bluuebunny/crossref_metadata_2025 huggingface dataset:
Picturing internal fractures of historical statues using ground penetrating radar method
Authors: Kadioglu S. , Kadioglu Y. K.
Published: April 2010

Abstract. The aim of the study is to formulate an approach to the monitoring of internal micro discontiniuties in a hybrid 2-D/3-D image of ground penetrating radar (GPR) data gathered on historical monument groups, and to indicate methodologically rearranging amplitude-color scale and its opacity functions to activate micro fractures in monument groups including three colossal women, three men, and 24 lion statues in Mustafa Kemal ATATÜRK's mausoleum (ANITKABIR) in Ankara, Turkey. Additionally, this paper illustrates the use of petrographic research to describe the monument and its groups. To achieve the aim, data measurements were carried out on the monument groups with spaced 10 cm profiles and 1.6 GHz antenna. The 3-D image was transparent 3-D volumes of the GPR data set that highlighted internal micro fractures and cavities in the statues. Rearranging appropriate amplitude-color scale and formulating the opaque of the data sets were the keys to the transparent 3-D data visualizations. As a result, the internal fractures and cavities were successfully visualized in the three women, three men and twenty-four lion statues. Micro fractures were observed particularly at the rim of the vesicular of the rocks under a polarizing microscope.
New discoveries with geophysics in the Accademia of Hadrian's Villa near Tivoli (Rome)
Authors: De Franceschini M. , Marras A. M.
Published: April 2010

Abstract. The Accademia Pilot Project concerns one of the lesser known buildings of Hadrian's Villa, the Accademia, which is still in private property and is not open to the public. One of the most significant and unique features of this building – and of the whole Villa – is a network of subterranean service corridors, which was seldom studied. For the first time we used Geophysics at Hadrian's Villa, to explore the subterranean tunnels of the Accademia and reconstruct their layout. The survey was done by archaeologist Anna Maria Marras for her Master thesis in Geo-technology (Marras, 2008) and gave very interesting results.
Microwave Tomographic approach for masonry investigation: some real results
Authors: Bavusi M. , Di Napoli R. , Soldovieri F.
Published: April 2010

Abstract. Ground Penetrating Radar (GPR) is an electromagnetic technique very appreciated by the community of the archaeologist and cultural heritage end-users community thanks to its appealing features in terms of non invasivity and rapidity of measurement and diagnostics. However, GPR data requires a high operator expertise in the data processing and interpretation. In the archaeological investigation, this drawback can be mitigated by the availability of a priori information about the archaeological scenario. On the other hand, in the case of the historical heritage, when the knowledge of constructive modalities and material of the structure may be completely missed, it is necessary to undertake other strategies of processing and interpretation. One of these can be provided by the use of novel inversion algorithms such as the Microwave Tomography (MT) which allows to reduce the subjectivity and the time consuming during the data processing. In this paper the MT was applied on raw data collected at two historical buildings of Chania (Crete, Greece). The first edifice is the Venizelo's House affected by visible fractures in its walls made up of cemented irregular stones. The second one is the headquarters of Prefecture of Chania showing some fractures along the floors. For these raw data, microwave tomography provided well detailed images which allowed to infer the fracture geometry and their extension in the host medium. This suggests microwave tomography can be a reliable complete processing tool requiring only the definition of the background scenario in terms of the dielectric permittivity and the conductivity of the host medium.
The TAMORA algorithm: satellite rainfall estimates over West Africa using multi-spectral SEVIRI data
Authors: Chadwick R. S. , Grimes D. I. F. , Saunders R. W. , Francis P. N. , Blackmore T. A.
Published: April 2010

Abstract. A multi-spectral rainfall estimation algorithm has been developed for the Sahel region of West Africa with the purpose of producing accumulated rainfall estimates for drought monitoring and food security. Radar data were used to calibrate multi-channel SEVIRI data from MSG, and a probability of rainfall at several different rain-rates was established for each combination of SEVIRI radiances. Radar calibrations from both Europe (the SatPrecip algorithm) and Niger (TAMORA algorithm) were used. 10 day estimates were accumulated from SatPrecip and TAMORA and compared with kriged gauge data and TAMSAT satellite rainfall estimates over West Africa. SatPrecip was found to produce large overestimates for the region, probably because of its non-local calibration. TAMORA was negatively biased for areas of West Africa with relatively high rainfall, but its skill was comparable to TAMSAT for the low-rainfall region climatologically similar to its calibration area around Niamey. These results confirm the high importance of local calibration for satellite-derived rainfall estimates. As TAMORA shows no improvement in skill over TAMSAT for dekadal estimates, the extra cloud-microphysical information provided by multi-spectral data may not be useful in determining rainfall accumulations at a ten day timescale. Work is ongoing to determine whether it shows improved accuracy at shorter timescales.
The effect of radar-based QPE on the Fractions Skill Score used at the QPF verification
Authors: Zacharov P. , Rezacova D.
Published: April 2010

Abstract. In this paper we show the influence of gauge adjustment technique, applied to radar-based rainfalls, on the results of QPF verification. The results were obtained for four convective events which produced heavy local rainfalls and caused local flash floods at the Czech territory. Numerical weather prediction model COSMO was run to obtain rainfall forecast and Fractions Skill Score was employed in the QPF verification. Three different radar-based quantitative precipitation estimates (QPE) were used for the verification and the verification results were compared. The QPE data sets consisted of: (a) raw radar-based rainfall values, (b) gauge corrected radar-based rainfalls with a simple domain-wide correction, and (c) radar-based rainfalls with a pixel related gauge adjustment. The results indicate small difference in area-related verification results and prove that the simple domain wide correction technique is sufficient for applying radar-based rainfalls as the verification data.
A case study of curriculum development related to the space environment and emerging space weather markets
Authors: Tulunay Y. , Tulunay E.
Published: April 2010

Abstract. Space weather is a new subject which has not yet become widely understood or appreciated. The University offers the unique opportunity to develop knowledge and understanding about space weather that can then be applied as graduates enter the mainstream society. In this paper, an example of curriculum development at the Istanbul Technical University, Faculty of Aeronautics and Astronautics, for formal education related to the space environment is presented in outline.
Space education in Kiruna, Northern Sweden
Authors: Sandahl I. , Wikström A.
Published: April 2010

Abstract. The town of Kiruna in the north of Sweden has a concentration of space activities and space research with, for example, the Swedish Institute of Space Physics, Esrange, the ESA Salmijärvi satellite station, and EISCAT (European Incoherent Scatter Radar) Scientific Association. The Department of Space Science is a joint department between the two most northern universities in Sweden, Luleå University of Technology and Umeå University in collaboration with the Swedish Institute of Space Physics. It offers a range of education programmes in the space field. There are bachelor and master programmes in space engineering, and a bridging programme for students without a science background from secondary school. The Department also contributes to courses for teachers, Ph.D. courses and secondary school level courses. One master´s program and a three week summer course are given entirely in English and welcome international students. Thanks to good cooperation with Esrange students can build and fly experiments on high altitude balloons and sounding rockets and also take a large responsibility for the management of the projects. Close interaction with research and industry is an important part of the education.
Role of the Radiophysical Research Institute (NIRFI) for promoting and teaching science in Russia
Authors: Snegirev S. D. , Fridman V. M. , Sheiner O. A.
Published: April 2010

Abstract. We present, how the Radiophysical Research Institute (NIRFI) has conducted work on the popularization of its scientific achievements in the areas of astronomy, solar physics, the Sun-Earth connection and associated geophysics.
OpenMI: the essential concepts and their implications for legacy software
Authors: Gregersen J. B. , Gijsbers P. J. A. , Westen S. J. P. , Blind M.
Published: April 2010

Abstract. Information & Communication Technology (ICT) tools such as computational models are very helpful in designing river basin management plans (rbmp-s). However, in the scientific world there is consensus that a single integrated modelling system to support e.g. the implementation of the Water Framework Directive cannot be developed and that integrated systems need to be very much tailored to the local situation. As a consequence there is an urgent need to increase the flexibility of modelling systems, such that dedicated model systems can be developed from available building blocks. The HarmonIT project aims at precisely that. Its objective is to develop and implement a standard interface for modelling components and other relevant tools: The Open Modelling Interface (OpenMI) standard. The OpenMI standard has been completed and documented. It relies entirely on the "pull" principle, where data are pulled by one model from the previous model in the chain. This paper gives an overview of the OpenMI standard, explains the foremost concepts and the rational behind it.
Investigation of the transferability of hydrological models and a method to improve model calibration
Authors: Hartmann G. , Bárdossy A.
Published: April 2010

Abstract. In order to find a model parameterization such that the hydrological model performs well even under different conditions, appropriate model performance measures have to be determined. A common performance measure is the Nash Sutcliffe efficiency. Usually it is calculated comparing observed and modelled daily values. In this paper a modified version is suggested in order to calibrate a model on different time scales simultaneously (days up to years). A spatially distributed hydrological model based on HBV concept was used. The modelling was applied on the Upper Neckar catchment, a mesoscale river in south western Germany with a basin size of about 4000 km2. The observation period 1961-1990 was divided into four different climatic periods, referred to as "warm", "cold", "wet" and "dry". These sub periods were used to assess the transferability of the model calibration and of the measure of performance. In a first step, the hydrological model was calibrated on a certain period and afterwards applied on the same period. Then, a validation was performed on the climatologically opposite period than the calibration, e.g. the model calibrated on the cold period was applied on the warm period. Optimal parameter sets were identified by an automatic calibration procedure based on Simulated Annealing. The results show, that calibrating a hydrological model that is supposed to handle short as well as long term signals becomes an important task. Especially the objective function has to be chosen very carefully.
Model system development and uncertainty for the provisionary management of extreme floods in large river basins
Authors: Lindenschmidt K.-E. , Fleischbein K. , Petrow T. , Vorogushyn S. , Theobald S. , Merz B.
Published: April 2010

Abstract. A research project is introduced in which a modelling system is being developed to quantify risks of extreme flooding in large river basins. In the system, computer models and modules are coupled to simulate the functional chain: hydrology - hydraulics - polder diversion - dyke failure - flooding - damage estimate - risk assessment. In order to reduce uncertainty in flood frequency analyses, data sets are complimented with information from historical chronicles and artwork. Probable maximum precipitation and discharge are calculated to indicate upper bounds of meteorological and hydrological extremes. Uncertainty analysis is investigated for different degrees of model complexity and compared at different basin scales.
Impact of global warming on ENSO phase change
Authors: Cabos Narvaez W. , Alvarez-Garcia F. , OrtizBeviá M. J.
Published: April 2010

Abstract. We compare the physical mechanisms involved in the generation and decay of ENSO events in a control (present day conditions) and Scenario (Is92a, IPCC 1996) simulations performed with the coupled ocean-atmosphere GCM ECHAM4-OPYC3. A clustering technique which objectively discriminates common features in the evolution of the Tropical Pacific Heat Content anomalies leading to the peak of ENSO events allows us to group into a few classes the ENSO events occurring in 240 years of data in the control and scenario runs. In both simulations, the composites of the groups show differences in the generation and development of ENSO. We present the changes in the statistics of the groups and explore the possible mechanisms involved.
Inter-annual variability of the Pelagic-Benthic coupling in the upwelling system off central Chile
Authors: Graco M. , Gutiérrez D. , Farías L.
Published: April 2010

Abstract. The coastal region of central Chile (36° S) is one of the most productive coastal systems, characterized by a marked seasonality in the upwelling regime, that brings subsurface waters rich in nutrient and poor in oxygen (ESSW) into the euphotic zone. This oceanographic condition depends basically on the equatorward wind strength and is modified on different time scales, with the El Niño-Southern Oscillation (ENSO) phenomenon as the main source of interannual variability in the Pacific Ocean. Here we present an effort to integrate physical and biogeochemical variability associated with in situ information and experiments at coastal stations off central Chile (36° S) in order to improve the knowledge on the pelagic-benthic coupling in this upwelling system during the warm ENSO phase or El Niño. Carbon fluxes exported from the water column to the sediments and the ammonium exchange across the sediment-water interface are discussed together with oceanographic and benthic conditions. All measurements and estimations were carried out from May 1997 until April 2001 at two stations, one located inside Concepción Bay (~28 m depth), and the other on the continental shelf at ~36° S (~88 m depth). The results show that the pelagic and benthic systems are strongly coupled off central Chile (36° S). Oceanographic variability associated with upwelling events (seasonal scale) and an El Niño event (interannual scale) was observed. The carbon fluxes exported to the sediments, the benthic conditions (i.e., quantity and quality of the sediment organic matter), and the ammonium exchange across the sediment-water interface, responded to the seasonal regime of upwelling during non El Niño years as well as to the ENSO related oceanographic variability.
The impact of El Niño-Southern Oscillation on the Canadian climate
Authors: Shabbar A.
Published: April 2010

Abstract. The quasi-periodic El Niño -Southern Oscillation (ENSO) phenomenon in the tropical Pacific Ocean produces the largest interannual variation in the cold season climate of Canada. The diabatic heating in the eastern tropical Pacific, associated with the warm phase of ENSO (El Niño), triggers Rossby waves which in turn gives rise to the Pacific-North American teleconnection (PNA) over the North American sector. The strongest cell of the PNA pattern lies over western Canada. In most of southern Canada, mean winter temperature distribution is shifted towards warmer values, and precipitation is below normal. The presence of El Niño provides the best opportunity to make skillful long-range winter forecast for Canada. A strong El Niño event, while bringing respite from the otherwise cold winter in Canada, can be expected to cost the Canadian economy two to five billion dollars.
Inter ENSO variability and its influence over the South American monsoon system
Authors: Drumond A. R. M. , Ambrizzi T.
Published: April 2010

Abstract. Previous studies have discussed the interannual variability of a meridional seesaw of dry and wet conditions over South America (SA) associated to the modulation of the South Atlantic Convergence Zone (SACZ). However, they did not explore if the variability inter ENSO (El Niño Southern Oscillation) can be related to the phase changes of this dipole. To answer this question, an observational work was carried out to explore the atmospheric and Sea Surface Temperature (SST) conditions related to the same ENSO signal and to opposite dipole phases. Rotated Empirical Orthogonal Function (REOF) analysis was applied over normalized Chen precipitation seasonal anomalies in order to find the dipole mode in the Austral Summer (December to February). The fourth rotated mode, explaining 6.6% of the total variance, consists of positive loading over the SACZ region and negative loading over northern Argentina. Extreme events were selected and enhanced activity of SACZ during the Summer season (SACZ+) was identified in nine years: five during La Niña events (LN) and two in El Niño episodes (EN). On the other hand, inhibited manifestations of this system (SACZ-) were identified in seven years: four in EN and two during LN. Power spectrum analysis indicated that the interannual variability of the precipitation dipole seems to be related to the low frequency and to the quasi-biennial part of ENSO variability. The ENSO events with the same signal can present opposite phases for the dipole. The results suggest that the displacement of the convection over Indonesia and western Pacific can play an important role to modulate the seesaw pattern.
How unusual was late 20th century El Niño-Southern Oscillation (ENSO)? Assessing evidence from tree-ring, coral, ice-core and documentary palaeoarchives, A.D. 1525-2002
Authors: Gergis J. L. , Fowler A. M.
Published: April 2010

Abstract. Multiple proxy records (tree-ring, coral, ice and documentary) were examined to isolate ENSO signals associated with both phases of the phenomenon for the period A.D. 1525-2002. To avoid making large-scale inferences from single proxy analysis, regional signals were aggregated into a network of high-resolution records, revealing large-scale trends in the frequency, magnitude and duration of pre-instrumental ENSO using novel applications of percentile analysis. Here we use the newly introduced coupled ocean-atmosphere ENSO index (CEI) as a baseline for the calibration of proxy records. The reconstruction revealed 83 extreme or very strong ENSO episodes since A.D. 1525, expanding considerably on existing ENSO event chronologies. Significantly, excerpts of the most comprehensive list of La Niña events complied to date are presented, indicating peak activity during the 16th to mid 17th and 20th centuries. Although extreme events are seen throughout the 478-year reconstruction, 43% of the extreme ENSO events noted since A.D. 1525 occur during the 20th century, with an obvious bias towards enhanced El Niño conditions in recent decades. Of the total number of extreme event years reconstructed, 30% of all reconstructed ENSO event years occur post-1940 alone suggesting that recent ENSO variability appears anomalous in the context of the past five centuries.
Relationship between the 1997/98 El Niño and 1999/2001 La Niña events and oil palm tree production in Tumaco, Southwestern Colombia
Authors: Cadena M. C. , Devis-Morales A. , Pabón J. D. , Málikov I. , Reyna-Moreno J. A. , Ortiz J. R.
Published: April 2010

Abstract. Although the relationship between ENSO events and oceanographic and meteorological conditions of Southwestern Colombia is well-known, very little work has been done to assess the related socio-economic impacts. This is the first effort made to determine the effect of such events on local climate and the impact of this variability on oil palm tree (Elaeis guineensis) production in the Tumaco municipality, which is located on Colombia's Pacific coast. First, we studied the correlation between sea surface temperature anomalies (SSTA) in the various El Niño regions and those observed off Tumaco. Next, we scrutinized the ENSO impact on regional climatic indicators, e.g. active solar radiation (hrs/day), air temperature (°C), and rain (mm). Finally, we analyzed the relationship between ENSO, Tumaco climate variability, and oil palm production (tons/hectare-month). Hours of active radiation increased (decreased) under El Niño (La Niña) conditions, as did average monthly precipitation rates and air temperature. ENSO-related climatic variability also had an important effect on the different developmental stages of the oil palm tree, thereby affecting its production. The worst scenario was found during La Niña, when reduced intensity of the rainy season (second semester) caused severe droughts in the region.
The variation of floods in the middle reaches of the Yangtze River and its teleconnection with El Niño events
Authors: Wu Y.-J. , Gough W. A. , Jiang T. , Kung H.-T.
Published: April 2010

Abstract. Middle reaches of the Yangtze River are the worst flooded segments along the Yangtze River. It is important to understand and study the variations of frequency and magnitude of historical floods in this area and how were they related to or affected by EI Niño in a long historical period. We applied the statistics and time series to study and analyze historical floods (1470-2000) and EI Niño events (1525-1995). The results show that the more floods occurred in the latest 200 years. The power-spectral analysis suggests the main cycle of flood variation is longer than that of EI Niño events. El Nino shows the fluctuations of about 2-year and 3~4 year period while the flood variation is not so significant but can also be identified in the period of 2, 8 and 40 years (it exceeds the level of confidence 0.03). Time series analyses of the fluctuation of flood and El Nino indicate that there is a significant correlation between the two at both high and moderate frequency sections. The result shows that the response of the floods along the middle reaches of the Yangtze River to the effects of El Nino events is not only delayed one or more than one year as suggested by many Chinese scientists, but it also can be somewhat longer delayed up to about 8 years. The result also indicates that the shorter the interval of EI Niño events, the sooner the flood events follows. In other words, flood could be delayed with longer time if the interval time of EI Niño events is longer.
From inferential statistics to climate knowledge
Authors: de H. N. Maia A. , Meinke H.
Published: April 2010

Abstract. Climate variability and change are risk factors for climate sensitive activities such as agriculture. Managing these risks requires "climate knowledge", i.e. a sound understanding of causes and consequences of climate variability and knowledge of potential management options that are suitable in light of the climatic risks posed. Often such information about prognostic variables (e.g. yield, rainfall, run-off) is provided in probabilistic terms (e.g. via cumulative distribution functions, CDF), whereby the quantitative assessments of these alternative management options is based on such CDFs. Sound statistical approaches are needed in order to assess whether difference between such CDFs are intrinsic features of systems dynamics or chance events (i.e. quantifying evidences against an appropriate null hypothesis). Statistical procedures that rely on such a hypothesis testing framework are referred to as "inferential statistics" in contrast to descriptive statistics (e.g. mean, median, variance of population samples, skill scores). Here we report on the extension of some of the existing inferential techniques that provides more relevant and adequate information for decision making under uncertainty.
Climatic variability related to El Niño in Ecuador − a historical background
Authors: Arteaga K. , Tutasi P. , Jiménez R.
Published: April 2010

Abstract. This paper reports on an investigation into the chronology of El Niño/Southern Oscillation (ENSO) events, during the period from the arrival of conquistadores in Ecuador in 1532 until the year 1900. A number of probable El Niño events and drought years can be dated from anecdotal reports of significant rainfall and drought in the equatorial region. The evidence of ENSO has been documented from early reports in the South America archives. A large number of books and articles have been reviewing from the Ecuadorian archives to obtain information on El Niño events that have occurred over the past centuries. This information is based on evidence obtained from the equatorial region, where strong and very strong El Niño events clearly separate the northern part of the Ecuadorian coast from the southern region, the normally rainy season specially from west-central to the south coast of Ecuador, as well as the drought years, reported in this region which is climatologically and oceanographically different from the moist Northern coast of Ecuador. Given the normal occurrence of rains in the southern coast of Ecuador, it is reasonable to expect that at least some of the major rainy seasons would be recorded in local chronicles and publications. This information has been compared with reports obtained from Peru. Relative strengths of events are based on such considerations as wind and current effects on travel times of ancient sailing ships, degree of physical damage and destruction, amounts of rainfall and flooding, human disease epidemic, mass mortality of endemic marine organism, rises in sea temperatures and sea levels, effects on coastal fisheries. This paper is the first survey of the historical sources concerned the rainfall and drought in Ecuador. In the course of this investigation we also noted some extended periods of time, near decadal or longer over the past records, when the amount and/or strength of El Niño and its resulting effects appeared to represent significant long-term climate changes.
The skill of empirical and combined/calibrated coupled multi-model South American seasonal predictions during ENSO
Authors: Coelho C. A. S. , Stephenson D. B. , Doblas-Reyes F. J. , Balmaseda M.
Published: April 2010

Abstract. This study addresses seasonal predictability of South American rainfall during ENSO. The skill of empirical and coupled multi-model predictions is assessed and compared. The empirical model uses the previous season August-September-October Pacific and Atlantic sea surface temperatures as predictors for December-January-February rainfall. Coupled multi-model 1-month lead December-January-February rainfall predictions were obtained from the Development of a European Multi-model Ensemble system for seasonal to inTERannual prediction (DEMETER) project. Integrated (i.e. combined and calibrated) forecasts that incorporate information provided by both the empirical and the coupled multi-model are produced using a Bayesian procedure. This procedure is referred to as forecast assimilation. The skill of the integrated forecasts is compared to the skill of empirical and coupled multi-model predictions. This comparison reveals that when seasonally forecasting December-January-February South American rainfall at 1-month lead-time the current generation of coupled models have a level of deterministic skill comparable to those obtained using simplified empirical approaches. However, Bayesian combined/calibrated forecasts provide better estimates of forecast uncertainty than the coupled multi-model. This indicates that forecast assimilation improves the quality of probabilistic predictions. The tropics and the area of South Brazil, Paraguay, Uruguay and Northern Argentina are found to be the two most predictable regions of South America. ENSO years are more predictable than neutral years, the latter having nearly null skill.
Exploitation of cloud top characterization from three-channel IR measurements in a physical PMW rain retrieval algorithm
Authors: Torricella F. , Cattani E. , Levizzani V.
Published: April 2010

Abstract. Rainfall intensity estimates by passive microwave (PMW) measurements from space perform generally better over the sea surface with respect to land, due to the problems in separating true rain signatures from those produced by surfaces having similar spectral behaviour (e.g. snow, ice, desert and semiarid grounds). The screening procedure aimed at recognizing the various surface types and delimit precipitation is based on tests that rely on PMW measurements only and global thresholds. The shortcoming is that the approach tries to discard spurious precipitating features (often detected over the land-sea border) thus leading to no-rain conservative tests and thresholds. The TRMM mission, with its long record of simultaneous data from the Visible and Infrared Radiometer System (VIRS), the TRMM Microwave Imager (TMI) and rain profiles from the Precipitation Radar (PR) allows for unambiguous testing of the usefulness of cloud top characterization in rain detection. An intense precipitation event over the North Africa is analysed exploiting a night microphysical RGB scheme applied to VIRS measurements to classify and characterize the components of the observed scenario and to discriminate the various types of clouds. This classification is compared to the rain intensity maps derived from TMI by means of the Goddard profiling algorithm and to the near-surface rain intensities derived from PR. The comparison allows to quantify the difference between the two rain retrievals and to assess the usefulness of RGB analysis in identifying areas of precipitation.
Socio-economic impacts of major floods in Italy from 1951 to 2003
Authors: Lastoria B. , Simonetti M. R. , Casaioli M. , Mariani S. , Monacelli G.
Published: April 2010

Abstract. Meteorological and hydrological monitoring and modeling, with particular regard for extreme hydrological events, represent important activities carried out by the Hydrological and Inland Waters Service of the Italian Agency for Environmental Protection and Technical Services (APAT). Recently, a study on the socio-economic effects of floods was published in the Italian Environmental Data Yearbook by APAT. It is based on processed data related to the major floods (i.e., events with at least a casualty or that have generated economic damages higher than 0.001% of the Gross Domestic Product) striking Italy between 1951 and 2003. Information was gathered from technical reports and/or databases belonging to APAT, Italian Regional Environmental Agencies (ARPAs), central and local authorities, research institutions and newspaper reports. These data are collected in tables reporting the number of flood events and of casualties and the amount of financial resources required for environmental restoration and/or for risk mitigation purposes. For year 2003, when APAT has begun a systematic monitoring of flood events in Italy, data concerning rainfall, number of persons involved, evacuation and urgent measures introduced to face the event (laws and acts) are also included. In this way, it was possible to realize a new database, in which flood events that caused the declaration of the state of emergency have been collected. Because of the difficulties in finding sufficiently reliable data for the period before the II World War, the collection of historical data started from 1951. During this period, about 50% of the flood events examined have caused at least 5 victims each, and about 10% more than 100; these data highlight the considerable social impact of flood events and suggest the importance of creating an integrated database to collect information about flood events involving all Europe. These two databases (the historical and updating archives) could be useful for taking into account the different anthropic impacts during the time, the real effectiveness of protection measures already realized and could represent a valid reference for further interventions.
Partitioning of snowy and rainy precipitation in a case of a north Adriatic frontal passage
Authors: Monai M. , Rossa A. M. , Bonan A. C.
Published: April 2010

Abstract. A case of snow fall in the plains of the Northern Italian region Veneto is presented from a forecasters' perspective. Contrasting forecast guidance came from the ECMWF global model and the limited area model LAMI. The former showed a marked warm-moist Sirocco flow coming from the Adriatic Sea onto the coast at all levels, the latter discerned a distinct cold air flow from the north-east along the foothills of the Alps. The integrated observing network of the Centro Meteorologico di Teolo ARPA Veneto revealed this cold-air structure and helped the forecaster in the choice of the forecast and underpin the snowfall alert to the road authorities. It is argued that this feature is a crucial element for the occurrence of snowfall over the Veneto plains, and that the high-resolution numerical weather prediction model was essential in describing this mesoscale feature. The nature of the north-easterly flow is thought to be a combination of a Bora like flow and a barrier jet induced by flow blocking by the Alps.
The structure of convective rain cells at mid-latitudes
Authors: Rebora N. , Ferraris L.
Published: April 2010

Abstract. Rain cells are structures which represent an important component of convective precipitation and a study of their properties represents a necessary step both towards improved stochastic models of small-scale precipitation and for the verification of deterministic high resolution local-area models. The case of intense convective precipitation in the tropics has been analysed in a recent study (von Hardenberg et al., 2003). Here we extend the analysis to mid-latitudes and we present results on the structure of convective rain cells observed by radar measurements in Italy. In particular we consider the average shape of precipitation cells and its dependence on radar resolution and the distributions of ellipticities.
Storm surge in the Adriatic Sea: observational and numerical diagnosis of an extreme event
Authors: Zampato L. , Umgiesser G. , Zecchetto S.
Published: April 2010

Abstract. Storm surge events occur in the Adriatic Sea, in particular during autumn and winter, often producing flooding in Venice. Sea levels are forecasted by numerical models, which require wind and pressure fields as input. Their performances depend crucially on the quality of those fields. The storm surge event on 16 November 2002 is analysed and simulated through a finite element hydrodynamic model of the Mediterranean Sea. Several runs were carried out, imposing different atmospheric forcings: wind fields from ECMWF analysis, high resolution winds from the limited area model LAMI and satellite observed winds from QuikSCAT (NASA). The performance of the hydrodynamic model in each case has been quantified. ECMWF fields are effective in reproducing the sea level in the northern Adriatic Sea, if the wind speed is enhanced by a suitable multiplying factor. High resolution winds from LAMI give promising results, permitting an accurate simulation of the sea level maxima. QuikSCAT satellite wind fields produce also encouraging results which claim, however, for further research.
An operational approach to the nowcasting of an intense thunderstorm over Liguria
Authors: Gallino S. , Turato B.
Published: April 2010

Abstract. In the period between late spring and early summer as well as in autumn, the Mediterranean is often affected by rapid development of intense convective systems. In some cases the operational NWP models are able to provide good indication of occurrence of such severe weather events (potential instability conditions) but often location and intensity of convective precipitation are poorly forecasted. The approach of "PV-thinking" revealed itself as a good tool to identify favorable conditions for triggering such systems, partially filling this lack of information and supporting meteorologists in the very short range weather forecast. Moreover, the advanced use of data provided by SEVIRI channels onboard MSG satellite, makes possible an effective application of the PV approach, improving forecast skill also in areas where local effects are not well described by the models and/or by the data assimilation. The aim of this work is to show how the application of the MSG tools together with the PV philosophy helps in the diagnosis and nowcasting of intense thunderstorms triggered by tropopause, with particular attention to a case of intense convection over northwestern Italy during spring 2005.
A probabilistic approach to the concept of Probable Maximum Precipitation
Authors: Papalexiou S. M. , Koutsoyiannis D.
Published: April 2010

Abstract. The concept of Probable Maximum Precipitation (PMP) is based on the assumptions that (a) there exists an upper physical limit of the precipitation depth over a given area at a particular geographical location at a certain time of year, and (b) that this limit can be estimated based on deterministic considerations. The most representative and widespread estimation method of PMP is the so-called moisture maximization method. This method maximizes observed storms assuming that the atmospheric moisture would hypothetically rise up to a high value that is regarded as an upper limit and is estimated from historical records of dew points. In this paper, it is argued that fundamental aspects of the method may be flawed or inconsistent. Furthermore, historical time series of dew points and "constructed" time series of maximized precipitation depths (according to the moisture maximization method) are analyzed. The analyses do not provide any evidence of an upper bound either in atmospheric moisture or maximized precipitation depth. Therefore, it is argued that a probabilistic approach is more consistent to the natural behaviour and provides better grounds for estimating extreme precipitation values for design purposes.
Regional scale analysis of the altimetric stream network evolution
Authors: Ghizzoni T. , Lomazzi M. , Roth G. , Rudari R.
Published: April 2010

Abstract. Floods result from the limited carrying capacity of stream channels when compared to the discharge peak value. The transit of flood waves - with the associated erosion and sedimentation processes - often modifies local stream geometry. In some cases this results in a reduction of the stream carrying capacity, and consequently in an enhancement of the flooding risk. A mathematical model for the prediction of potential altimetric stream network evolution due to erosion and sedimentation processes is here formalized. It works at the regional scale, identifying the tendency of river segments to sedimentation, stability, or erosion. The model builds on geomorphologic concepts, and derives its parameters from extensive surveys. As a case study, tendencies of rivers pertaining to the Valle d'Aosta region are analyzed. Some validation is provided both at regional and local scales of analysis. Local validation is performed both through a mathematical model able to simulate the temporal evolution of the stream profile, and through comparison of the prediction with ante and post-event river surveys, where available. Overall results are strongly encouraging. Possible use of the information derived from the model in the context of flood and landslide hazard mitigation is briefly discussed.
Artificial neural-network technique for precipitation nowcasting from satellite imagery
Authors: Rivolta G. , Marzano F. S. , Coppola E. , Verdecchia M.
Published: April 2010

Abstract. The term nowcasting reflects the need of timely and accurate predictions of risky situations related to the development of severe meteorological events. In this work the objective is the very short term prediction of the rainfall field from geostationary satellite imagery entirely based on neural network approach. The very short-time prediction (or nowcasting) process consists of two steps: first, the infrared radiance field measured from geostationary satellite (Meteosat 7) is projected ahead in time (30 min or 1 h); secondly, the projected radiances are used to estimate the rainfall field by means of a calibrated microwave-based combined algorithm. The methodology is discussed and its accuracy is quantified by means of error indicators. An application to a satellite observation of a rainfall event over Central Italy is finally shown and evaluated.
Physically based distributed hydrological modelling of the Upper Jordan catchment and investigation of effective model equations
Authors: Kunstmann H. , Heckl A. , Rimmer A.
Published: April 2010

Abstract. Sufficient freshwater availability in the water scarce environment of the Upper Jordan Catchment (UJC) is a central prerequisite for peaceful agricultural and industrial development. Hydrological modelling is required to understand terrestrial water balance and to provide scientifically sound estimates on water availability. This article aims at two related objectives: First the water balance of the UJC, a hydrogeologically complex catchment located at the borders of Israel, Syria and the Lebanon, is investigated. It is for the first time that a physically based model is set up for this region that accounts both for the entire terrestrial water balance and in particular for the groundwater-surface water interaction. It is shown that the model is able to describe observed river discharges satisfactorily. Secondly, it is investigated if observed and simulated runoff components can be explained by simple lumped approaches based on 1) linear filter theory and 2) neural networks and what the number of degrees of freedom for the runoff components is. It is exemplary shown for the Ayun subcatchment of the UJC that the simulated river discharge, the direct runoff component and the interflow runoff component as modelled by the physically based distributed hydrological model WaSiM can be described by simple effective equations with only 3 to 5 degrees of freedom. Application of simple lumped approaches to observed river discharge values showed much weaker performance.
Risk assessment and mapping of extreme floods in non-dyked communities along the Elbe and Mulde Rivers
Authors: Lindenschmidt K.-E. , Herrmann U. , Pech I. , Suhr U. , Apel H. , Thieken A.
Published: April 2010

Abstract. Assessing and mapping damage risk of floods for large river basins is still in its infancy. Damage risk is understood to be the combination of flood hazard and the vulnerability of communities to a flood of a particular return period. Risk is calculated and mapped for two communities in which dykes are not located for flood protection: Meissen on the Elbe River and Döbeln in the Mulde catchment. Different methodologies for the computation of flood depth and inundation extent of varying flood return periods (hazard) are compared. Exposure and relative damage to the flooding (vulnerability) based on land-use coverages of different scale are also compared and discussed. A property asset coverage completes the data requirements for the construction of the risk maps. Recommendations for continued research on risk assessments of large river basins conclude the study.
Multiscale investigations in a mesoscale catchment – hydrological modelling in the Gera catchment
Authors: Krause P. , Bäse F. , Bende-Michl U. , Fink M. , Flügel W. , Pfennig B.
Published: April 2010

Abstract. The application of the hydrological process-oriented model J2000 (J2K) is part of a cooperation project between the Thuringian Environmental Agency (Thüringer Landesanstalt für Umwelt und Geologie – TLUG) and the Department of Geoinformatics of the Friedrich-Schiller-University Jena focussing on the implementation of the EU water framework directive (WFD). In the first project phase J2K was parametrised and calibrated for a mesoscale catchment to quantify if it can be used as hydrological part of a multi-objective tool-box needed for the implementation of the WFD. The main objectives for that pilot study were: The development and application of a suitable distribution concept which provide the spatial data basis for various tasks and which reflects the specific physiogeographical variability and heterogeneity of river basins adequately. This distribution concept should consider the following constraints: The absolute number of spatial entities, which forms the basis for any distributive modelling should be as small as possible, but the spatial distributed factors, which controls quantitative and qualitative hydrological processes should not be generalised to much. The distribution concept of hydrological response units HRUs (Flügel, 1995) was selected and enhanced by a topological routing scheme (Staudenrausch, 2001) for the simulation of lateral flow processes. J2K should be calibrated for one subbasin of the pilot watershed only. Then the parameter set should be used on the other subbasins (referred as transfer basins) to investigate and quantify the transferability of a calibrated model and potential spatial dependencies of its parameter set. In addition, potential structural problems in the process description should be identified by the transfer to basins which show a different process dominance as the one which was used for calibration does. Model calibration and selection of efficiency criteria for the quantification of the model quality should be based on a comprehensive sensitivity and uncertainty analysis (Bäse, 2005) and multi-response validations with independent data sets (Krause and Flügel, 2005) carried out in advance in the headwater part of the calibration basin. To obtain good results in the transfer basins the calibrated parameter set could be adjusted slightly. This step was considered as necessary because of specific constraints which were not of significant importance in the calibration basin. This readjustment should be carried out on parameters which show a sensitive reaction on the identified differences in the environmental setup. Potential scaling problems of the process description, distribution concept or model structure should be identified by the comparison of the modelling results obtained in a small headwater region of the calibration basin with observed streamflow to find out if the selected efficiency measures show a significant change.
Integration of water balance models in RIVERTWIN
Authors: Götzinger J. , Jagelke J. , Barthel R. , Bárdossy A.
Published: April 2010

Abstract. In the project RIVERTWIN climate, hydrologic, groundwater and water quality models are integrated in order to evaluate river basin management plans established for the implementation of the EU Water Framework Directive. In such integrated models, which try to simulate all relevant processes in a river basin realistically, modelling of the water balance plays a key role. Therefore the integration of hydrological and groundwater models requires special attention. In this case study, the hydrological model simulates discharge and daily groundwater recharge in a high spatial resolution. Using the latter as input, the groundwater model calculates groundwater levels and groundwater runoff, which is then returned to the hydrological model. Such integration on the meso-scale brings up new problems such as commensurability, verification and compatibility of internal state variables and fluxes, but also provides the possibility to analyse the underlying assumptions and simplifications. As an example of this modelling approach the simulation of groundwater recharge, groundwater levels and groundwater runoff in the Neckar catchment are discussed and the problems of the current integration concept are described.