Multivariate trends in phytoplankton species groups in the southern North Sea     

Nicholson  Mike; Fryer  Rob; Maxwell  David 《ICES Journal of Marine Science》1998,55(4):581-586

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Using the SDIlight Approach in Teaching a Geoinformatics Master     

Barend Köbben  Rolf De By  Theodor Foerster  Otto Huisman  Rob Lemmens  Javier Morales 《Transactions in GIS》2010,14(Z1):25-37

ITC, the Faculty of Geo–Information Science and Earth Observation of the University of Twente, is an institute that aims at capacity building and institutional development, specifically in developing countries. In our Geoinformatics curriculum, we emphasise two principles. The first addresses the systematics of purposeful spatial data production and uptake into computerised systems; the second addresses the methodical construction of these computerised systems, applying principles of model – driven architecture, formal specification and transformational design of SDI nodes. The term Spatial Data Infrastructure (SDI) usually denotes large, complex systems, but its principles can also be applied in simple and cost–effective ways. This approach we have called SDI^light and it is of particular interest to our students that come from developing countries. We work with and build a software stack consisting of free and open source components. To achieve interoperability, we emphasise the use of open standards from the Open Geospatial Consortium and others. In this paper, we explain how our students apply the SDI^light approach in the GeoinformaticsMaster degree course. An important part of that course is a Case Study Application Building & Programming, in which students apply their knowledge in a ‘real–world’ project, with a focus on geo–information engineering skills. We conclude with a section that evaluates the effectiveness of using the SDI^light concept in teaching our Geoinformatics Master, and on the more general applicability of the methodology.  相似文献   

Techniques for measuring rock weathering: application to a dated fan segment sequence in southern Tunisia     

Kevin White  Rob Bryant  Nick Drake 《地球表面变化过程与地形》1998,23(11):1031-1043

There are a number of techniques for estimating the amount of weathering a clast has undergone. These usually have the objective of establishing an ordinal chronology of geomorphological surfaces, or investigation of site-specific conditions affecting weathering rates. Three such techniques are applied to a dated sequence of alluvial fan segments in southern Tunisia. Two of these techniques depend on measuring surface roughness (the micro-roughness meter and a displacement approach) and one uses the structural weakening of the rock fabric (Schmidt hammer). The micro-roughness meter enables calculation of standard deviation of surface height variation, root mean square roughness and surface autocorrelation function. Of these techniques, Schmidt hammer rebound values, standard deviation, root mean square roughness and the displacement technique show systematic changes on the three fan segments which are statistically significant at the 0·05 level. However, the amount of variance in all datasets is very large, indicating the need for caution in application of these techniques for relative dating. © 1998 John Wiley & Sons, Ltd.  相似文献   

Short-range variations in the micromorphology of a palaeosol from Wivenhoe in southeast England     

Rob. A. Kemp  Joanne S. Faulkner 《第四纪科学杂志》1998,13(3):233-243

The pedogenic histories of four adjacent profiles of a polygenetic palaeosol developed on a Middle Pleistocene terrace of the proto-Thames from Wivenhoe in southeast England are reconstructed on the basis of superposition of key micromorphological features. Despite a considerable variation in macromorphology, partly resulting from large-scale periglacial features, three of the profiles have similar micromorphological records in that they retain evidence for two phases of clay illuviation separated by a period of periglacial disruption. This reconstruction, however, seems to be incomplete because the fourth profile contains micromorphological evidence for a further illuviation–disruption cycle. The extent of this variation suggests that soil micromorphology should be used only with care to reconstruct pedogenic or pedosedimentary histories of complex polygenetic palaeosols, or to compare such palaeosols on different surfaces of chronosequences spanning periods of major climatic change. The variable and possibly limited resolution of micromorphology, together with the current uncertainty over the exact environmental signifiance of illuvial clay features, means that inferred pedogenic phases should be correlated with specific climatic stages only with considerable caution. © 1998 John Wiley & Sons, Ltd.  相似文献   

Introduction: Magnetism and site formation processes in archaeology     

Rob Sternberg 《Geoarchaeology》1998,13(1):1-1

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Statistical algorithms accounting for background density in the detection of UXO target areas at DoD munitions sites     

Brett D. Matzke  John E. Wilson  John E. Hathaway  Brent A. Pulsipher 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(2):181-191

Statistically defensible methods are presented for developing geophysical detector sampling plans and analyzing data for munitions response sites where unexploded ordnance (UXO) may exist. Detection methods for identifying areas of elevated anomaly density from background density are shown. Additionally, methods are described which aid in the choice of transect pattern and spacing to assure with degree of confidence that a target area (TA) of specific size, shape, and anomaly density will be identified using the detection methods. Methods for evaluating the sensitivity of designs to variation in certain parameters are also discussed. Methods presented have been incorporated into the Visual Sample Plan (VSP) software (free at ) and demonstrated at multiple sites in the United States. Application examples from actual transect designs and surveys from the previous two years are demonstrated.  相似文献   

Variation between bee communities on a sand dune complex in the Great Basin Desert,North America: Implications for sand dune conservation     

J.S. Wilson  O.J. Messinger  T. Griswold 《Journal of Arid Environments》2009,73(6-7):666-671

Sand dunes across the Mojave and Great Basin Deserts house rich bee communities. The pollination services these bees provide can be vital in maintaining the diverse, and often endemic, dune flora. These dune environments, however, are threatened by intense off-highway vehicle (OHV) use. Conservation efforts adopted by land managers often consist of setting aside a portion of a dune system that is off-limits to OHV use, but little work has been done showing the extent to which this protects native bee communities. A two-year study of bee communities on a Great Basin sand dune complex in Dugway Proving Ground located in northwestern Utah revealed low similarity index values between closely situated collecting plots (1–40 km apart). Similarity values ranged from 0.13 to 0.70 for species composition, and from 0.07 to 0.57 when similarity was weighted by abundance. Distance between plots had no significant relationship to similarity when richness and abundance were considered. Bee similarity between plots was significantly correlated with floral similarity. These results indicate that dune conservation strategies that preserve “representative” portions of dune systems may be insufficient to protect bees and the pollination services they provide.  相似文献   

Introduction to special issue on volcano–ice interactions on Earth and Mars: The state of the science     

Benjamin R. Edwards  Hugh Tuffen  Ian P. Skilling  Lionel Wilson 《Journal of Volcanology and Geothermal Research》2009,185(4):247-250

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KT3D_H2O: A Program for Kriging Water Level Data Using Hydrologic Drift Terms     

by Marinko Karanovic  Matthew Tonkin  David Wilson 《Ground water》2009,47(4):580-586

It is often necessary to estimate the zone of contribution to, or the capture zone developed by, pumped wells: for example, when evaluating pump-and-treat remedies and when developing wellhead protection areas for supply wells. Tonkin and Larson (2002) and Brochu and Marcotte (2003) describe a mapping-based method for estimating the capture zone of pumped wells, developed by combining universal kriging (kriging with a trend) with analytical expressions that describe the response of the potentiometric surface to certain applied stresses. This Methods Note describes (a) expansions to the techinque described by Tonkin and Larson (2002) ; (b) the concept of the capture frequency map (CFM), a technique that combines information from multiple capture zone maps into a single depiction of capture; (c) the development of a graphical user interface to facilitate the use of the methods described; and (d) the integration of these programs within the MapWindow geographic information system environment. An example application is presented that illustrates ground water level contours, capture zones, and a CFM prepared using the methods and software described.  相似文献   

Airborne laser swath mapping of the summit of Erebus volcano,Antarctica: Applications to geological mapping of a volcano     

Bea Csatho  Toni Schenk  Philip Kyle  Terry Wilson  William B. Krabill 《Journal of Volcanology and Geothermal Research》2008

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