Validation of the coastal storm risk assessment framework along the Emilia-Romagna coast

The Italian coasts are threatened by coastal flooding and erosion. The Emilia-Romagna region coastline is exposed to marine storms because of its low-lying nature and massive urbanization. Regional managers need comprehensive tools for coastal storm risk assessment. The RISC-KIT Coastal Risk Assessment Framework (CRAF) provides a conceptual framework, which includes hazard, exposure and vulnerability evaluation, to implement a screening process able to identify littoral zones that can be classified as hotspots (Phase 1) and to successively rank the identified hotspots to select the most critical ones (Phase 2). This study includes the results of the implementation of CRAF Phase 1 in the Emilia-Romagna coast. The method is based on a Coastal Index approach, calculated for 1 km length coastal sectors, applied taking into account both hazard and exposure indicators. The general methodology was partly modified thanks to the strong collaboration with the End-User (Servizio Geologico Sismico e dei Suoli, SGSS) which provided data, suggestions and comments at every step of the implementation. The SGSS also provided data to validate the outcomes of the CRAF methodology. Thus, the critical areas identified by the CRAF were compared with historical (1946â\u80\u932010) storm impacts, resulting in a reasonable agreement between the identified hotspots

Semi-probabilistic coastal flood impact analysis: From deterministic hazards to multi-damage model impacts

Coastal flood impact assessments are important tools for risk management and are performed by combining the hazard component with the vulnerability of exposed assets, to quantify consequences (or impacts) in terms of relative or absolute (e.g. financial) damage. The process generates uncertainties that should be taken into account for the correct representation of the consequences of floods. This study presents a coastal flood impact application at the spatial level of the Stavanger municipality (Norway), based on a multi-damage model approach able to represent impacts, and their overall uncertainty. Hazard modelling was performed using the LISFLOOD-FP code, taking into account historical extreme water level events (1988–2017) and relative sea level rise scenarios. Direct impacts were calculated in the form of relative and financial damage for different building categories, using flood damage curves. The results showed that the expected impacts are fewer than 50 flooded receptors and less than €1 million in damage in the current sea level scenario. The impacts could double by the end of the century, considering the most optimistic relative sea level scenario. The results were discussed considering the limitations of the approach for both hazard and impact modelling, that will be improved in future implementations. The outcome of this study may be useful for cost–benefit analyses of mitigation actions and local-scale plans for adaptation

Local-scale post-event assessments with GPS and UAV-based quick-response surveys:A pilot case from the Emilia-Romagna (Italy) coast

Coastal communities and assets are exposed to flooding and erosion hazards due to extreme storm events, which may increase in intensity due to climatological factors in the incoming future. Coastal managers are tasked with developing risk-management plans mitigating risk during all phases of the disaster cycle. This necessitates rapid, time-efficient post-event beach surveys that collect physical data in the immediate aftermath of an event. Additionally, the inclusion of local stakeholders in the assessment process via personal interviews captures the social dimension of the impact of the event. In this study, a local protocol for post-event assessment, the quick-response protocol, was tested on a pilot site on the Emilia-Romagna (Italy) coast in the aftermath of an extreme meteorological event that occurred in February 2015. Physical data were collected using both real-time kinematic Geographical Positions Systems and unmanned aerial vehicle platforms. Local stakeholders were interviewed by collecting qualitative information on their experiences before, during, and after the event. Data comparisons between local and regional surveys of this event highlighted higher data resolution and accuracy at the local level, enabling improved risk assessment for future events of this magnitude. The local survey methodology, although improvable from different technical aspects, can be readily integrated into regional surveys for improved data resolution and accuracy of storm impact assessments on the regional scale to better inform coastal risk managers during mitigation planning

A new European coastal flood database for low-medium intensity events

Coastal flooding is recognized as one of the most devastating natural disasters, resulting in significant economic losses. Therefore, hazard assessment is crucial to support preparedness and response to such disasters. Toward this, flood map databases and catalogues are essential for the analysis of flood scenarios, and furthermore they can be integrated into disaster risk reduction studies. In this study and in the context of the European Coastal Flood Awareness System (ECFAS) project (GA 101004211), which aimed to propose the European Copernicus Coastal Flood Awareness System, a catalogue of flood maps was produced. The flood maps were generated from flood models developed with LISFLOOD-FP for defined coastal sectors along the entire European coastline. For each coastal sector, 15 synthetic scenarios were defined focusing on high-frequency events specific to the local area. These scenarios were constructed based on three distinct storm durations and five different total-water-level (TWL) peaks incorporating tide, mean sea level, surge and wave setup components. The flood model method was extensively validated against 12 test cases for which observed data were collated using satellite-derived flood maps and in situ flood markers. Half of the test cases represented well the flooding with hit scores higher than 80ĝ€¯%. The synthetic-scenario approach was assessed by comparing flood maps from real events and their closest identified scenarios, producing a good agreement and global skill scores higher than 70ĝ€¯%. Using the catalogue, flood scenarios across Europe were assessed, and the biggest flooding occurred in well-known low-lying areas. In addition, different sensitivities to the increase in the duration and TWL peak were noted. The storm duration impacts a few limited flood-prone areas such as the Dutch coast, for which the flooded area increases more than twice between 12 and 36ĝ€¯h storm scenarios. The influence of the TWL peak is more global, especially along the Mediterranean coast, for which the relative difference between a 2- and 20-year return period storm is around 80ĝ€¯%. Finally, at a European scale, the expansion of flood areas in relation to increases in TWL peaks demonstrated both positive and negative correlations with the presence of urban and wetland areas, respectively. This observation supports the concept of storm flood mitigation by wetlands

Innovative Approaches for the Evaluation of Coastal Risk on Sandy Mediterranean Beaches

The increase in frequency and intensity of extreme coastal storms and the continuous exponential development of the coasts of the world are threatening coastal communities, exposing them to higher levels of risk. Notwithstanding the future projections are affected by large uncertainty, coastal managers, as recommended by the United Nations and the European Union, need to properly evaluate coastal risk in order to propose adequate risk reduction plans for the current and future climate change scenarios. This should be done while considering all the components that influence risk: hazard, vulnerability and exposure. The involvement of local stakeholders and the adoption of multi-disciplinary approaches, including social sciences, are becoming very common in coastal risk studies, supporting the idea that the same should be done at the management level, to properly address coastal risk issues. The work of this PhD thesis aimed at applying innovative approaches for the evaluation of coastal risk, at different scales, on Mediterranean sandy beaches. The innovations are related to fieldwork methodologies, numerical applications and coastal risk assessment. Part of the work was done in the framework of the EU FP7 RISC-KIT project, that aimed at providing tools in support of coastal managers, in order to increase the resilience of coastal communities. The approaches were implemented at locations along the Emilia-Romagna (Italy) and Catalunya (Spain) coasts. The first part of this thesis focuses on fieldwork activities. Post-storm and seasonal surveys were implemented based on up-to-date low-cost drones and photogrammetric techniques for post-processing. The approach allowed to collect local-scale high-resolution data used to integrate regional post-storm assessments, including qualitative information collected involving the local community, and to detect significant changes of the beach due to the influence of coastal storms and winds. Numerical models were used to analyze the propagation of errors due to the use of synthetic time-series of waves in a process-based chain of models used to simulate erosion and flooding hazards. Results were analyzed with a Bayesian-based approach. The use of synthetic time-series can produce significant errors in the hazard assessment, if compared with the use of real ones, and can influence the risk assessment. Then, two coastal risk assessments are presented, respectively at the local and regional levels. The studies were implemented using the RISC-KIT tools: the Coastal Risk Assessment Framework (CRAF) Phase 1 for the identification of critical areas (hotspots) at the regional level and the Bayesian-based Hotspot tool for testing local measures for disaster reduction, in the current and future scenarios. The CRAF Phase 1 was validated on the Emilia-Romagna coast, confirming that it is able to detect well-known hotspots. The Hotspot tool provided useful insights on the tested measures at the two analyzed case study sites, in Italy and Spain. The applications confirmed that the RISC-KIT approach for regional and local scale assessments is valuable for coastal managers, in order to propose adequate solutions for risk reduction. An interesting aspect of this PhD work is that the majority of the applications were implemented including local people and managers in the process. Large parts of the integrated risk assessments were supported by a strong collaboration between physical and social scientists, confirming that a multi-disciplinary approach is a key aspect in order to properly understand and reduce coastal risk. Coastal managers should take into account all the aspects analyzed in this PhD thesis that can affect risk assessments, from the fieldwork to the deskwork. They should be able to properly address risk by interacting with physical and social scientists, as well as with local communities, if they want to provide effective and acceptable risk reduction strategies.Le coste del mondo sono minacciate dall'incremento, in frequenza ed intensità, delle mareggiate e dello sviluppo costiero. Pertanto, le comunità costiere sono esposte a livelli di rischio sempre più elevati. Le Nazioni Unite e l'Unione Europea richiedono ai manager costieri di valutare il rischio delle coste per proporre piani di riduzione adeguati, sia per lo scenario attuale, sia per quello futuro, considerando i possibili effetti del cambiamento climatico, sebbene le proiezioni future siano caratterizzate da incertezze non trascurabili. Le valutazioni di rischio devono essere basate considerando pericolosità, vulnerabilità ed esposizione. Dovrebbero essere svolte adottando approcci multi-disciplinari e coinvolgendo i portatori di interesse. Il lavoro oggetto di questa tesi è stato svolto applicando approcci innovativi per la valutazione del rischio su spiagge sabbiose del Mediterraneo, a diverse scale spaziali. Le applicazioni riguardano diversi campi: rilievi di spiaggia, modellazione numerica e valutazione integrata del rischio. Parte del lavoro è stato svolto nell'ambito del progetto EU FP7 RISC-KIT, il cui obiettivo era fornire ai manager costieri strumenti utili alla riduzione del rischio ed all'incremento della resilienza delle comunità costiere. Gli approcci sono stati applicati in località costiere in Emilia-Romagna (Italia) e Catalogna (Spagna). La prima parte di questa tesi riguarda aspetti di misure sul campo. Sono stati utilizzati droni a basso costo e tecniche di fotogrammetria per rilievi post-evento e stagionali. Sono stati raccolti a scala locale dati ad alta risoluzione utili sia ad integrare rilievi post-evento a scala regionale, includendo informazioni qualitative ottenute coinvolgendo la comunità locale, sia all'analisi delle variazioni della spiaggia dovute alle mareggiate e ai venti. Sono stati utilizzati modelli numerici per analizzare, tramite approccio Bayesiano, la propagazione degli errori dovuti all'utilizzo di mareggiate sintetiche in input ad una catena di modelli per la simulazione dell'erosione ed inondazione costiera. L'uso di input sintetici produce errori significativi nella valutazione dei pericoli, se confrontato con l'uso di serie temporali reali, e può avere effetti importanti sulle successive analisi del rischio. Inoltre, si presentano due valutazioni di rischio, a scala regionale e locale. Sono stati applicati gli strumenti forniti da RISC-KIT, il Coastal Risk Assessment Framework (CRAF) Phase 1 per l'identificazione delle aree critiche (hotspot) a livello regionale e l'Hotspot tool, un approccio Bayesiano per l'analisi dell'efficacia di misure di riduzione del rischio, per gli scenari attuali e futuri. Il CRAF Phase 1 è stato validato per la costa dell'Emilia-Romagna dimostrandosi efficace nell'identificare aree critiche note. L'Hotspot tool ha fornito informazioni utili alla caratterizzazione delle misure in entrambi i casi studio, in Italia e Spagna. Le analisi hanno dimostrato che l'approccio di RISC-KIT è utile ai manager costieri per la preparazione di piani adeguati di riduzione del rischio. Un aspetto interessante di questo lavoro riguarda il coinvolgimento dei portatori di interesse e dei manager costieri nella maggior parte delle analisi svolte. La collaborazione tra studiosi delle scienze naturali e sociali è stata di estrema importanza per l'appropriata valutazione del rischio costiero a diverse scale spaziali. Questo conferma che l'approccio multi-disciplinare è un aspetto chiave per comprendere e ridurre il rischio costiero. I manager costieri dovrebbero tenere in considerazione tutti gli aspetti che influenzano le valutazioni di rischio presentati in questa tesi, dalle misure sul campo al lavoro alla scrivania. Dovrebbero interagire maggiormente con i ricercatori che studiano le coste, sia dal punto di vista fisico sia sociale, e con i portatori di interesse, per fornire strategie per la riduzione del rischio che siano efficaci e condivisibili

Evaluating Short-Term Tidal Flat Evolution Through UAV Surveys: A Case Study in the Po Delta (Italy)

The use of Unmanned Aerial Vehicles (UAV) on wetlands is becoming a common survey technique that is extremely useful for understanding tidal flats and salt marshes. However, its implementation is not straightforward because of the complexity of the environment and fieldwork conditions. This paper presents the morphological evolution of the Po della Pila tidal flat in the municipality of Porto Tolle (Italy) and discusses the reliability of UAV-derived Digital Surface Models (DSMs) for such environments. Four UAV surveys were performed between October 2018 and February 2020 on an 8 ha young tidal flat that was generated, amongst others, as a consequence of the massive sediment injection into the Po Delta system due to the floods of the 1950s and 1960s. The DSM accuracy was tested by processing (i.e., photogrammetry) diverse sets of pictures taken at different altitudes during the same survey day. The DSMs and the orthophotos show that the tidal flat is characterised by several crevasse splays and that the sediment provision depends strictly on the river. During the study period, the sediment budget was positive (gaining 800 m3/year and an average rate of vertical changes of 1.3 cm/year). Comparisons of DSMs demonstrated that neither lower flight altitudes (i.e., 20–100 m) nor the combination of more photos from different flights during the same surveys necessarily reduce the error in such environments. However, centimetric errors (i.e., RMSEs) are achievable flying at 80–100 m, as the increase of GCP (Ground Control Point) density is the most effective solution for enhancing the resolution. Guidelines are suggested for implementing high-quality UAV surveys in wetlands

Feasibility long-term numerical study of a mega-nourishment in the Northern Adriatic

The coastal area of Porto Garibaldi - Bellocchio (Ferrara, Italy) is subjected to erosion that affects both tourism and generates coastal risk. Mega-nourishments are nowadays one of the most promising measures to compensate erosion and the Dutch Sand Engine project is confirming their capability. A first-step numerical study of the implementation of a small mega-nourishment in the target area is described here including long-term impact-factor analyses on erosion, deposition and sediment transport. Results suggested that the measure can have long-term positive impacts on morphology and transport. Further studies are suggested to overcome the limitations and simplifications introduced in the current study

Analisi degli effetti della subsidenza indotta dalla coltivazione del giacimento “Agosta” sull’assetto della fascia costiera delle Vene di Bellocchio

Convenzione di ricerca tra Eni s.p.a. e il Dipartimento di Fisica e Scienze della Terra dell'Università di Ferrara (responsabile scientifico prof. Paolo Ciavola) - Il sistema oggetto dello studio si riferisce all’unità fisiografica compresa tra il canale di Porto Garibaldi e la foce del Fiume Reno. In particolare l’assetto morfologico del sistema è stato indagato considerando la presenza dei processi erosivi in corso, il ruolo svolto dal Canale Gobbino, il comportamento morfologico dei bassi fondali e la sedimentazione sulla zona emersa delle Vene di Bellocchio. Pertanto sono stati eseguiti due rilievi topografici della porzione emersa della spiaggia e un’indagine morfobatimetrica dei bassi fondali antistanti le Vene di Bellocchio, per aggiornare i rilievi esistenti anche in seguito all’impatto della mareggiata eccezionale del 05 febbraio 2015, al fine di ricostruire in dettaglio la topografia del sistema morfologico nel suo complesso

Indoor pollution in high altitude dwellings: an assessment of affecting factors across four Sherpa villages in the Khumbu region, Nepal.

Household air pollution (HAP) from biomass fuel smoke is a major health risk, especially in developing countries. The ventilation of buildings and the type of fume discharge could also affect HAP. The present study aims to investigate the impact of stove type and kitchen characteristics on levels of pollutants. In particular, we investigated the potential geometric ventilation of buildings using geometric ventilation index (GVI), the presence of chimneys, the type of fuel and the environmental carbon monoxide level (a marker of indoor pollution) in the households of four Sherpa villages located in a mountain region of Nepal at altitudes between 2500 and 3900 m. We analysed 114 buildings (76 private residences and 38 lodges that accommodate tourists). Lodges had a more effective discharge system and a higher GVI, which had an inverse, significant correlation with indoor CO levels (r¼0.52). The level of indoor CO was more than 50% higher in private residences than in lodges. In the univariate analysis, only the absence of a chimney was associated with higher indoor CO (OR 3.4 (CL95%, 1.2–10.0), p¼0.02). We conclude that the adoption of chimneys and sealed stoves with exhaust pipes should be the first measure taken to reduce pollutants inside the households of high mountain regions until a switch to clean fuels can be achieved

The Role of Different Total Water Level Definitions in Coastal Flood Modelling on a Low-Elevation Dune System

The present study investigates different combinations and methods for estimating the extreme Total Water Level (TWL) and its implications for predicting flood extension caused by coastal storms. This study analyses various TWL components and approaches and assesses how different methodologies alter flood predictions, with implications for warning systems and emergency responses. Using different combinations of individual TWL components, flood extension simulations were conducted using a hydrodynamic model in the Volano Beach area (Emilia-Romagna, Italy). A real coastal storm event was used as a reference for comparison. The findings indicate that the selection of individual TWL components and calculation methods significantly impacts flood extension predictions. The approaches, which involve calculating extreme values from a combined time series or the water level time series plus the extreme value of wave setup, yield the most realistic results, excluding the runup component. In comparison, the other combinations overestimate the flood. Incorporating hydromorphological models like XBeach could enhance the accuracy of runup estimations and improve the overall method reliability. Despite limitations such as runup estimation and the use of generic regional parameters, this study underscores the importance of the TWL combination selection in accurately predicting flood extents, emphasising the need for context-specific adaptations in environmental contexts