. Debris flow scenarios were
simulated with respect to rainfall events with 10, 50 and 100 yr
returning period, respectively. The possible economic loss and fatalities
caused by damage to buildings were assessed both in the settlement area and
in the low hazard settlement area regarding the simulated debris flow
events. Three modelled building types were adopted, i.e. hollow brick wood
(HBW), hollow brick concrete (HBC) and reinforced concrete (RC) buildings.
The results suggest that HBC structure achieves a good balance for the
cost-benefit relationship compared with HBW and RC structures and thus could
be an optimal choice for most of the new residential buildings in the Jiegu
township. The low hazard boundary presents significant risk reduction
efficiency in the 100 yr returning debris flow event. In addition, the
societal risk for the settlement area is unacceptable when the 100 yr
returning event occurs but reduces to ALARP (as low as reasonably
practicable) level as the low hazard area is considered. Therefore, the low
hazard area was highly recommended to be taken into account in the
reconstruction. Yet, the societal risk might indeed approach an unacceptable
level if one considers that YE has inevitably increased the occurrence frequency of
debris flow. The quantitative results should be treated as a perspective for
the reconstruction rather than precise numbers of future losses, owing to the
complexity of the problem and the deficiency of data.

http://www.nat-hazards-earth-syst-sci.net/13/2957/2013/ 2013/11/23 - 00:10

Rogue waves in a wave tank: experiments and modelingNatural Hazards and Earth System Science, 13, 2951-2955, 2013Author(s): A. LechugaIn past decades theoretical studies have been carried out with the double aim
of improving knowledge of the main characteristics of the rogue wave and of
attempting to predict its sudden appearance. We have tried to generate rogue
waves in a water wave tank, using a symmetric spectrum (Akhmediev et al.,
2011a) as input on the wave maker.

The next step has been to apply a theoretical model to the amplitude envelope
of these waves. After some considerations we agreed the best model to be an
analog of the Ginzburg–Landau equation.

http://www.nat-hazards-earth-syst-sci.net/13/2951/2013/ 2013/11/20 - 15:19

Focusing wave group on a current of finite depthNatural Hazards and Earth System Science, 13, 2941-2949, 2013Author(s): D. Merkoune, J. Touboul, N. Abcha, D. Mouazé, and A. EzerskyFormation of freak waves resulting from the wave packets propagating in
finite water depth on the background of a current is studied experimentally
and numerically. In the experiment, the freak waves appear as a result of
dispersion focusing of wave train excited by wave maker with modulated
frequency. The space evolution of the frequency modulated train is studied in
numerical simulations. We showed that in the water of finite depth, a
distance of focusing increases and amplitude in the focal point decreases in
comparison with infinite water depth. Experimental results are in good
agreement with numerical simulations if wave breaking of surface waves
does not occur.

http://www.nat-hazards-earth-syst-sci.net/13/2941/2013/ 2013/11/20 - 15:19

Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models.Natural Hazards and Earth System Science, 13, 2927-2939, 2013Author(s): J. A. Álvarez-Gómez, Í. Aniel-Quiroga, O. Q. Gutiérrez-Gutiérrez, J. Larreynaga, M. González, M. Castro, F. Gavidia, I. Aguirre-Ayerbe, P. González-Riancho, and E. CarreñoEl Salvador is the smallest and most densely populated country in Central
America; its coast has an approximate length of 320 km, 29
municipalities and more than 700 000 inhabitants. In El Salvador there were 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages
and resulting in hundreds of victims. Hazard assessment is commonly based on
propagation numerical models for earthquake-generated tsunamis and can be
approached through both probabilistic and deterministic methods. A deterministic
approximation has been applied in this study as it provides essential
information for coastal planning and management. The objective of the
research was twofold: on the one hand the characterization of the threat over
the entire coast of El Salvador, and on the other the computation of flooding
maps for the three main localities of the Salvadorian coast. For the latter
we developed high-resolution flooding models. For the former, due to the
extension of the coastal area, we computed maximum elevation maps, and from
the elevation in the near shore we computed an estimation of the run-up and
the flooded area using empirical relations. We have considered local sources
located in the Middle America Trench, characterized seismotectonically, and
distant sources in the rest of Pacific Basin, using historical and recent
earthquakes and tsunamis. We used a hybrid finite differences–finite
volumes numerical model in this work, based on the linear and non-linear
shallow water equations, to simulate a total of 24 earthquake-generated
tsunami scenarios. Our results show that at the western Salvadorian coast,
run-up values higher than 5 m are common, while in the eastern area,
approximately from La Libertad to the Gulf of Fonseca, the run-up values are
lower. The more exposed areas to flooding are the lowlands in the Lempa River
delta and the Barra de Santiago Western Plains. The results of the empirical
approximation used for the whole country are similar to the results obtained
with the high-resolution numerical modelling, being a good and fast
approximation to obtain preliminary tsunami hazard estimations. In Acajutla
and La Libertad, both important tourism centres being actively developed,
flooding depths between 2 and 4 m are frequent, accompanied with high
and very high person instability hazard. Inside the Gulf of Fonseca the
impact of the waves is almost negligible.

http://www.nat-hazards-earth-syst-sci.net/13/2927/2013/ 2013/11/20 - 15:19

Analysis of human vulnerability to the extreme rainfall event on 21–22 July 2012 in Beijing, ChinaNatural Hazards and Earth System Science, 13, 2911-2926, 2013Author(s): J. Liu and S.-Y. WangThe aim of this study is to characterize the extreme rainfall event on
21–22 July 2012 in Beijing, and its impact on human vulnerability. Based on
the available meteorological and rainfall data from Beijing meteorological
stations and Surface Weather Observation Stations, the study draws hourly
rainfall maps to simulate the rainfall amount and spatial distribution. Using
these maps, this paper provides a quantitative analysis of the impact of the
temporal and spatial characteristics of rainfall on the vulnerability of
three population groups, according to age, gender and total number of
victims. The results of three linear regression models indicate the different
effects of extreme rainfall parameters on victims with different
characteristics. The analysis of victim data in this extreme rainfall event
represents the distribution and characteristics of victims in the eight
affected districts, and concludes that the "vulnerable group" are males and
adults in this extreme rainfall event. This paper is an initial effort to
analyze the impact of an extreme rainfall event on the vulnerability of
populations with different characteristics quantitatively, which can be used
by stakeholders to prioritize the extreme rainfall event impact issues, and
develop contingency plans to address and prevent the human and structural
damages caused by the extreme rainfall events.

http://www.nat-hazards-earth-syst-sci.net/13/2911/2013/ 2013/11/20 - 15:19

Influence of targeted observations on short-term forecasts of high-impact weather events in the MediterraneanNatural Hazards and Earth System Science, 13, 2891-2910, 2013Author(s): J. Campins, B. Navascués, C. Santos, and A. Amo-BaladrónThe influence of targeted observations on short-range forecasts is tested
over two different periods of PREVIEW (2008) and MEDEX (2009) data targeting
field campaigns for a set of Mediterranean high-impact weather events. As
targeted observations we have used not only extra radiosondes, but also
enhanced satellite data observed in singular vector (SV)-based sensitive
regions. Three parallel observing system experiments, based on the High-Resolution Limited-Area Model (HIRLAM) data assimilation and forecast
system, have been conducted. Forecasts of the three experiments have been
assessed using both verifying analyses for upper-air fields, and surface
observations for several meteorological parameters. Furthermore,
quantitative precipitation forecasts (QPF) have been objectively verified
using the novel feature oriented Structure–Amplitude–Location (SAL) method.

The results obtained show that extra radiosondes have an overall positive
impact on the forecasts (average improvement of all upper-air variables and
vertical levels studied is 3.6%). When in addition to extra radiosonde
data also enhanced satellite data are assimilated, the overall forecast
skill is almost doubled. However, a distinct behaviour is found between the
PREVIEW and MEDEX cases. While for MEDEX cases the improvement is slight,
for PREVIEW cases the improvement is significant (average improvements of 1.7% and
8.9%, respectively, for the experiment with enhanced satellite data). It is
suggested that this is due to the location of the target areas and the
spatial distribution of the composite observing system and to the different
atmospheric predictability in these two periods.

http://www.nat-hazards-earth-syst-sci.net/13/2891/2013/ 2013/11/20 - 15:19

Flood risk management in Italy: challenges and opportunities for the implementation of the EU Floods Directive (2007/60/EC)Natural Hazards and Earth System Science, 13, 2883-2890, 2013Author(s): J. Mysiak, F. Testella, M. Bonaiuto, G. Carrus, S. De Dominicis, U. Ganucci Cancellieri, K. Firus, and P. GrifoniItaly's recent history is punctuated with devastating flood disasters
claiming high death toll and causing vast but underestimated economic, social
and environmental damage. The responses to major flood and landslide
disasters such as the Polesine (1951), Vajont (1963), Firenze (1966),
Valtelina (1987), Piedmont (1994), Crotone (1996), Sarno (1998), Soverato
(2000), and Piedmont (2000) events have contributed to shaping the country's
flood risk governance. Insufficient resources and capacity, slow
implementation of the (at that time) novel risk prevention and protection
framework, embodied in the law 183/89 of 18 May 1989, increased the reliance
on the response and recovery operations of the civil protection. As a result,
the importance of the Civil Protection Mechanism and the relative body of
norms and regulation developed rapidly in the 1990s. In the aftermath of the
Sarno (1998) and Soverato (2000) disasters, the Department for Civil
Protection (DCP) installed a network of advanced early warning and alerting
centres, the cornerstones of Italy's preparedness for natural hazards and a
best practice worth following. However, deep convective clouds, not uncommon
in Italy, producing intense rainfall and rapidly developing localised floods
still lead to considerable damage and loss of life that can only be reduced
by stepping up the risk prevention efforts. The implementation of the EU
Floods Directive (2007/60/EC) provides an opportunity to revise the model of
flood risk governance and confront the shortcomings encountered during more
than 20 yr of organised flood risk management. This brief communication
offers joint recommendations towards this end from three projects funded by
the 2nd CRUE ERA-NET (http://www.crue-eranet.net/) Funding Initiative:
FREEMAN, IMRA and URFlood.

http://www.nat-hazards-earth-syst-sci.net/13/2883/2013/ 2013/11/20 - 15:19

Preface: 11th Plinius Conference on Mediterranean StormsNatural Hazards and Earth System Science, 13, 2871-2882, 2013Author(s): M.-C. Llasat, G. Boni, R. Deidda, A. Mugnai, and J. Salat

http://www.nat-hazards-earth-syst-sci.net/13/2871/2013/ 2013/11/16 - 15:28

A wavefront orientation method for precise numerical determination of tsunami travel timeNatural Hazards and Earth System Science, 13, 2863-2870, 2013Author(s): I. V. Fine and R. E. ThomsonWe present a highly accurate and computationally efficient method (herein,
the "wavefront orientation method") for determining the travel time of
oceanic tsunamis. Based on Huygens' Principle, the method uses an eight-point
grid-point pattern and the most recent information on the orientation of the
advancing wavefront to determine the time for a tsunami to travel to a
specific oceanic location. The method is shown to provide improved accuracy
and reduced anisotropy compared with the conventional multiple grid-point
method presently in widespread use.

http://www.nat-hazards-earth-syst-sci.net/13/2863/2013/ 2013/11/16 - 15:28

Pre-, co-, and post- rockslide analysis with ALOS/PALSAR imagery: a case study of the Jiweishan rockslide, ChinaNatural Hazards and Earth System Science, 13, 2851-2861, 2013Author(s): C. Zhao, Q. Zhang, Y. Yin, Z. Lu, C. Yang, W. Zhu, and B. LiOn 5 June 2009, a catastrophic rockslide debris flow occurred at the crest
of the Jiweishan range, Chongqing Municipality, China, killing 74 people and
injuring an additional eight. We use L-band ALOS/PALSAR imagery to address
landslide processes before, during and after the slide. We employ three
different SAR methods, i.e., short baseline subsets (SBAS) interferometric
SAR (InSAR), SAR backscattering intensity change, and InSAR stacking
algorithm, to study any ground deformation before the rockslide, investigate
the affected area, and calculate the topographic change by this slide,
respectively. First, continuous deformation has been observed based on the
available ALOS/PALSAR InSAR imagery during June and December 2007. Second,
the area affected by the landslide can be inferred based on changes in SAR
backscattering intensity as well as surface topography, with an estimated
area of 0.47 million m2. Last, an InSAR-derived post-slide digital
elevation model has allowed us to estimate surface height changes due to the
slide, reaching about −80 m at the source region and about 60 m in the
deposit region, respectively. Our InSAR-derived estimates have been
validated using in situ data and 3-D lidar measurements.

http://www.nat-hazards-earth-syst-sci.net/13/2851/2013/ 2013/11/15 - 14:07

Landslide and debris flow susceptibility zonation using TRIGRS for the 2011 Seoul landslide eventNatural Hazards and Earth System Science, 13, 2833-2849, 2013Author(s): D. W. Park, N. V. Nikhil, and S. R. LeeThis paper presents the results from the application of a regional,
physically based stability model: Transient Rainfall Infiltration and
Grid-based Regional Slope-stability analysis (TRIGRS) for a region on
Woomyeon Mountain, Seoul, South Korea. This model couples an infinite-slope
stability analysis with a one-dimensional analytical solution to predict the
transient pore pressure response to the infiltration of rainfall. TRIGRS
also adopts the geographic information system (GIS) framework for
determining the whole behaviour of a slope. In this paper, we suggest an
index for evaluating the results produced by the model. Particular attention
is devoted to the prediction of routes of debris flow, using a runoff
module.

In this context, the paper compares observed landslide and debris flow
events with those predicted by the TRIGRS model. The TRIGRS model,
originally developed to predict shallow landslides, has been extended in
this study for application to debris flows. The results predicted by the
TRIGRS model are presented as safety factor (FS) maps corresponding to
transient rainfall events, and in terms of debris flow paths using methods
proposed by several researchers in hydrology.

In order to quantify the effectiveness of the model, we proposed an index
called LRclass (landslide ratio for each predicted FS class). The
LRclass index is mainly applied in regions where the
landslide scar area is not well defined (or is unknown), in order to avoid
overestimation of the model results. The use of the TRIGRS routing module
was proposed to predict the paths of debris flow, especially in areas where
the rheological properties and erosion rates of the materials are difficult
to obtain. Although an improvement in accuracy is needed, this module is
very useful for preliminary spatio-temporal assessment over wide areas. In
summary, the TRIGRS model is a powerful tool of use to decision makers for
susceptibility mapping, particularly when linked with various advanced
applications using GIS spatial functions.

http://www.nat-hazards-earth-syst-sci.net/13/2833/2013/ 2013/11/15 - 14:07

Landslide susceptibility estimation by random forests technique: sensitivity and scaling issuesNatural Hazards and Earth System Science, 13, 2815-2831, 2013Author(s): F. Catani, D. Lagomarsino, S. Segoni, and V. TofaniDespite the large number of recent advances and developments in landslide
susceptibility mapping (LSM) there is still a lack of studies focusing on
specific aspects of LSM model sensitivity. For example, the influence of
factors such as the survey scale of the landslide conditioning variables
(LCVs), the resolution of the mapping unit (MUR) and the optimal number and
ranking of LCVs have never been investigated analytically, especially on
large data sets.

In this paper we attempt this experimentation concentrating on the impact of
model tuning choice on the final result, rather than on the comparison of
methodologies. To this end, we adopt a simple implementation of the random
forest (RF), a machine learning technique, to produce an ensemble of
landslide susceptibility maps for a set of different model settings, input
data types and scales. Random forest is a combination of Bayesian trees that
relates a set of predictors to the actual landslide occurrence. Being it a
nonparametric model, it is possible to incorporate a range of numerical or
categorical data layers and there is no need to select unimodal training
data as for example in linear discriminant analysis. Many widely
acknowledged landslide predisposing factors are taken into account as mainly
related to the lithology, the land use, the geomorphology, the structural
and anthropogenic constraints. In addition, for each factor we also include
in the predictors set a measure of the standard deviation (for numerical
variables) or the variety (for categorical ones) over the map unit.

As in other systems, the use of RF enables one to estimate the relative
importance of the single input parameters and to select the optimal
configuration of the classification model. The model is initially applied
using the complete set of input variables, then an iterative process is
implemented and progressively smaller subsets of the parameter space are
considered. The impact of scale and accuracy of input variables, as well as
the effect of the random component of the RF model on the susceptibility
results, are also examined. The model is tested in the Arno River basin
(central Italy). We find that the dimension of parameter space, the mapping
unit (scale) and the training process strongly influence the classification
accuracy and the prediction process.

This, in turn, implies that a careful sensitivity analysis making use of
traditional and new tools should always be performed before producing final
susceptibility maps at all levels and scales.

http://www.nat-hazards-earth-syst-sci.net/13/2815/2013/ 2013/11/14 - 09:32