The chemical compositions of Antarctic iron meteorites and their classification

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Vagueness and the trade-off between the classification and delineation of geographic regions – an ontological analysis

For inherently vague and granular phenomena such as ecoregions, ecosystems, biomes, and biotopes, the interplay of granularity and vagueness leads to a trade-off in the classification and delineation of such phenomena: the goal of preciseness (lack of vagueness) of the delineation contradicts the goal of building a sophisticated classification system using the Aristotelian method of classification. This trade-off is based on the reliance on local qualities for a precise delineation of particular regions and the reliance on nonlocal qualities that serve as differentia in the Aristotelian classification. An ontological analysis of the logical interrelations between vagueness, granularity, and scale is critical for developing logically rigorous, nonlocal, and nonarbitrary classification and delineation systems for inherently vague and granular geographic phenomena.     

Climatological characteristics of the tropics in China： climate classification schemes between German scientists and Huang Bingwei

Reviewing some important German scientists who have developed climatic regionalization schemes either on a global or Chinese scale, their various definitions of the tropical climate characteristics in China are discussed and compared with Huang Bingwei‘s climate classification scheme and the identification of the tropical climate therein. It can be seen that, due to different methodological approaches of the climatic regionalization schemes, the definitions of the tropics vary and hence also their spatial distribution in China. However, it is found that the tropical climate type occupies only a peripheral part of southern China, though it firmly represents a distinctive type of climate that is subsequently associated with a great economic importance for China. As such, the tropical climate type was mostly identified with its agro-climatological significance, that is by giving favourable growing conditions all-year round for perennial crops with a great heat demand. Tropical climate is, hence, conventionally regarded to be governed by all-year round summer conditions “where winter never comes“.     

Region-Building — a Comparison of Methods

This study deals with the use of quantitative methods to build up uniform or formal regions, the construction of farming-type regions in eastern Norway being used as an example. To achieve reasonable uniformity in the size of the basic areal units, some of the original administrative areas are first combined; the resulting areal units are then described by four orthogonal variables extracted by principal component analysis. Six different methods of aggregating the basic units to form regions are discussed, each method using the same measure of similarity (D²) between the basic units. The homogeneity of the regions produced by these methods is compared, and Ward's method (Ward 1963) shown to give the best (though not necessarily the optimal) solution.     

Origin of Lower Cretaceous quartzose arenites in northern India and the Indus Basins of Pakistan—The result of provenance composition,weathering or diagenesis?

Lower Cretaceous (Aptian-Albian) sandstones of the Ghaggar-Hakra Formation in the Barmer Basin of northwest Rajasthan, India, have a complex depositional history which is confusing given they are quartzose arenites. The heavy mineral grains are very well-rounded, and the assemblage is dominated by zircon and rutile grains suggesting that the sediments have been recycled multiple times, whilst the presence of staurolite indicates a metapelite provenance component. Petrographical analysis suggests that extreme diagenesis cannot account for the quartzose arenite composition, despite Early Cretaceous soil formation and at least two periods of subsequent telogenetic modification. An alternative explanation to extreme chemical weathering in the provenance area is that the Ghaggar-Hakra sandstones are multi-cycle sediments derived, at least in part, from the quartzose arenites of the Cambrian Jodhpur Group. This analysis suggests that variations in detrital mineralogy across the Western India Rift System and Indus Basins are the result of transcontinental fluvial transport systems sourcing sediment from specific basement highs (Nagar Parker High, Devikot High, Deodar Ridge and Aravalli Mountain Range) mixed with varying proportions of sediment derived from sandstones of the Jodhpur Group. Consequently, we suggest that Cretaceous fluvial systems were controlled by the local palaeogeographies within the failed rifts of the Barmer and Cambay Basins and that both basins formed barriers to sediment transport from the Aravalli Mountain Range across the northwest Indian plate and into surrounding basins.     

Application of Participatory Development Theory in Wetland Ecotourism Initiatives——A Case Study of Baiyangdian in Anxin of Hebei Province

As one of the few ecological wetlands in North China,Baiyangdian bears multiple important ecological functions,including ①adjusting the ecological balance of North China;②safeguarding the downstream areas,especially Tianjin City,the Beijing-Shanghai Railway and Huabei Oil Field;③serving as the reservoir for the North-to-South Water Diversion Project and the emergent use of water for Beijing;④conserving biodiversity.Wetland ecotourism is a scientific and wise use pattern for wetland resources,through which,a source of financing is provided for wetland conservation,economic alternatives are generated for local people to reduce overexploitation on wetland resources and the public awareness of environmental protection is enhanced.Since wetland ecotourism can benefit the co-existence between human and nature and promote social equity between people,it enjoys broad promise for popularization and implementation.The proactive cooperation and sound interaction between main stakeholders,and the wide participation of the community residents,will guarantee the sustainable development of wetland ecotourism.Based on the analysis of current status of participation and interactive relationships of the main stakeholders in Baiyangdian tourism,this article made an attempt to apply the theory of participatory development to the ecotourism initiatives of Baiyangdian wetland,discussed and brought forward the countermeasures to improve community participation in wetland ecotourism under the guidance of this theory.     

The Coefficient of Localization—An Addendum

Geographical data sets sometimes contain missing observations that need to be estimated. A statistical approach to the problem is discussed for multivariate normal spatial data sets satisfying the first-order spatial Markov property with constant mean, where the information at neighboring or contiguous observed sites is used to estimate the missing values. The completed data are used to estimate the parameters of the distribution. The procedure is iterative. The approach is a special case of the Orchard and Woodbury missing information principle. The paper concludes with an illustrative empirical example using rainfall data from an area of Kansas and Nebraska. The quality of the estimates for different sites are compared.     

The suburban bias of American society?

Past research has characterized countries as displaying the traits of urban or rural bias. Neither concept fits the United States well. We propose, as a hypothesis for research, that it may better be understood as displaying a suburban bias vis-à-vis both urban and rural populations. Drawing on the urban and rural bias literatures, we discuss two forms that suburban bias might take, allocational and dispositional, and the ways in which they might be identified. We offer initial evidence of a prevailing suburban bias in the United States in two spheres, those of judicial interpretation and American planning history, and conclude with suggestions for further research on the hypothesis.     

Are Fractal Dimensions of the Spatial Distribution of Mineral Deposits Meaningful?

It has been proposed that the spatial distribution of mineral deposits is bifractal. An implication of this property is that the number of deposits in a permissive area is a function of the shape of the area. This is because the fractal density functions of deposits are dependent on the distance from known deposits. A long thin permissive area with most of the deposits in one end, such as the Alaskan porphyry permissive area, has a major portion of the area far from known deposits and consequently a low density of deposits associated with most of the permissive area. On the other hand, a more equi-dimensioned permissive area, such as the Arizona porphyry permissive area, has a more uniform density of deposits. Another implication of the fractal distribution is that the Poisson assumption typically used for estimating deposit numbers is invalid. Based on datasets of mineral deposits classified by type as inputs, the distributions of many different deposit types are found to have characteristically two fractal dimensions over separate non-overlapping spatial scales in the range of 5–1000 km. In particular, one typically observes a local dimension at spatial scales less than 30–60 km, and a regional dimension at larger spatial scales. The deposit type, geologic setting, and sample size influence the fractal dimensions. The consequence of the geologic setting can be diminished by using deposits classified by type. The crossover point between the two fractal domains is proportional to the median size of the deposit type. A plot of the crossover points for porphyry copper deposits from different geologic domains against median deposit sizes defines linear relationships and identifies regions that are significantly underexplored. Plots of the fractal dimension can also be used to define density functions from which the number of undiscovered deposits can be estimated. This density function is only dependent on the distribution of deposits and is independent of the definition of the permissive area. Density functions for porphyry copper deposits appear to be significantly different for regions in the Andes, Mexico, United States, and western Canada. Consequently, depending on which regional density function is used, quite different estimates of numbers of undiscovered deposits can be obtained. These fractal properties suggest that geologic studies based on mapping at scales of 1:24,000 to 1:100,000 may not recognize processes that are important in the formation of mineral deposits at scales larger than the crossover points at 30–60 km.     

The corridor effect of metropolitan spatialextension and optimization of landscape structure—the case of Beijing

TherehavebeenseveraldozensofyearssincethedevelopmentandstUdyofthemetropolitanareasindevelopedcountries.Atpresent,somemetropolisesaresteppingintothestageofmetropolitandevelopmentinChina.Thegeneraltrendisunavoidablethatbuilt-upareaexpandsandrurallandturnsintourbanones.Butunderthedriveofgoingmerelyaftereconomicbenefit,man}.'collectivesandindividualsillegallyoccupycultivatedlandandgreenbelts,whichintensifiesurbanenvironmentalpollution,wasteslandresourceandmakesthebuilt-upareaexpanduncontrollabl}'…