An evaluation of acid deposition on cation leaching and weathering rates of an Andosol and a Cambisol   总被引：1，自引：0，他引：1  

Rannveig Guicharnaud  Graeme I. Paton 《Journal of Geochemical Exploration》2006,88(1-3):279

An evaluation of the response of an Andosol and a Cambisol to acid deposition and weathering rates was studied by using a controlled laboratory leaching experiment. Both soils where derived from mafic parent material, a Histic Andosol from Western Iceland and a Cambisol from North East Scotland. De-ionized water and water acidified with H₂SO₄ (pH 3) was leached through reconstructed soil columns to simulate 34 years of precipitation.Acidic input increased cation leaching and weathering rates in both soil types and reduced pH levels. The Andosol proved generally to have higher weathering rates, leaching potential, ion exchange and acid-buffering capacity as well as maintaining a relatively steady pH despite intense acidic input. This was due to differences in parent material and mineral composition. The Andosol was developed from basaltic volcanic tephra, which had higher dissolution rates due to its amorphous mineral structures. The Cambisol was developed from gabbro with more stable mineral structures.  相似文献   

Analysing Product-Specific Behaviour to Support Process Dependent Updates in a Dynamic Spatial Updating Model     

Lesley M Arnold  Graeme L Wright 《Transactions in GIS》2005,9(3):397-419

A scale‐independent database that allows derived maps to be dynamically updated from a centrally maintained data source is an appealing alternative to traditional map revision techniques, which by today's standards are costly and inefficient. This paper presents a dynamic spatial updating model that supports automated updating of non‐standard maps in a scale‐independent database‐centric map production environment. Maps derived from the database are not separate data sets, but rather active views of the database. Each derived map is displayed in a unique way by implementing cartographic operations at the map level. While the operations applied require user involvement for strategic cartographic decisions, and algorithmic initiation and control, the technique allows geographic data to be processed cartographically without affecting the geometric integrity of the database. Each time a derived map is opened it retrieves the spatial data (and updates) from the database and applies the unique cartographic representation methods that persist on the individual derived maps. Database updates are automatically triggered to cartographic products, as process dependent updates, according to their individual product‐specific behaviour. This paper investigates product‐specific behaviour (product multiplicities) and the cartographic processing requirements to support dynamic spatial updating techniques in an object‐oriented map publishing environment. These techniques are implemented in an off‐the‐shelf software environment using ArcGIS.  相似文献   

Kinematics of the Danakil microplate     

Graeme Eagles  Richard Gloaguen Cynthia Ebinger 《Earth and Planetary Science Letters》2002,203(2):607-620

A refinement and extrapolation of recent motion estimates for the Danakil microplate, based on ancient kinematic indicators in the Afar region, describes the evolution of a microplate in the continental realm. The Danakil horst is an elevated part of this microplate, exposing a Precambrian basement within the Afar depression, the site of the Nubia-Somalia-Arabia triple junction. We compare evidence for strike- or oblique-slip faults in data from the Afar depression and southern Red Sea to small circles about published poles of rotation for the Danakil microplate with respect to Nubia. A reconstruction about the preferred pole reunites lengths of a Precambrian shear zone on the Nubia and Danakil sides and preserves a uniform basement fabric strike through Nubia, Danakil and Yemen. Since at least magnetic chron C5 (∼11 Ma) Danakil rotated about a different pole with respect to Nubia than either Somalia or Arabia, but between chrons C5 and C2A Nubia-Danakil motion was a close approximation to Nubia-Somalia motion. Since C2A relative motions of the Danakil microplate have been independent of movements on any of the neighbouring plate boundaries. We relate this to the onset of oceanic-type accretion within Afar. The resulting eastwards acceleration of Danakil was accommodated by westwards propagation of the Gulf of Aden rift that became the new, discrete, plate boundary between the Danakil microplate and the Somalia plate. Present-day activity suggests that the Red Sea and Aden rifts will link through Afar, thereby isolating the Danakil horst as a microcontinent on the Arabian margin.  相似文献   

Addressing Social and Community Planning Issues with Spatial Information     

Graeme Hugo 《The Australian geographer》2001,32(3):269-293

In Australia today, there is still relatively limited use being made of spatial information systems (SIS). Nevertheless, the technology and methodology is developing rapidly. What is already available has the capacity to assist in the process of making social service provision and community planning more people oriented, more effective and more equitable in its outcomes. Recognising the need for a sound social science context, this paper demonstrates, using a range of examples especially geared towards rural and regional Australia, the work of the National Key Centre for Social Applications of Geographical Information Systems.  相似文献   

Reply to: P. Roperch, A. Tassara and B. Townley, Discussion on “Paleomagnetism applied to magnetic anomaly interpretation: a new twist to the search for mineralisation in northern Chile”     

Graeme K. Taylor 《Mineralium Deposita》2001,36(2):197-198

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The systematic position of Equus hydruntinus, an extinct species of Pleistocene equid     

Ariane Burke  Vera Eisenmann  Graeme K. Ambler 《Quaternary Research》2003,59(3):459

Palaeolithic people commonly hunted Equus hydruntinus, an extinct species of equid whose cursorial body proportions suggest an adaptation to semi-arid conditions. Despite the frequency with which it is encountered in fossil deposits, only partial cranial remains have been reported until now. As a result, the systematic affiliation of the species remains a subject of controversy. Two nearly complete E. hydruntinus crania are presented here for the first time. These skulls show that E. hydruntinus is a distinct species, more closely related to the hemiones (Asiatic asses) than to any other equid. This suggests that the social organisation of E. hydruntinus followed one of two known equid sociotypes: resource defense territoriality.  相似文献   

The Girls' Home, Bangkok, Thailand: Developing Thoughts on Democracy     

Graeme Bristol 《Singapore journal of tropical geography》2002,23(3):348-362

This paper describes an exercise with children in the implementation of housing rights. Based on the argued opinion that housing rights cannot be exercised without participation and that participation without knowledge is pretence, a Kids and Architecture programme was initiated with a group of 40 children — displaced from homes in the Klong Toey slum in Bangkok — at a girls' home run by the Human Development Foundation (HDF). The programme, developed in two phases and involving students from the King Mongkut's University of Technology Thonburi (KMUTT), School of Architecture, set about to teach these children some of the elements of architecture so that they could participate in the design of their own housing. From this experiment a number of conclusions are drawn about the implementation of housing rights and about the teaching of architecture, both to children and architecture students.  相似文献   

GIS: A Computing Perspective     

Graeme Aggett 《New Zealand geographer》1997,53(1):64-64

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Transition fields from kinematic dynamo calculations     

Graeme Sarson 《Surveys in Geophysics》1996,17(2):215-218

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REGIONAL GEOGRAPHY OF ANGLO-AMERICA     

Graeme  Wynn 《New Zealand geographer》1975,31(2):196-196

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