Radiometric mapping of the Berg River estuary     

Ivan Henrico  Susan Henrico  Rikus le Roux  Jacques Bezuidenhout 《Transactions in GIS》2023,27(1):105-114

Geographic Information Systems (GIS) consists of various tools to perform spatial analyses in a wide variety of disciplines, including radiometric analysis to characterize the distribution of natural radionuclide concentrations. Recently, open-source GIS has become popular among geospatial users because it can be freely used, and powerful tools are constantly developed to enhance software capabilities. Gamma-ray spectroscopy was used to measure the concentrations of these natural radionuclides by dragging a Delta Underwater Gamma System (DUGS) among the sediment in the Berg River estuary located in Velddrif, South Africa. In this study, QGIS was used to visually illustrate and interpret the distribution of natural radionuclides, that is, potassium (K⁴⁰), thorium (Th²³²), and uranium (U²³⁸). These concentrations can be used to investigate various geographical and geological phenomena, which include sediment processes. The data were then interpreted to derive sediment characteristics. Various features of tidal estuaries were demonstrated by the results.  相似文献   

Using GIS to improve public health emergency response in rural areas during the COVID-19 crisis: A case study of South Carolina,US     

Patricia Carbajales-Dale  Dusti Annan-Coultas  Anjali Joseph  Martie Thompson  Roxana Jafarifiroozabadi  Susan P. Limber  Bonnie Holaday  Sahar Mihandoust 《Transactions in GIS》2023,27(4):975-995

Geographic information systems (GIS) have become essential tools in the public health domain, especially when it comes to monitoring and surveillance of disease. The purpose of this article is to describe and explore the benefits of using GIS to improve public health emergency response during a global pandemic and, in particular, how to effectively optimize the allocation of public health resources in a rural setting using a data-driven approach that considers the multifactorial demand for new COVID-19 testing sites. Herein, the authors present their interprofessional project as an example of such efforts to inform applications for practice. The team developed a GIS-based multicriteria decision analysis model for use by decision-makers and public health experts in similar future planning and response scenarios. Focus is placed on rural characteristics (e.g., accessibility), vulnerable populations, and daily changing conditions (e.g., COVID-19 daily case fluctuations) that create additional challenges for public health agencies and policymakers.  相似文献   

American Migration,Settlement, and “Belonging” in Francophone Canada     

Susan W. Hardwick 《Geographical review》2014,104(3):259-276

More Americans now reside in Canada than at any time since the Vietnam War. Of particular note is the surprisingly large population of immigrants from the United States who now reside in Montreal—Francophone Canada's largest and most diverse city. This article documents and analyzes the migration experiences, spatial patterns, and “sense of belonging” of Americans in Montreal during the post–Vietnam era framed within the larger political and linguistic context of the city's “Two Solitudes.” Findings are based on information compiled from archival materials, census records, structured and unstructured interviews, survey questionnaires, participant observation, and fieldwork. My overarching goal is to embed the experiences and patterns of this English‐speaking group of immigrants in predominately French‐speaking Montreal during the past five decades—one of the most dramatic and divisive periods of time in Montreal and in Quebec as a whole.  相似文献   

Monitoring above-zone temperature variations associated with CO2 and brine leakage from a storage aquifer     

Mehdi Zeidouni  Jean-Philippe Nicot  Susan D. Hovorka 《Environmental Earth Sciences》2014,72(5):1733-1747

CO₂ injection in saline aquifers induces temperature changes owing to processes such as Joule–Thomson cooling, endothermic water vaporization, exothermic CO₂ dissolution besides the temperature discrepancy between injected and native fluids. CO₂ leaking from the injection zone, in addition to initial temperature contrast due to the geothermal gradient, undergoes similar processes, causing temperature changes in the above zone. Numerical simulation tools were used to evaluate temperature changes associated with CO₂ leakage from the storage aquifer to an above-zone monitoring interval and to assess the monitorability of CO₂ leakage on the basis of temperature data. The impact of both CO₂ and brine leakage on temperature response is considered for three cases (1) a leaky well co-located with the injection well, (2) a leaky well distant from the injector, and (3) a leaky fault. A sensitivity analysis was performed to determine key operational and reservoir parameters that control the temperature signal in the above zone. Throughout the analysis injection-zone parameters remain unchanged. Significant pressure drop upon leakage causes expansion of CO₂ associated with Joule–Thomson cooling. However, brine may begin leaking before CO₂ breakthrough at the leakage pathway, causing heating in the above zone. Thus, unlike the pressure which increases in response to both CO₂ and brine leakage, the temperature signal may differentiate between the leaking fluids. In addition, the strength of the temperature signal correlates with leakage velocity unlike pressure signal whose strength depends on leakage rate. Increasing leakage conduit cross-sectional area increases leakage rate and thus increases pressure change in the above zone. However, it decreases leakage velocity, and therefore, reduces temperature cooling and signal. It is also shown that the leakage-induced temperature change covers a small area around the leakage pathway. Thus, temperature data will be most useful if collected along potential leaky wells and/or wells intersecting potential leaky faults.  相似文献   

Significant Increase of Oil and Natural Gas Reserves throughout 2013     

HAO Ziguo  FEI Hongcai  HAO Qingqing  Susan TURNER 《《地质学报》英文版》2014,88(2):718-718

正China’s Ministry of Land and Resources announced on 27th February 2014 that proven reserves of oil,natural gas and coal continued to increase significantly,and that their production shows a steady increase.This greatly improves China’s support capacity of fossil fuel resources.Oil resources:In 2013,China newly discovered oil geological reserves yielded 10.84×108 t,and  相似文献   

Classification and detection of dominant factors in geospatial patterns of traditional settlements in China     

Wu  Shaolin  Di  Baofeng  Ustin  Susan L.  Stamatopoulos  Constantine A.  Li  Jierui  Zuo  Qi  Wu  Xiao  Ai  Nanshan 《地理学报(英文版)》2022,32(5):873-891

Journal of Geographical Sciences - The geospatial distribution pattern in traditional Chinese settlements (TCSs) reflects the traditional harmony between humans and nature, which has been learned...  相似文献   

In pursuit of procedural justice: Lessons from an analysis of 56 forest carbon project designs     

Kimberly R. Marion Suiseeya  Susan Caplow 《Global Environmental Change》2013,23(5):968-979

  相似文献   

Preserving the unpreservable: a lost world rediscovered at Christian Malford, UK     

Philip R. Wilby  Keith Duff  Kevin Page  & Susan Martin 《Geology Today》2008,24(3):95-98

The small village of Christian Malford, Wiltshire (UK) is known to palaeontologists the world over because of the chance discovery of an astonishing fossil bonanza in the mid-nineteenth century. Pits in the Jurassic Oxford Clay yielded thousands of specimens of exquisitely preserved ammonites, fish and crustaceans, but became most famous for squid-like cephalopods and belemnites (collectively termed coleoids) with fossilized soft-parts. The precise location of the find has remained obscure, until now, and a new attempt is underway to understand the ancient environment that triggered this unusual preservation.  相似文献   

Anatomy of individual agglutinates from a lunar highland soil     

Abhijit BASU  David S. McKAY  Richard V. MORRIS  Susan J. WENTWORTH 《Meteoritics & planetary science》1996,31(6):777-782

Abstract— We report results of our investigation of the relationship between values of I_s/FeO (relative concentration of nanophase Fe⁰ divided by total FeO content), glass abundance, total Fe content, and degree of digestion of <20 μm clasts for 22 individual agglutinates (250–1000 μm) from the mature Apollo 16 soil 61181 (I_s/FeO = 82 units in the <250 μm fraction). Agglutinates are important products of space weathering on the Moon, and they influence spectral observations at visible and near-IR wavelengths. Values of I_s/FeO for individual agglutinates (250–1000 μm) within this single soil span a range from 3 to 262 units which is larger than the range observed for all Apollo 16 bulk soils (～0 to 110 units). No correlation was observed between I_s/FeO and glass abundance and FeO concentrations for either agglutinitic glass or whole agglutinate particles under investigation. Our results suggest that the variation in I_s/FeO for agglutinates from a single soil may be in part a consequence of natural mixing processes on the Moon that produce highly-variable environments (with respect to surface exposure) for agglutinate formation and in part to variable kinetics of reactions in an agglutinate melt, which are influenced by a variety of factors including melt composition, temperature, impactor velocity, and quench rate. We cannot exclude but do not see evidence for other processes including addition of exotic agglutinates, micrometeoritic bombardment into compositionally-diverse microtargets, recycling of agglutinates, preferential melting of very fine soil particles, and production of nanophase Fe⁰ in amorphous rims of very fine irradiated lunar grains contributing to the observed variation of I_s/FeO.  相似文献   

Evidence for Chemical Heterogeneity in the Nucleus of C/1995 O1 (Hale–Bopp)     

Lederer  Susan M.  Campins  Humberto 《Earth, Moon, and Planets》2002,90(1-4):381-389

We present an analysis of OH, CN, and C₂ jets observed in thecoma of Comet Hale–Bopp on UT April 22, 23, and 25, 1997. Monte Carlomodels designed to simulate the gas jets were employed to analyze thenuclear active areas responsible for the observed coma gas jets. Ourresults indicate that four active areas are necessary to reproduce theCN and C₂ jets while five active areas are required to simulatethe OH jets. The additional OH active area must produce significantlevels of OH, but cannot emit measurable quantities of either carbonradical. This difference suggests that the nucleus of Comet Hale–Boppis chemically heterogeneous.  相似文献