Impact of Rainfall Assimilation on High-Resolution Hydrometeorological Forecasts over Liguria, Italy

Abstract The autumn of 2014 was characterized by a number of severe weather episodes over Liguria (northern Italy) associated with floods and remarkable damage. This period is selected as a test bed to evaluate the performance of a rainfall assimilation scheme based on the nudging of humidity profiles and applied to a convection-permitting meteorological model at high resolution. The impact of the scheme is assessed in terms of quantitative precipitation forecast (QPF) applying an object-oriented verification methodology that evaluates the structure, amplitude, and location (SAL) of the precipitation field, but also in terms of hydrological discharge prediction. To attain this aim, the meteorological model is coupled with the operational hydrological forecasting chain of the Ligurian Hydrometeorological Functional Centre, and the whole system is implemented taking operational requirements into account. The impact of rainfall data assimilation is large during the assimilation period and still relevant in the following 3 h of the free forecasts, but hardly lasts more than 6 h. However, this can improve the hydrological predictions. Moreover, the impact of the assimilation is dependent on the environment characteristics, being more effective when nonequilibrium convection dominates, and thus an accurate prediction of the local triggering for the development of the precipitation system is required

Quantitative Flood Forecasting on Small- and Medium-Sized Basins: A Probabilistic Approach for Operational Purposes

Abstract The forecast of rainfall-driven floods is one of the main themes of analysis in hydrometeorology and a critical issue for civil protection systems. This work describes a complete hydrometeorological forecast system for small- and medium-sized basins and has been designed for operational applications. In this case, because of the size of the target catchments and to properly account for uncertainty sources in the prediction chain, the authors apply a probabilistic framework. This approach allows for delivering a prediction of streamflow that is valuable for decision makers and that uses as input quantitative precipitation forecasts (QPF) issued by a regional center that is in charge of hydrometeorological predictions in the Liguria region of Italy. This kind of forecast is derived from different meteorological models and from the experience of meteorologists. Single-catchment and multicatchment approaches have been operationally implemented and studied. The hydrometeorological forecasting chain has been applied to a series of case studies with encouraging results. The implemented system makes effective use of the quantitative information content of rainfall forecasts issued by expert meteorologists for flood-alert purposes

Effects of Increasing Horizontal Resolution in a Convection-Permitting Model on Flood Forecasting: The 2011 Dramatic Events in Liguria, Italy

Abstract Coupling meteorological and hydrological models is a common and standard practice in the field of flood forecasting. In this study, a numerical weather prediction (NWP) chain based on the BOLogna Limited Area Model (BOLAM) and the MOdello LOCale in Hybrid coordinates (MOLOCH) was coupled with the operational hydrological forecasting chain of the Ligurian Hydro-Meteorological Functional Centre to simulate two major floods that occurred during autumn 2011 in northern Italy. Different atmospheric simulations were performed by varying the grid spacing (between 1.0 and 3.0 km) of the high-resolution meteorological model and the set of initial/boundary conditions driving the NWP chain. The aim was to investigate the impact of these parameters not only from a meteorological perspective, but also in terms of discharge predictions for the two flood events. The operational flood forecasting system was thus used as a tool to validate in a more pragmatic sense the quantitative precipitation forecast obtained from different configurations of the NWP system. The results showed an improvement in flood prediction when a high-resolution grid was employed for atmospheric simulations. In turn, a better description of the evolution of the precipitating convective systems was beneficial for the hydrological prediction. Although the simulations underestimated the severity of both floods, the higher-resolution model chain would have provided useful information to the decision-makers in charge of protecting citizens

Pain perception and migraine

Background: It is well-known that both inter-and intra-individual differences exist in the perception of pain; this is especially true in migraine, an elusive pain disorder of the head. Although electrophysiology and neuroimaging techniques have greatly contributed to a better understanding of the mechanisms involved in migraine during recent decades, the exact characteristics of pain threshold and pain intensity perception remain to be determined, and continue to be a matter of debate.Objective: The aim of this review is to provide a comprehensive overview of clinical, electrophysiological, and functional neuroimaging studies investigating changes during various phases of the so-called "migraine cycle" and in different migraine phenotypes, using pain threshold and pain intensity perception assessments.Methods: A systematic search for qualitative studies was conducted using search terms "migraine," "pain," "headache," "temporal summation," "quantitative sensory testing," and "threshold," alone and in combination (subject headings and keywords). The literature search was updated using the additional keywords "pain intensity," and "neuroimaging"to identify full-text papers written in English and published in peer-reviewed journals, using PubMed and Google Scholar databases. In addition, we manually searched the reference lists of all research articles and review articles.Conclusion: Consistent data indicate that pain threshold is lower during the ictal phase than during the interictal phase of migraine or healthy controls in response to pressure, cold and heat stimuli. There is evidence for preictal sub-allodynia, whereas interictal results are conflicting due to either reduced or no observed difference in pain threshold. On the other hand, despite methodological limitations, converging observations support the concept that migraine attacks may be characterized by an increased pain intensity perception, which normalizes between episodes. Nevertheless, future studies are required to longitudinally evaluate a large group of patients before and after pharmacological and non-pharmacological interventions to investigate phases of the migraine cycle, clinical parameters of disease severity and chronic medication usage

Equivalent modelling of reciprocating engines generators for microgrid frequency response analysis

Typical microgrid configurations include small-scale generation units that belong to the class of reciprocating engines (gas, diesel, heavy fuel oil). A simplified equivalent model for representing the frequency response of a given set of this kind of generators is proposed in this paper. The model parameters are tuned to obtain frequency responses compliant with the performance classes stated by the ISO 8528-5 standard. The result is a set of equivalent and simple models that can be used to simulate the frequency response within a given microgrid configuration that includes a set of reciprocating engines generators. Finally, a suitable validation of the proposed models is carried out using two highly detailed models of real diesel and heavy fuel oil generators

Mortars and plasters - How to characterize mortar and plaster degradation

AbstractThe degradation of mortars and plasters can represent a threat for their preservation. That is why a deep understanding of the degradation mechanisms and the identification of degradation patterns is strongly recommended for who is in charge of conservation of archaeological sites and of built heritage in general. Here, it has been described what are the main degrading agents that can be detected on mortars and plasters and how they act to produce degradation. Moreover, an overview of the analyses which can be carried out directly on site and in laboratory as well has been reported. The knowledge that can be achieved by using such methods represents an essential tool to set up a suitable conservation plan. In addition, a more detailed analysis can also have a research purpose, since they can be useful to clarify some mechanisms and interactions that still remain unclear

An Efficiency-Based Power Management Strategy for an Isolated Microgrid Project

The microgrids design for remote locations represents one of the most important and critical applications of the microgrid concept. It requires the correct sizing and the proper utilization of the different sources to guarantee the economical feasibility and the reliability of the supply. This study illustrates an efficiency-based power management strategy, designed for an undergoing microgrid project, where the sizing process of the resources (diesel generators, battery energy storage system, and PV plant) is obtained using a mixed-integer optimization algorithm. The proposed power management strategy guarantees the efficient exploitation of the power sources, which is one of the key elements of the optimal sizing process, being naturally included in the definition of the energy cost functions. The effectiveness of the power control strategy is validated by means of quasi-dynamic simulations on the complete microgrid model, where sources are defined by the optimal problem solution, while the cabling (size and length) and the main switchboards location reflect the expected system layout. Results obtained from the simulation of the microgrid electrical system include losses, and allow to verify and to highlight the desired quantities, such as the quality of supply at each busbar (voltage magnitude), and the state of charge of the energy storage system

Application of an integrated hydrological nowcasting chain on Liguria Region

Presentación realizada en la 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019