http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2013-05-25T20:31:03Z http://hdl.handle.net/2067/1111 Title: Utilizzo di immagini satellitari ad alta risoluzione per il monitoraggio delle superfici tagliate a raso in boschi cedui Authors: Giuliarelli, Diego Abstract: Obiettivo del presente lavoro è valutare le potenzialità di immagini satellitari ad alta risoluzione geometrica per il monitoraggio dei tagli a raso in boschi cedui dell’Italia centro-meridionale. Attraverso l’integrazione di un set multitemporale di immagini multispettrali SPOT5 e dati ancillari viene prodotta per interpretazione a video e successiva digitalizzazione in ambiente GIS la mappatura delle superfici ceduate. Per l’intera area investigata e per gli stessi anni di acquisizione del dato satellitare sono state reperite, presso i Comandi Stazione del Corpo Forestale dello Stato, le statistiche relative alle comunicazioni e autorizzazioni al taglio dei cedui rilasciate ai proprietari forestali dagli enti competenti per territorio. In seguito a validazione, la cartografia realizzata viene impiegata per valutare l’attendibilità dei dati forniti al Sistema Statistico Nazionale relativamente ai prelievi legnosi. Il confronto tra i due tipi di dati raccolti, avvenuto sulla base di un campione di 1127 unità amministrative, evidenzia una significativa sottostima della statistica ufficiale, con un rapporto medio fra superficie ceduata individuata da satellite e corrispondente statistica amministrativa pari a 1,41. Le motivazioni di tale sottostima sono verosimilmente riconducibili a processi semplificati di autorizzazione al taglio dei cedui e alla mancata tempestività di registrazione e/o perdita di dati che in alcuni casi gravano sul flusso di informazioni esistente tra gli enti amministrativi e il Corpo Forestale dello Stato incaricato di alimentare la statistica forestale ufficiale. Alla luce della sperimentazione condotta, viene proposta una procedura operativa basata sull’impiego di immagini SPOT5 per la calibrazione statistica del dato amministrativo in esame. La mappatura generata per interpretazione visuale delle immagini SPOT5 viene altresì utilizzata per testare l’accuratezza di differenti metodi di classificazione semi-automatica delle tagliate a raso. Le performance di approcci di classificazione object-oriented e pixel-oriented sono valutate in termini di accuratezza tematica raggiunta, applicando le due procedure a differenti sistemi di nomenclatura e set di dati in input. La sperimentazione evidenzia un possibile impiego operativo delle tecniche object-oriented finalizzato al riconoscimento semi-automatico delle superfici ceduate, mentre l’applicazione delle tecniche pixel-oriented non appare idonea.; The aim of this work is to test the potential of high resolution satellite images for monitoring coppice clearcuts in central-southern Italy. Through integration of a multitemporal set of multispectral SPOT5 images and ancillary information, a clearcuts map is produced by on-screen interpretation and subsequent digitalization in GIS environment. Official clearcut declarations by forest owners, collected by the national forest authority (Corpo Forestale dello Stato), are gathered for the same area and same years of satellite data acquisition. The obtained maps are used for assessing eventual differences with wood harvesting data of the National Statistic System (ISTAT). The comparison between the two kinds of data, carried out on a sample of 1127 administrative units, highlights a significant underestimation of the official statistics, with an average ratio between clearcut area observed by SPOT5 and the corresponding administrative statistics equal to 1,41. The underestimation by the administrative data is likely due to the simplified process of authorization of coppice clearcuts as well as the eventual lack of timeliness and/or loss of data that sometimes hinder the information flow from administrative bodies to national forest authority, that is in charge of feeding the official forest statistics. In the light of the experimentation carried out, an operational procedure by SPOT5 images is proposed for the statistical calibration of the administrative data on wood harvesting. Mapping by on-screen interpretation is also used for assessing the thematic accuracy of clearcut maps produced by semi-automatic classification procedures, experimentally developed with reference to various nomenclature systems and input dataset. Experimentation results highlight the potential of object-oriented classification techniques for clearcuts semi-automatic delineation, whereas the pixel-oriented procedure application has proven to be unsuitable. Description: Dottorato di ricerca in Ecologia forestale 2009-02-09T23:00:00Z http://hdl.handle.net/2067/2082 Title: Large-scale monitoring of coppice forest clearcuts by multitemporal very high resolution satellite imagery. A case study from central Italy Authors: Chirici, Gherardo; Giuliarelli, Diego; Biscontini, Daniele; Tonti, Daniela; Mattioli, Walter; Marchetti, Marco; Corona, Piermaria Abstract: Reliable assessment of forest resource stock, productivity and harvesting is a commonly agreed objective of environmental monitoring programs. Distinctively, the assessment of wood harvesting has become even more relevant to evaluate the sustainability of forest management and to quantify forest carbon budget. This paper presents the development and testing of procedures for assessing forest harvesting in coppice forests by very high resolution (VHR) satellite imagery. The study area is located in central Italy over approximately 34,000 km2. A set of SPOT5 HRG multispectral images was acquired for the study years (2002–2007). Official administrative statistics of coppice clearcutswere also acquired.More than 9500 clearcuts weremapped and dated by on-screen interpretation of the SPOT5 images. In a subset of the study area various methods for semi-automatic clearcut mapping were tested by pixel- and object-oriented approaches. The following results are presented: (i) clearcut map developed by visual interpretation of the SPOT5 images resulted in high thematic (overall accuracy of 0.99) and geometric (rootmean square error of clearcut boundary delineation of 5.3 m) reliability; (ii) object-oriented approach achieved significantly better accuracy than pixel-based methods for semi-automatic classification of the coppice clearcuts; (iii) comparison between mapped clearcut area and official forest harvesting statistics proved a significant underestimation by the latter (65% of the total mapped clearcut area). A sample-based procedure exploiting VHR satellite imagery is finally proposed to correct the official statistics of coppice clearcuts. Description: L'articolo è disponibile sul sito dell'editore www.sciencedirect.com 2010-12-31T23:00:00Z http://hdl.handle.net/2067/2083 Title: Sperimentazione di tecniche object oriented per la classificazione di uso/copertura del suolo Corine Land Cover da immagini satellitari a media risoluzione Authors: Giuliarelli, Diego; Corona, Piermaria; Lamonaca, Andrea Abstract: This work aims to assess the potential of segmentation and object oriented classification techniques of satellite images with medium spatial resolution, for land use/cover (Corine Land Cover, CLC) mapping. The tested procedures are assessed both in term of thematic accuracy and working time, with reference to a study area of about 4000 km2 in central Italy. The automatic procedure is carried out by segmentation of the pan-sharpened image and by subsequent classification using membership and standard nearest neighbour functions. Results are evaluated by sample circular photoplots taken from digital IT2000 orthophotos coverage. In terms of overall accuracy, object oriented classification achieves better results than conventional on screen interpretation. The classification shows difficulties for the identification of the “mixed” classes of CLC nomenclature system; however, even in these cases the object oriented techniques provide higher producer and user accuracy than on screen interpretation. On the whole, since they are able to produce more objective and more accurate cartographic products at similar costs, the application of the tested automatic techniques seems to be preferred to the conventional on screen interpretation for satellite images with medium spatial resolution. Description: L'articolo è disponibile sul sito dell'editore www.sisef.it 2006-12-31T23:00:00Z http://hdl.handle.net/2067/2092 Title: Confronto sperimentale tra superfici a ceduo tagliate a raso osservate mediante immagini satellitari ad alta risoluzione e tagliate riscontrate amministrativamente Authors: Corona, Piermaria; Giuliarelli, Diego; Lamonaca, Andrea; Mattioli, Walter; Tonti, Daniela; Chirici, Gherardo; Marchetti, Marco Abstract: The aim of this work is to test the potential of SPOT5 satellite images for monitoring coppice clearcuts. The clearcuts, delineated by on screen interpretation of the satellite images, are compared with the administrative statistics reported for a sample of 230 administrative units. Administrative statistics result significantly lower than those by satellite images, with an average ratio between clearcut area observed by SPOT5 images within each sample unit and the corresponding administrative statistics equal to 1.45. The underestimation by the administrative data is likely due to the simplified process of authorization of coppice clearcuts as well as the eventual lack of timeliness and/or loss of data that sometimes hinder the information flow from administrative bodies to National Forest Service, that is in charge of feeding the official forest statistics. In the light of the experimentation carried out, an operational procedure by SPOT5 images is proposed for the statistical calibration of administrative data about coppice clearcuts. Description: L'articolo è disponibile sul sito dell'editore www.sisef.it 2006-12-31T23:00:00Z http://hdl.handle.net/2067/2113 Title: Surveying black pine plantations in the province of Rieti (Italy) Authors: Lamonaca, Andrea; Calvani, Paolo; Giuliarelli, Diego; Corona, Piermaria Abstract: Durante il secolo scorso furono realizzati molti rimboschimenti di pino nero in ambito appenninico al fine di recuperare terreni degradati. Vari Autori hanno formulato proposte di gestione per la rinaturalizzazione di questi soprassuoli. La loro applicazione comporta però elevati costi di rilievo in sede di analisi. Obiettivo di questa nota è la proposizione di una metodologia di inventario ricognitivo degli attributi di questo tipo di soprassuoli che consenta di ottenere dati sufficientemente attendibili su ampie superfici, a costi relativamente contenuti. A livello sperimentale è stata realizzata la mappatura dei rimboschimenti di pino nero della provincia di Rieti. La tecnica k-NN è stata utilizzata per spazializzare la provvigione legnosa a partire da aree di saggio a terra con l’ausilio di un’immagine telerilevata Landsat 7 ETM+. A scopo esemplificativo, gli aspetti inventariali sono integrati da misure ecologico-paesistiche per la descrizione spaziale dei rimboschimenti mappati.; In the last century large afforestation programs were carried out in the Apennines to recover degraded lands, mainly by Pinus nigra plantations. Currently, many Authors have proposed management guidelines to foster the naturalization of such woodlands. However, such an option requires the availability of detailed surveys. The aim of this note is to propose a survey protocol for qualifying the landscape pattern of pine reafforestations and for mapping their growing stock on the basis of the k-Nearest Neighbor (k-NN) techniques. A case study application by Landsat 7 ETM+ imagery is here reported concerning the Pinus nigra plantations in the province of Rieti (Central Italy). 2007-12-31T23:00:00Z http://hdl.handle.net/2067/2117 Title: Post fire natural regeneration monitoring with the integrated use of high resolution remotely sensed images: the case study of the Pineta di Castel Fusano Authors: Chirici, Gherardo; Balsi, Marco; Bertini, Roberta; Bonora, Nico; Chiavetta, Ugo; Ottaviano, Marco; Corona, Piermaria; Lamonaca, Andrea; Giuliarelli, Diego; Mastronardi, Alessandro; Nardinocchi, Giovanni; Sambucini, Valter; Tonti, Daniela; Marchetti, Marco Abstract: La pineta di Castel Fusano (Roma) è stata colpita il 4 luglio del 2000 da un importante incendio boschivo in seguito al quale si è avviata nell’area una intensa rinnovazione naturale sia per via gamica che agamica. Ai fini di monitoraggio della suddetta rinnovazione sono stati realizzati una serie di rilievi a terra in aree campione nel 2003 e nel 2006. Negli stessi anni è stata acquisita la copertura di immagini telerilevate multispettrali ad altissima risoluzione Ikonos e Quick Bird. Scopo del presente lavoro è la sperimentazione di diverse metodologie finalizzate alla modellizzazione delle relazioni esistenti tra i dati telerilevati acquisiti e le misure realizzate a terra per la stima e la mappatura dei fenomeni di rinnovazione gamica e agamica. Sono stati per questo sperimentati metodi sia tradizionali di analisi regressiva multivariata, sia di tipo non parametrico, con algoritmi basati su reti neurali (Relevance Vector Machine e Multi-Layer Perceptron) e k-Nearest Neighbors. Le attività si inquadrano nell’ambito del progetto GRINFOMED - MEDIFIRE per il quale è stato realizzato un apposito software denominato Spatial Forest Modeller (SFM) capace di analizzare le relazioni tra variabili telerilevate e misurate a terra e di individuare i modelli predittivi migliori in modo da derivare mappe tematiche delle variabili acquisite mediante campionamento a terra. Il contributo illustra i dati acquisiti, le metodologie di analisi e di modellizzazione e i risultati ottenuti. Viene inoltre illustrato il funzionamento del software SFM.; Stone pine stand of Castel Fusano (Rome) burnt on July the 4th 2000 during a huge wildfire. As a consequence of the fire an intensive natural sexual and asexual regeneration began. In order to monitor such a regeneration field surveys were carried out in 2003 and 2006 in sample plots. Remotely sensed high resolution images from Ikonos and Quick Bird were acquired for the same years. The purpose of this work is to test different methodologies for modeling existing relationships between remotely sensed images and ground collected data in order to estimate and to map both sexual and asexual regeneration. For such a purpose different methodologies were tested: step-wise Muliple Linear Regression, Neural Networks (Relevance-Vector-Machine and the Multi-Layered-Perceptron) and the k-Nearest-Neighbors. These activities were carried out within the framework of the GRINFOMED- MEDIFIRE also developing a specific software named Spatial Forest Modeler (SFM) able to analyze existing relationships between remotely sensed variables and data collected in the field in order to identify the best available models to map and estimate the studied variables acquired on the basis of a field sampling design. The present paper presents data collected in the field, analysis and modeling methods and achieved results. The SFM software is also presented. 2007-12-31T23:00:00Z http://hdl.handle.net/2067/1902 Title: Deadwood in forest stands close to old-growthness under Mediterranean conditions in the Italian Peninsula Authors: Corona, Piermaria; Lombardi, Fabio; Chirici, Gherardo; Marchetti, Marco; Tognetti, Roberto; Lasserre, Bruno; Barbati, Anna; Ferrari, Barbara; Di Paolo, Silvia; Giuliarelli, Diego; Iovino, Francesco; Nicolaci, Antonino; Bianchi, Livio; Maltoni, Alberto; Travaglini, Davide Abstract: Considering that indicators of old-growth features can vary across the European ecoregions, this paper provides some results to identify the distinctive traits of old-growth forests in the Mediterranean ecoregion. Deadwood occurrence as indicator of naturalness is investigated in some remote forest areas that have developed in absence of anthropogenic disturbance over the past few decades. Eleven study sites across the Italian peninsula were elected and records of deadwood were carried out in 1-ha size plots. Deadwood volume, deadwood types and decay stages were inventoried in the selected sites. The amounts of deadwood indicate a large variability among the investigated forest stands: the total volume ranged between 2 and 143 m3ha-1, with an average of 60 m3ha-1. Lying deadwood is the most abundant component of deadwood in the investigated forests, due to the natural mortality occurring in the stands in relation to the processes established in the last decades. On the contrary, stumps are the less represented type of deadwood in almost all the study areas. All the decay classes are present in each study site. The amount of deadwood in Southern Europe, even if lower than that reported for North and Central European countries, could have a different meaning due to the faster decay occurring in Mediterranean forest ecosystems. For this reason, old-growth features and the characteristics of each indicator should be framed and referred to well-defined climatic and biogeographic contexts. Distinctively, under the conditions here investigated, three main deadwood features prove to characterize forest stands close to old-growthness: a ratio of dead to living wood not lower than 10%; lying deadwood much more abundant than the standing one; large range of deadwood size and decay classes across all the deadwood components. 2009-12-31T23:00:00Z http://hdl.handle.net/2067/1903 Title: Support of multispectral very high solution remotely sensed imagery for old-growth beech forest detection. Authors: Di Paolo, Silvia; Giuliarelli, Diego; Ferrari, Barbara; Barbati, Anna; Corona, Piermaria Abstract: In the Mediterranean basin human activity has modified landscapes for millennia,nevertheless there are few remote forest areas relatively untouched long enough from direct anthropogenic disturbance to develop old-growth attributes. The aim of this note is to assess the potential of QuickBird (QB) satellite multispectral imagery for detecting old-growth forest stands, considering as case study a Mediterranean beech forest in central Italy. The segmentation-based analysis of QB image proved to be a promising tool to detect scaledependent pattern of forest structural heterogeneity. Values of remotely sensed attributes are compared in old-growth and not-old-growth stands: the statistical analysis showed that oldgrowthness is associated to the variability of multispectral reflectance from the image objects (polygons). Green band variability, notably, expressed by Ratio_band_2 has proven to be helpful for predicting old-growthness. 2009-12-31T23:00:00Z http://hdl.handle.net/2067/2309 Title: Experimenting the design-based k-NN approach for mapping and estimation under forest management planning Authors: Mattioli, Walter; Quatrini, Valerio; Di Paolo, Silvia; Di Santo, Daniele; Giuliarelli, Diego; Angelini, Alice; Portoghesi, Luigi; Corona, Piermaria Abstract: Estimation and mapping of forest attributes are a fundamental support for forest management planning. This study describes a practical experimentation concerning the use of design-based k-Nearest Neighbors (k-NN) approach to estimate and map selected attributes in the framework of inventories at forest management level. The study area was the Chiarino forest within the Gran Sasso and Monti della Laga National Park (central Italy). Aboveground biomass and current annual increment of tree volume were selected as the attributes of interest for the test. Field data were acquired within 28 sample plots selected by stratified random sampling. Satellite data were acquired by a Landsat 5 TM multispectral image. Attributes from field surveys and Landsat image processing were coupled by k-NN to predict the attributes of interest for each pixel of the Landsat image. Achieved results demonstrate the effectiveness of the k-NN approach for statistical estimation, that is compatible with the produced forest attribute raster maps and also proves to be characterized, in the considered study case, by a precision double than that obtained by conventional inventory based on field sample plots only. Description: L'articolo è disponibile sul sito dell'editore www.sisef.it 2011-12-31T23:00:00Z