On the geochemistry of gases and noble gas isotopes (including 222Rn) in deep crustal fluids: the 4000 m KTB-pilot hole fluid production test 2002–03

The concentrations of H₂, O₂, CO₂, and concentrations and isotopic composition of the noble gases (including ²²²Rn), N₂, CH₄, and higher hydrocarbons dissolved in 4000 m deep‐seated fluids from a 12‐month fluid production test in the KTB pilot hole were analyzed. This determination of the gas geochemistry during the test in combination with the knowledge of the hydraulic data provides relevant information about the fluid hydraulics of the deep system. All gas concentrations and isotopic signatures, except for ²²²Rn, showed constancy during the course of the test. This, in combination with large fluid flow rates at a moderate water table drawdown, imply an almost infinite fluid reservoir in 4000 m depth. From the change in ²²²Rn‐activity as a function of pump rate, the contribution of smaller and wider pores to the overall fluid flow in an aquifer can be deduced. This ²²²Rn‐activity monitoring proved therefore to be a valuable instrument for the qualitative observation of the scavenging of pore and fracture surfaces, a hydraulic feature invisible to standard hydraulic testing tools. The observance of this scavenging effect is due to (i) the continuous on‐line geochemical monitoring, (ii) the durability of the test, (iii) a change in pump rate during the course of the test, and (iv) due to the short half‐life of ²²²Rn. The fluids have a 5.9% mantle He component, and a δ²¹Ne excess of 14%, and a noble gas model age of about (5.5–6.2) ± 2.0 Myr. The mean N₂/Ar‐ratio of 516 and δ¹⁵N‐data of about +1.5‰ indicates sedimentary or metamorphic origin of N₂. The hydrocarbons, amounting to 33 vol.% in the gas phase, are derived from thermal decomposition of marine organic matter of low maturity. But a key question, the identification of the potential source region of the fluids and the migration pathway, is still unidentified.     

GIS与人文地理学的发展

本文初步分析了GIS兴起的背景及其主要功能,在剖析信息社会中人文地理学发展所面临的机遇和挑战基础上,就GIS在人文地理学中的作用和发展方向进行了阐述,并就加速GIS与人文地理学的结合提出了几点对策。     

Incorporating Soil Associations into Linear Programming Models for Development of Irrigation Scenarios

An inadequate streamflow supply in Saginaw Bay, Michigan, affects the irrigation development in the region. Linear programming (LP) models are developed in this paper to help irrigation planners determine optimal irrigation scenarios. To incorporate the spatial variations of the soil and climate into the optimization models, soil associations are used as the basic analysis unit for estimating crop yields, irrigation requirements, and expected economic returns. The yields and irrigation requirements of corn, drybeans, and soybeans are simulated by the CERES-MAIZE, BEANGRO, and SOYGRO models at each of the twelve soil associations in the study area over the period of 1951–1980. The yield and irrigation requirement of sugarbeets are simulated by the YIELD model for all the soils in the study area over the period of 1956–1987. The crop prices, simulated crop yields and irrigation requirements, and variable costs are used to compute the expected gross margins and other coefficients in the LP models. The optimization results provide irrigation scenarios that are linked to specific soil associations, which are more useful to decision makers for identifying and targeting individual soils for irrigation development than are the spatially lumped optimal solutions. This study demonstrates that through integration of GIS and simulation models, spatial variations of the climate, soil, and water resources can be better represented in the optimization models to produce more realistic irrigation scenarios.     

A Hybrid Approach for Mass Valuation of Residential Properties through Geographic Information Systems and Machine Learning Integration

Geographic Information Systems (GIS) and Machine Learning methods are now widely used in mass property valuation using the physical attributes of properties. However, locational criteria, such as as proximity to important places, sea or forest views, flat topography are just some of the spatial factors that affect property values and, to date, these have been insufficiently used as part of the valuation process. In this study, a hybrid approach is developed by integrating GIS and Machine Learning for mass valuation of residential properties. GIS-based Nominal Valuation Method was applied to carry out proximity, terrain, and visibility analyses using Ordnance Survey and OpenStreetMap data, than land value map of Great Britain was produced. Spatial criteria scores obtained from the GIS analyses were included in the price prediction process in which global and spatially clustered local regression models are built for England and Wales using Price Paid Data and Energy Performance Certificates data. Results showed that adding locational factors to the property price data and applying a novel nominally weighted spatial clustering algorithm for creating a local regression increased the prediction accuracy by about 45%. It also demonstrated that Random Forest was the most accurate ensemble model.     

Potential Contributions of Spatial Analysis to Geographic Information Systems for Transportation (GIS-T)

Geographic information systems (GIS) are having tremendous impacts on many scientific and application domains. The traditional subfield of spatial analysis is witnessing a major resurgence and enhancement due to GIS and geographical information science (GISci), an interdisciplinary field focusing on the theory and methodology underlying GIS software. The interdisciplinary field of geographic information systems for transportation (GIS-T) has emerged to focus on the role of GIS in transportaton analysis and planning. This paper suggests the benefits of closer linkages between spatial analysis, GISci, and transportation through a focused review of spatial analytical issues and their potential contributions to GIS-T. Specifically, this paper reviews the following issues: (i) modifiable areal units; (ii) boundary problems and spatial sampling; (iii) spatial dependence and spatial heterogeneity; and (iv) alternative representations of geographic environments. The discussion highlights the general issues as well as identifies their specific relevance to GIS-T. In addition, this paper identifies some emerging tools from GISci that can address these spatial analytical issues in GIS-T.     

Teaching critical open GIS

Higher-education geographic information system (GIS) curricula largely marginalize and separate instruction of critical GIS and open GIS, paralleling a divide between GIS and non-GIS in geography. GIS is typically represented as a singular, infallibly objective, and universally applicable technology. GIS generally dismisses the critiques from human geography, while critical human geography dismisses GIS for its association with positivism and unethical applications. Teaching critical open GIS may bridge this divide, creating a transformative pedagogical space for human geography to affectively and effectively engage with open GIS technology at the level of code. Critical open GIS students practice and critique GIS as conflicted insiders, bridging the divide between GIS and non-GIS in their geography education. Reviews of GIS curricula find support for teaching critical and open GIS, but reviews of texts and syllabi confirm their marginalization and separation. A new critical open GIS course is introduced, using GIS in development and political ecology as integrative frameworks.     

Undertaking a Dissertation from Start to Finish: The Process and Product

Advocates for using a geographic information system (GIS) in education assert that GIS improves student learning. However, studies to clarify the relationship between learning and using GIS are still needed. This study examines the effects of using Web-based GIS maps in place of paper maps on students' geography content knowledge and motivation (self-efficacy) when taking college-level introductory human geography (N = 171). Hierarchical regression analysis shows that using Web-based GIS is positively related to post-test self-efficacy and post-test geography content knowledge.     

信息时代的地理学研究——NCGIA对若干理论问题的探索

本文以美国国家基金委员会资助美国国家地理信息与分析中心(NCGIA)进行的瓦伦纽斯(Varenius)研究项目有关信息时代地理学研究的一系列中期研究报告与论文为基础,介绍了中心一些著名学者以地理学家独特的地理哲学思维,对信息时代的地理学研究若干理论问题所作的新探索与阐述,旨在为国内学者了解、追踪地理信息科学的新发展,开展地理信息科学的跨世纪研究提供借鉴。     

A tetradic analysis of GIS and society using McLuhan's law of the media

The social implications of GIS have been debated over the past five years among scholars in several disciplines. GIS have been either conceived by practitioners as value‐free, neutral tools for problem‐solving or castigated by critical social theorists as socially biased technologies serving only corporate and state interests. Neither of these polarized views is very helpful in understanding the complex relationship between GIS and society. This paper argues that GIS are increasingly becoming media for communicating various crucial social and environmental information to the general public. By reconceptualizing GIS as media, the paper conducts a detailed tetradic analysis on the social implications of GIS using Marshall McLuhan's law of media. The analysis reveals the paradoxical and ambivalent nature of GIS technology. To make GIS fulfill democratic ideals in society, this paper calls for a shift of perspective, from viewing them as instruments for problem‐solving to viewing them as media for communication. This shift from instrumental to communicative rationality enables us to examine more critically and holistically how space, people and environment have been represented, manipulated and visualized in GIS and thus promotes a more critical and democratic GIS practice .     

Changing Water Depths in the Eastern Part of Sydney Harbour due to Human Impacts

Sydney Harbour has been significantly modified by human impacts from the start of the European settlement in 1788. Land clearing has accelerated soil erosion, resulting in increased sedimentation. Dredging has deepened many areas to accommodate ever-larger ships. In this paper a GIS method is used to map bathymetric changes in the eastern part of the harbour from 1903 to more recently. Dredged areas are apparent in the entrance and in wharfage areas, while sedimentation is most marked around the deepest section, which is well inside the harbour itself. In this latter region sediment has built up considerably, to over 3 m in some locations, and ship-induced motions appear to have had an impact. Despite these changes the overall depth of the eastern part of the harbour has changed little. This work is of interest to maritime archaeologists because it brings out the types of processes by which sediments can accumulate and be removed thus altering a harbour’s seabed and potentially burying, exposing or erasing archaeological sites and artefacts.     

Estimation of soil erosion on cultivated fields on the hilly Meghalaya Plateau,North-East India

The estimation of soil erosion rates in complex subtropical agricultural systems of hilly environment is difficult and most of the traditional methods have serious limitations. The ¹³⁷Cs technique allows to obtain relatively quickly retrospective medium term soil erosion results. The objective of this study was using ¹³⁷Cs approach to quantify soil loss under agricultural system which develops under growing human pressure on the hilly terrain of the Meghalaya Plateau. The measured values of caesium inventory for all sampling points are between 2% and 63% of the reference value of caesium inventory. The estimated annual soil loss for sampling points located on the slope are between 29 and 79 Mg·ha⁻¹·yr⁻¹ in the case of an improved mass balance model. It means that soil erosion in this manually tilled agricultural area cannot be neglected.     

The Potential Relationship Between Archaeological Artifact Exposure and Surface Geomorphic Processes: Northeastern Peloponnese,Greece

Complex interactions between topography, near-surface geology, active tectonics, climate, and human activity shape a landscape, conditioning archaeological deposits and making sediment deposits from surface erosion important archives. There is a potential relationship between the intensity of geomorphic processes and surface artifact distribution. This study assesses the potential relationship between soil erosion by water and the spatial distribution of archaeological surface artifacts in the Inachos River watershed, Greece. The mountainous, semi-arid Mediterranean region is particularly vulnerable to soil loss. Soil erosion is quantified by applying the Revised Universal Soil Loss Equation in a GIS framework. Estimates of soil loss vary spatially compared to surface artifact finds of the pedestrian survey of the Western Argolid Regional Project. A statistically significant relationship is identified between surface erosion rates and artifact density. Preferential topography for occupation suggests this is an associative rather than causative relationship. Knowledgeable interpretation of artifact distribution enables accurate reconstruction of human settlement history.     

云南省反贫困地理信息系统建设初探

本文从信息系统为决策支持服务的角度出发,以GIS、RS为手段,综合自然、经济、社会、环境等因素,多学科交叉,设计反贫困GIS的总体框架结构,研究和解决面向管理和决策的数据模型,实现致贫基本因素、贫困类型分布与贫困形势变化监测等方面的信息查询与辅助决策分析为一体的综合地理信息系统,为区域反贫困决策的各层次提供辅助分析与决策支持,为反贫困决策提供科学依据。     

Geostatistical Prediction and Simulation of Point Values from Areal Data

The spatial prediction and simulation of point values from areal data are addressed within the general geostatistical framework of change of support (the term support referring to the domain informed by each measurement or unknown value). It is shown that the geostatistical framework (i) can explicitly and consistently account for the support differences between the available areal data and the sought-after point predictions, (ii) yields coherent (mass-preserving or pycnophylactic) predictions, and (iii) provides a measure of reliability (standard error) associated with each prediction. In the case of stochastic simulation, alternative point-support simulated realizations of a spatial attribute reproduce (i) a point-support histogram (Gaussian in this work), (ii) a point-support semivariogram model (possibly including anisotropic nested structures), and (iii) when upscaled, the available areal data. Such point-support-simulated realizations can be used in a Monte Carlo framework to assess the uncertainty in spatially distributed model outputs operating at a fine spatial resolution because of uncertain input parameters inferred from coarser spatial resolution data. Alternatively, such simulated realizations can be used in a model-based hypothesis-testing context to approximate the sampling distribution of, say, the correlation coefficient between two spatial data sets, when one is available at a point support and the other at an areal support. A case study using synthetic data illustrates the application of the proposed methodology in a remote sensing context, whereby areal data are available on a regular pixel support. It is demonstrated that point-support (sub-pixel scale) predictions and simulated realizations can be readily obtained, and that such predictions and realizations are consistent with the available information at the coarser (pixel-level) spatial resolution.     

Fore-Arc and Back-Arc Ground Motion Prediction Model for Vrancea Intermediate Depth Seismic Source

A next generation ground motion model for the prediction of spectral accelerations both in the fore-arc and back-arc regions of the Carpathians Mountains is developed in this research for the Vrancea intermediate depth seismic source in Romania. This ground motion prediction equation (GMPE) is an updated version of the model given in Vacareanu et al. [2014] and is applicable in both the fore-arc and the back-arc regions. The strong ground motion database from which the prediction model is derived consists of over 700 triaxial accelerograms from Vrancea subcrustal seismic events, as well as from other intermediate-depth earthquakes produced in other seismically active regions in the world. The applicability of this ground motion prediction model in both the fore-arc and the back-arc region is tested using the analysis of residuals. Moreover, the appropriateness of this GMPE for soil classes B and C defined in EN 1998-1, as well as for average soil conditions is investigated. All results suggest that this model is an improvement of the previous versions of ground motion prediction equations for Vrancea intermediate-depth seismic source and its use in both the fore-arc and the back-arc regions make it a reliable candidate for more accurate seismic hazard studies of Romania.     

Facilitating spatial thinking in world geography using Web-based GIS

Advocates for geographic information system (GIS) education contend that learning about GIS promotes students’ spatial thinking. Empirical studies are still needed to elucidate the potential of GIS as an instructional tool to support spatial thinking in other geography courses. Using a non-equivalent control group research design, this study examines the effect of using Web-based GIS in a world geography course on the development of students’ spatial thinking abilities. The findings indicate that Web-based GIS activities implemented in this study significantly enhanced students’ spatial thinking skills.     

Sampling Design and Inferential Bias in Archaeological Soil Chemistry

The ways and extent to which sampling design influences data collection and archaeological inference is a constant concern for archaeologists. Yet, spatial analyses based on anthrosol chemistry have been less willing to concede this problem and to explore potential solutions. This article reviews the recent literature on soil sampling for spatial studies and then uses an example from prehispanic Honduras to examine how both quantitative and qualitative interpretations of soil chemical patterns can shift when sampling design changes. The results of this study suggest that the principal challenges to selecting an appropriate sampling design are in determining the sample size and density, as well as recognizing and adequately dealing with variation in the soil properties being measured. These findings provide cautionary tales for spatial studies aimed at using soil chemical data to infer activity patterns in the archaeological record.     

Exposure to Cadmium and Lead in an Agropastoral Iron Age Population

Metals present in the environment (soil, water and atmosphere) can affect food safety and human health through bio‐accumulation and bio‐magnification phenomena. Human exposure to the metals may take place through the environment and by ingesting contaminated food (including water), determining harmful effects usually detectable over the long term. Starting with the Industrial Revolution, local occurrence and concentration of metallic contaminants in the environment have been exponentially increasing: it has been assessed that, nowadays, daily absorption of lead, by North American people, is noticeably greater than that during prehistoric times. In this study, we measured concentrations of cadmium, lead and zinc in 153 bone samples (femurs) of Iron Age inhabitants of Central Italy (Abruzzo): the Samnites from the Alfedena Necropolis (2600–2400 bp ). The data found are in agreement with the results of similar published studies. Heavy metal concentrations varied widely among samples with the exception of zinc. A significant difference (p same Mann–Whitney test <0.05) in cadmium bone levels was found between male (0.08–1.8 mg/kg, median 0.31 mg/kg) and female samples (0.05–1.3 mg/kg, median 0.53 mg/kg). Copyright © 2014 John Wiley & Sons, Ltd.     

Sampling and analysis of geothermal fluids

Sampling of geothermal fluids presents some problems not encountered when sampling surface and nonthermal ground waters. Specific collection techniques are required to obtain representative samples because of the elevated temperature and boiling of these fluids, the effect of exposing them to the atmosphere and cooling of the samples. Sample treatment during collection depends on the analytical method to be used. When sampling wet‐steam wells, both the liquid and the vapour fractions should be collected at the same fluid separation pressure. When sampling fumarole steam, maximum information is obtained if the total discharge is collected into a single container without separating the gas and the steam condensate fractions. Silica polymerization affects the solution pH. The only way to obtain reliable pH measurement of a water sample supersaturated with respect to amorphous silica is to measure it on site, before the onset of polymerization. This paper provides an outline of the geothermal sampling techniques and analytical methods currently in use in Iceland. Sampling of hot‐water and wet‐steam wells is described, as is sampling of hot springs, fumaroles and gas bubbling through hot‐spring waters. Detailed procedures are given for the analysis of total carbonate carbon and total sulphide sulphur in geothermal water and steam condensate samples.     

Small core,big network: a comprehensive approach to GIS teaching practice based on digital three-dimensional campus reconstruction

Geographic information science (GIS) features a wide range of disciplines and has broad applicability. Challenges associated with rapidly developing GIS technology and the currently limited teaching and practice materials hinder universities from cultivating highly skilled GIS graduates. Based on the idea of “small core, big network,” a comprehensive and interesting approach to GIS teaching practice is introduced in which a variety of key knowledge areas and technologies are effectively incorporated into a single project. A year-long assignment based on this approach was conducted, providing the students with practical training and successfully resulting in a digital three-dimensional representation of the campus.