1,720,970 research outputs found
Gli effetti del cambiamento climatico sul regime idrologico nelle Alpi: Un caso di studio in Italia = Climate change will affect hydrological regimes in the Alps: A case study in Italy
Full text linkClimate change will affect hydrological cycle and water resources in the Alps. Here we sketched potential future (2045-2054) hydrological cycle under prospective climate change scenarios within an Alpine river of Italy: Serio (ca. 300 km2). Therein, hydrology is highly dependent upon snow cover cycle, very likely to be affected by climate changes. We set up and validated a hydrological model able to mimic water resources regime of the river. We then use downscaled future temperature and precipitation from two general circulation models GCMs to feed the hydrological model and obtain projected hydrological regimes, at flow sections at different altitudes within the catchment. The scenarios and storylines from the adopted GCMs differ from one another with respect to projected precipitation and temperature amount, but agree upon decrease of the former and increase of the latter. All hydrological scenarios agree upon prospective shrinkage of seasonal snow cover due to increased temperature, and upon prospective increase of Fall and Winter stream flows as due to increased liquid precipitation. Lower discharges are projected during Spring and Summer, in view of decreased rainfall and snow cover at thaw, and the CCSM3 model provides shifting of thaw season to one month earlier. Higher catchments are more impacted because Winter flows increase more proportionally. © 2013 Journal of Alpine Research
Modelling soil removal from snow avalanches: a case study in the North-Western Italian Alps
No full textEffects of future climate change on a river habitat in an italian alpine catchment
No full textThe impact of prospective climate change on the hydrological and ecological status of the mountain stretch of the Serio river (ca. 300 km2) in the Northern Italian Alps was investigated. A hydrological model was used to mimic theflow regime, and experimental suitability curves were used to assess weighted usable area (WUA) for brown trout ( Salmo trutta ) in different stages (adult, young, and spawning), and four macroinvertebrates families ( Leuctridae, Heptageniidae, Limnephilidae, and Limoniidae ). Discharge-WUA curves were obtained using instream flow incremental methodology/physical habitat simulation system (IFIM-PHABSIM), and a seasonal WUA assessment was carried out. The future (until 2100) hydrological cycle was projected using outputs from two general circulation models from Assessment Report 5 of the Intergovernmental Panel on Climate Change (IPCC). The results display a potential for a large flow decrease yearly, until -60% at 2050 and -56% at 2090. Spring melt peaks will be largely dampened, with the largest projected decrease of -60% in 2050 and -66% in 2090. Also fall flows will be largely smoothed, down to -70% for 2050 and -56% for 2090. To quantify habitat quality, a specific quantile WUA20%, was used and exceeded presently for 292 days in a year, and the percentage of critical days nc% when WUA < WUA20%. Adult trouts will have decreasing nc% yearly (from 20% now to down to 13% in 2090), increasing in winter and spring and decreasing in fall. Young trouts will have decreasing nc% yearly (from 20% now to down to 2% in 2040 and 2090), but increasing in winter. Spawning, occurring in winter, will have lower nc% (from 16% now, to down to 8% in 2090). Macroinvertebrate families will have constant nc% yearly, unless for Leuctridae (from 20% now to up to 38% in 2050), and noticeable decrease of nc% in winter for Leuctridae until 2090, increase in spring and summer, and decrease in fall for all families until 2090. Correlation analysis of the WUA against weather and hydrological variables displayed that temperature is the most influencing variable, decreasing habitat suitability for all species in fall, and increasing suitability in spring, unless for young trouts
Future Hydrological Regimes in the Upper Indus Basin: A Case Study from a High-Altitude Glacierized Catchment
Full text linkThe mountain regions of the Hindu Kush, Karakoram, and Himalayas (HKH) are considered Earth’s “third pole,” and water from there plays an essential role for downstream populations. The dynamics of glaciers in Karakoram are complex, and in recent decades the area has experienced unchanged ice cover, despite rapid decline elsewhere in the world (the Karakoram anomaly). Assessment of future water resources and hydrological variability under climate change in this area is greatly needed, but the hydrology of these high-altitude catchments is still poorly studied and little understood. This study focuses on a particular watershed, the Shigar River with the control section at Shigar (about 7000 km2), nested within the upper Indus basin and fed by seasonal melt from two major glaciers (Baltoro and Biafo). Hydrological, meteorological, and glaciological data gathered during 3 years of field campaigns (2011–13) are used to set up a hydrological model, providing a depiction of instream flows, snowmelt, and ice cover thickness. The model is used to assess changes of the hydrological cycle until 2100, via climate projections provided by three state-of-the-art global climate models used in the recent IPCC Fifth Assessment Report under the representative concentration pathway (RCP) emission scenarios RCP2.6, RCP4.5, and RCP8.5. Under all RCPs, future flows are predicted to increase until midcentury and then to decrease, but remaining mostly higher than control run values. Snowmelt is projected to occur earlier, while the ice melt component is expected to increase, with ice thinning considerably and even disappearing below 4000 m MSL until 2100
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
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