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Pubblicazioni Scientifiche
Filtri di ricerca 4 risultati
Pubblicazioni per anno
Application of k-nearest neighbor on multispectral images to estimate forest parameters; Aplicação de k-nearest neighbor em imagens multispectrais para a estimativa de parâmetros florestais
Giongo
,
Marcos Vinicius
,
Chiavetta
,
U.
,
Soares Koehler
,
Henrique Soares
,
Machado
,
S. A.
,
Kirchner
,
Flávio Felipe
Mostra abstract
Natural resources management requires several parameters estimate in order to support the identification of the best alternatives to forest areas management. In particular, forest ecosystems require a complex and increasing set of descriptive information, where forest inventories put up important information, however not in a continuous spatial way. Lately, several scientific researches have been focusing on establishing methodologies to relate data from field to those obtained from multispectral images. Modeling these relations can extend the estimates of forest inventory data to not sampled areas. This research evaluated performance of non-parametric analysis using the K-Nearest Neighbor (k-NN) on SPOT 5 images. It evaluated the results obtained from the spatialization of some forest attributes in a forest area located at Molise, Italy. Among several methodologies for spatial distance calculations, the use of multiregressive non-parametric distances revealed the best results. Density and number of species on the ground revealed a Pearson correlation coefficient of = 0.58 as compared to data obtained from multispectral images, lightly lower than the obtained for basal area and volume, which were = 0.62 and 0.71, respectively.
Assessment of potential bioenergy from coppice forests trough the integration of remote sensing and field surveys
Lasserre
,
Bruno
,
Chirici
,
Gherardo
,
Chiavetta
,
U.
,
Garfì
,
Vittorio
,
Tognetti
,
Roberto
,
Drigo
,
Rudi
,
Di Martino
,
P.
,
Marchetti
,
Marco
remote sensing
forest inventory
sustainable forest management
coppice
firewood biomass
k-nearest neighbours
Mostra abstract
A spatially explicit knowledge of forest resources is essential to support the sustainable use of wood as a fuel for producing energy (firewood).This paper describes the integrated use of remotely sensed data and sample based forest inventories to derive a biomass map for coppice forest, resulted estimated potential biomass available is contrasted with local domestic consumptions at the municipality level. The test was carried out in an environmentally and socially homogeneous district of Apennine Mountains (Alto Molise, south-central Italy) coupling multispectral high resolution Landsat 7 ETM+ satellite imagery and a local forest inventory trough the application of the non-parametric estimation procedure k-Nearest Neighbours (k-NN). Several forest management scenarios were applied in order to evaluate their impact on the potential availability of firewood from coppice forests.The paper introduces data and methods used and presents the achieved results both in terms of the accuracy of the biomass map produced by k-NN and of the relationship between the potential availability and demand for firewood.These results demonstrated that k-NN is able to estimate the biomass of coppice forest in the test area with an accuracy level comparable with recent similar application of k-NN carried out in Boreal regions (RMSE of 25.6%).The application of different forest management scenarios have a significant impact on local estimated firewood balance between potential supply from coppice forests and demand for domestic consumption, depending of the scenarios the net balance changed up to 84%. © 2010 Elsevier Ltd.
Post fire natural regeneration monitoring with the integrated use of high resolution remotely sensed images: The case study of the Pineta di Castel Fusano; Monitoraggio della rinnovazione naturale post incendio tramite l'uso integrato di immagini telerilevate ad alta risoluzione: Il caso della pineta di Castel Fusano
Chirici
,
Gherardo
,
Balsi
,
Marco
,
Bertini
,
Roberta
,
Bonora
,
Nico
,
Chiavetta
,
U.
,
Ottaviano
,
Marco
,
Corona
,
P.
,
Lamonaca
,
Andrea
,
Giuliarelli
,
Diego
,
Mastronardi
,
Alessandro
,
Nardinocchi
,
Giovanni
,
Sambucini
,
Valter
,
Tonti
,
Daniela
,
Marchetti
,
Marco
remote sensing
forest wildfires
k-nearest neighbors
natural re generation
neural networks
spatialisation
Mostra abstract
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.
Estimation of forest attributes by integration of inventory and remotely sensed data in Alto Molise; Stima di attributi forestali tramite integrazione di dati inventariali e immagini telerilevate nell'Alto Molise
Chiavetta
,
U.
,
Chirici
,
Gherardo
,
Lamonaca
,
Andrea
,
Lasserre
,
Bruno
,
Ottaviano
,
Marco
,
Marchetti
,
Marco
Mostra abstract
Forest ecosystems for their important multifunctional value, need a complex and increasing amount of descriptive information to support their management. Ecological and environmental related attributes have became nowadays important as traditional ones, such as wood growing stock and basal area. The correct application of Sustainable Forest Management criteria is boosted by spatial contiguous knowledge of such attributes. For such a reason in the last years a huge number of scientific experiences in the forest area have been concentrated to study the relationship between data acquired in the field and remotely sensed multispectral images. Models based on such relationships can be used to estimate and map forest attributes acquired in the field on the basis of a statistical sampling design. can be sucould not take in consideration spatially structured data. In last years many researches have focused on possible relationships between field data and remote sensed informations derived from multispectral imagery. Modeling these relationships allows to extend inventory data to not explored surfaces. In this paper were discussed results on spatializing forest biometrical attributes, tree heterogeneity and dimensional heterogeneity assessed during an inventory of Mountain Community "Alto Molise" (IS) throw Spot 5 and Lansat TM 7 imagery. For this purpose a multilinear regression and a k-Nearest Neighbor classifier were used.