1,721,086 research outputs found
Hydrological, mechanical and spatial characterisation of root reinforcement in Mediterranean shrub vegetated slopes
No full text[182] Dani A., Giadrossich F., Preti F., Schwarz M., 2008, Hydrological, mechanical and spatial characterisation of root reinforcement in Mediterranean shrub vegetated slopes, EGU 2008, Wie
Root profile assessment by means of Hydrological, pedological and above-ground vegetation information for bio-engineering purposes
No full textContinuous Quantum Gate Sets and Pulse-Class Meta-Optimization
Full text linkReduction of the circuit depth of quantum circuits is a crucial bottleneck to enabling quantum technology. This depth is inversely proportional to the number of available quantum gates that have been synthesized. Moreover, quantum gate-synthesis and control problems exhibit a vast range of external parameter dependencies, both physical and application specific. In this paper, we address the possibility of learning families of optimal-control pulses that depend adaptively on various parameters, in order to obtain a global optimal mapping from the space of potential parameter values to the control space and hence to produce continuous classes of gates. Our proposed method is tested on different experimentally relevant quantum gates and proves capable of producing high-fidelity pulses even in the presence of multiple variables or uncertain parameters with wide ranges
Contaminazione del sottosuolo da NAPL nel bacino del Valdarno Medio: analisi territoriale e sperimentazione in condizioni controllate
No full textUno sversamento istantaneo di tetracloroetilene in condizioni controllate entro un monolite indisturbato di terreno mostra il potere impermeabilizzante di un livello acquitardo della copertura. Un'analisi territoriale evidenzia la relazione fra ubicazione delle aree contaminate, relativamente al Valdarno Medio, e grado di protezione del primo acquifer
Terraced landscapes: From an old best practice to a potential hazard for soil degradation due to land abandonment.
No full textAmong the most evident landscape signatures of the human fingerprint, the terraces related to agricultural activities are of great importance. This technique is widely used in various parts of the world under various environmental conditions. In some areas, terraced landscapes can be considered a historical heritage and a cultural ecosystem service to be adequately preserved. However, terraced landscapes subject to abandonment can progressively increase gully erosion and cause terrace failure. Partly because of changes in societal perspective and migration towards metropolitan areas, some countries have been affected by serious and wide abandonment of agricultural lands in recent decades. This review aims to discuss the current state of agricultural terraced landscapes, underlining critical issues and likely solutions. The paper is structured in three main sections. The introduction provides an overview of the available literature on terraced landscapes and their critical issues. The second section presents three case studies: the first is located in the so-called Cinque Terre area (Liguria, Northern Italy), the second is placed in the Chianti Classico area (Tuscany, Central Italy), and the third refers to the renowned Amalfi Coast (Salerno, Southern Italy). The last section of the review relates to likely solutions (non-structural and structural management) and future challenges (use of high-resolution topography derived by lidar) for suitable management of such environments
Indagini sperimentali sulla resistenza degli apparati radicali
No full textLa presente memoria è relativa alle misure di resistenza a trazione di radici condotte recentemente presso la sezione Idronomia del Dipartimento Ingegneria Agraria Forestale dell’Università di Firenze.
Le specie studiate sono Spartium junceum e Robinia pseudoacacia, tipiche dell’ambiente mediterraneo, per il loro utilizzo in interventi di sistemazione idraulico forestale. Si illustrano le procedure di campionamento, scavo, prelievo non distruttivo e conservazione). Sono descritte la strumentazione messa a punto presso il Laboratorio di Tecnologia del Legno del Dipartimento di Scienze e Tecnologie Ambientali Forestali dell’Università di Firenze e le modalità di prova per le misure del carico di rottura delle radici evidenziandone le caratteristiche significative, in particolare relativamente agli ancoraggi dei campioni ed alla velocità di misura.
Sono presentate le curve resistenza a trazione in funzione del diametro ricavate dalle prove condotte
Mean root depth estimation at landslide slopes
No full texttPlant rooting systems affect slope stability through the soil reinforcement given by the root network.The vertical root distribution in particular is crucial for the assessment of the critical slip surface in slopestability analyses. We propose here an expeditious way to assess the major characteristics of the rootsystem at landslide slopes.More in detail, we extend and validate an ecohydrological model proposed for flat terrain and water-dependent ecosystems by Laio et al. (2006). This model has the merit to use readily available climaticand pedologic descriptors to predict the mean root depth, but its extension to hillslopes in semi-humidenvironments requires validation. The model has been improved and then tested on a case study innorthern Tuscany (Italy) which considers 17 landslide sites where the tree rooting systems have beenmeasured.The results show a quite good match between observed and modeled mean root depths. The accuracyof the results largely depends on the improvements brought to the model in the parameters estimationphase, in particular through the application of the Curve Number method and through the refinement ofthe definition of the growing season. The results show that in 14 cases out of 17 the error is lower than30%. Furthermore, the error becomes lower than 30% at all sites if we take into account differences amongsoils in the estimation of the portion of precipitation which infiltrates into the soil. These results provethe potential of the proposed method: using few and quite readily available parameters, it allows one todetermine the mean root depths of vegetation with good accuracy: an important parameter for stabilityassessment of vegetated slopes on a large scal
Un profeta dell’ambientalismo nell’Italia dell’Ottocento. Il geografo americano George Perkins Marsh.
No full textGeorge Pekinsh Marsh è considerato un “profeta” dell’ambientalismo contemporaneo , in quanto nella seconda metà dell’Ottocento ha concettualizzato in modo sistematico gli effetti dell’intervento umano sull’ambiente naturale. Nato negli Stati Uniti orientali nel 1801, ha vissuto a lungo in Italia, nei primi decenni dopo l’Unità e proprio durante il suo soggiorno a Torino, a Firenze e a Roma, ha scritto il libro che condensa le sue acquisizioni più originali, sull’impatto delle attività umane rispetto all’ambiente naturale, L’uomo e la natura. Ossia la superficie terrestre modificata per opera dell’uomo . La figura di Marsh riveste interesse anche per la sua biografia e per le sue intersezioni culturali e disciplinari: infatti, come è stato evidenziato, i confronti fra l’ambiente del nuovo mondo- specialmente quello del Vermont da cui proveniva- e le condizioni dell’Europa e del Mediterraneo dove si è trovato a vivere, hanno stimolato in lui la ricerca e il coordinamento delle acquisizioni scientifiche sul degrado dell’ambiente e sugli effetti dell’antropizzazione del territorio, che stavano emergendo nel suo tempo .
Marsh sarà influenzato ed influenzerà la cultura italiana della seconda metà dell’Ottocento, specialmente nel campo della scienza idraulica e delle nascenti scienze forestali. L’attenzione a questo autore ci permette quindi di gettare uno sguardo sulla consapevolezza del degrado dell’ambiente, presente anche in Italia in questo periodo, e sulla percezione della necessità di conservazione delle risorse a questa conseguente
Coupling a distributed hydrological model with a vegetated slope stability model
No full textVegetation significantly influences the hydrological and mechanical properties which are relevant for the stability of shallow soils along sloping surfaces. In view of the complexity of soil plant hydrological interactions, the quantification of root mechanical reinforcement remains a challenge. In this paper we couple root reinforcement models with a quasi-dynamic wetness index (QDI), which is specifically designed for estimating the local wetness conditions by accounting for the character of the upslope topography and the time of the lateral soil moisture distribution. The overall modelling strategy can be effectively employed for assessing the relative hazard of shallow landslides accounting for vegetation patterns and dominant forest management practices. The methodology is applied to an area located in Northern Tuscany to assess the effect of root degradation after tree logging on the spatial occurrence of shallow landslides during extreme rainfall events
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