1,721,089 research outputs found
Analysis of the impact of conservation measures on stream flow regime in catchments of the Loess Plateau, China
No full textCatchments in the Loess Plateau have been under the influence of human activities for centuries. In the last four decades, soil conservation measures have accelerated and intensified. These measures were designed to reduce soil erosion, improve agricultural productivity, and enhance environmental quality. It is important to evaluate the effects of these measures on hydrology in order to develop sustainable catchment management plans in the region. This study evaluated changes in stream flow data for four selected catchments in the Loess Plateau following large-scale soil conservation measures. The non-parametric Mann-Kendall test was used to identify trends in annual stream flow and the results showed significant downward trends in three of the four catchments. The Pettitt test indicated that a change point occurred in 1978 in these three catchments. Annual precipitation in all the catchments showed no significant trend during the period of record. Comparison of daily flow duration curves for two 20-year periods (1957-1978) and (1979-2003) showed significant changes in stream flow regime. Reduction in most percentile flows varied between 20 and 45%, and the reduction in low flows was greatest. Overall, the reductions in daily flow were increasing with time, with significant changes occurring in the 1990s. However, it is not clear whether these catchments have seen the full effects of the soil conservation measures, so the results of this study might underestimate the final impact of soil conservation on stream flow regime. Copyright (c) 2007 John Wiley & Sons, Ltd
Near-Surface Wind Speed
No full textDaily near-surface wind speeds (u) grids have been developed over all of Australia at a 0.01° spatial resolution by interpolating terrestrial anemometers measurements from an expanded network for 1975–2006. For these new grids, the Australian-averaged u trend for 1975–2006 was -0.009 m s-1 a-1 (agreeing with earlier site-based studies) with stilling over 88% of the land-surface. This new dataset can be used in numerous environmental applications, including benchmarking general circulation models to improve the representation of key parameters that govern u estimation. The methodology implemented here can be applied globally.\n\nDataset Creation Date: 2008-07-15\n\nDatasets updated on Jan 2019 to include year 2018\n\nLineage: The original point data were supplied by Bureau of Meteorology, specifically the Australian Daily Wind Data Product IDCJC06.200706 was used. Daily wind-run (km/day) from low-set anemometers (< 3 m) were converted to daily average wind-speed (m/s) using the method reported in McVicar et al. (2008). These data were then spatially interpolated using ANUSPLIN Version 4.3 (Hutchinson 2004). A tri-variate thin plate spline (TVTPS) as a function of longitude, latitude and distance inland from coast (Hutchinson et al., 1984) was the primary model to interpolate the data. A transformation of distance from the coast (d) in km was applied to capture the impact of seabreezes and land-breezes on wind speed. The TVTPS model was successfully used to fit over 95% of the days. However, for a less than 5% of days there were issues successfully fitting this primary model. Most of these days were fit by applying a square-root transformation to the input dependent data (i.e., the daily average wind speed) prior to fitting the spline. Refer to the Readme file for more details \n\nCredit:\nThis dataset was developed by the Time Series Remote Sensing Team, CSIRO Land and Water in conjunction with other researchers outlined in the paper documenting this research : McVicar, T.R., Van Niel, T.G., Li, L.T., Roderick, M.L., Rayner, D.P., Ricciardulli, L. and Donohue, R.J. (2008) Wind speed climatology and trends for Australia, 1975-2006: Capturing the stilling phenomenon and comparison with near-surface reanalysis output. Geophysical Research Letters, 35, L20403, doi:10.1029/2008GL035627. This work was supported by the affiliations listed on the same paper.\
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
Vegetation cover condition (Cooper region)
No full textVegetation cover condition is an assessment of how much impact disturbances (including management activities) have had on ground cover. Condition is assessed using Compere, a relative performance bench marking framework that compares one location's value to the values of all biophysically equivalent locations in a given region. Resulting condition estimates range from 0 (lowest observed cover among equivalents) to 1 (highest observed). Underlying total vegetation cover data are the total fraction of ground covered by green and senesced plant material. Cover condition has been assessed yearly from 2001 to 2018 at a grid resolution of 500 m. \n\nThis work was conducted by the CSIRO as part of the Australian Government's Geological and Bioregional Assessments program (https://www.bioregionalassessments.gov.au/gba). This collection includes the output vegetation cover condition grids, the novel input datasets not elsewhere available and the computer code used to perform the analyses and to generate the figures contained in the associated journal article currently (June 2021) submitted to Ecosphere (Donohue, R.J., Mokany, K., McVicar, T.R. and O'Grady, A.P. Identifying management-driven dynamics in vegetation cover: applying the Compere framework to Cooper Creek, Australia)\n\nLineage: Annual rainfall, historical NDVI (Normalised Difference Vegetation Index), slope and total cover fraction data were used to calculate cover condition. Annual rainfall was from the Bureau of Meteorology daily 5 km gridded data (Jeffrey et al., 2001). NDVI was from MODIS MOD13Q1 and MOD09Q1 data. Slope was from the CSIRO’s SRTM 9sec digital elevation model data (Gallant et al., 2011). Cover was from CSIRO’s fractional cover data (derived from MCD43A4 data, Guerschman and Hill, 2018). Surface Water Points data and the Sturt National Park boundary data were used to test results. These were sourced from Crossman and Li (2015) and Commonwealth of Australia (2019), respectively. Background NDVI, slope and annual rainfall were used quantify locations that were biophysically equivalent to a given target location. The total cover fraction of the target was compared to that from all ‘equivalent’ locations to yield a relative ranking of the target’s cover value. This is interpreted directly as cover condition. This was repeated for all locations (grid cells) and years. An assessment of the impact of the mining industry on cover condition across the Cooper region was undertaken, using confidential well location data. See associated publications for more details. Jones, D.A., Wang, W., & Fawcett, R. (2009). High-quality spatial climate data sets for Australia. Australian Meteorological and Oceanographic Journal, 58, 233-248. Gallant, J.C., Dowling, T.I., Read, A.M., Wilson, N., Tickle, P.K., & Inskeep, C. (2011). 1 second SRTM-derived Digital Elevation Models User Guide. Canberra: Geoscience Australia. Guerschman, J.P., & Hill, M.J. (2018). Calibration and validation of the Australian fractional cover product for MODIS collection 6. Remote Sensing Letters, 9, 696-705. DOI: 10.1080/2150704X.2018.1465611. Crossman, S., & Li, O. (2015). Surface Hydrology points (Regional). Geosciences Australia. Canberra. http://pid.geoscience.gov.au/dataset/ga/83132. Commonwealth of Australia (2019). Collaborative Australian Protected Areas Database (CAPAD) 2018. Commonwealth of Australia. Canberra
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
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
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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