Search results for "Spatial"
showing 10 items of 2121 documents
Diel variability in counts of reef fishes and its implications for monitoring
2006
Studies of reef fish assemblages in space rarely consider the effects of temporal variability on spatial comparisons, and when they do, usually examine timescales of months to years. The nature of fish monitoring surveys is such that particular locations may be surveyed at one time of day, and surveys designed to establish the degree of spatial variability in assemblages may be confounded if the order of sampling within treatments is not randomised with respect to time of day. In this study, we tested the degree of temporal variability in temperate reef fish counts at the same sites in New Zealand and Italy, within and between days. Repeated counts separated by months returned quite differe…
Application and evaluation of biomagnetic and biochemical monitoring of the dispersion and deposition of volcanically-derived particles at Mt. Etna, …
2010
article i nfo Article history: Received 6 August 2009 Accepted 4 January 2010 Available online xxxx Biomagnetic monitoring, using tree leaves as passive surfaces for particle collection, has been shown to be a promising technique for assessing the dispersion and deposition of particles in the context of anthropogenic pollution. By comparing leaves' magnetic properties with trace metal levels measured in the leaves, we here assess the utility of the biomagnetic technique as a sensitive, fast and inexpensive method for assessment of volcanic plume deposition. Samples of sweet chestnut leaves (Castanea sativa) were collected from the area surrounding Mt. Etna volcano in Sicily during the 2008 …
Deglaciation history of Latvia
2004
This chapter discusses the deglaciation history of Latvia. The earliest deglaciation schemes of Latvia were based entirely on morphological features. The spatial distribution of glacial landforms, with crests transverse to glacier movement combined with radiocarbon dates and biostratigraphical evidence, have provided the principal data for the reconstruction of the deglaciation process from the mid-1960s until the present. A deglaciation history should be based on multiple criteria. Attention should be paid to the identification of ice-marginal formations, and complex studies are also needed, including the investigation of the spatial distribution and internal composition of subglacial land…
Contrasting textural record of two distinct metamorphic events of similar P-T conditions and different durations
2005
A structural, metamorphic and geochronological study of the StareMesto belt implies the existence of two distinct metamorphic events of similar peak P-T conditions (700-800 � C, 8-10 kbar) during the Cambro-Ordovician and the Carboniferous tectonometamorphic events. The hypothesis of two distinct periods of metamorphism was suggested on the basis of structural discordance between an undoubtedly Carboniferous granodiorite sill intrusion and earlier Cambro-Ordovician fabrics of a banded amphibolite complex. The analysis of crystal size distribution (CSD) shows high nucleation density (N0) and low average growth rate (Gt) for Carboniferous mylonitic metagabbros and mylonitic granodiorites. The…
Intercomparison of SO2 camera systems for imaging volcanic gas plumes
2015
Abstract SO 2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO 2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO 2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO 2 cameras. In the first part of the experiment, the various technical designs are compared and the advantage…
A fuzzy-based tool for modelization and analysis of the vulnerability of aquifers: a case study
2005
Abstract A fuzzy-based tool, called FUZZY-SRA (Fuzzy Spatial Reliability Analysis), is used for realizing a more “reliable” study of the values of the final parameters concerning the vulnerability of aquifers located in the territory of Cava de' Tirreni, city in the district of Salerno (Italy). The SINTACS method is adopted for evaluating the involved parameters and these evaluations are modelled from attributes represented from triangular fuzzy numbers which supply the overall final information if combined with suitable algebraic operations. The tool FUZZY-SRA is implemented inside a GIS (Geographical Information Systems) software.
Sweet chestnut (Castanea sativa) leaves as a bio-indicator of volcanic gas, aerosol and ash deposition onto the flanks of Mt Etna in 2005–2007
2009
Sweet chestnut leaves (Castanea sativa) collected from the flanks of Mt Etna volcano in 2005-2007 were analysed by inductively-coupled plasma mass spectrometry to investigate the spatial and temporal variability of element concentrations. The aim of this work was to determine whether these leaves are a bio-indicator for volcanic gas, aerosol and ash deposition and to gain new insights into the environmental effects of quiescent and eruptive volcanic plumes. Results show a positive correlation between sample variability in the concentration of elements in Castanea sativa and enrichment factors of elements in the plume. The spatial and temporal variability of chalcophilic elements (As, Cd, Cu…
Environmental and spatial correlates of community composition, richness and status of boreal lake macrophytes
2013
Abstract We assessed the relative roles of natural covariates, human disturbance (water quality and catchment land use) together with geography in driving variation in aquatic macrophyte community composition, richness and status among 101 lakes in southern and central Finland. In addition to all species together, we studied different growth forms (i.e. emergent and submerged macrophytes and aquatic bryophytes) separately. Partial redundancy analysis (taxonomic composition) and partial least-squares regression (species richness and status index) were employed to display the share of variability in macrophyte assemblages that was attributable to the environmental factors (both natural and hu…
On Augmented Reality for the Learning of 3D-Geometric Contents: A Preliminary Exploratory Study with 6-Grade Primary Students
2019
Nowadays, Augmented Reality (AR) is one of the emerging technologies with a greater impact in the Education field. Research has proved that AR-based activities improve the teaching and learning processes. Also, the use of this type of technology in classroom facilitates the understanding of contents from different areas as Arts, Mathematics or Science. In this work we propose an AR-based instruction in order to explore the benefits in a 6th-grade Primary course related to 3D-geometry shapes. This first experiment, designed from an exploratory approach, will shed light on new study variables to perform new implementations whose conclusions become more consistent. The results obtained allow u…
Effet du relief sur la variabilité de descripteurs des saisons des pluies en Afrique de l’Est.
2011
6 pages; International audience; Les variations spatiales des différents descripteurs des saisons des pluies tropicales (durée, fréquence et intensitédes pluies…) sont mal connues, notamment en régions accidentées. Elles ont pourtant une réelle incidence agroclimatique.Au Kenya, ces descripteurs sont fortement contraints par la géographie, y compris aux échelles fines. L’exemple du versantest du Mont Kenya montre une gamme de conditions agro-écologiques, sous l’influence du schéma général reliantl’augmentation des pluies avec l’altitude. L’altitude influence principalement la durée des deux saisons des pluies (Long etShort rains). La fréquence des jours de pluies est également modulée par l…