This page has only limited features, please log in for full access.
Windstorms represent one of the main large-scale disturbances that shape the European landscape and influence its forest structure, so post-event restoration activities start to gain a major role in mountainous forest management. After a disturbance event, biological legacies may enhance or maintain multiple ecosystem services of mountain forests such as protection against natural hazards, biodiversity conservation, or erosion mitigation. However, the conservation of all these ecosystem services after stand-replacing events could go against traditional management practices, such as salvage logging. Thus far, the impact of salvage logging and removal of biological legacies on the protective function of mountain stands has been poorly studied. Structural biological legacies may provide protection for natural regeneration and may also increase the terrain roughness providing a shielding effect against gravitational hazards like rockfall. The aim of this project is to understand the dynamics of post-windthrow recovery processes and to investigate how biological legacies affect the multifunctionality of mountain forests, in particular the protective function. To observe the role of biological legacies we performed 3000 simulations of rockfall activity on windthrown areas. Results show the active role of biological legacies in preventing gravitational hazards, providing a barrier effect and an energy reduction effect on rockfall activity. To conclude, we underline how forest management should take into consideration the protective function of structural legacies. A suggestion is to avoid salvage logging in order to maintain the multifunctionality of damaged stands during the recovery process.
Maximiliano Costa; Niccolò Marchi; Francesco Bettella; Paola Bolzon; Frédéric Berger; Emanuele Lingua. Biological Legacies and Rockfall: The Protective Effect of a Windthrown Forest. Forests 2021, 12, 1141 .
AMA StyleMaximiliano Costa, Niccolò Marchi, Francesco Bettella, Paola Bolzon, Frédéric Berger, Emanuele Lingua. Biological Legacies and Rockfall: The Protective Effect of a Windthrown Forest. Forests. 2021; 12 (9):1141.
Chicago/Turabian StyleMaximiliano Costa; Niccolò Marchi; Francesco Bettella; Paola Bolzon; Frédéric Berger; Emanuele Lingua. 2021. "Biological Legacies and Rockfall: The Protective Effect of a Windthrown Forest." Forests 12, no. 9: 1141.
Different mitigation measures with vegetation have been proposed to sustainably manage rainwater, among which green roofs have demonstrated to be a valid solution in urbanized areas. Green roofs have gained interest also in Italy, but their spreading is generally based on application of ready-to-use packages, poorly tested in the specific climate conditions. A study was carried out to evaluate the green roof solution most suitable in the humid, subtropical climate context of Veneto Plain (north-eastern Italy) to reduce outflow volumes from building roofs into the urban drainage systems. Twelve different microcosm combinations of extensive green roof (three plant mixtures × two substrates × two storage/drainage layers) were tested and compared with gravel (considered as a conventional flat roof with gravel ballast). The tested drainage/storage layers were a preformed layer in recycled HDPE (PL) and an expanded perlite mineral layer (ML), and the growth medium layers were recycled brick substrate (RS) and volcanic substrate (VS). Three different mixtures of native plant species were transplanted: Sedum (SE), herbaceous perennial (HE), and suffruticose (SF). Results showed that all the green roof systems have a good ability to manage rainwater, with a retention ranging on average from 46.2% (SE-RS-PL microcosms) to 62.9% (SF-RS-ML microcosms) of the precipitation in the two-year period (September 2014–August 2016), against 15.4%, retained by gravel. Over the two-year period, the retained rainfall volumes were about 100% for all the light rainy events (<10 mm) and varied within a range of 48%–95% for medium rainy events (≥10 and <25 mm) and 20%–88% for heavy rainy events (≥25 mm), depending on rainfall depth and the antecedent weather period. The layer that gave the highest relative contribution to the stormwater retention was the vegetation layer, followed by the drainage/storage layers and then the substrate layer. In particular, SF plants decreased the outflows by 15.2% on average compared to SE, and ML layer retained more than 10% of precipitation compared to PL layer. At last, the analysis of variance showed that, within each layer, the more effective in water retention, able to generate less outflow volumes, was similarly suffruticose and herbaceous mixtures, the crushed bricks substrate, and the mineral drainage/storage layer.
Lucia Bortolini; Francesco Bettella; Giampaolo Zanin. Hydrological Behaviour of Extensive Green Roofs with Native Plants in the Humid Subtropical Climate Context. Water 2020, 13, 44 .
AMA StyleLucia Bortolini, Francesco Bettella, Giampaolo Zanin. Hydrological Behaviour of Extensive Green Roofs with Native Plants in the Humid Subtropical Climate Context. Water. 2020; 13 (1):44.
Chicago/Turabian StyleLucia Bortolini; Francesco Bettella; Giampaolo Zanin. 2020. "Hydrological Behaviour of Extensive Green Roofs with Native Plants in the Humid Subtropical Climate Context." Water 13, no. 1: 44.
As a consequence of climate change, the impact of pluvial flooding is expected to increase in the next decades. Despite citizens’ poor knowledge, several types of stormwater infrastructure can be implemented to mitigate the impact of future events. This paper focuses on the implementation of green and grey stormwater interventions (i.e., with or without vegetation) on private properties. Framed by the Protection Motivation Theory, a survey-based case study analysis, carried out in a pluvial flooding-prone area of the Veneto Region (Italy), highlights the main factors driving people’s willingness to implement these interventions. The analysis shows that the implementation of grey stormwater infrastructures is driven by the perceived threat and the amount of past pluvial flooding damage (i.e., the direct experience as a proxy of prior knowledge) while the implementation of green stormwater infrastructures is driven also by additional factors (awareness of these interventions, age and education level of the citizens). Based on these results, lack of knowledge on innovative stormwater interventions represents a critical barrier to their implementation on private properties, and it confirms the need for specific dissemination and information activities.
Francesco Pagliacci; Edi Defrancesco; Francesco Bettella; Vincenzo D’Agostino. Mitigation of Urban Pluvial Flooding: What Drives Residents’ Willingness to Implement Green or Grey Stormwater Infrastructures on Their Property? Water 2020, 12, 3069 .
AMA StyleFrancesco Pagliacci, Edi Defrancesco, Francesco Bettella, Vincenzo D’Agostino. Mitigation of Urban Pluvial Flooding: What Drives Residents’ Willingness to Implement Green or Grey Stormwater Infrastructures on Their Property? Water. 2020; 12 (11):3069.
Chicago/Turabian StyleFrancesco Pagliacci; Edi Defrancesco; Francesco Bettella; Vincenzo D’Agostino. 2020. "Mitigation of Urban Pluvial Flooding: What Drives Residents’ Willingness to Implement Green or Grey Stormwater Infrastructures on Their Property?" Water 12, no. 11: 3069.
The role of green roofs in reducing drainage fluxes is known, but despite extensive analysis in the literature, methods to predict the hydrologic performance for a given green roof composition are scarce. These methods are useful for the hydraulic design and for planning regulations that impose specific hydrological responses. This research investigates on the prediction of the drainage fluxes produced below a green roof with initial water content equal to its water retention capacity (worst-case scenario). Laboratory tests were performed to analyse the rainfall-drainage relationship for green-roof and single components (growing media and drainage storage layers) under specific rainfall intensities. Two types of largely used drainage/storage layers and growth media were analysed, both singularly and in combination. The experiments consider two rainfall events lasting 10 min with constant intensity. The results indicate that the Curve Number (CN) method (U.S. Soil Conservation Service) with a simple adaptation can be used to reproduce the green-roof hydrologic behaviour under antecedent moisture conditions comparable with those of the experiments. In fact, the water retention capacity, controlling the water-output initiation below the green roof, can be used as threshold variable of a step function, above which the CN method is applicable and below which drainage fluxes are practically null. Through this position, the CN assignment for a composite greenroof can be consistently estimated using the proprieties of the single components (drainage/storage layer and growing medium) and it provides values that are very close to those of waterproof media and quite higher than those suggested in companion researches. Drainage amounts are predicted with a standard error equal to 1.50 mm, which corresponds to 5.7% of the mean value observed. After rain initiation, the steady state condition of the drainage flux has proved to be markedly affected by the growing medium and drainage layer composing the system, which result effective in discriminating the green roof performance.
Francesco Bettella; Vincenzo D'Agostino; Lucia Bortolini. Drainage flux simulation of green roofs under wet conditions. Journal of Agricultural Engineering 2018, 49, 242 -252.
AMA StyleFrancesco Bettella, Vincenzo D'Agostino, Lucia Bortolini. Drainage flux simulation of green roofs under wet conditions. Journal of Agricultural Engineering. 2018; 49 (4):242-252.
Chicago/Turabian StyleFrancesco Bettella; Vincenzo D'Agostino; Lucia Bortolini. 2018. "Drainage flux simulation of green roofs under wet conditions." Journal of Agricultural Engineering 49, no. 4: 242-252.
Debris flows are one of the most common geomorphic processes in steep mountainous areas. The control of their propagation on alluvial fans is fundamental; valley bottoms are usually characterised by high damage potential because they contain concentrations of inhabitants and infrastructure. It is well known that forests have a protective function in that they reduce the triggering of debris flows, as well as hinder their motion and promote deposition, but a quantitative assessment of these effects is still lacking. Using laboratory experiments that simulate debris-flow depositional processes, this research investigated the ability of forests to reduce debris-flow runout and depositional area. The experiments considered two different forest types, high forests and coppice forests, and four volumetric concentrations of sediment (0.50, 0.55, 0.60, and 0.65). The results confirmed that the sediment concentration of the flow is a key factor in determining the geometry of the deposits. On the other hand, forests can reduce debris-flow runout distance and, in general terms, affect the characteristics of their deposits. The results showed that vegetation appear to reduce debris-flow motion especially when the debris-flow kinematic load at the fan apex is low. About the sediment concentration of the mixture, high forest did not exhibit a clear behaviour while coppice forest appears to promote significant deposition at all of the tested concentrations, and this effect increases with the solid concentration (reductions in runout between approximately 20% and 30% at CV=0.50 and CV=0.65, respectively, were observed). Due to their higher tree density, in fact, coppice forests seem to have a better protective effect than the rigid trunks of high forest trees. For this last type of forest, a relationship between the H/L ratio, which represents energy dissipation, have been found and compared with the scenario without forest.
Francesco Bettella; Tamara Michelini; Vincenzo D'agostino; Gian Battista Bischetti. The ability of tree stems to intercept debris flows in forested fan areas: A laboratory modelling study. Journal of Agricultural Engineering 2018, 49, 42 -51.
AMA StyleFrancesco Bettella, Tamara Michelini, Vincenzo D'agostino, Gian Battista Bischetti. The ability of tree stems to intercept debris flows in forested fan areas: A laboratory modelling study. Journal of Agricultural Engineering. 2018; 49 (1):42-51.
Chicago/Turabian StyleFrancesco Bettella; Tamara Michelini; Vincenzo D'agostino; Gian Battista Bischetti. 2018. "The ability of tree stems to intercept debris flows in forested fan areas: A laboratory modelling study." Journal of Agricultural Engineering 49, no. 1: 42-51.
Debris flow is a gravity-driven process, which is characterized by a travelling dense surge including large boulders, and it is followed by a more fluid tail. These characteristics make difficult the measurement of the mean flow velocity by means of common hydraulic techniques. Different methods can be used at real scale and small-scale to measure the front velocity but a dedicate comparison between available methods is still lacking. This research aims to compare the front velocity measurements in the transport zone of a miniature debris flow using three devices: i) a common digital video camera (29 frames per second); ii) a high speed thermo camera (60 fps); and iii) a laser photoelectric sensors system. The statistical analysis of data has highlighted no significant differences exist between front velocities obtained by means of the video camera and the thermo camera, whereas photocells data statistically differ from those achieved via the other systems. Some lack of data recorded by photocell was documented, while the thermo camera technique did not show significant loss of information being also helpful to detect the kinematic behaviour of single particles. Finally, the tests confirmed the influence of the solid volumetric concentration in the debris-flow mechanics, which promotes, ceteris paribus, the debris-flow slowing down.
Francesco Bettella; Gian Battista Bischetti; Vincenzo D'agostino; Simone Virginio Marai; Enrico Ferrari; Tamara Michelini. Comparison of measurement methods of the front velocity of small-scale debris flows. Journal of Agricultural Engineering 2015, 46, 129 -137.
AMA StyleFrancesco Bettella, Gian Battista Bischetti, Vincenzo D'agostino, Simone Virginio Marai, Enrico Ferrari, Tamara Michelini. Comparison of measurement methods of the front velocity of small-scale debris flows. Journal of Agricultural Engineering. 2015; 46 (4):129-137.
Chicago/Turabian StyleFrancesco Bettella; Gian Battista Bischetti; Vincenzo D'agostino; Simone Virginio Marai; Enrico Ferrari; Tamara Michelini. 2015. "Comparison of measurement methods of the front velocity of small-scale debris flows." Journal of Agricultural Engineering 46, no. 4: 129-137.