http://www.adv-geosci.net/ Advances in Geosciences Latest Articlesenhttp://www.adv-geosci.net/26/99/2010/<b>The morphodynamic responses of artificial embayed beaches to storm events</b><br /><br />Advances in Geosciences, 26, 99-103, 2010<br /><br />Author(s): E. Ojeda, J. Guillén, and F. Ribas<br /><br />The morphological changes caused by storm events in two Barcelona beaches were recorded using video monitoring techniques during the period 2001–2006. Changes in shoreline position and configuration and submerged bar position and shape were analyzed during the 25 major storm events that occurred during the study period. Beach responses to storms were grouped into three categories: shoreline advance or retreat (including rotation), sandbar migration and/or configuration change (linear or crescentic shape) and formation of megacusps. This work provides examples of the differential adaptation of both beaches to the same storm and of some unexpected morphological responses of both beaches. The response of the beach to storm events is not straightforward because wave conditions are not the only relevant parameter to be considered. In particular, in such embayed beaches it is crucial to take into account their specific morphodynamic configuration prior to the storm.Thu, 02 Sep 2010 00:00:00 +0200http://www.adv-geosci.net/26/93/2010/<b>Connecting European snow cover variability with large scale atmospheric patterns</b><br /><br />Advances in Geosciences, 26, 93-97, 2010<br /><br />Author(s): E. Bartolini, P. Claps, and P. D'Odorico<br /><br />Winter snowfall and its temporal variability are important factors in the development of water management strategies for snow-dominated regions. For example, mountain regions of Europe rely on snow for recreation, and on snowmelt for water supply and hydropower. It is still unclear whether in these regions the snow regime is undergoing any major significant change. Moreover, snow interannual variability depends on different climatic variables, such as precipitation and temperature, and their interplay with atmospheric and pressure conditions. This paper uses the EASE Grid weekly snow cover and Ice Extent database from the National Snow and Ice Data Center to assess the possible existence of trends in snow cover across Europe. This database provides a representation of snow cover fields in Europe for the period 1972–2006 and is used here to construct snow cover indices, both in time and space. These indices allow us to investigate the historical spatial and temporal variability of European snow cover fields, and to relate them to the modes of climate variability that are known to affect the European climate. We find that both the spatial and temporal variability of snow cover are strongly related to the Arctic Oscillation during wintertime. In the other seasons, weaker correlation appears between snow cover and the other patterns of climate variability, such as the East Atlantic, the East Atlantic West Russia, the North Atlantic Oscillation, the Polar Pattern and the Scandinavian Pattern.Wed, 01 Sep 2010 00:00:00 +0200http://www.adv-geosci.net/27/57/2010/<b>Evaluation of three different regional climate change scenarios for the application of a water balance model in a mesoscale catchment in Northeast Germany</b><br /><br />Advances in Geosciences, 27, 57-64, 2010<br /><br />Author(s): M. Wegehenkel, U. Heinrich, H. Jochheim, K. C. Kersebaum, and B. Röber<br /><br />Future climate changes might have some impacts on catchment hydrology. An assessment of such impacts on e.g. ground water recharge is required to derive adaptation strategies for future water resources management. The main objective of our study was an analysis of three different regional climate change scenarios for a catchment with an area of 2415 km² located in the Northeastern German lowlands. These data sets consist of the STAR-scenario with a time period 1951–2055, the WettReg-scenario covering the period 1961–2100 and the grid based REMO-scenario for the time span 1950–2100. All three data sets are based on the SRES scenario A1B of the IPCC. In our analysis, we compared the meteorological data for the control period obtained from the regional climate change scenarios with corresponding data measured at meteorological stations in the catchment. The results of this analysis indicated, that there are high differences between the different regional climate change scenarios regarding the temporal dynamics and the amount of precipitation. In addition, we applied a water balance model using input data obtained from the different climate change scenarios and analyzed the impact of these different input data on the model output groundwater recharge. The results of our study indicated, that these regional climate change scenarios due to the uncertainties in the projections of precipitation show only a limited suitability for hydrologic impact analysis used for the establishment of future concrete water management procedures in their present state.Fri, 27 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/26/89/2010/<b>Trend analysis of the wave storminess: the wave direction</b><br /><br />Advances in Geosciences, 26, 89-92, 2010<br /><br />Author(s): M. Casas-Prat and J. P. Sierra<br /><br />In this paper changes in the wave pattern of the Catalan coast are analyzed in terms of wave storminess and wave direction based on series of 44 years of hindcast wave data. The analysis is performed employing two different techniques: one resulting from the combination of regression and bootstrapping and the other applying a Bayesian method. Although the trends are, in general, null, in some locations there are clear changes in the wave directional frequencies. These changes can significatively affect coastal hydrodynamics and morphodynamics.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/23/87/2010/<b>Relationships between lightning and rainfall intensities during rainy events in Cyprus</b><br /><br />Advances in Geosciences, 23, 87-92, 2010<br /><br />Author(s): S. Michaelides, K. Savvidou, and K. Nicolaides<br /><br />The objective of this work is to study the relationship between the number of lightning recorded by a network of lightning detectors and the amount of rainfall recorded by the network of automatic rain gauges, during rainy events in Cyprus. This study aims at revealing possible temporal and spatial "relationships" between rainfall and lightning intensities. The data used are based on the available records of hourly rainfall data and the "associated" lightning data, with respect to both time and space. The search for temporal and spatial relationships between lightning and rainfall is made by considering various time-lags between lightning and rainfall, and by varying the area around the rain gauge which the associated lightning data set refers to. The methodology adopted in this paper is a statistical one and rainy events registered under the European Project "FLASH" are examined herein.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/51/2010/<b>Using Python as a coupling platform for integrated catchment models</b><br /><br />Advances in Geosciences, 27, 51-56, 2010<br /><br />Author(s): P. Kraft, S. Multsch, K. B. Vaché, H.-G. Frede, and L. Breuer<br /><br />Interdisciplinary sharing of knowledge is a key for understanding matter fluxes in landscapes. However, models of transport and reactive fluxes from different disciplines need to work seamlessly together, to capture the tight feedback loops between different compartments and process domains of a landscape. Techniques to facilitate the integration of model codes for integrated catchment modelling exist, but are still scarcely used. In this paper, we are testing a scripting language, Python as a model coupling platform, and demonstrates effects of feedback loops on a virtual agriculturally used hillslope.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/45/2010/<b>Global-scale analysis of satellite-derived time series of naturally inundated areas as a basis for floodplain modeling</b><br /><br />Advances in Geosciences, 27, 45-50, 2010<br /><br />Author(s): L. Adam, P. Döll, C. Prigent, and F. Papa<br /><br />Floodplains play an important role in the terrestrial water cycle and are very important for biodiversity. Therefore, an improved representation of the dynamics of floodplain water flows and storage in global hydrological and land surface models is required. To support model validation, we combined monthly time series of satellite-derived inundation areas (Papa et al., 2010) with data on irrigated rice areas (Portmann et al., 2010). In this way, we obtained global-scale time series of naturally inundated areas (NIA), with monthly values of inundation extent during 1993–2004 and a spatial resolution of 0.5°. For most grid cells (0.5&deg;&times;0.5&deg;), the mean annual maximum of NIA agrees well with the static open water extent of the Global Lakes and Wetlands database (GLWD) (Lehner and Döll, 2004), but in 16% of the cells NIA is larger than GLWD. In some regions, like Northwestern Europe, NIA clearly overestimates inundated areas, probably because of confounding very wet soils with inundated areas. In other areas, such as South Asia, it is likely that NIA can help to enhance GLWD. NIA data will be very useful for developing and validating a floodplain modeling algorithm for the global hydrological model WGHM. For example, we found that monthly NIAs correlate with observed river discharges.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/37/2010/<b>Impact of climate change on water balance of forest sites in Rhineland-Palatinate, Germany</b><br /><br />Advances in Geosciences, 27, 37-43, 2010<br /><br />Author(s): G. V. Grigoryan, M. C. Casper, J. Gauer, A. C. Vasconcelos, and P. P. Reiter<br /><br />It is expected that the biomass productivity of forest stands will be influenced by global climate change. In order to adapt forest management to this fact a model based approach was developed in cooperation with forestry experts. The concept aims at detecting the link between climate, terrain and soil parameters with the biomass productivity of some tree species. This article gives an insight into the first two steps of this approach. At first the WaSiM-ETH 8.2 model was parameterised to simulate various forest sites. Furthermore, different drought stress indices were applied to the simulated water balance time series. The impact of variations of climate, topography and soil characteristics on water balance was plausibly simulated. All drought stress indices detected years which were dominated by dry conditions. However, the indices related to soil water content were more selective than those related to evapotranspiration. Drought stress indices for one future climate projection have shown an increasing frequency of drought stress during vegetation period. Thus, the first two steps are capable components to detect the link between water balance with climate, terrain and soil parameters.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/29/2010/<b>Hydrological system analysis and modelling of the Nam Co basin in Tibet</b><br /><br />Advances in Geosciences, 27, 29-36, 2010<br /><br />Author(s): P. Krause, S. Biskop, J. Helmschrot, W.-A. Flügel, S. Kang, and T. Gao<br /><br />The Tibetan Plateau and the adjacent high mountain regions of the Himalayas play an important role in the global climate dynamic through its impact on the Asian monsoon system, which in turn is impacting the water resources of this extremely vulnerable region. To provide further knowledge about the changing impact of rainfall patterns, spatial and temporal variability of snow cover contribution, amount of snow and ice melt runoff, evapotranspiration as well as dynamics of wetlands and permafrost water balance studies are required. This is of particular importance in terms of global climate change because of a severe gap in the knowledge of the short, mid and long term implications on the hydrological system. <br><br> This study concentrates on the macroscale catchment of the lake Nam Co, located at 4718 m a.s.l. at the foot of the Nyainqentanglha Mountains in central Tibet (30° N, 90° E). The water balance of the Nam Co basin is dominated by semi-arid climate, snow and ice melt runoff and high evaporation rates due to the high radiation input and the low air humidity. The observed temperature rise, glacier retreat, permafrost decay and lake level increase indicate significant system changes and the high sensitivity of the Tibetan Plateau on global warming. The development of a suitable water balance model and its preliminary application was the main objective of this study. The development was done with the Jena Adaptable Modelling System JAMS along with existing scientific process components of the J2000 module library which were partly further developed to reflect the specific conditions of the high elevation Nam Co basin. <br><br> The preliminary modelling exercise based on gridded data from a downscaled ECHAM5 data set provided reasonable estimates about the important hydrological water balance components of the Nam Co basin. With the modelling results the observed lake level rise could be reproduced and it could be shown that the runoff from the glaciered areas seems to be the most important component to explain the increasing amount of lake water.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/21/2010/<b>Payment schemes for hydrological ecosystem services as a political instrument for the sustainable management of natural resources and poverty reduction – a case study from Belén, Nicaragua</b><br /><br />Advances in Geosciences, 27, 21-27, 2010<br /><br />Author(s): J. Hack<br /><br />The importance of intact ecosystems for human-wellbeing as well as the dependence on functions and services they provide is undoubted. But still neither the costs of ecosystem degradation nor the benefits from ecosystem functions and services appear on socio-economic balance sheets when development takes place. Consequently overuse of natural resources is socio-economically promoted by conventional resource management policies and external effects (externalities), equally positives and negatives, remain unregarded. <br><br> In this context the potential of payments for hydrological ecosystem services as a political instrument to foster sustainable natural resource use, and rural development shall be investigated. This paper introduces the principle concept of such payments, presents a case study from Nicaragua and highlights preliminary effects of the application of this instrument on natural resource use and development.Wed, 25 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/11/2010/<b>From hydrological modelling to decision support</b><br /><br />Advances in Geosciences, 27, 11-19, 2010<br /><br />Author(s): U. Haberlandt<br /><br />Decision support for planning and management of water resources needs to consider many target criteria simultaneously like water availability, water quality, flood protection, agriculture, ecology, etc. Hydrologic models provide information about the water balance components and are fundamental for the simulation of ecological processes. Objective of this contribution is to discuss the suitability of classical hydrologic models on one hand and of complex eco-hydrologic models on the other hand to be used as part of decision support systems. The discussion is based on results from two model comparison studies. It becomes clear that none of the hydrologic models tested fulfils all requirements in an optimal sense. Regarding the simulation of water quality parameters like nitrogen leaching a high uncertainty needs to be considered. Recommended for decision support is a hybrid metamodel approach, which comprises a hydrologic model, empirical relationships for the less dynamic processes and makes use of simulation results from complex eco-hydrologic models through second-order modelling at a generalized level.Mon, 23 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/27/1/2010/<b>Application of WaSiM-ETH model to Northern German lowland catchments: model performance in relation to catchment characteristics and sensitivity to land use change</b><br /><br />Advances in Geosciences, 27, 1-10, 2010<br /><br />Author(s): H. Bormann and S. Elfert<br /><br />The hydrological catchment model WaSiM-ETH (Water Balance Simulation Model) is a spatially distributed, process- and grid-based hydrological catchment model which was primarily developed to simulate the water balance of mountainous catchments. In this study, the ability of WaSiM-ETH was tested to describe the hydrological processes of lowland catchments. In addition, the resulting model performance was related to subcatchment characteristics and the model's sensitivity to possible future land use change. The prediction of the hydrological effects of land use change is a major challenge in contemporary hydrological model applications. The study revealed that WaSiM-ETH is a suitable tool for the simulation of the hydrological behaviour of lowland catchments. However, for a few subcatchments model validation failed. Analysing the correlation between model performance and physiographic catchment characteristics revealed that WaSiM-ETH performs better in sloped catchments compared to plane ones. Modelling results were also better in heterogeneous catchments with respect to soils and vegetation compared to homogenous ones. However, the hydrological reaction to land use change scenarios was similar in all investigated catchments.Mon, 23 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/26/83/2010/<b>Storm-induced coastal hazard assessment at regional scale: application to Catalonia (NW Mediterranean)</b><br /><br />Advances in Geosciences, 26, 83-87, 2010<br /><br />Author(s): E. Bosom and J. A. Jiménez<br /><br />A methodology for coastal hazard assessment at regional scale is presented and applied to the Catalan coast (NW Mediterranean). The method separately evaluates erosion and inundation hazards by using wave time series and beach characteristics (slope and sediment grain size). Obtained hazard time series are fitted to extreme probability distributions for different coastal sectors which are defined in function of local wave climate. This approach allows to compare the spatial variation of hazard intensities for a given probability of occurrence and, thus, to objectively identify the most hazardous areas along the coast in terms of erosion and inundation. Obtained results indicate that the coast north of Barcelona is more hazardous than the southern coast regarding inundation for any given probability. With respect to storm-induced erosion, the central coast of Catalonia is the less hazardous area, although spatial variations in erosion along the coast are smaller than the observed for inundation.Mon, 02 Aug 2010 00:00:00 +0200http://www.adv-geosci.net/26/77/2010/<b>The use of products from ground-based GNSS observations in meteorological nowcasting</b><br /><br />Advances in Geosciences, 26, 77-82, 2010<br /><br />Author(s): E. Terradellas and B. Téllez<br /><br />Convective rainfall is often focalized in areas of moisture convergence. A close relationship between precipitation and fast variations of vertically-integrated water vapour (IWV) has been found in numerous cases. Therefore, continuous monitoring of atmospheric humidity and its spatial distribution is crucial to the operational forecaster for a proper nowcasting of heavy rainfall events. <br><br> The microwave signals continuously broadcasted by the Global Navigation Satellite Systems (GNSS) satellites are influenced by the water vapour as they travel through the atmosphere. Estimates of IWV retrieved from ground-based GNSS observations may, then, constitute a source of information on the horizontal distribution and the time evolution of atmospheric humidity. At the Spanish Meteorological Agency (AEMET), a near-real-time map of IWV estimates retrieved from ground GNSS measurements in the Iberian Peninsula and West Mediterranean region is operationally built and presented to the forecaster. The maps are generated every 15 minutes following a one-dimensional variational assimilation scheme with the previous map as the background state. <br><br> A case study is presented in order to illustrate some strengths and weaknesses of the product, to assess the potential benefit of using GNSS products in nowcasting and to define the steps to be done in order to make use of the full potential of the method.Thu, 22 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/71/2010/<b>Bayesian trend analysis for daily rainfall series of Barcelona</b><br /><br />Advances in Geosciences, 26, 71-76, 2010<br /><br />Author(s): M. I. Ortego, J. Gibergans-Báguena, R. Tolosana-Delgado, J. J. Egozcue, and M. C. Llasat<br /><br />A Point-Over-Threshold approach using a reparameterization of the Generalized Pareto Distribution (GPD) has been used to assess changes in the daily rainfall Barcelona series (1854–2006). A Bayesian approach, considering the suitable scale and physical features of the phenomenon, has been used to look for these alterations. Two different models have been assessed: existence of abrupt changes in the new GPD parameters due to modifications of the observatory locations and trends in these GPD parameters, pointing to a climate change scenario.Thu, 15 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/25/181/2010/<b>Reply to Comment on "Hierarchical Bayesian space-time interpolation versus spatio-temporal BME approach" by Kolovos (2009)</b><br /><br />Advances in Geosciences, 25, 181-181, 2010<br /><br />Author(s): I. Hussain, J. Pilz, and G. Spoeck<br /><br />No abstract available.Tue, 13 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/25/179/2010/<b>Comment on "Hierarchical Bayesian space-time interpolation versus spatio-temporal BME approach" by Hussain et al. (2010)</b><br /><br />Advances in Geosciences, 25, 179-179, 2010<br /><br />Author(s): A. Kolovos<br /><br />No abstract available.Tue, 13 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/25/167/2010/<b>Flower elliptical-orbit constellation exploiting millimetre-wave radiometry and radio occultation for meteo-climatological applications</b><br /><br />Advances in Geosciences, 25, 167-177, 2010<br /><br />Author(s): F. S. Marzano and D. Cimini<br /><br />This paper reports on the potential of combining elliptical-orbit Flower constellations with millimeter-wave radiometry and radio-occultation, a mission concept briefly named FloRad2. The advantages of flower constellation with respect to conventional orbits are discussed, including the flexibility ensuring increasing coverage with separate launches. Millimeter-wave radiometry and radio-occultation receivers provide the advantage to design fairly compact payloads that comply well with current technology of mini-satellites. Millimeter-wave radiometry and radio-occultation techniques are somewhat complementary and an optimal combination of these observations results in atmospheric products with enhanced vertical and horizontal resolutions. Thus, the combination of small, light payloads employing millimeter-wave radiometry and radio-occultation with Flower elliptical-orbit constellations may result in an optimal compromise between retrieval performances and system complexity that is ideal for continued long-term missions with meteorological and climatological applications.Tue, 13 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/65/2010/<b>Spatial variability and trends of the rain intensity over Greece</b><br /><br />Advances in Geosciences, 26, 65-69, 2010<br /><br />Author(s): H. D. Kambezidis, I. K. Larissi, P. T. Nastos, and A. G. Paliatsos<br /><br />In this study, the spatial and temporal variability of the mean annual rain intensity in Greece are examined during a 41-year period (1962–2002). The meteorological datasets concern monthly rain amounts (mm) and the respective monthly durations (h) recorded at thirty two meteorological stations of the Hellenic National Meteorological Service, which are uniformly distributed on Greek territory, in order to calculate the mean monthly rain intensity. All the rain time series used in the analysis were tested by the application of the short-cut Bartlett test of homogeneity. The spatial distribution of the mean annual rain intensity is studied using the Kriging interpolation method, while the temporal variability, concerning the mean annual rain intensity trends along with their significance (Mann-Kendall test), is analysed. <br><br> The findings of the analysis show that statistically significant negative trends (95% confidence level) appear mainly in the west sub-regions of Greece, while statistically significant positive trends (95% confidence level) appear in the wider area of Athens and the complex of Cyclades Islands. Further analysis concerning the seasonal rain intensity is needed, because there are different seasonal patterns, taking into account that, convective rain in Greece occurs mainly within the summer season.Fri, 09 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/61/2010/<b>The effect of observation timescales on the characterisation of extreme Mediterranean precipitation</b><br /><br />Advances in Geosciences, 26, 61-64, 2010<br /><br />Author(s): A. M. Camarasa Belmonte, J. Soriano García, and M. J. López-García<br /><br />This paper analyses the behaviour of five rainfall indicators (maximum intensity, cumulative rainfall, irregularity, probability of rain and persistence of rain) over different observation timescales ranging from 5 min to 24 h. It covers a large area on the Mediterranean side of the Iberian Peninsula (River Júcar Water Authority, 43 000 km²) on a continuous basis over a period of 14 years (1994–2007). The results show that the behaviour of extreme Mediterranean rainfall is heavily dependent on the observation timescale. There are a number of turning points in the indicator trends which occur on different timescales (1 and 6 h in the case of rain intensity and irregularity, 6 h for cumulative rainfall and between 15 and 30 min for the persistence of rain) and may be relevant for the determination of thresholds used in water management.Fri, 09 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/53/2010/<b>Violent storms within the Sea: dense water formation episodes in the NW Mediterranean</b><br /><br />Advances in Geosciences, 26, 53-59, 2010<br /><br />Author(s): J. Salat, P. Puig, and M. Latasa<br /><br />Heat and water exchanges in the ocean occur almost exclusively at the surface. As water compressibility is very low, stratification of the fluid is expected and horizontal motion is predominant in the sea interior. Among the few processes that may introduce a vertical component in the water motion are those that increase surface water density by freezing, cooling or evaporation. Those processes triggering convective motion are enhanced by cold surface air, dry wind and low solar radiation. Therefore, convective cells are more likely to occur when the temperature of the air at the sea surface is lower than sea surface temperature. Conversely, rain, river runoff, solar heating, calm and condensation at surface enhance stratification. Convective motion at sea has several scales ranging from few meters at the upper ocean, causing the surface mixed layer, to the entire water column, in what is known as deep convection. Only few places in the world ocean are suitable for deep convection, and only under particular weather conditions. In this paper, a brief review of the response to these particular conditions in the NW Mediterranean is presented in what is known as dense water formation. The violent sinking and spreading of water parcels that reach the deep sea floor in few hours is described. These are "hidden" mediterranean storms, occurring under the sea surface, "on the other side of the mirror".Wed, 07 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/49/2010/<b>Tornado activity in Greece within the 20th century</b><br /><br />Advances in Geosciences, 26, 49-51, 2010<br /><br />Author(s): P. T. Nastos and J. T. Matsangouras<br /><br />Tornado activity is associated with extreme convective weather which can cause extended damage and even in some cases the loss of life. The complex inland terrain of Greece along with the Ionian Sea at the west and the Aegean Sea at the east appear to be a favorable area for fury phenomena such as tornadoes, waterspouts and funnel clouds. <br><br> In this study, the spatial and temporal variability of tornado activity in Greece for the period 1900–1999 are presented. The spatial distribution of tornadoes, waterspouts and funnel clouds reveals the vulnerability of specific geographical areas, such as the west Greece and the south Aegean Sea. As far as the intra annual variability is concerned, the maximum of tornado activity dominates within the cold period of the year (October–March) while according to the daily distribution, tornadoes happen frequently during the warm hours of the day. It is remarkable to mention that in Greece, within the 20th century, the tornado activity caused the loss of 4 lifes, the injury of 40 people and numerous damages on human constructions and cultivations.Wed, 07 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/45/2010/<b>Reconstructing the 1874 Santa Tecla flash flood in the Ondara River (Ebro Basin, NE Spain)</b><br /><br />Advances in Geosciences, 26, 45-48, 2010<br /><br />Author(s): J. C. Balasch, J. Tuset, and J. L. Ruiz-Bellet<br /><br />The <i>Santa Tecla</i> flash flood, a very heavy event occurred in Tàrrega (Catalonia, NE Iberian Peninsula) in 1874, was reconstructed with hydraulic and hydrological modelling tools. The hydrograph obtained in a first stage and the basin soil moisture information ultimately allowed the estimation of the range of the rainstorm magnitude which caused the flash flood. The reconstruction of historical floods has proved useful to improve the flood probability analysis, especially in ungauged basins.Fri, 02 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/39/2010/<b>Precipitation downscaling using random cascades: a case study in Italy</b><br /><br />Advances in Geosciences, 26, 39-44, 2010<br /><br />Author(s): B. Groppelli, D. Bocchiola, and R. Rosso<br /><br />We present a Stochastic Space Random Cascade (SSRC) approach to downscale precipitation from a Global Climate Model (hereon, <i>GCM</i>s) for an Italian Alpine watershed, the Oglio river (1440 km²). The SSRC model is locally tuned upon Oglio river for spatial downscaling (approx. 2 km) of daily precipitation from the NCAR Parallel Climate Model. We use a 10 years (1990–1999) series of observed daily precipitation data from 25 rain gages. Scale Recursive Estimation coupled with Expectation Maximization algorithm is used for model estimation. Seasonal parameters of the multiplicative cascade are accommodated by statistical distributions conditioned upon climatic forcing, based on regression analysis. The main advantage of the SSRC is to reproduce spatial clustering, intermittency, self-similarity of precipitation fields and their spatial correlation structure, with low computational burden.Fri, 02 Jul 2010 00:00:00 +0200http://www.adv-geosci.net/26/33/2010/<b>On some relationships between storms and plankton dynamics</b><br /><br />Advances in Geosciences, 26, 33-38, 2010<br /><br />Author(s): F. Peters<br /><br />The physico-chemical fields of the pelagic environment are constantly fluctuating at different spatial and temporal scales. Storms are extreme events of such fluctuations that cascade down to small scales to alter nutrient availability to microscopic algae or swimming and mating behaviour of motile plankton. Mediterranean storms sometimes are also responsible for the transport of micro and macronutrients from Saharan origin, albeit the significance for marine production is still under question. In coastal ecosystems, storms represent dissolved nutrient injections via run-off and resuspension that trigger planktonic succession events. Storms may also have a role in the development and mitigation of harmful algal blooms, events with economic and health consequences that are of growing societal concern. Based on laboratory experiments on the effects of turbulence on swimming behaviour and population growth of dinoflagellates, a conceptual sequence of events is proposed for bloom initiation. <br><br> Overall, storms affect, directly or indirectly, the dynamics of plankton and hence ecosystem production and cannot be considered catastrophic or hazardous in this context. The full potential of such relationships will be evidenced once biological time series match the resolution and spatial coverage of meteorological and oceanic data. As the frequency and intensity of storms is subject to global change, future oceanic ecosystem production should be affected as well.Wed, 30 Jun 2010 00:00:00 +0200http://www.adv-geosci.net/26/25/2010/<b>From regional climate simulations to the hydrological information needed for basin scale impact studies</b><br /><br />Advances in Geosciences, 26, 25-31, 2010<br /><br />Author(s): I. Portoghese, E. Bruno, and M. Vurro<br /><br />The accuracy of local downscaling of rainfall predictions provided by climate models is crucial for the assessment of climate change impacts on hydrological processes because the presence of bias in downscaled precipitation may produce large bias in the assessment of soil moisture dynamics, river flows, and groundwater recharge. <br><br> In this study, the output of a regional climate model (RCM) is downscaled using a stochastic modelling of the point rainfall process able to adequately reproduce the daily rainfall intermittency which is one of the crucial aspects for the hydrological processes characterizing Mediterranean environments. The historical time-series from a dense rain-gauge network were used for the analysis of the RCM bias in terms of dry and wet daily period and then to investigate the predicted alteration in the local rainfall regime. A Poisson Rectangular Pulse (PRP) model (Rodriguez-Iturbe et al., 1987) was finally adopted for the stochastic generation of local daily rainfall as a continuous-time point process with forcing parameters resulting from the bias correction of the RCM scenario.Wed, 30 Jun 2010 00:00:00 +0200http://www.adv-geosci.net/26/19/2010/<b>Numerical study of a banded precipitation event over Italy</b><br /><br />Advances in Geosciences, 26, 19-23, 2010<br /><br />Author(s): P. Malguzzi, M. Fantini, and A. Buzzi<br /><br />Satellite images of 30 October 2008 show the development over north-central Italy of rainbands and multiple waves during a strong south-westerly wind episode associated with a deepening synoptic trough and cold front passage. The event was studied by means of the ISAC model chain constituted of the hydrostatic model BOLAM and the nested non-hydrostatic model MOLOCH at 1.1 km resolution. Diagnostics of model output was performed to reveal the physical origin of the dynamical features and precipitation field as simulated. Based on our results we propose a theoretical framework in which symmetric instability underlies some of the observed precipitation patterns.Wed, 30 Jun 2010 00:00:00 +0200http://www.adv-geosci.net/26/13/2010/<b>Landslide damage assessment using the Support Analysis Framework (SAF): the 2009 landsliding event in Calabria (Italy)</b><br /><br />Advances in Geosciences, 26, 13-17, 2010<br /><br />Author(s): O. Petrucci, A. A. Pasqua, and G. Gullà<br /><br />In this paper, a simplified methodological approach is used to assess damage indices related to landslide phenomena that occurred in Calabria (Italy) between November 2008 and January 2009. This approach, which was designed for and applied to single landslides, uses the Support Analysis Framework (SAF), a procedure containing the elements that can be damaged by a landslide grouped in categories. In this paper, we test wide-ranging use of the SAF on a number of landslides, assessing landslide damage on a municipal scale to get a final estimate of the amount of damage caused by all of the landslides that occurred in a selected municipality. <br><br> Data regarding the damage caused by landslides were gathered from the press. Daily newspapers were systematically collected and elaborated to assess direct, indirect and intangible damage caused during the abovementioned period by a rainfall-triggered <i>landsliding event</i>. In the paper, regional- and provincial-scale results are described, and the methodological approach is briefly described. <br><br> The application of the proposed methodological approach to the 2009 landsliding event shows that the results can be used to summarise landslide damage from a complex event in order to better plan an intervention strategy at a regional, provincial or municipal scale. <br><br> The availability of newspaper data during the event and the speed of the proposed approach allow for rapid location of the damaged sectors during the event, which will continuously upgrade the regional damage framework. This can all be done almost in "real time". <br><br> For regional agencies, this framework can be a starting point to both manage the emergency and to acquire and interpret data giving a more detailed damage distribution so that a response can be organised. Moreover, based on the damage assessment, a characterisation of the landsliding event can also be carried out and used to describe the damage scenario occurring after each type of event.Wed, 30 Jun 2010 00:00:00 +0200http://www.adv-geosci.net/26/7/2010/<b>Sensitivity of precipitation forecasts to convective parameterization in the October 2007 Flash Flood in the Valencia Region (Eastern Spain)</b><br /><br />Advances in Geosciences, 26, 7-11, 2010<br /><br />Author(s): I. Gómez, F. Pastor, and M. Estrela<br /><br />The Valencia region, on the Mediterranean coast of the Iberian Peninsula, is an area prone to torrential rains, especially the north of Alicante province and the south of Valencia province. In October 2007, a torrential rain event with accumulated rainfall values exceeding 400 mm in less than 24 h affected the aforementioned areas, producing flash floods that caused extensive economic losses and human casualties. Several simulations of this rain event have been performed with the Regional Atmospheric Modeling System (RAMS) to test the influence of the different convective parameterization scheme implemented in the model on the precipitation forecast.Wed, 30 Jun 2010 00:00:00 +0200http://www.adv-geosci.net/26/1/2010/<b>Study of the precipitation evolution in Catalonia using a mesoscale model (1971–2000)</b><br /><br />Advances in Geosciences, 26, 1-6, 2010<br /><br />Author(s): A. Barrera-Escoda and J. Cunillera<br /><br />In this work the MM5 mesoscale model is used in order to analyse the temporal evolution of the precipitation for the period 1971–2000 in Catalonia (NE Iberian Peninsula). Three one-way nested domains with 135, 45 and 15 km horizontal grid resolution and 23 vertical levels have been used. The simulation is performed nesting MM5 into the ERA40 reanalyses. Dynamical nudging is applied to the first domain. However, nudging is not applied in the second and third domains. In order to assess the performance of the developed methodology (main spatio-temporal precipitation characteristics), the results obtained in each simulation are compared with those obtained from ERA40 and observational data. <br><br> The results show a climatologically reliable distribution of the simulated precipitation spatial patterns for annual, semi-annual, spring and summer precipitation compared to those obtained from 1100 rain gauges covering the whole study area. For winter and autumn the goodness of the results is much lower. Furthermore, the results for 15-km outputs are better than the 45-km ones. The simulations also reproduce well the evolution of annual anomalies for Catalonia and the probability density function (PDF) of monthly mean precipitation. They also improve the precipitation outputs from ERA40, which present an important negative trend and a drier PDF for the period 1971–2000. On the other hand, extreme values are not well reproduced by the simulation. Despite this fact, hydric extremes derived from extreme values (i.e. extreme rainy days and flood records) are well captured by the model.Wed, 30 Jun 2010 00:00:00 +0200