Skip to Content

Instrukcja korzystania z Biblioteki

Serwisy:

Ukryty Internet | Wyszukiwarki specjalistyczne tekstów i źródeł naukowych | Translatory online | Encyklopedie i słowniki online

Translator:

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)

Landslides triggered by the 12 January 2010 Port-au-Prince, Haiti, Mw = 7.0 earthquake: visual interpretation, inventory compiling, and spatial distribution statistical analysisNatural Hazards and Earth System Science, 14, 1789-1818, 2014Author(s): C. Xu, J. B. H. Shyu, and X. XuThe 12 January 2010 Port-au-Prince, Haiti, earthquake (Mw= 7.0) triggered
tens of thousands of landslides. The purpose of this study is to investigate
the correlations of the occurrence of landslides and the thicknesses of their erosion
with topographic, geologic, and seismic parameters. A total of
30 828 landslides triggered by the earthquake covered a total area of 15.736 km2,
distributed in an area more than 3000 km2, and the volume of
landslide accumulation materials is estimated to be about 29 700 000 m3.
These landslides are of various types, mostly belonging to shallow disrupted landslides and rock falls, but also include coherent deep-seated
landslides and rock slides. These landslides were delineated using pre- and
post-earthquake high-resolution satellite images. Spatial distribution maps
and contour maps of landslide number density, landslide area percentage, and
landslide erosion thickness were constructed in order to analyze the spatial
distribution patterns of co-seismic landslides. Statistics of size
distribution and morphometric parameters of co-seismic landslides were
carried out and were compared with other earthquake events in the world.
Four proxies of co-seismic landslide abundance, including landslides
centroid number density (LCND), landslide top number density (LTND),
landslide area percentage (LAP), and landslide erosion thickness (LET) were
used to correlate co-seismic landslides with various environmental
parameters. These parameters include elevation, slope angle, slope aspect,
slope curvature, topographic position, distance from drainages, lithology,
distance from the epicenter, distance from the Enriquillo–Plantain Garden
fault, distance along the fault, and peak ground acceleration (PGA). A
comparison of these impact parameters on co-seismic landslides shows that
slope angle is the strongest impact parameter on co-seismic landslide
occurrence. Our co-seismic landslide inventory is much more detailed than
other inventories in several previous publications. Therefore, we carried
out comparisons of inventories of landslides triggered by the Haiti
earthquake with other published results and proposed possible reasons for any
differences. We suggest that the empirical functions between earthquake
magnitude and co-seismic landslides need to be updated on the basis of the
abundant and more complete co-seismic landslide inventories recently available.

http://www.nat-hazards-earth-syst-sci.net/14/1789/2014/ 2014/07/22 - 17:30

Investigating the influence of topographic irregularities and two-dimensional effects on surface ground motion intensity with one- and two-dimensional analysesNatural Hazards and Earth System Science, 14, 1773-1788, 2014Author(s): G. Ç. İnce and L. YılmazoğluIn this work, the surface ground motion that occurs during an earthquake in
ground sections having different topographic forms has been examined with one
and two dynamic site response analyses. One-dimensional analyses were
undertaken using the Equivalent-Linear Earthquake Response Analysis (EERA)
program based on the equivalent linear analysis principle and the Deepsoil
program which is able to make both equivalent linear and nonlinear analyses
and two-dimensional analyses using the Plaxis 8.2 software. The viscous
damping parameters used in the dynamic site response analyses undertaken with
the Plaxis 8.2 software were obtained using the DeepSoil program. In the
dynamic site response analyses, the synthetic acceleration over a 475-year
return period representing the earthquakes in Istanbul was used as the basis
of the bedrock ground motion. The peak ground acceleration obtained different
depths of soils and acceleration spectrum values have been compared. The
surface topography and layer boundaries in the 5-5' cross section which
cuts across the study area west to east were selected in order to examine the
effect of the land topography and layer boundaries on the analysis results,
and were flattened and compared with the actual status. The analysis results
showed that the characteristics of the surface ground motion change in
relation to the varying local soil conditions and land topography.

http://www.nat-hazards-earth-syst-sci.net/14/1773/2014/ 2014/07/20 - 00:14

Soil erosion in an avalanche release site (Valle d'Aosta: Italy): towards a winter factor for RUSLE in the AlpsNatural Hazards and Earth System Science, 14, 1761-1771, 2014Author(s): S. Stanchi, M. Freppaz, E. Ceaglio, M. Maggioni, K. Meusburger, C. Alewell, and E. ZaniniSoil erosion in Alpine areas is mainly related to extreme topographic and
weather conditions. Although different methods of assessing soil erosion
exist, the knowledge of erosive forces of the snow cover needs more
investigation in order to allow soil erosion modeling in areas where the snow
lays on the ground for several months. This study aims to assess whether the
RUSLE (Revised Universal Soil Loss Equation) empirical prediction model,
which gives an estimation of water erosion in t ha yr−1 obtained from
a combination of five factors (rainfall erosivity, soil erodibility,
topography, soil cover, protection practices) can be applied to mountain
areas by introducing a winter factor (W), which should account for the soil
erosion occurring in winter time by the snow cover. The W factor is
calculated from the ratio of Ceasium-137 (137Cs) to RUSLE erosion rates.
Ceasium-137 is another possible way of assessing soil erosion rates in the
field. In contrast to RUSLE, it not only provides water-induced erosion but
integrates all erosion agents involved. Thus, we hypothesize that in mountain
areas the difference between the two approaches is related to the soil
erosion by snow. In this study we compared 137Cs-based measurement of
soil redistribution and soil loss estimated with RUSLE in a mountain slope
affected by avalanches, in order to assess the relative importance of winter
erosion processes such as snow gliding and full-depth avalanches. Three
subareas were considered: DS, avalanche defense structures, RA, release area,
and TA, track area, characterized by different prevalent winter processes.
The RUSLE estimates and the 137Cs redistribution gave significantly
different results. The resulting ranges of W evidenced relevant differences
in the role of winter erosion in the considered subareas, and the application
of an avalanche simulation model corroborated these findings. Thus, the
higher rates obtained with the 137Cs method confirmed the relevant role
of winter soil erosion. Despite the limited sample size (11 points), the
inclusion of a W factor in RUSLE seems promising for the improvement of
soil erosion estimates in Alpine environments affected by snow movements.

http://www.nat-hazards-earth-syst-sci.net/14/1761/2014/ 2014/07/16 - 17:37

Soil erosion in an avalanche release site (Valle d'Aosta: Italy): towards a winter factor for RUSLE in the AlpsNatural Hazards and Earth System Science, 14, 1761-1771, 2014Author(s): S. Stanchi, M. Freppaz, E. Ceaglio, M. Maggioni, K. Meusburger, C. Alewell, and E. ZaniniSoil erosion in Alpine areas is mainly related to extreme topographic and
weather conditions. Although different methods of assessing soil erosion
exist, the knowledge of erosive forces of the snow cover needs more
investigation in order to allow soil erosion modeling in areas where the snow
lays on the ground for several months. This study aims to assess whether the
RUSLE (Revised Universal Soil Loss Equation) empirical prediction model,
which gives an estimation of water erosion in t ha yr−1 obtained from
a combination of five factors (rainfall erosivity, soil erodibility,
topography, soil cover, protection practices) can be applied to mountain
areas by introducing a winter factor (W), which should account for the soil
erosion occurring in winter time by the snow cover. The W factor is
calculated from the ratio of Ceasium-137 (137Cs) to RUSLE erosion rates.
Ceasium-137 is another possible way of assessing soil erosion rates in the
field. In contrast to RUSLE, it not only provides water-induced erosion but
integrates all erosion agents involved. Thus, we hypothesize that in mountain
areas the difference between the two approaches is related to the soil
erosion by snow. In this study we compared 137Cs-based measurement of
soil redistribution and soil loss estimated with RUSLE in a mountain slope
affected by avalanches, in order to assess the relative importance of winter
erosion processes such as snow gliding and full-depth avalanches. Three
subareas were considered: DS, avalanche defense structures, RA, release area,
and TA, track area, characterized by different prevalent winter processes.
The RUSLE estimates and the 137Cs redistribution gave significantly
different results. The resulting ranges of W evidenced relevant differences
in the role of winter erosion in the considered subareas, and the application
of an avalanche simulation model corroborated these findings. Thus, the
higher rates obtained with the 137Cs method confirmed the relevant role
of winter soil erosion. Despite the limited sample size (11 points), the
inclusion of a W factor in RUSLE seems promising for the improvement of
soil erosion estimates in Alpine environments affected by snow movements.

http://www.nat-hazards-earth-syst-sci.net/14/1761/2014/ 2014/07/16 - 17:37

Comparison of event landslide inventories: the Pogliaschina catchment test case, ItalyNatural Hazards and Earth System Science, 14, 1749-1759, 2014Author(s): A. C. Mondini, A. Viero, M. Cavalli, L. Marchi, G. Herrera, and F. GuzzettiEvent landslide inventory maps document the extent of populations of
landslides caused by a single natural trigger, such as an earthquake, an
intense rainfall event, or a rapid snowmelt event. Event inventory maps are
important for landslide susceptibility and hazard modelling, and prove useful
to manage residual risk after a landslide-triggering event. Standards for the
preparation of event landslide inventory maps are lacking. Traditional
methods are based on the visual interpretation of stereoscopic aerial
photography, aided by field surveys. New and emerging techniques exploit
remotely sensed data and semi-automatic algorithms. We describe the
production and comparison of two independent event inventories prepared for
the Pogliaschina catchment, Liguria, Northwest Italy. The two inventories show
landslides triggered by an intense rainfall event on 25 October 2011, and
were prepared through the visual interpretation of digital aerial photographs
taken 3 days and 33 days after the event, and by processing a
very-high-resolution image taken by the WorldView-2 satellite 4 days after
the event. We compare the two inventories qualitatively and quantitatively
using established and new metrics, and we discuss reasons for the differences
between the two landslide maps. We expect that the results of our work can
help in deciding on the most appropriate method to prepare reliable event
inventory maps, and outline the advantages and the limitations of the
different approaches.

http://www.nat-hazards-earth-syst-sci.net/14/1749/2014/ 2014/07/15 - 13:18

Evaluating the effectiveness of flood damage mitigation measures by the application of propensity score matchingNatural Hazards and Earth System Science, 14, 1731-1747, 2014Author(s): P. Hudson, W. J. W. Botzen, H. Kreibich, P. Bubeck, and J. C. J. H. AertsThe employment of damage mitigation measures (DMMs) by individuals is an important
component of integrated flood risk management. In order to promote efficient
damage mitigation measures, accurate estimates of their damage mitigation
potential are required. That is, for correctly assessing the damage
mitigation measures' effectiveness from survey data, one needs to control for
sources of bias. A biased estimate can occur if risk characteristics differ
between individuals who have, or have not, implemented mitigation measures.
This study removed this bias by applying an econometric evaluation technique
called propensity score matching (PSM) to a survey of German households along three
major rivers that were flooded in 2002, 2005, and 2006. The application of
this method detected substantial overestimates of mitigation measures'
effectiveness if bias is not controlled for, ranging from nearly
EUR 1700 to 15 000 per measure. Bias-corrected effectiveness
estimates of several mitigation measures show that these measures are still
very effective since they prevent between EUR 6700 and 14 000 of
flood damage per flood event. This study concludes with four main
recommendations regarding how to better apply propensity score matching in
future studies, and makes several policy recommendations.

http://www.nat-hazards-earth-syst-sci.net/14/1731/2014/ 2014/07/15 - 13:18

Discharge of landslide-induced debris flows: case studies of Typhoon Morakot in southern TaiwanNatural Hazards and Earth System Science, 14, 1719-1730, 2014Author(s): J.-C. Chen and M.-R. ChuangThree debris-flow gullies, the Hong-Shui-Xian (HSX),
Sha-Xin-Kai (SXK), and Xin-Kai-Dafo (XKD) gullies, located in the Shinfa area
of southern Taiwan, were selected as case studies on the discharge of
landslide-induced debris flows caused by Typhoon Morakot in 2009. The
inundation characteristics of the three debris flows, such as the debris-flow
volume V, deposition area Ad, and maximum flow depth, were
collected by field investigations and simulated using the numerical modeling
software FLO-2D. The discharge coefficient cb, defined as the
ratio of the debris-flow discharge Qdp to the water-flow discharge
Qwp, was proposed to determine Qdp, and Qwp
was estimated by a rational equation. Then, cb was calibrated by
a comparison between the field investigation and the numerical simulation of
the inundation characteristics of debris flows. Our results showed that the
values of cb range from 6 to 18, and their values are affected
by the landslide ratio RL. Empirical relationships for
cb versus RL, Qdp versus Qwp,
Qdp versus V, and Ad versus V are also presented.

http://www.nat-hazards-earth-syst-sci.net/14/1719/2014/ 2014/07/15 - 13:18

A hybrid model for mapping simplified seismic response via a GIS-metamodel approachNatural Hazards and Earth System Science, 14, 1703-1718, 2014Author(s): G. Grelle, L. Bonito, P. Revellino, L. Guerriero, and F. M. GuadagnoIn earthquake-prone areas, site seismic response due to
lithostratigraphic sequence plays a key role in seismic hazard assessment. A
hybrid model, consisting of GIS and metamodel (model of model) procedures,
was introduced aimed at estimating the 1-D spatial seismic site response in
accordance with spatial variability of sediment parameters. Inputs and
outputs are provided and processed by means of an appropriate GIS model,
named GIS Cubic Model (GCM). This consists of a block-layered parametric
structure aimed at resolving a predicted metamodel by means of pixel to
pixel vertical computing. The metamodel, opportunely calibrated, is able to
emulate the classic shape of the spectral acceleration response in relation
to the main physical parameters that characterize the spectrum itself.
Therefore, via the GCM structure and the metamodel, the hybrid model
provides maps of normalized acceleration response spectra. The hybrid model
was applied and tested on the built-up area of the San Giorgio del Sannio
village, located in a high-risk seismic zone of southern Italy. Efficiency
tests showed a good correspondence between the spectral values resulting
from the proposed approach and the 1-D physical computational models.
Supported by lithology and geophysical data and corresponding accurate
interpretation regarding modelling, the hybrid model can be an efficient
tool in assessing urban planning seismic hazard/risk.

http://www.nat-hazards-earth-syst-sci.net/14/1703/2014/ 2014/07/15 - 13:18

Atmospheric processes triggering the central European floods in June 2013Natural Hazards and Earth System Science, 14, 1691-1702, 2014Author(s): C. M. Grams, H. Binder, S. Pfahl, N. Piaget, and H. WernliIn June 2013, central Europe was hit by a century flood affecting the
Danube and Elbe catchments after a 4 day period of heavy
precipitation and causing severe human and economic loss. In this
study model analysis and observational data are investigated to
reveal the key atmospheric processes that caused the heavy
precipitation event. The period preceding the flood was
characterised by a weather regime associated with cool and unusual
wet conditions resulting from repeated Rossby wave breaking
(RWB). During the event a single RWB established a reversed
baroclinicity in the low to mid-troposphere in central Europe with
cool air trapped over the Alps and warmer air to the north. The
upper-level cut-off resulting from the RWB instigated three
consecutive cyclones in eastern Europe that unusually tracked
westward during the days of heavy precipitation. Continuous
large-scale slantwise ascent in so-called "equatorward ascending"
warm conveyor belts (WCBs) associated with these cyclones is found
as the key process that caused the 4 day heavy precipitation
period. Fed by moisture sources from continental evapotranspiration,
these WCBs unusually ascended equatorward along the southward
sloping moist isentropes. Although "equatorward ascending" WCBs
are climatologically rare events, they have great potential for
causing high impact weather.

http://www.nat-hazards-earth-syst-sci.net/14/1691/2014/ 2014/07/05 - 14:14

Deformation information system for facilitating studies of mining-ground deformations, development, and applicationsNatural Hazards and Earth System Science, 14, 1677-1689, 2014Author(s): J. Blachowski, W. Milczarek, and P. StefaniakThe paper presents the concept of the deformation information system (DIS) to
support and facilitate studies of mining-ground deformations. The proposed
modular structure of the system includes data collection and data
visualisation components, as well as spatial data mining, modelling and
classification modules. In addition, the system integrates interactive
three-dimensional models of the mines and local geology. The system is used
to calculate various parameters characterising ground deformation in space
and time, i.e. vertical and horizontal displacement fields, deformation
parameters (tilt, curvature, and horizontal strain) and input spatial
variables for spatial data classifications. The core of the system in the
form of an integrated spatial and attributive database has been described.
The development stages and the functionality of the particular components
have been presented and example analyses utilising the spatial data mining
and modelling functions have been shown. These include, among other things,
continuous vertical and horizontal displacement field interpolations,
calculation of parameters characterising mining-ground deformations,
mining-ground category classifications, data extraction procedures and data
preparation preprocessing procedures for analyses in external applications.

The DIS has been developed for the Walbrzych coal mines area in SW Poland
where long-time mining activity ended at the end of the 20th century
and surface monitoring is necessary to study the present-day condition of the
former mining grounds.

http://www.nat-hazards-earth-syst-sci.net/14/1677/2014/ 2014/07/05 - 14:14

A simple model for the estimation of the number of fatalities due to floods in central EuropeNatural Hazards and Earth System Science, 14, 1663-1676, 2014Author(s): M. Brazdova and J. RihaIn this paper a model for the estimation of the number of potential
fatalities is proposed based on data from 19 past floods in central Europe.
First, the factors contributing to human losses during river floods are
listed and assigned to the main risk factors: hazard – exposure –
vulnerability. The order of significance of individual factors has been
compiled by pairwise comparison based on experience with real flood events. A
comparison with factors used in existing models for the estimation of
fatalities during floods shows good agreement with the significant factors
identified in this study. The most significant factors affecting the number
of human losses in floods have been aggregated into three groups and
subjected to correlation analysis. A close-fitting regression dependence is
proposed for the estimation of loss of life and calibrated using data from
selected real floods in central Europe. The application of the proposed model
for the estimation of fatalities due to river floods is shown via a flood
risk assessment for the locality of Krnov in the Czech Republic.

http://www.nat-hazards-earth-syst-sci.net/14/1663/2014/ 2014/07/05 - 14:14

Streamflow simulation methods for ungauged and poorly gauged watershedsNatural Hazards and Earth System Science, 14, 1641-1661, 2014Author(s): A. Loukas and L. VasiliadesRainfall–runoff modelling procedures for ungauged and poorly gauged
watersheds are developed in this study. A well-established hydrological
model, the University of British Columbia (UBC) watershed model, is selected
and applied in five different river basins located in Canada, Cyprus, and
Pakistan. Catchments from cold, temperate, continental, and semiarid climate
zones are included to demonstrate the procedures developed. Two methodologies
for streamflow modelling are proposed and analysed. The first method uses
the UBC watershed model with a universal set of parameters for water
allocation and flow routing, and precipitation gradients estimated from the
available annual precipitation data as well as from regional information on
the distribution of orographic precipitation. This method is proposed for
watersheds without streamflow gauge data and limited meteorological station
data. The second hybrid method proposes the coupling of UBC watershed model
with artificial neural networks (ANNs) and is intended for use in poorly
gauged watersheds which have limited streamflow measurements. The two
proposed methods have been applied to five mountainous watersheds with
largely varying climatic, physiographic, and hydrological characteristics.
The evaluation of the applied methods is based on the combination of graphical
results, statistical evaluation metrics, and normalized goodness-of-fit
statistics. The results show that the first method satisfactorily simulates
the observed hydrograph assuming that the basins are ungauged. When limited
streamflow measurements are available, the coupling of ANNs with the
regional, non-calibrated UBC flow model components is considered a successful
alternative method to the conventional calibration of a hydrological model
based on the evaluation criteria employed for streamflow modelling and flood
frequency estimation.

http://www.nat-hazards-earth-syst-sci.net/14/1641/2014/ 2014/07/02 - 13:15

Uncertainty and sensitivity analyses in seismic risk assessments on the example of Cologne, GermanyNatural Hazards and Earth System Science, 14, 1625-1640, 2014Author(s): S. Tyagunov, M. Pittore, M. Wieland, S. Parolai, D. Bindi, K. Fleming, and J. ZschauBoth aleatory and epistemic uncertainties associated with different sources
and components of risk (hazard, exposure, vulnerability) are present at each
step of seismic risk assessments. All individual sources of uncertainty
contribute to the total uncertainty, which might be very high and, within
the decision-making context, may therefore lead to either very conservative
and expensive decisions or the perception of considerable risk. When
anatomizing the structure of the total uncertainty, it is therefore
important to propagate the different individual uncertainties through the
computational chain and to quantify their contribution to the total value of
risk. The present study analyses different uncertainties associated with the
hazard, vulnerability and loss components by the use of logic trees. The
emphasis is on the analysis of epistemic uncertainties, which represent the
reducible part of the total uncertainty, including a sensitivity analysis of
the resulting seismic risk assessments with regard to the different
uncertainty sources. This investigation, being a part of the EU FP7 project
MATRIX (New Multi-Hazard and Multi-Risk Assessment Methods for Europe), is
carried out for the example of, and with reference to, the conditions of the
city of Cologne, Germany, which is one of the MATRIX test cases. At the same
time, this particular study does not aim to revise nor to refine the hazard
and risk level for Cologne; it is rather to show how large are the existing
uncertainties and how they can influence seismic risk estimates, especially
in less well-studied areas, if hazard and risk models adapted from other
regions are used.

http://www.nat-hazards-earth-syst-sci.net/14/1625/2014/ 2014/06/28 - 12:12

Risk estimation for future glacier lake outburst floods based on local land-use changesNatural Hazards and Earth System Science, 14, 1611-1624, 2014Author(s): S. Nussbaumer, Y. Schaub, C. Huggel, and A. WalzEffects of climate change are particularly strong in high-mountain regions.
Most visibly, glaciers are shrinking at a rapid pace, and as a consequence,
glacier lakes are forming or growing. At the same time the stability of
mountain slopes is reduced by glacier retreat, permafrost thaw and other
factors, resulting in an increasing landslide hazard which can potentially
impact lakes and therewith trigger far-reaching and devastating outburst
floods. To manage risks from existing or future lakes, strategies need to be
developed to plan in time for adequate risk reduction measures at a local
level. However, methods to assess risks from future lake outbursts are not
available and need to be developed to evaluate both future hazard and future
damage potential.

Here a method is presented to estimate future risks related to glacier lake
outbursts for a local site in southern Switzerland (Naters, Valais). To
generate two hazard scenarios, glacier shrinkage and lake formation modelling
was applied, combined with simple flood modelling and field work.
Furthermore, a land-use model was developed to quantify and allocate land-use
changes based on local-to-regional storylines and three scenarios of land-use
driving forces. Results are conceptualized in a matrix of three land-use and
two hazard scenarios for the year 2045, and show the distribution of risk in
the community of Naters, including high and very high risk areas. The study
underlines the importance of combined risk management strategies focusing on
land-use planning, on vulnerability reduction, as well as on structural
measures (where necessary) to effectively reduce future risks related to lake
outburst floods.

http://www.nat-hazards-earth-syst-sci.net/14/1611/2014/ 2014/06/28 - 12:12

Potential ecological risk assessment and prediction of soil heavy-metal pollution around coal gangue dumpNatural Hazards and Earth System Science, 14, 1599-1610, 2014Author(s): X. Jiang, W. X. Lu, H. Q. Zhao, Q. C. Yang, and Z. P. YangThe aim of the present study is to evaluate the potential ecological risk and
trend of soil heavy-metal pollution around a coal gangue dump in Jilin
Province (Northeast China). The concentrations of Cd, Pb, Cu, Cr and Zn were
monitored by inductively coupled plasma mass spectrometry (ICP-MS). The
potential ecological risk index method developed by Hakanson (1980) was
employed to assess the potential risk of heavy-metal pollution. The potential
ecological risk in the order of
ER(Cd) > ER(Pb) > ER(Cu) > ER(Cr) > ER(Zn)
have been obtained, which showed that Cd was the most important factor
leading to risk. Based on the Cd pollution history, the cumulative
acceleration and cumulative rate of Cd were estimated, then the fixed number
of years exceeding the standard prediction model was established, which was
used to predict the pollution trend of Cd under the accelerated accumulation
mode and the uniform mode. Pearson correlation analysis and correspondence
analysis are employed to identify the sources of heavy metals and the
relationship between sampling points and variables. These findings provided
some useful insights for making appropriate management strategies to prevent
or decrease heavy-metal pollution around a coal gangue dump in the Yangcaogou
coal mine and other similar areas elsewhere.

http://www.nat-hazards-earth-syst-sci.net/14/1599/2014/ 2014/06/28 - 12:12

WebGIS as boundary tools between scientific geoinformation and disaster risk reduction action in volcanic areasNatural Hazards and Earth System Science, 14, 1591-1598, 2014Author(s): G. Le Cozannet, M. Bagni, P. Thierry, C. Aragno, and E. KouokamAs the amount of spatial data is growing, there is increased interest in
developing tools to explore, visualize and interpret them, with the final
aim of informing decision making efficiently. Within the European MIAVITA
project, we examined this issue in the case of volcanic areas, where
existing geospatial databases are particularly complex due to the number of
threats to be considered, including volcanic (e.g. lava flows, ash fall)
and non-volcanic hazards, such as landslides or tsunamis. We involved a
group of hazard and risk analysts and managers, civil security officers, GIS
analysts and system developers to design a Web-based geographical
information system (WebGIS). We tested the system at the Mount Cameroon
volcano, taking advantage of a complex hazard and risk geographical
database. This study enabled identifying key requirements for such tools in
volcanic areas, such as the need to manage user privileges differently
according to their profile and the status of the volcano. This work also
highlights that, in addition to the development of large geoinformation
clearinghouses, there is a need for site-specific information systems
focused on working procedures of users, in order to fill the last gap
between data producers and users.

http://www.nat-hazards-earth-syst-sci.net/14/1591/2014/ 2014/06/25 - 20:26

Projecting flood hazard under climate change: an alternative approach to model chainsNatural Hazards and Earth System Science, 14, 1579-1589, 2014Author(s): J. M. Delgado, B. Merz, and H. ApelFlood hazard projections under climate change are typically derived
by applying model chains consisting of the following elements:
"emission scenario – global climate model – downscaling, possibly
including bias correction – hydrological model – flood frequency
analysis". To date, this approach yields very uncertain results, due
to the difficulties of global and regional climate models to
represent precipitation. The implementation of such model chains
requires major efforts, and their complexity is high.

We propose for the Mekong River an alternative approach which is
based on a shortened model chain: "emission scenario – global
climate model – non-stationary flood frequency model". The
underlying idea is to use a link between the Western Pacific monsoon
and local flood characteristics: the variance of the monsoon drives
a non-stationary flood frequency model, yielding a direct estimate of
flood probabilities. This approach bypasses the uncertain
precipitation, since the monsoon variance is derived from
large-scale wind fields which are better represented by climate
models. The simplicity of the monsoon–flood link allows deriving
large ensembles of flood projections under climate change. We
conclude that this is a worthwhile, complementary approach to the
typical model chains in catchments where a substantial link between
climate and floods is found.

http://www.nat-hazards-earth-syst-sci.net/14/1579/2014/ 2014/06/24 - 13:13

Spatio-temporal patterns of recent and future climate extremes in the eastern Mediterranean and Middle East regionNatural Hazards and Earth System Science, 14, 1565-1577, 2014Author(s): E. Kostopoulou, C. Giannakopoulos, M. Hatzaki, A. Karali, P. Hadjinicolaou, J. Lelieveld, and M. A. LangeRecent and future changes in temperature and precipitation climate extremes
are estimated using the Hadley Centre PRECIS ("Providing REgional Climates
for Impacts Studies") climate model for the eastern Mediterranean and Middle
East region. The area of interest is considered vulnerable to extreme
climate events as there is evidence for a temperature rise while
precipitation tends to decline, suggesting likely effects on vital
socioeconomic sectors in the region. Observations have been obtained for the
recent period (1961–1990) and used to evaluate the model output. The spatial
distribution of recent temporal trends in temperature indicates strong
increasing in minimum temperature over the eastern Balkan Peninsula, Turkey
and the Arabian Peninsula. The rate of warming reaches
0.4–0.5 °C decade−1 in a large part of the domain, while
warming is expected to be strongest in
summer (0.6–0.7 °C decade−1) in the eastern Balkans and western Turkey. The trends in
annual and summer maximum temperature are estimated at approximately 0.5 and
0.6 °C decade−1 respectively. Recent estimates do not indicate
statistically significant trends in precipitation except for individual
sub-regions. Results indicate a future warming trend for the study area over
the last 30 years of the 21st century. Trends are estimated to be positive
and statistically significant in nearly the entire region. The annual trend
patterns for both minimum and maximum temperature show warming rates of
approximately 0.4–0.6 °C decade−1, with pronounced warming over the Middle
Eastern countries. Summer temperatures reveal a gradual warming
(0.5–0.9 °C decade−1) over much of the region. The model projects drying
trends by 5–30% in annual precipitation towards the end of the 21st
century, with the number of wet days decreasing at the rate of 10–30 days year−1,
while heavy precipitation is likely to decrease in the
high-elevation areas by 15 days year−1.

http://www.nat-hazards-earth-syst-sci.net/14/1565/2014/ 2014/06/24 - 13:13

An assessment of landslide susceptibility in the Faifa area, Saudi Arabia, using remote sensing and GIS techniquesNatural Hazards and Earth System Science, 14, 1553-1564, 2014Author(s): T. Alharbi, M. Sultan, S. Sefry, R. ElKadiri, M. Ahmed, R. Chase, A. Milewski, M. Abu Abdullah, M. Emil, and K. ChounairdAn integrated approach was adopted over Faifa Mountain and its surroundings,
in Saudi Arabia, to identify landslide types, distribution, and controlling
factors, and to generate landslide susceptibility maps. Given the
inaccessibility of the area, we relied on remote sensing observations and
GIS-based applications to enable spatial analysis of data and extrapolation
of limited field observations. Susceptibility maps depicting debris flows
within ephemeral valleys (Type I) and landslides caused by failure along
fracture planes (Type II) were generated. Type I susceptibility maps were
generated applying linear relationships between normalized difference
vegetation index (NDVI) and threshold slope values (30°), both of
which were extracted over known debris flow locations. For Type II
susceptibility maps, landslides were predicted if fracture planes had strike
values similar to (within 20°) those of the slope face strike and dip
angles exceeding the friction, but not the slope angles. Comparisons between
predicted and observed debris flows yielded success rates of 82%
(ephemeral valleys); unverified predictions are interpreted as future
locations of debris flows. Our approach could serve as a replicable model for
many areas worldwide, in areas where field measurements are difficult to
obtain and/or are cost prohibitive.

http://www.nat-hazards-earth-syst-sci.net/14/1553/2014/ 2014/06/24 - 13:13

Projecting flood hazard under climate change: an alternative approach to model chainsNatural Hazards and Earth System Science, 14, 1579-1589, 2014Author(s): J. M. Delgado, B. Merz, and H. ApelFlood hazard projections under climate change are typically derived
by applying model chains consisting of the following elements:
"emission scenario – global climate model – downscaling, possibly
including bias correction – hydrological model – flood frequency
analysis". To date, this approach yields very uncertain results, due
to the difficulties of global and regional climate models to
represent precipitation. The implementation of such model chains
requires major efforts, and their complexity is high.

We propose for the Mekong River an alternative approach which is
based on a shortened model chain: "emission scenario – global
climate model – non-stationary flood frequency model". The
underlying idea is to use a link between the Western Pacific monsoon
and local flood characteristics: the variance of the monsoon drives
a non-stationary flood frequency model, yielding a direct estimate of
flood probabilities. This approach bypasses the uncertain
precipitation, since the monsoon variance is derived from
large-scale wind fields which are better represented by climate
models. The simplicity of the monsoon–flood link allows deriving
large ensembles of flood projections under climate change. We
conclude that this is a worthwhile, complementary approach to the
typical model chains in catchments where a substantial link between
climate and floods is found.

http://www.nat-hazards-earth-syst-sci.net/14/1579/2014/ 2014/06/24 - 13:12

Spatio-temporal patterns of recent and future climate extremes in the eastern Mediterranean and Middle East regionNatural Hazards and Earth System Science, 14, 1565-1577, 2014Author(s): E. Kostopoulou, C. Giannakopoulos, M. Hatzaki, A. Karali, P. Hadjinicolaou, J. Lelieveld, and M. A. LangeRecent and future changes in temperature and precipitation climate extremes
are estimated using the Hadley Centre PRECIS ("Providing REgional Climates
for Impacts Studies") climate model for the eastern Mediterranean and Middle
East region. The area of interest is considered vulnerable to extreme
climate events as there is evidence for a temperature rise while
precipitation tends to decline, suggesting likely effects on vital
socioeconomic sectors in the region. Observations have been obtained for the
recent period (1961–1990) and used to evaluate the model output. The spatial
distribution of recent temporal trends in temperature indicates strong
increasing in minimum temperature over the eastern Balkan Peninsula, Turkey
and the Arabian Peninsula. The rate of warming reaches
0.4–0.5 °C decade−1 in a large part of the domain, while
warming is expected to be strongest in
summer (0.6–0.7 °C decade−1) in the eastern Balkans and western Turkey. The trends in
annual and summer maximum temperature are estimated at approximately 0.5 and
0.6 °C decade−1 respectively. Recent estimates do not indicate
statistically significant trends in precipitation except for individual
sub-regions. Results indicate a future warming trend for the study area over
the last 30 years of the 21st century. Trends are estimated to be positive
and statistically significant in nearly the entire region. The annual trend
patterns for both minimum and maximum temperature show warming rates of
approximately 0.4–0.6 °C decade−1, with pronounced warming over the Middle
Eastern countries. Summer temperatures reveal a gradual warming
(0.5–0.9 °C decade−1) over much of the region. The model projects drying
trends by 5–30% in annual precipitation towards the end of the 21st
century, with the number of wet days decreasing at the rate of 10–30 days year−1,
while heavy precipitation is likely to decrease in the
high-elevation areas by 15 days year−1.

http://www.nat-hazards-earth-syst-sci.net/14/1565/2014/ 2014/06/24 - 13:12

An assessment of landslide susceptibility in the Faifa area, Saudi Arabia, using remote sensing and GIS techniquesNatural Hazards and Earth System Science, 14, 1553-1564, 2014Author(s): T. Alharbi, M. Sultan, S. Sefry, R. ElKadiri, M. Ahmed, R. Chase, A. Milewski, M. Abu Abdullah, M. Emil, and K. ChounairdAn integrated approach was adopted over Faifa Mountain and its surroundings,
in Saudi Arabia, to identify landslide types, distribution, and controlling
factors, and to generate landslide susceptibility maps. Given the
inaccessibility of the area, we relied on remote sensing observations and
GIS-based applications to enable spatial analysis of data and extrapolation
of limited field observations. Susceptibility maps depicting debris flows
within ephemeral valleys (Type I) and landslides caused by failure along
fracture planes (Type II) were generated. Type I susceptibility maps were
generated applying linear relationships between normalized difference
vegetation index (NDVI) and threshold slope values (30°), both of
which were extracted over known debris flow locations. For Type II
susceptibility maps, landslides were predicted if fracture planes had strike
values similar to (within 20°) those of the slope face strike and dip
angles exceeding the friction, but not the slope angles. Comparisons between
predicted and observed debris flows yielded success rates of 82%
(ephemeral valleys); unverified predictions are interpreted as future
locations of debris flows. Our approach could serve as a replicable model for
many areas worldwide, in areas where field measurements are difficult to
obtain and/or are cost prohibitive.

http://www.nat-hazards-earth-syst-sci.net/14/1553/2014/ 2014/06/24 - 13:12

Flood frequency analysis supported by the largest historical floodNatural Hazards and Earth System Science, 14, 1543-1551, 2014Author(s): W. G. Strupczewski, K. Kochanek, and E. BogdanowiczThe use of non-systematic flood data for statistical purposes depends
on the reliability of the assessment of both flood magnitudes and their return period.
The earliest known extreme flood year is usually the beginning of the
historical record. Even if one properly assesses the magnitudes of historic
floods, the problem of their return periods remains unsolved. The matter at
hand is that only the largest flood (XM) is known during whole historical
period and its occurrence marks the beginning of the historical period and
defines its length (L). It is common practice to use the earliest known flood
year as the beginning of the record. It means that the L value selected is an
empirical estimate of the lower bound on the effective historical
length M. The estimation of the return period of XM based on its occurrence
(L), i.e. ^M = L, gives a severe upward bias. The problem
arises that to estimate the time period (M) representative of the largest
observed flood XM.

From the discrete uniform distribution with support 1, 2, ... , M of the
probability of the L position of XM, one gets ^L = M/2. Therefore
^M = 2L has been taken as the return period of XM and as the
effective historical record length as well this time. As in the systematic
period (N) all its elements are smaller than XM, one can get
^M = 2t( L+N).

The efficiency of using the largest historical flood (XM) for large
quantile estimation (i.e. one with return period T = 100 years)
has been assessed using the maximum likelihood (ML) method with various length of systematic
record (N) and various estimates of the historical period length
^M comparing accuracy with the case when systematic records
alone (N) are used only. The simulation procedure used for the purpose
incorporates N systematic record and the largest historic flood
(XMi) in the period M, which appeared in the Li year of the historical period. The simulation results for
selected two-parameter distributions, values of their parameters, different
N
and M values are presented in terms of bias and root mean square error RMSEs of the quantile of
interest are more widely discussed.

http://www.nat-hazards-earth-syst-sci.net/14/1543/2014/ 2014/06/21 - 09:44

Seasonal predictability of the 2010 Russian heat waveNatural Hazards and Earth System Science, 14, 1531-1542, 2014Author(s): P. Katsafados, A. Papadopoulos, G. Varlas, E. Papadopoulou, and E. MavromatidisThe atmospheric blocking over eastern Europe and western Russia that
prevailed during July and August of 2010 led to the development of a
devastating Russian heat wave. Therefore the question of whether the event
was predictable or not is highly important. The principal aim of this study
is to examine the predictability of this high-impact atmospheric event on a
seasonal timescale. To this end, a set of dynamical seasonal simulations have
been carried out using an atmospheric global circulation model (AGCM). The
impact of various model initializations on the predictability of this
large-scale event and its sensitivity to the initial conditions has been also
investigated. The ensemble seasonal simulations are based on a modified
version of the lagged-average forecast method using different lead-time
initializations of the model. The results indicated that only a few
individual members reproduced the main features of the blocking system 3
months ahead. Most members missed the phase space and the propagation of the
system, setting limitations in the predictability of the event.

http://www.nat-hazards-earth-syst-sci.net/14/1531/2014/ 2014/06/19 - 20:42

Empirical atmospheric thresholds for debris flows and flash floods in the southern French AlpsNatural Hazards and Earth System Science, 14, 1517-1530, 2014Author(s): T. Turkington, J. Ettema, C. J. van Westen, and K. BreinlDebris flows and flash floods are often preceded by intense, convective
rainfall. The establishment of reliable rainfall thresholds is an important
component for quantitative hazard and risk assessment, and for the
development of an early warning system. Traditional empirical thresholds
based on peak intensity, duration and antecedent rainfall can be difficult to
verify due to the localized character of the rainfall and the absence of
weather radar or sufficiently dense rain gauge networks in mountainous
regions. However, convective rainfall can be strongly linked to regional
atmospheric patterns and profiles. There is potential to employ this in
empirical threshold analysis.

This work develops a methodology to determine robust thresholds for flash
floods and debris flows utilizing regional atmospheric conditions derived
from ECMWF ERA-Interim reanalysis data, comparing the results with rain-gauge-derived thresholds. The method includes selecting the appropriate atmospheric
indicators, categorizing the potential thresholds, determining and testing
the thresholds. The method is tested in the Ubaye Valley in the southern
French Alps (548 km2), which is known to have localized convection
triggered debris flows and flash floods. This paper shows that instability of
the atmosphere and specific humidity at 700 hPa are the most important
atmospheric indicators for debris flows and flash floods in the study area.
Furthermore, this paper demonstrates that atmospheric reanalysis data are an
important asset, and could replace rainfall measurements in empirical
exceedance thresholds for debris flows and flash floods.

http://www.nat-hazards-earth-syst-sci.net/14/1517/2014/ 2014/06/19 - 20:42

The extreme runoff index for flood early warning in EuropeNatural Hazards and Earth System Science, 14, 1505-1515, 2014Author(s): L. Alfieri, F. Pappenberger, and F. WetterhallSystems for the early detection of floods over continental and global domains
have a key role in providing a quick overview of areas at risk, raise the
awareness and prompt higher detail analyses as the events approach. However,
the reliability of these systems is prone to spatial inhomogeneity, depending
on the quality of the underlying input data and local calibration.

This work proposes a simple approach for flood early warning based on
ensemble numerical predictions of surface runoff provided by weather
forecasting centers. The system is based on a novel indicator, referred to as
an extreme runoff index (ERI), which is calculated from the input data
through a statistical analysis. It is designed for use in large or poorly
gauged domains, as no local knowledge or in situ observations are needed for
its setup. Daily runs over 32 months are evaluated against calibrated
hydrological simulations for all of Europe. Results show skillful flood early
warning capabilities up to a 10-day lead time. A dedicated analysis is
performed to investigate the optimal timing of forecasts to maximize the
detection of extreme events. A case study for the central European floods of
June 2013 is presented and forecasts are compared to the output of a
hydro-meteorological ensemble model.

http://www.nat-hazards-earth-syst-sci.net/14/1505/2014/ 2014/06/17 - 22:21

Forecasting wind-driven wildfires using an inverse modelling approachNatural Hazards and Earth System Science, 14, 1491-1503, 2014Author(s): O. Rios, W. Jahn, and G. ReinA technology able to rapidly forecast wildfire dynamics would lead to a paradigm shift in the
response to emergencies, providing the Fire Service with essential information about the ongoing
fire. This paper presents and explores a novel methodology to forecast wildfire dynamics
in wind-driven conditions, using real-time data assimilation and inverse modelling. The
forecasting algorithm combines Rothermel's rate of spread theory with a perimeter expansion model
based on Huygens principle and solves the optimisation problem with a tangent linear approach and
forward automatic differentiation. Its potential is investigated using synthetic data
and
evaluated in different wildfire scenarios. The results show the capacity of the method to
quickly predict the location of the fire front with a positive lead time (ahead of the
event) in the order of 10 min for a spatial scale of 100 m. The greatest strengths of our
method are lightness, speed and flexibility. We specifically tailor the forecast to be efficient and
computationally cheap so it can be used in mobile systems for field deployment and operativeness.
Thus, we put emphasis on producing a positive lead time and the means to maximise it.

http://www.nat-hazards-earth-syst-sci.net/14/1491/2014/ 2014/06/14 - 22:53

Forecasting wind-driven wildfires using an inverse modelling approachNatural Hazards and Earth System Science, 14, 1491-1503, 2014Author(s): O. Rios, W. Jahn, and G. ReinA technology able to rapidly forecast wildfire dynamics would lead to a paradigm shift in the
response to emergencies, providing the Fire Service with essential information about the ongoing
fire. This paper presents and explores a novel methodology to forecast wildfire dynamics
in wind-driven conditions, using real-time data assimilation and inverse modelling. The
forecasting algorithm combines Rothermel's rate of spread theory with a perimeter expansion model
based on Huygens principle and solves the optimisation problem with a tangent linear approach and
forward automatic differentiation. Its potential is investigated using synthetic data
and
evaluated in different wildfire scenarios. The results show the capacity of the method to
quickly predict the location of the fire front with a positive lead time (ahead of the
event) in the order of 10 min for a spatial scale of 100 m. The greatest strengths of our
method are lightness, speed and flexibility. We specifically tailor the forecast to be efficient and
computationally cheap so it can be used in mobile systems for field deployment and operativeness.
Thus, we put emphasis on producing a positive lead time and the means to maximise it.

http://www.nat-hazards-earth-syst-sci.net/14/1491/2014/ 2014/06/14 - 22:53

Temporal variations and change in forest fire danger in Europe for 1960–2012Natural Hazards and Earth System Science, 14, 1477-1490, 2014Author(s): A. Venäläinen, N. Korhonen, O. Hyvärinen, N. Koutsias, F. Xystrakis, I. R. Urbieta, and J. M. MorenoUnderstanding how fire weather danger indices changed in the past and how
such changes affected forest fire activity is important in a changing
climate. We used the Canadian Fire Weather Index (FWI), calculated from two
reanalysis data sets, ERA-40 and ERA Interim, to examine the temporal
variation of forest fire danger in Europe in 1960–2012. Additionally, we
used national forest fire statistics from Greece, Spain and Finland to
examine the relationship between fire danger and fires. There is no obvious
trend in fire danger for the time period covered by ERA-40 (1960–1999),
whereas for the period 1980–2012 covered by ERA Interim, the mean FWI shows
an increasing trend for southern and eastern Europe which is significant at the
99% confidence level. The cross correlations calculated at the national level
in Greece, Spain and Finland between total area burned and mean FWI of the
current season is of the order of 0.6, demonstrating the extent to which the current
fire-season weather can explain forest fires. To summarize, fire risk is
multifaceted, and while climate is a major determinant, other factors can
contribute to it, either positively or negatively.

http://www.nat-hazards-earth-syst-sci.net/14/1477/2014/ 2014/06/13 - 13:35

Characterising the relationship between weather extremes in Europe and synoptic circulation featuresNatural Hazards and Earth System Science, 14, 1461-1475, 2014Author(s): S. PfahlExtreme weather events in Europe are closely linked to anomalies of the
atmospheric circulation and in particular to circulation features like
cyclones and atmospheric blocking. In this study, this linkage is
systematically characterised with the help of conditional cyclone and
blocking frequencies during precipitation, wind gust and temperature extremes
at various locations in Europe. Such conditional frequency fields can serve
as a dynamical fingerprint of the extreme events and yield insights into
their most important physical driving mechanisms. Precipitation extremes over
the ocean and over flat terrain are shown to be closely related to cyclones
in the vicinity and the associated dynamical lifting. For extreme
precipitation over complex terrain, cyclone anomalies are found at more
remote locations, favouring the flow of moist air towards the topography.
Wind gust extremes are associated with cyclone and blocking anomalies in
opposite directions, with the cyclones occurring mostly over the North and
Baltic seas for extreme events in central Europe. This setting is associated
with pronounced surface pressure gradients and thus high near-surface wind
velocities. Hot temperature extremes in northern and central Europe typically
occur in the vicinity of a blocking anticyclone, where subsidence and
radiative forcing are strong. Over southern Europe, blocking anomalies are
shifted more to the north or northeast, indicating a more important role of
warm air advection. Large-scale flow conditions for cold extremes are similar
at many locations in Europe, with blocking anomalies over the North Atlantic
and northern Europe and cyclone anomalies southeast of the cold extreme, both
contributing to the advection of cold air masses. This characterisation of
synoptic-scale forcing mechanisms can be helpful for better understanding and
anticipating weather extremes and their long-term changes.

http://www.nat-hazards-earth-syst-sci.net/14/1461/2014/ 2014/06/07 - 08:26

Corrigendum to "Heavy rainfall episodes over Liguria in autumn 2011: numerical forecasting experiments" published in Nat. Hazards Earth Syst. Sci., 14, 1325–1340, 2014Natural Hazards and Earth System Science, 14, 1459-1459, 2014Author(s): A. Buzzi, S. Davolio, P. Malguzzi, O. Drofa, and D. MastrangeloNo abstract available.

http://www.nat-hazards-earth-syst-sci.net/14/1459/2014/ 2014/06/07 - 08:26

Assessment of the effectiveness of flood adaptation strategies for HCMCNatural Hazards and Earth System Science, 14, 1441-1457, 2014Author(s): R. Lasage, T. I. E. Veldkamp, H. de Moel, T. C. Van, H. L. Phi, P. Vellinga, and J. C. J. H. AertsCoastal cities are vulnerable to flooding, and flood risk to coastal cities
will increase due to sea-level rise. Moreover, Asian cities in particular are
subject to considerable population growth and associated urban developments,
increasing this risk even more. Empirical data on vulnerability and the cost
and benefits of flood risk reduction measures are therefore paramount for
sustainable development of these cities. This paper presents an approach to
explore the impacts of sea-level rise and socio-economic developments on
flood risk for the flood-prone District 4 in Ho Chi Minh City, Vietnam, and
to develop and evaluate the effects of different adaptation strategies (new
levees, dry- and wet proofing of buildings and elevating roads and buildings).

A flood damage model was developed to simulate current and future flood risk
using the results from a household survey to establish stage–damage curves
for residential buildings. The model has been used to assess the effects of
several participatory developed adaptation strategies to reduce flood risk,
expressed in expected annual damage (EAD). Adaptation strategies were
evaluated assuming combinations of both sea-level scenarios and land-use
scenarios. Together with information on costs of these strategies, we
calculated the benefit–cost ratio and net present value for the adaptation
strategies until 2100, taking into account depreciation rates of 2.5% and
5%.

The results of this modelling study indicate that the current flood risk in
District 4 is USD 0.31 million per year, increasing up to USD 0.78 million per year in
2100. The net present value and benefit–cost ratios using a discount rate of
5 % range from USD −107 to −1.5 million, and from 0.086 to 0.796 for the
different strategies. Using a discount rate of 2.5% leads to an increase
in both net present value and benefit–cost ratio. The adaptation strategies
wet-proofing and dry-proofing generate the best results using these economic
indicators. The information on different strategies will be used by the
government of Ho Chi Minh City to determine a new flood protection
strategy. Future research should focus on gathering empirical data right
after a flood on the occurring damage, as this appears to be the most
uncertain factor in the risk assessment.

http://www.nat-hazards-earth-syst-sci.net/14/1441/2014/ 2014/06/07 - 08:26

Numerical investigation of stability of breather-type solutions of the nonlinear Schrödinger equationNatural Hazards and Earth System Science, 14, 1431-1440, 2014Author(s): A. Calini and C. M. SchoberIn this article we conduct a broad numerical investigation of stability of
breather-type solutions of the nonlinear Schrödinger (NLS) equation, a
widely used model of rogue wave generation and dynamics in deep water. NLS
breathers rising over an unstable background state are frequently used to
model rogue waves. However, the issue of whether these solutions are robust
with respect to the kind of random perturbations occurring in physical
settings and laboratory experiments has just recently begun to be addressed.
Numerical experiments for spatially periodic breathers with one or two modes
involving large ensembles of perturbed initial data for six typical random
perturbations suggest interesting conclusions. Breathers over an unstable
background with N unstable modes are generally unstable to small
perturbations in the initial data unless they are "maximal breathers"
(i.e., they have N spatial modes). Additionally, among the maximal
breathers with two spatial modes, the one of highest amplitude due to
coalescence of the modes appears to be the most robust. The numerical
observations support and extend to more realistic settings the results of our
previous stability analysis, which we hope will provide a useful tool for
identifying physically realizable wave forms in experimental and
observational studies of rogue waves.

http://www.nat-hazards-earth-syst-sci.net/14/1431/2014/ 2014/06/07 - 08:26

Corrigendum to "Increasing flood exposure in the Netherlands: implications for risk financing" published in Nat. Hazards Earth Syst. Sci., 14, 1245–1255, 2014Natural Hazards and Earth System Science, 14, 1429-1429, 2014Author(s): B. Jongman, E. E. Koks, T. G. Husby, and P. J. WardNo abstract available.

http://www.nat-hazards-earth-syst-sci.net/14/1429/2014/ 2014/06/07 - 08:26

Flood design recipes vs. reality: can predictions for ungauged basins be trusted?Natural Hazards and Earth System Science, 14, 1417-1428, 2014Author(s): A. Efstratiadis, A. D. Koussis, D. Koutsoyiannis, and N. MamassisDespite the great scientific and technological advances in flood hydrology,
everyday engineering practices still follow simplistic approaches that are
easy to formally implement in ungauged areas. In general, these "recipes"
have been developed many decades ago, based on field data from typically few
experimental catchments. However, many of them have been neither updated nor
validated across all hydroclimatic and geomorphological conditions. This has
an obvious impact on the quality and reliability of hydrological studies,
and, consequently, on the safety and cost of the related flood protection
works. Preliminary results, based on historical flood data from Cyprus and
Greece, indicate that a substantial revision of many aspects of flood
engineering procedures is required, including the regionalization formulas
as well as the modelling concepts themselves. In order to provide a
consistent design framework and to ensure realistic predictions of the flood
risk (a key issue of the 2007/60/EU Directive) in ungauged basins, it is
necessary to rethink the current engineering practices. In this vein, the
collection of reliable hydrological data would be essential for
re-evaluating the existing "recipes", taking into account local
peculiarities, and for updating the modelling methodologies as needed.

http://www.nat-hazards-earth-syst-sci.net/14/1417/2014/ 2014/06/06 - 00:28

The North Sea Andrea storm and numerical simulationsNatural Hazards and Earth System Science, 14, 1407-1415, 2014Author(s): E. M. Bitner-Gregersen, L. Fernandez, J. M. Lefèvre, J. Monbaliu, and A. ToffoliA coupling of a spectral wave model with a nonlinear phase-resolving model
is used to reconstruct the evolution of wave statistics during a storm
crossing the North Sea on 8–9 November 2007. During this
storm a rogue wave (named the Andrea wave) was recorded at the Ekofisk
field. The wave has characteristics comparable to the well-known New Year
wave measured by Statoil at the Draupner platform 1 January 1995.
Hindcast data of the storm at the nearest grid point to the Ekofisk field
are here applied as input to calculate the evolution of random realizations
of the sea surface and its statistical properties. Numerical simulations are
carried out using the Euler equations with a higher-order spectral method
(HOSM). Results are compared with some characteristics of the Andrea wave
record measured by the down-looking lasers at Ekofisk.

http://www.nat-hazards-earth-syst-sci.net/14/1407/2014/ 2014/06/06 - 00:28

On the behavior of site effects in central Mexico (the Mexican volcanic belt – MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011Natural Hazards and Earth System Science, 14, 1391-1406, 2014Author(s): A. Clemente-Chavez, F. R. Zúñiga, J. Lermo, A. Figueroa-Soto, C. Valdés, M. Montiel, O. Chavez, and M. ArroyoThe Mexican volcanic belt (MVB) is a seismogenic zone that transects the
central part of Mexico with an east–west orientation. The seismic risk and
hazard of this seismogenic zone has not been studied in detail due to the
scarcity of instrumental data as well as because seismicity in the
continental regime of central Mexico is not too frequent. However, it is
known that there are precedents of large earthquakes (Mw > 6.0)
that have taken place in this zone. The valley of Mexico City (VM) is the
sole zone, within the MVB, that has been studied in detail. Studies have
mainly focused on the ground amplification during large events such as the
1985 subduction earthquake that occurred off coast of Michoacán. The
purpose of this article is to analyze the behavior of site effects in the MVB
zone based on records of shallow earthquakes (data not reported before) that
occurred in the zone between 1998 and 2011. We present a general overview of
site effects in the MVB, a classification of the stations in order to reduce
the uncertainty in the data when obtaining attenuation parameters in future
works, as well as some comparisons between the information presented here and
that presented in previous studies.

A regional evaluation of site effects and Fourier acceleration spectrum
(FAS) shape was estimated based on 80 records of 22 shallow earthquakes
within the MVB zone. Data of 25 stations were analyzed. Site effects were
estimated by using the horizontal-to-vertical spectral ratio (HVSR)
methodology. The results show that seismic waves are less amplified in the
northeast sites of the MVB with respect to the rest of the zone and that it
is possible to classify two groups of stations: (1) stations with negligible
site amplification (NSA) and (2) stations with significant site amplification
(SSA). Most of the sites in the first group showed small (<3)
amplifications while the second group showed amplifications ranging from 4
to 6.5 at frequencies of about 0.35, 0.75, 15 and 23 Hz. With these groups
of stations, average levels of amplification were contrasted for the first
time with those caused by the subduction zone earthquakes. With respect to
the FAS shapes, most of them showed similarities at similar epicentral
distances. Finally, some variations of site effects were found when compared
to those obtained in previous studies on different seismicity regions. These
variations were attributed to the location of the source.

These aspects help to advance the understanding about the amplification
behavior and of the expected seismic risk on central Mexico due to large
earthquakes within the MVB seismogenic zone.

http://www.nat-hazards-earth-syst-sci.net/14/1391/2014/ 2014/06/06 - 00:28

The results of experimental studies of VLF–ULF electromagnetic emission by rock samples due to mechanical actionNatural Hazards and Earth System Science, 14, 1383-1389, 2014Author(s): A. A. PanfilovThe paper presents the results
of laboratory experiments on electromagnetic emissions excitation (the
electric component of electromagnetic fields) by rock samples due to
different forms of mechanical stress applications. It was shown that samples
generate electric impulses with different spectra when the impact action,
gradual loading or dynamic friction is applied. It was ascertained that level
and spectral compositions of signals, generated by rock samples, change with
an increasing number of hits. It was found that strong electromagnetic
signals, generated while rock samples were fracturing, were accompanied by
repetitive weak but perceptible variations in the electric field intensity in
short frequency ranges.

http://www.nat-hazards-earth-syst-sci.net/14/1383/2014/ 2014/06/03 - 15:28

Temporal variations in the wind and wave climate at a location in the eastern Arabian Sea based on ERA-Interim reanalysis dataNatural Hazards and Earth System Science, 14, 1371-1381, 2014Author(s): P. R. Shanas and V. Sanil KumarTemporal variations in wind
speed and significant wave height (SWH) at a location in the eastern Arabian
Sea are studied using ERA-Interim reanalysis data from 1979 to 2012. A
shallow water location is selected for the study since measured buoy data are
available close to the location for comparison with the reanalysis data. The
annual mean wind speed shows a statistically significant decreasing trend of
1.5 cm s−1 year−1, whereas a statistically insignificant
increasing trend of 3.6 cm s−1 year−1 is observed for annual
maximum wind speed due to the local events that altered the trend in annual
maximum wind speed. Weakening of SWH during one of the peak monsoon months
(August) is identified from the monthly analysis of SWH, which shows a higher
upward trend in SWH during the southwest monsoon period, with an exception
during August. The annual mean SWH shows a slight upward trend
(0.012 cm year−1), whereas a larger upward trend
(1.4 cm year−1) is observed for annual maximum SWH. Both identified
trends are statistically insignificant. The influence of tropical cyclone
activity is also studied and it is found that the maximum SWH and wind speed
during 1996 are directly related to the cyclonic event.

http://www.nat-hazards-earth-syst-sci.net/14/1371/2014/ 2014/05/29 - 19:57

Flood risk assessment: concepts, modelling, applicationsNatural Hazards and Earth System Science, 14, 1361-1369, 2014Author(s): G. TsakirisNatural hazards have caused severe consequences to the natural, modified and
human systems in the past. These consequences seem to increase with time due
to both the higher intensity of the natural phenomena and the higher value of
elements at risk. Among the water-related hazards, flood hazards have the
most destructive impacts. The paper presents a new systemic paradigm for the
assessment of flood hazard and flood risk in the riverine flood-prone areas.
Special emphasis is given to the urban areas with mild terrain and
complicated topography, in which 2-D fully dynamic flood modelling is
proposed. Further, the EU flood directive is critically reviewed and examples
of its implementation are presented. Some critical points in the flood
directive implementation are also highlighted.

http://www.nat-hazards-earth-syst-sci.net/14/1361/2014/ 2014/05/28 - 10:39