4,203 research outputs found
Forest cover influence on regional flood frequency assessment in Mediterranean catchments
No full textThe paper aims at evaluating to what extent the forest cover can explain the component of runoff coefficient as defined in a regional flood frequency analysis based on the application of the rational formula coupled with a regional model of the annual maximum rainfall depths. The analysis is addressed to evaluate the component of the runoff coefficient which cannot be captured by the catchment lithology alone. Data mining is performed on 75 catchments distributed from South to Central Italy. Cluster and correlation structure analyses are conducted for distinguishing forest cover effects within catchments characterized by hydro-morphological similarities. We propose to improve the prediction of the runoff coefficient by a linear regression model, exploiting the ratio of the forest cover to the catchment critical rainfall depth as dependent variable. The proposed regression enables a significant bias correction of the runoff coefficient, particularly for those small mountainous catchments, characterised by larger forest cover fraction and lower critical rainfall depth
Scale-dependent relations in land cover biophysical dynamics
No full textThe exploration of the relationships between plant biotic dynamics and scale can reveal important information on ecosystem spatial organization by addressing preservation of information integrity in upscaling/downscaling procedures of land-surface parameterization for environmental modeling applications. Scale-dependent relations of vegetation dynamics are investigated in this study by using emergent biophysical characteristics obtained through a predictive multidimensional model of vegetation anomalies derived from remote-sensing observations. In particular, the analysis is focused on the spatial organization of some phenological parameters including deterministic variations (seasonal range, interannual variability, jump discontinuities) and stochastic components (plant memory, spatial correlations). The analysis is performed using MODIS-based Normalized Difference Vegetation Index (NDVI) 16-day composites for the period from March 2000 to December 2006 over Italy at different levels of spatial aggregation (1-8. km). Scale-dependences of the statistical moments of the phenological parameters are quantified through simple power laws for five distinct vegetated land covers. Results suggest that some biophysical characteristics, especially deterministic components, show no preferential spatial scale for important coverage. In particular, broad-leaved forests and natural grasslands are characterized by deterministic and low-distance spatial components well explained by scale relationships, which are modulated by possible spatiotemporal dynamics of climatic drivers. Agricultural lands show high scale-dependent relations on short-term biophysical memory sources and low-distance spatial components of phenology likely related to hierarchical interactions of anthropogenic and ecological processes; whereas mixed patterns of croplands and natural areas generally present no consistent scaling relations. © 2011 Elsevier B.V
MATLAB codes to monitor time-varying forest resilience at regional-to-global scales
No full textThe persistence and functionality of forest ecosystems are highly dependent on their capacity to withstand and recover from natural and anthropogenic perturbations, i.e., their resilience. Understanding the underlying mechanisms of forest resilience and its recent dynamics is therefore of paramount importance to develop sound conservation and management plans. We investigated how forest resilience, quantified in terms of critical slowing down indicators, has changed over the period 2000-2020, by integrating satellite-based vegetation indices with machine learning. The proposed methodology is purely data-driven and therefore reproducible, applicable at large scales, and in line with the measurement/reporting/verification process of UNFCCC. Results of this study have been published in Forzieri et al. (2022).
MATLAB computing codes developed in the afore-mentioned work are made publicly available here and briefly described to facilitate reproducibility and applicability. All datasets utilized are publicly available and are not included in this archive. Please refer to Forzieri et al., 2022 for more details.</p
Assessment of hyperspectral MIVIS sensor capability for heterogeneous landscape classification
No full textThe potential and limitations of the hyperspectral remote sensing MIVIS sensor (Multispectral Infrared Visible Imaging Spectrometer) in classifying heterogeneous landscapes are explored in this study. In order to quantify the discriminant information derived from selected MIVIS subsets we classified a monitored scenario by progressively increasing the feature space dimensionality. The hyperspectral subsets are defined through the Sequential Forward Selection algorithm, while mapping processes have been performed through the Maximum Likelihood, Spectral Angle Mapper and Spectral Information Divergence classifiers. Impacts of spectral bands on the overall classification accuracies and single land cover-scale reliability, as well as possible dimensionality effects (Hughes phenomenon) are investigated. The analysis is tested on a 20-km stretch of the Marecchia River (Emilia Romagna, Italy) by using MIVIS data acquired in autumn 2009 and 2010 for a 17-class mapping including complex urban/rural areas. For the considered dataset, the MIVIS sensor showed an equipment failure: of the nominal 102-band MIVIS dataset, only the first 24 bands, spanning within the 0.441–1.319 μm spectral range, were exploitable. Nevertheless, the available information provided valuable discriminant contributions in land cover mapping (Maximum Likelihood Overall Accuracy ∼85%) with encouraging reliability on mixed forests, croplands, and no-vegetated floodplain patterns, whereas riparian vegetation and urban zones exhibited low classification accuracies. The relationship between the spectral space dimensionality and the minimum training-set size that is necessary to achieve a given inter-class separability has also been experimentally investigated by progressively under-sampling the original training set. The maximum under-sampling factor that avoided a decrease in the overall accuracy turned out to be, at maximum, 15 for the considered data set.JRC.H.7 - Climate Risk Managemen
ES4LUCC: A GIS-tool for remotely monitoring landscape dynamics
No full textGiven the potential impacts of land cover changes on surface processes, accurate mapping of landscape dynamics is a crucial task in environmental monitoring. The use of commercial software for remote sensing of landscape changes requires appropriate expertise in sensor technology and computing resources that are not always available to decision makers. This paper presents the development of an experimental prototype of a lightweight and user-friendly GIS tool – ES4LUCC – a semiautomatic software for change detection and classification of land use/cover. The tool is based on image processing techniques applied on multi-temporal remotely sensed spectral and surface model data. The GIS-based tiling approach allows to non-specialists of remote sensing to manage high-dimensional data even from low performance computing platforms. The paper synthesizes the implemented digital image processing that form the basis of ES4LUCC, including data correction, classification and change detection, map refinements. It also describes the software architecture, the main IDL modules and the integration with GIS through a tight coupling approach and.dll calling functions. The main modelling process is controlled through a powerful GUI developed as part of the ArcMap component of ESRI ArcGIS. The software is tested by using bi-temporal color-infrared ADS40 and Light detection and ranging data acquired on a 80-km transect of the Marecchia river (Italy). The outputs of ES4LUCC give an understanding of the natural- and human-induced surface processes, such as urban planning, agricultural and forest practices, fluvial dynamics and slope instability. The model provides reliable maps (90.77% overall classification accuracy) that represent useful layers for environmental landscape management.JRC.H.7 - Climate Risk Managemen
Le «buone letture». 2. Giovanni Casati
No full textIl saggio è costituito da due parti, la prima delle quali, dedicata alla fondazione della Federazione italiana delle biblioteche circolanti cattoliche, è stata pubblicata nel precedente numero dei «Nuovi Annali», XXVII (2013), pp. 137-163. In questa seconda parte viene delineata la figura intellettuale di Giovanni Casati, che diresse la «Rivista di letture» dal 1912 al 1944, trasformando il periodico della Federazione in una rivista impegnata nella divulgazione della cultura cattolica. A questo impegno militante Casati fece corrispondere un intenso programma editoriale, che trovò espressione nella pubblicazione di saggi letterari, di manuali e opere repertoriali.The study consists of two parts; the first is dedicated to the history of the Federazione italiana delle biblioteche circolanti cattoliche since its foundation (1904) up to 1912 and was published in the previous volume of the «Nuovi Annali », XXVII (2013), pp. 137-163. In this second part, the author outlines the intellectual figure of Giovanni Casati, who directed the «Rivista di letture» from 1912 to 1944, transforming the magazine of the Federation in a journal engaged in the spreading of Catholic culture. To this militant engagement Casati matched an intense publishing program, which found its expression in the publication of literary essays, manuals and reference works
Comico e tragico del diritto nella novellistica italiana: il novelliere di Giovanni Sercambi
No full textNelle novelle di età tardomedievale ed umanistica, a causa del loro carattere fortemente realistico, il diritto ha un posto importante, poiché rappresenta un elemento centrale e ineliminabile della vita della comunità. Il novelliere di Giovanni Sercambi da Lucca non fa eccezione, anche se l’autore non ha una cultura giuridica né s’interessa in modo specifico al diritto. Il presente saggio vuole analizzare sotto tale profilo queste novelle per verificare quale concezione del diritto emerge da esse e come la narrazione ne risulti arricchita.In the late medieval and humanistic novellas, owing to their very realistic character, the right is an important central and inevitable element in community life. Giovanni Sercambi’s novelliere is no exception even if the author lacks a legal culture, nor is specifically interested in right. This essay intends to analyze these novellas under this profile to verify what kind of right they consider and how the stories are enriched
Bird presence vegetation complexity data in Melbourne, Australia. Data created in 2018 by Giovanni Carrabs.
No full textBird presence and vegetation complexity data from Melbourne, Australia. Data created for a university thesis project and publication in 2018. Author: Giovanni Carrabs.</p
Chapter Atto biografo di Giovanni Gualberto
No full textThe paper examines the Vita s. Iohannis Gualberti by Atto, reconstructing its genesis and fortune. Probably the author wrote this hagiography when he was abbot and before becoming bishop of Pistoia. He re-elaborated the Life of the saint by Andrea of Strumi, adapting it to a changed historical and ecclesiastical context. The text was successful among the Vallombrosan Order and it was used by later hagiographers to create epitomes and rewritings of the Life of Giovanni Gualberto
Author of newly released Bicycles, Nikki Giovanni gives tips on writing a love poem
No full textA new book of love poetry has been published by internationally known author Nikki Giovanni, University Distinguished Professor of English at Virginia Tech
- …
