1,720,991 research outputs found
Comparing leaf area index estimates in a Mediterranean forest using field measurements, Landsat 8, and Sentinel-2 data
Full text linkBackground Leaf area index (LAI) is a key indicator for the assessment of the canopy’s processes such as net pri mary production and evapotranspiration. For this reason, the LAI is often used as a key input parameter in ecosystem services’ modeling, which is emerging as a critical tool for steering upcoming urban reforestation strategies. However,
LAI feld measures are extremely time-consuming and require remarkable economic and human resources. In this context, spectral indices computed using high-resolution multispectral satellite imagery like Sentinel-2 and Landsat 8, may represent a feasible and economic solution for estimating the LAI at the city scale. Nonetheless, as far as we
know, only a few studies have assessed the potential of Sentinel-2 and Landsat 8 data doing so in Mediterranean forest ecosystems. To fll such a gap, we assessed the performance of 10 spectral indices derived from Sentinel-2 and Landsat 8 data in estimating the LAI, using feld measurements collected with the LI-COR LAI 2200c as a reference. We hypothesized that Sentinel-2 data, owing to their fner spatial and spectral resolution, perform better in estimating vegetation’s structural parameters compared to Landsat 8.
Results We found that Landsat 8-derived models have, on average, a slightly better performance, with the best model (the one based on NDVI) showing an R2 of 0.55 and NRMSE of 14.74%, compared to R2 of 0.52 and NRMSE of 15.15% showed by the best Sentinel-2 model, which is based on the NBR. All models were afected by spectrum satu ration for high LAI values (e.g., above 5).
Conclusion In Mediterranean ecosystems, Sentinel-2 and Landsat 8 data produce moderately accurate LAI estimates during the peak of the growing season. Therefore, the uncertainty introduced using satellite-derived LAI in ecosystem services’ assessments should be systematically accounted fo
Mismatch of regulating ecosystem services for sustainable urban planning. PM10 removal and urban heat island effect mitigation in the municipality of Rome (Italy)
No full textBalancing the ecosystem service (ES) mismatch should be a goal of sustainable urban planning. However, (i) many urban areas lack an assessment of this mismatch and (ii) scientific findings are not easily translatable into good practices. In this study, we assessed the mismatch for two regulating ESs—regulation of air quality (intended as PM10 removal by vegetation) and urban temperature regulation—in the Municipality of Rome (Italy). The spatial distribution of the ES mismatch was then used to identify priority intervention areas (PIAs), namely those that would benefit the most from targeted urban planning. To do so, we computed composite indicators of supply and demand for each ES, adopting a process-based approach. Additionally, a monetary valuation of the related benefits associated with urban green infrastructure is provided. Our findings suggest that regulation of air quality falls short in highly urbanized areas, whereas a mismatch in urban temperature regulation
is observed in both highly urbanized areas and some agricultural lands. The majority of the PIAs fall in the eastern and southern sectors of the Municipality of Rome. Our findings also indicate that urban planning should consider urban regeneration practices and reforestation of existing green areas within the PIAs. Sustainable urban planning can produce remarkable environmental benefits, as estimated, for the Municipality of Rome, up to several hundred million euros per year, depending on the methodology used for the monetary valuation
Regulating ecosystem services and green infrastructure. Assessment of urban heat island effect mitigation in the municipality of Rome, Italy
No full textThe Urban Heat Island (UHI) effect is one of the main environmental impacts of urbanization, affecting directly human health and well-being of the city dwellers, and also contributing to worsen environmental quality. As a key strategy to address sustainable urban development, the EU has advocated the development of Nature-Based solutions, such as the implementation of Green Infrastructure (GI), which can deliver a wide range of Regulating Ecosystem Services (ES). In this article, the ES of climate regulation provided by GI has been analyzed in the Municipality of Rome, Italy, characterized by a complex territory and by a Mediterranean climate. The methodological approach allowed to characterize the UHI and to analyze its features in a spatially explicit way and on a seasonal basis, through the Land Surface Temperature (LST) derived from Landsat-8 data. The cooling capacity of different GI elements (peri-urban forest, urban forest, street trees), as well as the effect of vegetation cover and tree diversity on the provision of this regulating ES were assessed. The results show that GI significantly mitigates the hot urban climate during summer, with an effect that is dependent on the GI element and the environmental constrains to which it is exposed. NDVI and tree cover resulted the main indicators of the provision of the ES of climate regulation, highlighting that GI elements such as urban and peri-urban forests have the highest potential to provide this ES in a Mediterranean city. In the context of the Mapping and Assessment of Ecosystems and their Services (MAES) process, our results lend support to claims that GI is important for an ecosystem-based climate adaptation strategy in urban environments, contributing to the definition of knowledge based criteria and indicators, relevant for decision-making in Mediterranean cities
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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