Search results for "Land cover"
showing 10 items of 149 documents
Carbon Stocks in Peri-Urban Areas: A Case Study of Remote Sensing Capabilities
2014
Peri-urban areas are the extension of cities into contiguous areas, where households and farms coexist. Carbon stocks (CSs) assessment, a concept here extended to urban features, has not yet been studied in depth over peri-urban areas due to uncertainties in such CSs quantification, level of detail required about construction materials, and the high spatial variability of those stocks. Remote sensing (RS)-based techniques have been successfully utilized in urban areas for assessing phenomena such as soil sealing, sprawl patterns, and dynamics of surface imperviousness, especially focusing on land cover classification at high to medium spatial scales. Over the floodplain study area of Emilia…
Analysis of broadband surface BRDFs derived from TOA SW CERES measurements for surfaces classified by the IGBP land cover
2012
Most studies on the reflectance properties of the Earth's surface are addressed estimating the bidirectional reflectance distribution function (BRDF) of high spatial resolution and high spectral resolution satellite measurements. This article assesses the development of broadband (BB) BRDFs from radiances corresponding to large footprints classified according to the International Geosphere-Biosphere Programme (IGBP) land-cover classification. Top-of-atmosphere (TOA) shortwave (SW) CERES (Clouds and the Earth's Radiant Energy System) measurements are employed to invert the bidirectional reflectance factor (BRF) Rahman–Pinty–Verstraete (RPV) model for regions identified with the same IGBP typ…
Monitoring daily evapotranspiration at a regional scale from Landsat-TM and ETM+ data: Application to the Basilicata region
2008
Summary The increasing interest of hydrological, climatic and meteorological models in the different components of the surface energy balance has encouraged the development of operational methods for estimating surface energy fluxes at a regional scale. In this paper, a sequence of three high-resolution satellite-based surface energy fluxes images are analyzed over an extensive area with a large variety of land uses. Two images from Landsat 7-ETM+ (1999, 2002) and one from Landsat 5-TM (2004) are collected covering the whole Basilicata region (Southern Italy). A Simplified version of a Two-Source Energy Balance (STSEB) model is used to retrieve the surface sensible heat flux. A balance betw…
L-Band Vegetation optical depth and effective scattering albedo estimation from SMAP
2017
Abstract Over land the vegetation canopy affects the microwave brightness temperature by emission, scattering and attenuation of surface soil emission. Attenuation, as represented by vegetation optical depth (VOD), is a potentially useful ecological indicator. The NASA Soil Moisture Active Passive (SMAP) mission carries significant potential for VOD estimates because of its radio frequency interference mitigation efforts and because the L-band signal penetrates deeper into the vegetation canopy than the higher frequency bands used for many previous VOD retrievals. In this study, we apply the multi-temporal dual-channel retrieval algorithm (MT-DCA) to derive global VOD, soil moisture, and ef…
A generalized soil-adjusted vegetation index
2002
Operational monitoring of vegetative cover by remote sensing currently involves the utilisation of vegetation indices (VIs), most of them being functions of the reflectance in red (R) and near-infrared (NIR) spectral bands. A generalized soil-adjusted vegetation index (GESAVI), theoretically based on a simple vegetation canopy model, is introduced. It is defined in terms of the soil line parameters (A and B) as: GESAVI=(NIRBRA)/(R+Z), where Z is related to the red reflectance at the cross point between the soil line and vegetation isolines. As Z is a soil adjustment coefficient, this new index can be considered as belonging to the SAVI family. In order to analyze the GESAVI sensitivity to s…
Factors Influencing Soil Organic Carbon Stock Variations in Italy During the Last Three Decades
2010
Soils contain about three times the amount of carbon globally available in vegetation, and about twice the amount in the atmosphere. However, soil organic carbon (SOC) has been reduced in many areas, while an increase in atmospheric CO2 has been detected. Recent research works have shown that it is likely that past changes in land use history and land management were the main reasons for the loss of carbon rather than higher temperatures and changes of precipitation resulting from climate change. The primary scope of this work was to estimate soil organic carbon stock (CS) variations in Italy during the last three decades and to relate them to land use changes. The study was also aimed at f…
Multi-temporal analysis of MODIS Land Products over the Amazon region
2012
In a global warming scenario there is an increase interest in examining climate trends at specific biomes such as the tropical rainforest biome. The Amazonian region is the largest carbon sink, so changes in this area are expected to have a direct impact over the climate change. In this work we analyse the temporal evolution (trends and anomalies) of different land parameters from 2001 to 2010 over the Amazonian forest. For this purpose, we used Moderate Resolution Imaging Spectroradiometer (MODIS) Land Products at 0.05° latitude/longitude Climate Modeling Grid (CMG), namely, combined Terra/Aqua 16-day Albedo (MCD43C3), Terra monthly Land Surface Temperature & Emissivity (MOD11C3), Terra mo…
Construcción de una tipología rural/urbana para los municipios españoles
2016
[ES] Este artículo pretende establecer criterios para delimitar de modo riguroso qué es lo que constituye un territorio rural o urbano, dadas las limitaciones de las metodologías tradicionales. En segundo lugar, se propone una tipología rural/urbana a escala municipal para España tomando en consideración tres criterios: la demografía —combinando densidades con umbrales mínimos de población— la información sobre coberturas y usos del suelo y el grado de accesibilidad desde el mundo rural a las ciudades. El resultado es el establecimiento de seis tipos distintos de municipios.
Conventional and fuzzy comparisons of large scale land cover products: Application to CORINE, GLC2000, MODIS and GlobCover in Europe
2012
One of the major drawbacks of land cover products is the lack of interoperability among them. Since their development was driven by different national or international initiatives, they were developed for different purposes and hold diverse technical characteristics. Thus, comparison among products and quality monitoring is necessary in assessing their usefulness. This paper provides a methodology to compare global land cover maps that allows for differences in legend definitions among products. Two different approaches were considered for map comparison, a Boolean approach and a new methodology based on fuzzy set theory in which the Land Cover Classification System (LCCS) acted as a genera…
A Comparison of Advanced Regression Algorithms for Quantifying Urban Land Cover
2014
Quantitative methods for mapping sub-pixel land cover fractions are gaining increasing attention, particularly with regard to upcoming hyperspectral satellite missions. We evaluated five advanced regression algorithms combined with synthetically mixed training data for quantifying urban land cover from HyMap data at 3.6 and 9 m spatial resolution. Methods included support vector regression (SVR), kernel ridge regression (KRR), artificial neural networks (NN), random forest regression (RFR) and partial least squares regression (PLSR). Our experiments demonstrate that both kernel methods SVR and KRR yield high accuracies for mapping complex urban surface types, i.e., rooftops, pavements, gras…