1,720,955 research outputs found
A Multi-Century Meteo-Hydrological Analysis in the Italian Alps: Daily Streamflow (1862–2022) at Different Time Scales
No full textIn this paper, the second longest time series of daily hydrometric levels and streamflow for an Italian river, Adige, in the Italian Alps, also one of the longest worldwide and unpublished so far, is reconstructed and analyzed. Daily streamflow prior to 1923, when the official mean daily discharge was first published, is estimated based on daily water levels collected since January 1862, cross-section geometry, discharge, and surface velocity measurements at the hydrometric station of Trento. The main objective of this paper is the identification, attribution, and quantification of the impact of natural and anthropic factors on changes in streamflow in a mountain region with marked orographic and climatic gradients. The resulting 161-year-long time series, until December 2022, for this 9763 km2 catchment is firstly analyzed in search of trends and their statistical significance, spectral properties at different time scales and periods, changes in the monthly regime prior to and after the constructions of reservoirs. The observed -1.0 mm year-1 slope of the annual streamflow linear trendline is statistically significant and indicates a decline of -1.4% per decade of available streamflow in the river, similar to the one observed in nearby basins. The spectral analysis conducted with the wavelet transform indicates that a sudden change of spectral properties and trends of daily streamflow occurred inside the pre- and post-reservoir construction period and can be explained also as a result of a more environment-oriented legislation. A wavelet coherence spectrum between streamflow and teleconnection indices indicates the existence of a significant coherence with the Atlantic Multidecadal Oscillation only. The comparison with estimated actual reference evapotranspiration losses and temperature points out that the observed temperature increase is not sufficient to explain the observed hydrological losses, being precipitation almost constant over the observation period. The observed increase of 86 mm of hydrological losses over the last century is explained in terms of water withdrawals for agricultural, civil, and industrial needs (38 mm), enhanced evapotranspiration due to temperature increase (30 mm), expanded artificial lakes' surface (1 mm), the residual of 17 mm being attributed to land-use changes with afforestation
A multi-century meteo-hydrological analysis for the Adda river basin (Central Alps). Part II : Daily runoff (1845–2016) at different scales
Full text linkA high-quality daily runoff time series of the Lake Como inflow and outflow, the longest for Italian Alps, was reconstructed for the 1845–2016 period in the Adda river basin. It was compared with contemporary monthly precipitation and temperature observations and estimated potential evapotranspiration losses. Trend analyses were conducted for daily flow maxima and 7-day duration minima of inflows into the lake showing a non-significant decrease and a significant increase, respectively. Although the annual precipitation time series exhibits a non-significant decrease, annual runoff volumes decrease with a rate of −136 mm⋅century−1, with a significance level of 5%. Possible causes of variability of rainfall and runoff as North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation and Western Mediterranean Oscillation indexes and sunspot activity were also explored. Wavelet spectra analyses of monthly precipitation and runoff show some changes in the energy both at small and large scales and are effective in pointing out phenomena as droughts and the effects of dams' regulation. Conversely, wavelet coherence spectra indicate a weak correlation of NAO and sunspots with precipitation. In addition, the analysis of temperature and potential evapotranspiration tendencies suggests that the decrease of runoff has to be ascribed mostly to anthropogenic factors, including water abstraction for irrigation and increased evapotranspiration losses due to natural afforestation and, only in part, to climatic variability
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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