Seepage measurements from Long Lake,Indiana Dunes National Lakeshore

 Long Lake, located near Lake Michigan within the dune-complexes of Indiana Dunes National Lakeshore, USA, was formed some time during the Pleistocene and Holocene epochs. A surficial aquifer underlies Long Lake, which is either a source or sink for the later. The hydrologic processes in the lakeshore and surrounding environs have been significantly altered during the agricultural, municipal, and industrial development of the region. Limited data suggest that the organisms of Long Lake have elevated levels of several contaminants. This study attempts to quantify seepage within the lake to assess the potential threat to groundwater quality. Seepage measurements and minipiezometric tests were used to determine seepage within the lake. Seepage measurements and minipiezometric tests suggest that water seeps out of Long Lake, thus recharging the groundwater that flows southwest away from the lake. There is a great deal of variability in the seepage rate, with a mean of 11.5×10^–4±11.2×10^–4 m d^–1. The mean seepage rate of 0.3 m yr^–1 for Long Lake is greater than the 0.2 m yr^–1 recharge rate estimated for the drainage basin area. The Long Lake recharge volume of 2.5×10⁵ m³ yr^–1 is approximately 22% of the volume of the lake and is significant when compared to the total surface recharge volume of 4.8×10⁵ m³ yr^–1 to the upper aquifer of the drainage area. There is a potential for contamination of the groundwater system through seepage from the lake from contaminants derived from aerial depositions. Received: 16 August 1995 · Accepted: 18 September 1995     

地理学在全球变化研究中的学科地位及重要作用

分析了当前全球变化研究的主要特点,指出地理学在全球变化研究中将发挥日益重要的作用。提出了地理学在全球变化研究中应着重开展研究的4个方面的重点科学问题。     

Mobilising generosity, framing geopolitics: Narrating crisis in the homeland through diasporic media

This paper provides an account of the humanitarian interventions enacted by the Croatian–American diaspora during the secessionist conflicts in Yugoslavia during the 1990s. Whilst undeniably an act of generosity towards ‘distant strangers’, actions such as these also represent a much more complex reality – they are an outcome of a complex set of relations and processes, in which the ethical choices of individuals become bound up with nationalist ideologies, geopolitical questions and, crucially, knowledge and understanding of distant events. In particular, this paper considers the ways in which generosity is mobilised through the framing of Balkan geopolitics through diasporic media. In so doing, it becomes possible to deepen the dialogue between work on geography and ethics on the one hand, and critical geopolitics on the other. In particular, the paper argues that due attention needs to be paid to the ways in which such ‘networks of concern’ are constructed in a variety of banal and mundane ways.     

From reality to model: Operationalism and the value chain of particle-size analysis of natural sediments

This paper deals with key issues concerning operationalism and the value chain in particle-size analysis (PSA), and addresses conceptual problems of PSA measurement. In order to obtain the highest quality of information contained in a set of sediment samples, one has to follow an approach called operationalism, i.e. a set of recipe-like sequential operations by which a scientific proposition can be verified or rejected. Review of the literature indicates that particle sizing as a methodology suffers from excessive verbosity and professional jargon, and has never really matured. Is the PSA crisis a result of a fundamental failure of concepts and paradigms, or is it just a technical problem related to work methods? Although PSA is fundamental to the understanding of sedimentary processes, as well as being a basic tool in earth sciences and engineering, there is still no generally accepted and standardized mode of operationalism after more than a century of intensive scientific work. The sedimentological community is called upon to come up with a unified and standardized approach.     

关于美中基础地理信息产品及其分发模式的思考

作为当今经济和科技最发达的国家,美国在基础地理信息产品建设和分发服务方面是代表世界最先进水平的国家之一,其丰富的基础地理信息系列产品、优秀的网络分发服务系统、完善的数据共享和更新策略等都值得我们学习和借鉴。本文介绍了美国基础地理信息产品的种类、发展及其分发服务模式,并根据我国的实际情况,在相关方面提出了几点建议。     

Aerial survey for archaeology

Aerial photography for archaeology has been developing its approaches and techniques over the past 100 years so that it now integrates the results of reconnaissance with extensive interpretative and analytical surveys. This paper introduces the philosophy and approach of the English Heritage (EH) Aerial Survey team, covering aerial reconnaissance and the National Mapping Programme (NMP), as well as the potential developments and opportunities in Europe. In the 1980s there was a debate over the nature of the evidence derived from aerial photographs, especially how to describe archaeological features. As part of NMP a classification and recording system has been devised which meets most of the users' needs, be they national organisations, county archaeologists, commercial contractors or university-based researchers. The maps and records produced by NMP are used to further our understanding of the past human settlement in England, not only at the individual site level, but also in regional or landscape contexts. This paper provides an overview of the current progress of NMP and acts as an entrée for explaining the current research and recording of archaeological landscapes throughout Europe. Recent developments in Britain and Europe have provided the opportunity for a greater priority to be given to aerial survey and accelerating programmes of mapping. In Europe the ending of the cold war has allowed greater access to aerial photographs and the possibility of beginning new reconnaissance, as well as introducing new forms of remote sensing. All these developments have led to a transformation of our understanding of prehistoric, Roman and medieval archaeology.     

Lipid biomarkers and carbon-isotopes of modern travertine deposits (Yellowstone National Park, USA): Implications for biogeochemical dynamics in hot-spring systems

Lipid biomarkers and ¹³C fractionation patterns were used to understand the dynamics of carbon cycling during microbial metabolisms in different environments of travertine precipitation (called facies) at Spring AT-1 on Angel Terrace in the Mammoth Hot Springs complex of Yellowstone National Park, USA. Microbial mats that encrust travertine deposits were collected for analyses of lipid biomarkers and carbon isotopes along the continuous drainage outflow system of Spring AT-1. The spring water exhibits a continuous temperature drop from 71°C in the vent at top to 24°C in the distal slope at bottom. Phospholipid fatty acids (PLFA) and glycolipid fatty acids (GLFA) exhibit distinctly different compositions in each of the facies, which are consistent with partitioning of the bacterial 16S rRNA gene sequences in the Spring AT-1 travertine facies (Fouke et al., 2003).The δ¹³C composition of total biomass within the microbial mats decreases from −16.1‰ in the vent to −23.5‰ in the distal slope. However, lower values occur in the pond (−26.0‰) and the proximal slope (−28.0‰) between the vent and the distal slope. Isotopic compositions of PLFA and GLFA have variations similar to those of total biomass. The average δ¹³C values of PLFA are −12.4 ± 5.2‰ (n = 10 individual fatty acids, same below) in the vent, −33.0 ± 3.1‰ (n = 11) in the pond, −33.7 ± 3.8‰ (n = 16) in the proximal slope, and −22.4 ± 3.4‰ (n = 10) in the distal slope; the average δ¹³C values of GLFA are −19.6 ± 3.0‰ (n = 3) in the vent, −30.4 ± 4.7‰ (n = 8) in the pond, −36.9 ± 2.8‰ (n = 12) in the proximal slope, and −27.9 ± 3.1‰ (n = 13) in the distal slope. In particular, fatty acids in the vent are enriched in ¹³C relative to the total biomass, which is consistent with the notion that the biosynthetic pathways of the extant microbial community in the vent may be dominated by Aquificales using the reversed tricarboxylic acid cycle. Fractionations between fatty acids and total biomass in the pond, the proximal slope and the distal slope suggest the involvement of other biosynthetic pathways for CO₂ fixation by extant microbial populations. The results indicate that lipid biomarkers provide valuable information on the changing diversity and activity of microbial communities in different depositional environments. Carbon-isotope fractionations, on the other hand, can provide insight into the operating biosynthetic pathways associated with different organisms in the changing environment. This integrated approach may serve as a powerful tool for identifying functional metabolism within a community and identify shifts in microbial community structure in modern hot-spring systems.     

Determining factors of the development of a national financial center: the case of China

This study explores, theoretically and empirically, one of the important issues of the geography of finance, namely the location of high-level financial services. Specifically, we will try to explain why foreign financial services are spatially concentrated in a particular city so as to form a national financial center in China. By reviewing various forces behind the formation of a financial center, we argue that information problems have created the need for geographic agglomeration of financial activities based on the source of information. This is true even in an era when financial markets work through sophisticated telecommunication networks. Based on a survey of the actual location of multinational corporation (MNC) regional headquarters, and through investigation of reasons for the agglomeration of these headquarters, we anticipate that Beijing, as the prime source of policy information, is more likely than other Chinese cities to be the national pre-eminent financial center when the Chinese financial markets become more open to foreign firms in the near future. This study illustrates, using China as a case study, that geography still provides strong justification of why major financial services continue to have a high degree of spatial agglomeration in particular locations, despite the fact that the electronic transmission of information has substantially reduced the friction of distance.     

国内外生态旅游研究的主要方向及进展

本文从旅游对环境的影响着手，通过对生态旅游研究现有的文献分析，主要阐述了作为可持续旅游实现形式的生态旅游与生态环境的关系，生态旅游概念与内涵的研究，生态旅游的景观生态学研究和生态旅游的地理学研究等几个方面，生态旅游的基础理论研究主要集中在生态旅游概念、内涵和特征的探讨，而生态旅游实践的研究主要是特定区域的生态旅游规划案例的研究，同时指出了生态旅游今后应加强的几个研究领域。     

Discipline games, disciplinary games and the need for a post-disciplinary practice: responses to Nigel Thrift’s ‘The future of geography’

In this response to Nigel Thrift’s ‘The future of geography’, I highlight the performative qualities of academic response. As a counter to Thrift’s optimism, I argue that such debate is inevitably parochial and imperialist. I question the validity of such ‘discipline games’ in a post-disciplinary world, emphasise the importance of a performative reading of academic futures and highlight that geographical journal space remains worryingly within-discipline, rather than post-disciplinary. More generally, I suggest that there are clear material risks to continuing to play discipline games in a post-disciplinary world.