Determination of the "Difficult" Elements Ag, B, Ge, Mo, Sn, Tl and W in Geochemical Reference Samples and Silicate Rocks of the GeoPT Proficiency Testing Series by DC Arc Atomic Emission Spectrometry

Reference samples of rocks from the Institute of Geochemistry, Irkutsk (IGI) and the Research Institute of Applied Physics, Irkutsk University (RIAP) and silicate rocks from the GeoPT proficiency testing series were analysed with the aim of determining Ag, B, Ge, Mo, Sn, Tl and W abundances by an atomic-emission method with air-stabilized D.C. arc excitation. Many of the results reported are without recommended or assigned values. The results are compared with compilation data from the literature and, where possible, with assigned values for samples of the Geo PT series.     

A spatial dynamic model of population changes in a vulnerable coastal environment

This study developed a spatial dynamic model to examine the coupled natural–human responses in the form of changes in population and associated developed land area in the Lower Mississippi River Basin region. The goal was to identify key socioeconomic factors (utility) and environmental factors (hazard damages, elevation, and subsidence rate) that affected population changes, as well as to examine how population changes affected the local utility and the local environment reciprocally. We first applied areal interpolation techniques with the volume-preserving property to transform all the data at Year 2000 into a unified 3 km by 3 km cellular space. We then built an Elastic Net model to extract 12 variables from a set of 33 for the spatial dynamic model. Afterward, we calibrated the neighborhood effects with a genetic algorithm and use the spatial dynamic model to simulate population and developed land area in 2010. Furthermore, we took a Monte Carlo approach for analyzing the uncertainty of the model outcome. Our accuracy assessment shows that the model on average slightly overpredicts the number of population and the developed land percentage at 2010, as indicated by the low values of mean absolute deviation (MAD) due to quantity. On the other hand, the MADs due to allocation are larger than the MADs due to quantity, with most outliers found in the New Orleans region where population and urban development declined significantly during 2000–2010 after Hurricane Katrina. The proposed model sheds light on the complex relationships between coastal hazards and human responses and provides useful insights to strategic development for coastal sustainability.     

On the ascent and emplacement of granitoid magma bodies dynamic-thermal numerical models

The intrusion of granitoid magmas is understood as a lower and mid crustal process. Field observations and laboratory experiments give strong reason that most granitoid plutons are formed by diapiric ascent and emplacement of large magma bodies.On this basis, the ascent and emplacement of granitoid magmas is modelled by two-dimensional finite element calculations. The physical concept for this process provides convective transport of matter and heat, an isolated finite source region, variable source temperatures as well as variable density and viscosity contrasts.The model calculations show that the structural development of the model intrusion bodies is highly dependent on the physical properties of the magma and its surroundings. The most important among them are density and viscosity. Due to the different initial conditions, stocks of several plutons in the case of high viscosity contrast or flat magma sources as well as nappe-shaped intrusion structures as a result of low viscosity contrast can be understood by the intrusive mode of emplacement. The enlargement of the negative density contrast leads to an increase of the rate of ascent, so that more advanced intrusion structures are developed.

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Zusammenfassung Die Intrusion granitoider Magmen ist ein Prozeß der unteren und mittleren Kruste. Feldbefunde und Laboruntersuchungen geben Hinweise darauf, daß die meisten granitoiden Plutone durch diapirischen Aufstieg und Platznahme ausgedehnter Magmenkörper entstehen.Auf dieser Grundlage werden der Aufstieg und die Platznahme granitoider Magmen mit Hilfe von zweidimensionalen Finite Elemente Rechnungen modelliert. Das physikalische Konzept beinhaltet den konvektiven Transport von Masse und Energie, eine isolierte finite Quellregion, veränderliche Quelltemperaturen sowie einen variablen Dichte- und Viskositätskontrast.Die Modellrechnungen zeigen, daß die strukturelle Entwicklung der Modellmagmenkörper in hohem Maße von den physikalischen Parametern des Magmas und seiner Umgebung, vor allem Dichte und Viskosität, abhängt. Gemäß den unterschiedlichen Anfangsbedingungen können sowohl einige stockförmige Plutone im Falle eines hohen Viskositätskontrastes oder flacher Magmaquellen als auch deckenförmige Intrusionsstrukturen als Folge eines geringen Viskositätskontrastes mit Hilfe des intrusiven Einlagerungskonzeptes verstanden werden. Die Erhöhung des negativen Dichtekontrastes führt zu einer Erhöhung der Aufstiegsrate, so daß fortgeschrittenere Platznahmestrukturen erreicht werden können.

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Résumé L'intrusion des magmas granitoïdes est un processus qui intéresse la croûte inférieure et moyenne. Les observations de terrain et les expériences en laboratoire fournissent des arguments très sérieux en faveur de la formation des plutons par montée diapirique et mise en place de corps magmatiques de grandes dimensions.Sur base de cette conception, la montée et la mise en place de magmas granitoïdes a fait l'objet d'une modélisation par éléments finis à deux dimensions. Un tel modèle fait appel à un transport convectif de matière et de chaleur, à une région-source isolée de dimension finie, à une source de température variable ainsi qu' à divers contrastes de densité et de viscosité.Les calculs montrent que le développement structural des corps intrusifs ainsi modélisés dépend essentiellement des propriétés physiques du magma et de son encaissant, en particulier de la densité et de la viscosité. Etant données diverses conditions initiales, la modélisation rend compte de plusieurs types de culots plutoniques dans le cas de contrastes de viscosité élevés ou de sources de magma d'extension horizontale, ainsi que d'intrusions en forme de nappe dans le cas de faibles contrastes de viscosité. L'accroissement des contrastes de viscosité négatifs contribue à augmenter la vitesse d'ascension, ce qui permet le développement de structures d'intrusion plus évoluées.

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— , . , . . : , , . , , , . , , . .

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Notation a thermal expansion coefficient - C_p specific heat capacity - Di dissipation number (model specific) - g gravity acceleration - dynamic viscosity - h heigth of model - thermal diffusivity - Q heat flow - Ra Rayleigh number - R(v) differential operator - p density - t time - T absolute temperature - v velocity - V volume - w vertical component of velocity - x horizontal coordinate - stream function - z vertical coordinate     

Education in cartography: what is the status of young people’s map-reading skills?

Due to recent technological progress, maps have become more popular than ever before. This is especially true for young people, who interact with these technologies on a daily basis. Therefore, it is essential that these potential map users possess sufficient knowledge and skills to process the content of cartographic products. A user study was conducted during which pupils (aged 11–18 years) and geography students (>18 years) had to solve a number of cartography questions using topographic maps. The data were analyzed statistically, taking into account a number of potentially influencing factors (user characteristics) on the participants’ results: age, gender, youth club membership, knowledge about the area, among others. The results show a rising trend in the pupils’ scores with increasing age, which can be explained by education in cartography at school. Geography students perform much better, but no influence of any other user characteristics was detected. For pupils, knowledge about the area and gender might be considered as influencing factors. However, the detected influence of gender depends on the scoring system.     

On the Issues of Scale,Resolution, and Fractal Analysis in the Mapping Sciences*

Scale and resolution have long been key issues in geography. The rapid development of analytical cartography, GIS, and remote sensing (the mapping sciences) in the last decade has forced the issues of scale and resolution to be treated formally and better defined. This paper addresses the problem of scale and resolution in geographical studies, with special reference to the mapping sciences. The fractal concept is introduced, and its use in identifying the scale and resolution problem is discussed. The implications of the scale and resolution problem on studies of global change and modeling are also explored.     

The impact of Hurricane Katrina on urban growth in Louisiana: an analysis using data mining and simulation approaches

ABSTRACT

Understanding human dynamics after a major disaster is important to the region’s sustainable development. This study utilized land cover data to examine how Hurricane Katrina has affected the urban growth pattern in the Mississippi Delta in Louisiana. The study analyzed land cover changes from non-urban to urban in three metropolitan areas, Baton Rouge, New Orleans-Metairie, and Hammond, for two time periods, pre-Katrina (2001–2006) and post-Katrina (2006–2010). The study first applied a focal filter to extract continuous urban areas from the scattered urban pixels in the original remote sensing images. Statistical analyses were applied to develop initial functions between urban growth probability and several driving factors. A genetic algorithm was then used to calibrate the transition function, and cellular automata simulation based on the transition function was conducted to evaluate future urban growth patterns with and without the impact of Hurricane Katrina. The results show that elevation has become a much more important factor after Hurricane Katrina, and urban growth has shifted to higher elevation regions. The elevation most probable for new urban growth increased from 10.84 to 11.90 meters. Moreover, simulated future urban growth in this region indicates a decentralized trend, with more growth occurring in more distant regions with higher elevation. In the New Orleans metropolitan area, urban growth will continue to spill across Lake Pontchartrain to the satellite towns that are more than 50 minutes away by driving from the city center.