Tunnel stradali - L’analisi costi-benefici come strumento per l’adeguamento

TRA I CRITERI GUIDA NELL’ASSUMERE DECISIONI NELLA GESTIONE DEL RISCHIO, NEI CASI DI ADEGUAMENTO DELLE GALLERIE STRADALI, IL DECRETO LEGISLATIVO 264/2006 INDICA ANCHE L’ANALISI COSTI-BENEFICI. DI SEGUITO UN APPROFONDIMENTO DELLA QUESTIONE SVILUPPATA CONFRONTANDO IL DETTATO NORMATIVO CON LE RECENTI “LINEE GUIDA PER LA VALUTAZIONE DEGLI INVESTIMENTI IN OPERE PUBBLICHE” NEI SETTORI DI COMPETENZA DEL MINISTERO DELLE INFRASTRUTTURE E DEI TRASPORTI DEL 1° GIUGNO 2017

Cross-border critical transportation infrastructure: a multi-level index for resilience assessment

Today, more than ever before, our society depends on interdependent infrastructure systems, such as transportation, energy, water, and telecommunications networks. These systems are often considered critical because they are necessary for the organization, functionality, and stability of a modern industrialized country. However, these infrastructures are vulnerable to accidents, malicious failures, and disruptions that could generate consequences impacting on the economy, health, safety, and welfare of the citizens of a country or of several neighboring countries. The disruption of critical cross-border transportation infrastructure, road or rail, as a result of a major event can affect the area where the event occurs and a wider area. Depending on the type and duration of an event, which can be natural or anthropogenic in origin, it is possible to estimate the impacts on the mobility of people and goods in terms of delays (alternative routes), increased traffic (congestion), and a potential increase in accidents. For instance, in 2019 there was an accident in Rastatt (Germany) that affected rail traffic on the Karlsruhe-Basel line of the Rhine-Alpine corridor in Europe. The rail line was disrupted for more than 50 days, causing disservices and about 2 billion Euro in economic losses in Germany, Switzerland, and Italy. The extended disruption of road and rail sections can have consequences (impacts) not only on the transport system but also on the socio-economic system in a macro-regional context. The research is part of the SICt project - Resilience of Critical Cross-Border Infrastructure developed in the Interreg VA Italy-Switzerland Programme 2014-2020. The work aims to define a RI - Resilience Index for the road and rail transport network falling within the study area. The RI index describes the capability of each network element (i-th link) to cope with a relevant event. The formulation of the index involves the calculation of three independent indicators: i) RIRM - Rescue Management related to the resources that can be activated and used to cope with an event; ii) RIPP - Plans & Management related to the speed with which the necessary resources can be activated and in fact, considers management aspects such as the presence of plans and procedures; iii) RIRN - Network & Traffic related to the robustness of the elements of the transport network. This work aims to present the proposed model and its application to the project area that includes the Lombardy Region (Italy) and the Canton Ticino (Switzerland) within the SICt Project

Leakage and spillover effects of forest management on carbon storage: theoretical insights from a simple model.

Leakage (spillover) refers to the unintended negative (positive) consequences of forest carbon (C) management in one area on C storage elsewhere. For example, the local C storage benefit of less intensive harvesting in one area may be offset, partly or completely, by intensified harvesting elsewhere in order to meet global timber demand. We present the results of a theoretical study aimed at identifying the key factors determining leakage and spillover, as a prerequisite for more realistic numerical studies.We use a simple model of C storage in managed forest ecosystems and their wood products to derive approximate analytical expressions for the leakage induced by decreasing the harvesting frequency of existing forest, and the spillover induced by establishing new plantations, assuming a fixed total wood production from local and remote (non-local) forests combined.We find that leakage and spillover depend crucially on the growth rates, wood product lifetimes and woody litter decomposition rates of local and remote forests. In particular, our results reveal critical thresholds for leakage and spillover, beyond which effects of forest management on remote C storage exceed local effects. Order of magnitude estimates of leakage indicate its potential importance at global scales

An ADMM approach for day-ahead scheduling of a local energy community

The paper deals with the day-ahead operational planning of a grid-connected local energy community (LEC) consisting of several prosumers each equipped with generating units, loads and battery energy storage units. The prosumers are connected to the same low-voltage distribution network. In order to preserve, as much as possible, the confidentiality of the features and forecast of prosumers' equipment, the problem is addressed by designing a specific distributed procedure based on the alternating direction method of multipliers (ADMM). The distributed procedure provides the scheduling of the batteries to limit the balancing action of the external grid. Results obtained for various case studies are compared with those obtained by a centralized approach. The values of the objective function, the profiles of the power exchanged with the utility grid and the profile of the energy stored in the batteries provided by the distributed approach are in close agreement with those calculated by the centralized one

Preliminary evaluation of infrastructure and mobility services in mega-event: the Italian case study

Mega-events play an important role in the urban agenda of contemporary metropolises. This importance lies in the fact that such events are seen as possible catalysts for the urban development of a metropolis and more generally of a territory, and an opportunity to establish them as global cities. The planning and programming of a mega-event can be a country's showcase on the international landscape, and the mobility sector plays a significant role in defining its success or failure. Transport infrastructure generally requires high resources for both construction and maintenance even after the event. Therefore, in order to ensure a good outcome, it needs to be planned strategically at multiple levels; this condition brings a benefit to both the host city and the community. The main purpose of this study is to analyze a mega event like the Olympic Games by highlighting the relationship between existing mobility solutions and sustainable solutions considering also the surrounding area. This is to enable the creation of new intelligent transportation options. The Olympic Games, in fact, can represent a valuable opportunity to modernize the existing infrastructure of a country by improving the level of service and quality. The study considers, on the one hand, the expected demand for transport during the event and, on the other, the specific features of the different solutions that can be adopted to meet mobility needs

Chance-constrained Calculation of the Reserve Service Provided by EV Charging Station Clusters in Energy Communities

The concept of energy community is currently under investigation as it is considered central into the energy transition process. One of the main aspects of the successful implementation of community lays in the energy management system that coordinates exchanges among prosumers. This paper deals with the optimal energy management of a local energy community of dc microgrids with electric vehicle charging stations, considering local reserve provided by storage units and vehicle batteries. A two-stage optimal procedure is proposed to assess the optimal scheduling of resources for each community participant. Additionally, the optimal up and down reserve levels able to cover random fluctuations in photovoltaic generation within each EV-based microgrid are determined by a set of specific chance constraints

Xylem Functional Traits as Indicators of Health in Mediterranean Forests

Purpose of Review: We conducted a literature survey and meta-analysis to assess, in Mediterranean forests impacted by drought, the role of xylem functional traits as indicators of tree health, and their potential to adjust over a range of climatic conditions to support tree performance and survival. We aimed also to depict the geographic variability of xylem functional traits among Mediterranean forest trees as a tool for regional scale-oriented vulnerability assessment. Recent Findings: Associations were investigated among xylem functional traits, hydraulic safety, and whole plant drought resistance for tree species in Mediterranean-type climates. Variable data were available from a number of study cases of Mediterranean forest communities impacted by intense drought, wherein tree growth and xylem functional traits were investigated along with tree decline and dieback episodes. Variable data were available from a number of studies that analyzed xylem trait adjustments to climatic conditions at different temporal scales. Summary: We observed differing growth patterns and xylem conduit area responses in healthy and unhealthy trees and we sketched hydraulic strategies that may fit observed patterns. Overall, a clear role of xylem conduit size as stand-alone tree health indicator did not emerge. We showed that xylem traits may adjust along different temporal scales and may support the performance and health of Mediterranean tree species over a range of climatic conditions. We outlined substantial geographic variability in xylem traits across the Mediterranean region, suggesting patchy responses to increasing drought. Knowledge gaps and needed lines of research are highlighted

Road Tunnels Operation: Effectiveness of Emergency Teams as a Risk Mitigation Measure

Managing a major event in a road tunnel requires more resources than an open-air event. In the case of fire, the confined environment of road tunnels can represent a critical situation for both users and rescuers. The safety level of a tunnel can be estimated by using dedicated risk models that consider, on the one hand, the traffic (type, quantity and distribution) of a tunnel and, on the other hand, the structural and plant safety measures. According to the European Directive, road tunnel managers can adopt additional safety measures aimed at increasing the level of safety for users exposed to the consequences of an accidental event. One of these measures is the rapid intervention of emergency teams located in the proximity of the tunnel. These teams use pick-up and scooter vehicles properly equipped to cope with a fire event and have detailed knowledge of the specific tunnel system. A further advantage of the emergency teams is the possibility of supporting the evacuation of tunnel users by providing indications on emergency exits, bypasses and safe places considering the evolution of the specific event. In this perspective, the present research contributes to the evaluation of the emergency teams’ effectiveness. Thus, the emergency team was included as a safety measure within a risk analysis model for road tunnels developed by the authors in previous works. After an analysis of the technical and scientific literature, we focused on 15 interventions carried out on some highway tunnels in Italy between the year 2019 and the year 2021. The intervention times of the teams were analyzed using data provided by Strada dei Parchi S.p.A., a company that manages 14 highway tunnels in Italy. These 14 tunnels range in length from 589 m to 10,121 m and are subject to the European Directive. The observed intervention times of the emergency teams range between 2 min and 10 min with an average value of 5.9 min. Such a short intervention time is possible because emergency teams are in the proximity of the different tunnels. Because of the short intervention time and the training of the personnel, all the fires were properly managed by the teams. Furthermore, considering the results of the scientific literature and the data presented in this work, it was possible to estimate and validate an effectiveness value (higher than 90%) of the emergency teams to be used within the risk analysis model developed by the authors and which can also be used in other risk analysis models

Stomatal conductance and leaf water potential responses to hydraulic conductance variation in Pinus pinaster seedlings

In this study, tree hydraulic conductance (K tree) was experimentally manipulated to study effects on short-term regulation of stomatal conductance (g s), net photosynthesis (A) and bulk leaf water potential (Ψleaf) in well watered 5–6 years old and 1.2 m tall maritime pine seedlings (Pinus pinaster Ait.). K tree was decreased by notching the stem and increased by progressively excising the root system and stem. Gas exchange was measured in a chamber at constant irradiance, vapour pressure deficit, leaf temperature and ambient CO2 concentration. As expected, we found a strong and positive relationship between g s and K tree (r = 0.92, P = 0.0001) and between A and K tree (r = 0.9, P = 0.0001). In contrast, however, we found that the response of Ψleaf to K tree depended on the direction of change in K tree: increases in K tree caused Ψleaf to decrease from around −1.0 to −0.6 MPa, but reductions in K tree were accompanied by homeostasis in Ψleaf (at −1 MPa). Both of these observations could be explained by an adaptative feedback loop between g s and Ψleaf, with Ψleaf prevented from declining below the cavitation threshold by stomatal closure. Our results are consistent with the hypothesis that the observed stomatal responses were mediated by leaf water status, but they also suggest that the stomatal sensitivity to water status increased dramatically as Ψleaf approached −1 MPa