1,720,965 research outputs found
Investigation of Groundwater Contribution to Stream Flow under Climate and Land Use Changes: A Case Study in British Columbia, Canada
No full textGroundwater contributes a significant proportion of stream flow, and its contribution varies temporally throughout the year. The objective of this study was to investigate the temporal dynamics of groundwater contribution to stream flow under the effects of climate and land use changes. A study area of the Mainstem sub-watershed of the Kiskatinaw River watershed, British Columbia, Canada was used as a case study. A physically conceptual model, Gridded Surface Subsurface Hydrologic Analysis (GSSHA), was developed for the study area. One greenhouse gas (GHG) emission scenario (i.e., B1: more integrated and environmental friendly world) was used for climate change study for 2012-2016, and land use changes scenarios were generated for short-term period (2012-2016) due to limited future projected land use data. The simulation results revealed that climate change affects significantly the temporal patterns of mean groundwater contribution to stream flow. Due to precipitation variability, these contributions varied monthly, seasonally, and annually. When land use changes (i.e., increasing forest clear cut area, and decreasing forest and agricultural areas) were combined with climate change scenarios, these contributions were decreased due to changes in the flow patterns to the regime with more surface runoff and stream flow but less groundwater discharge. Compared to the reference period (2007-2011), the mean annual groundwater contribution to stream flow from 2012 to 2016 under the B1 climate change scenario and the combined effects of B1 scenario and land use changes is expected to decrease by 1.8% and 4.3%, respectively, due to increased precipitation (on average 3.6% under the B1 scenario) and temperature (on average 0.36°C under the B1 scenario), and land use changes. The results obtained from this study will provide useful information for seasonal and annual water extractions from the river and allocation to the stakeholders for future water supply, as well as ecological conditions of the stream, which will be beneficial to aquatic ecosystems. They will also provide how land use changes can impact the groundwater contribution to stream flow, which will be useful for planning of water resources management considering future climate and land use changes
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Assessing the effects of water withdrawal for hydraulic fracturing on surface water and groundwater - a review
No full textThe interaction between groundwater and surface water plays an important role in the function of riparian ecosystems and sustainable water resource management. Hydraulic fracturing, an unconventional oil and gas well stimulation method, has increased dramatically in North America in an effort to exploit previously inaccessible shale oil and gas reserves. Hydraulic fracturing often requires several thousand cubic meters of water to fracture the source formations. Use of such a high volume of water has raised considerable public concern over the sustainability of this activity and the potential impacts on surface water and groundwater. This paper provides a review of the published literature addressing the effects of water withdrawal for hydraulic fracturing on surface water and groundwater. The potential effects of such withdrawal are: decreased volume of water in rivers, streams, lakes and aquifers; alteration of natural flow regimes; regional water shortages during periods of drought; creating conflicts with other water users in water-stressed regions; inadequate downstream water availability; reduced downstream water quality for human uses, due to less water availability for dilution; and degradation of habitat and aquatic ecosystem function, impacting local wildlife. This review demonstrates that relatively little attention has been paid to quantify and understand these interactions, and suggests that there is a significant need for further research in this area to address the currently limited availability of data
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Groundwater -- surface water interaction under the effects of climate and land use changes.
Get PDFHistorical observed data and future climate projections provide enough evidence that water resources systems (i.e., surface water and groundwater) are extremely vulnerable to climate change. However, the impact of climate change on water resources systems varies from region to region. Therefore, climate change impact studies of water resources systems are of interest at regional to local scales. These studies provide a better understanding of the sensitivity of water resources systems to changes in climatic variable (i.e., precipitation and temperature), and help to manage future water resources. In addition to climate change, human-induced land use changes also significantly affect water resources systems. Therefore, climate and land use changes can provide offsetting and additive impacts on water resources systems depending on the region and watershed characteristics. In this dissertation research, groundwater-surface water (GW-SW) interaction under the effects of climate and land use changes were investigated through the development of a Gridded Surface Subsurface Hydrologic Analysis (GSSHA) modeling system using a case study in Kiskatinaw River watershed (KRW), British Columbia, Canada. --Leaf i.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b200682
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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