1,721,183 research outputs found
Evaluation of marine flooding impacts along the coast of Emilia-Romagna (Italy): new methods and comparison with user-driven assessments
No full textThe Comacchio municipality, located in the northern part of the Emilia-Romagna region, northern Italy, is exposed
to the impact of marine storms that can cause large inundations. The case study is represented by the coastal
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villages of Lido degli Estensi and Spina (Ferrara province) that are located in a low-lying area. The Adriatic Sea is
generally low energetic, but significant storms can occur. The coast is highly urbanized and exploited for tourism,
therefore the exposure of different receptors is high. The presentation will focus on new tools developed in a
recent EU-FP7 project specifically designed to provide end-users charged with managing flood protection and
resilience. The tools include an impact-based database of marine storms, a series of numerical tools and an
impact assessment tool. The tools could be used to increase resilience for the local communities as well as
provide an example exportable to other European areas. The regional authorities have implemented a
methodology to identify the extension of flood-prone areas in the framework of the EU flood directive. The
regional maps, implemented with a simplified GIS-based methodology, are compared to the maps developed
within the RISC-KIT project (www.risckit.eu) in order to identify similarities and dissimilarities in terms of
prediction of flooding extension. The RISC-KIT maps were produced with a modelling chain that includes XBeach
(1D) and LISFLOOD-FP models. The impact to several identified receptors (households, structures and
infrastructures) was assessed through the INDRA model and compared to the risk maps issued by the regional
authorities
Testing coastal DRR in current and climate change scenarios – Artificial winter dune system in a highly touristic beach in the Northern Adriatic
No full textArtificial dunes are common features built along the coast of the Emilia-Romagna region (Italy) that act as temporary protections during the stormy season in order to prevent damages and inundation to the structures located on the backshore. The RER coast is in fact characterised by low sandy beaches that are exploited for tourism and where beach huts are permanently present on the rear part of the beach. While scientists and regional managers already provided proofs of the capacity of the artificial dunes to lower the hazard component, any study has never investigated their direct impacts in the current (CS) and climate change scenarios (CCS). The RISC-KIT project (www.risckit.eu) provided a methodology for testing DRRs at local level integrating hydro-morphological numerical modelling with a Bayesian Network to assess the consequences of extreme events for different scenarios. The approach was applied at the beach of Lido degli Estensi and Spina (Comacchio, Italy) in the Emilia-Romagna coast. It is a highly touristic area with concessions directly facing the sea, providing sun-and-beach tourism services during summer time, and private residences, commercial activities and hotels at the seafront. The flooding and erosion hazards were analyzed, along with their impacts. A 2DH XBeach model was built and forced with a large number of triangular storms, representative of many different representative combinations of waves' and total water level's ranges observed at regional level. Flooding and erosion results were input into a Bayesian Network which included, as feeding variables categories, deep water boundary conditions (including the CCS trigger), receptors (type and location of assets at the coast), hazard intensity affecting the receptors, impacts and DRR. Therefore, it was possible to integrate a flood damage curve and an erosion potential damage function for the analyzed receptors (beach concessions and residential/commercial buildings), in order to calculate the direct impacts. The artificial dune system was implemented, as representative of the DRR scenario, modifying the topography through the DuneMaker 2.0 Matlab tool. The CCS was implemented through a predicted RSLR under RCP8.52050. The results evidenced that the DRR positively influenced both flooding and erosion hazard intensities distributions. The impacts for the CS showed that, potentially: 20% of residential and commercial buildings and 90% of concessions will be preserved from flood impacts; more than 50% of concessions will be preserved from erosion impacts. The impacts of the CCS evidenced that, potentially: 65% of residential and commercial buildings and 95% of concessions will be preserved from flood impacts; more than 30% of concessions will be preserved from erosion. The positive effect on coastal extreme storm impacts of the implementation of the artificial dunes was evidenced and quantified in comparison with current and climate change scenarios without any DRR implemented. Ongoing studies on the artificial winter dunes, comparing field drone observations and numerical modelling, are being implemented starting from October 2016. Besides, the methodology, if properly adapted, can be applied for any type of DRR, as demonstrated by the RISC-KIT project. It is able to help managers in comparing DRR solutions or strategic alternatives
Testing Green DRR Solutions by Dune Reconstruction at a Rapidly Eroding Coast in the Adriatic Sea
No full textIn the current scenario of climate change and increased sea-level the occurrence of high water level storms threatens
coastal landscapes that lye at a low elevation. Naturally coastal dunes provide the so-called first line of defence. At eroding
coastlines their reconstruction offers the opportunity to build dynamic coastal defences, in opposition to more static
approaches like sea-walls. In order to properly design a revegetated dune, modeling must be undertaken to identify the
optimal dune height and width able to withstand the effect of an exceptional storm. The primary role of the plants is to
modify the velocity profile above them: this implies to introduce in the model credible values of the drag coefficient that also
reflect the spatial distribution of the different plant species and the density of stems per unit area.
Numerical tests of the effectiveness of dune reconstruction and revegetation as a Disaster Risk Reduction (DRR) measure
were undertaken on the Bellocchiocoastline, south of Porto Garibaldi, in the northern Adriatic sea coast of Emilia-Romagna.
The work was developed as a part of the EU FP7-RISC-KIT project, which elected the site as the pilot case study after
selection of a number of highly exposed hotspots (Armaroli and Duo, 2017). A detailed digital elevation model was
producedmerginga topographic Lidarfor the emerged area, a nearshore bathymetric Lidar up to -4.5 m water depth and a
multibeam bathymetric survey for the offshore up to – 10 m. The storm selected to test the efficiency of the natured-based
DRR occurred on 5-6 of February 2015, with a maximum offshore significant wave height of 4.66 m and a peak of 1.2 m of
water level above MSL. These conditions approximately correspond to a return period of 50 years. The two-dimensional
domain extends 3000 m alongshore and 3600 m cross-shore. The resolution of the ranges from 18m alongshore and 21m
cross-shore at the offshore open boundary at (10 depth) to 1m cross-shore and 8m alongshore in the area where the dune
is located. The reconstructed dune was built mimicking the current dune but enlarging it and increasing its crest, according
to literature knowledge of comparable dune systems in the region. The vegetation was introduced according to spatial
distribution of local species assuming either the current stem density or doubling it. Two indicators were chosen to assess
performance, respectively the Maximum Water Volume (MWV) and the sediment volume variation (SVV).
The results outline a reduction of inundation with the reconstructed dune (Fig. 1a), which is still breached and overtopped
at some points. If the vegetation is reconstructed on the dune there is considerable decrease of inundation (Fig. 1b).
Minimum changes are observed between normal and high density of vegetation for the reduction of MWV (Fig. 1c). The
high-density vegetation set-up provides instead the most efficient solution for SVV reduction. Further tests will be
undertaken at a number of European sites in the context of the EU H2020-ANYWHERE Project, encompassing also
different vegetation taxonomy and distribution
Evaluating short-term tidal flat evolution through UAV surveys: A case study in the Po Delta (Italy)
No full textThe 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
Dune reconstruction and revegetation as a potential measure to decrease coastal erosion and flooding under extreme storm conditions
No full textThe high water level and extreme waves that occur during a storm may threaten coastal landscapes, including densely populated zones that may also suffer from erosion, increasing the flooding magnitude and the total risk level. Climate change and future sea-level rise may result in an increased impact of storms due to the changes in the frequency and/or magnitude of the extremes of these water levels and/or waves. Coastal dunes and their associated vegetation communities act as a barrier to storm surges and wind waves, reducing flooding and coastal erosion. Therefore, nature-based solutions to protect coastal areas have gained attention in the last years. This contribution aims at evaluating the effectiveness of dune system rehabilitation as a Disaster Risk Reduction (DRR) measure under the current and future sea level scenarios at a rapidly eroding coastline in Bellocchio (Italy, Northern Adriatic Sea). The design of the dune reconstruction and revegetation was performed according to the morphodynamics and ecosystem characteristics of the current dune system. The effectiveness of the DRR was assessed based on numerical tests. The hydro-morphodynamic model XBeach reproduced morphological changes and inundation caused by a recent extreme event. The proposed DRR results in an increase of 22% of the sediment budget of the dune-beach system under the current sea level, and of the 57% and 82% under future sea level rise, for low and high hazard scenarios, respectively. The maximum water volume of the flooding is reduced by 42% in the current sea level. The expected increase of maximum flooding water volume under future high hazard and low hazard scenarios is reduced of 25% and 59%, respectively. These benefits are discussed along with a simplified cost analysis. It is concluded that the complete rehabilitation (reconstruction and revegetation) of the dune system represents a proper Disaster Reduction Solution under current and future sea level rise scenarios
Uncertainty of drone-derived dems and significance of detected morphodynamics in artificially scraped dunes
Full text linkThis work capitalises on the morphodynamic study of a scraped artificial dune built on the sandy beach of Porto Garibaldi (Comacchio, Italy) as a barrier to protect the touristic facilities from sea storms during the winter season and contributes to understanding of the role of elevation data uncertainty and uniform thresholds for change detection (TCDs) on the interpretation of volume change estimations. This application relies on products derived from unmanned aerial vehicle (UAV) surveys and on the evaluation of the uncertainty associated with volume change estimations to interpret the case study morphodynamics under non-extreme sea and wind conditions. The analysis was performed by comparing UAV-derived digital elevation models (DEMs)-root mean squared error (RMSE) vs. global navigation satellite system (GNSS) < 0.05 m-and orthophotos, considering the significance of the identified changes by applying a set of TCDs. In this case, a threshold of similar to 0.15 m was able to detect most of the morphological variations. The set of TCD <= 0.15 m was considered to discuss the significance of minor changes and the uncertainty of volume change calculations. During the analysed period (21 December 2016-20 January 2017), water levels and waves affected the front of the artificial dune by eroding the berm area; winds remodelled the entire dune, moving the loose sand around the dune and further inland; sediment volumes mobilised by sea and wind forcing were comparable. This work suggests that UAV-derived coastal morphological variations should be interpreted by integrating: (i) a set of uniform thresholds to detect significant changes; (ii) the uncertainty generated by the propagation of the original uncertainty of the elevation products; (iii) the characteristics of the morphodynamic drivers evaluated by adopting uncertainty-aware approaches. Thus, the contribution of subtle morphological changes-magnitudes comparable with the instrumental accuracy and/or the assessed propagated uncertainty-can be properly accounted for
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Coastal cliff retreat and landslide processes: a preliminary quantitative characterization at Portonovo-Trave cliffs (Conero, Ancona, Italy)
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