共查询到20条相似文献，搜索用时 31 毫秒
1.
Said Ettazarini 《Environmental Geology》2006,50(6):919-929
This study takes the groundwater of the Moroccan limestone aquifer of Oum Er-Rabia as an example of statistical and cartographical approaches in water resources management. Statistical analyses based on frequency distribution and PCA methods revealed the homogeneity of waters with the existence of abnormal points and have helped to assess correlations between the studied variables. The mapping approach illustrated that waters are influenced by the lithology of the surrounding rocks and are of Ca–Mg–HCO3, Ca–Mg–Cl–SO4, and mixed types according to the Piper classification. The quality of water is of high to medium, north of the basin, but it is of medium to bad, NE and south, due to excessive contents of chloride, sulfate and nitrate. According to the US Salinity Laboratory classification, water used for irrigation in the eastern and the southern parts of the basin should take into consideration the drainage conditions, the nature of plants and the addition of gypsum doses.
相似文献
| Said EttazariniEmail: Phone: +212-66-407610 |
2.
The irreversible water–rock mass exchanges leading to the production of the Fiume Grande valley (Calabria, Italy) stream waters
and groundwaters, starting from local rainwaters, were simulated through reaction path modeling in reaction progress (stoichiometric)
mode. The simulations assumed bulk dissolution of a phyllitic rock and calcite and precipitation of gibbsite, kaolinite, amorphous
silica, illite, a smectite solid mixture, a hydroxide solid mixture, and a trigonal carbonate solid mixture. The analytical
contents of major and trace elements in stream waters and groundwaters were satisfactorily reproduced. However, further investigations
are necessary to clarify the fate of As in this natural systems.
相似文献
| Rosanna De RosaEmail: |
3.
Melt inclusion formation mechanisms and compositional effects in high-An feldspar and high-Fo olivine in anhydrous mafic silicate liquids 总被引：1，自引：1，他引：0
Important aspects of melt inclusion formation and potential compositions effects have been addressed through a series of experiments using anorthite/fosterite saturated anhydrous mafic liquids. Experimental charges were cooled from 1,300 to 1,230 and 1,210°C at rates of 1–10°/min followed by 0–24 h isothermal periods. Hopper and skeletal crystal morphologies with variable degrees of completeness developed during the cooling period. Planar overgrowth of these textures during isothermal periods led to the formation of inclusions, the majority of which formed after 6 h of isothermal run time. We suggest that the change in morphologies is related to a decrease in growth rates and changes in dominant growth mechanisms. In general, inclusion compositions were uniform and similar to the host glass, indicating that with the isothermal times required for most inclusions to form, a boundary layer was not entrapped that could be detected within the limits of our analyses.
相似文献
| Edward KohutEmail: Phone: +1-541-7373023Fax: +1-541-7371200 |
| Roger L. NielsenEmail: Phone: +1-541-7371235 |
4.
Modeling stream-aquifer interactions in a shallow aquifer, Choele Choel Island, Patagonia, Argentina 总被引：3，自引：1，他引：2
A groundwater/surface-water interaction model was developed for the shallow alluvial aquifer of the Choele Choel Island in
Patagonia, Argentina. In this semiarid climate, agriculture is sustained by an irrigation/drainage system. During the irrigation
season, seepage losses through unlined distribution canals in irrigated fields contribute to elevated groundwater levels,
jeopardizing fruit productivity in some areas. Moreover, high stream stages during the irrigation season interfere with groundwater
drainage. The model utilized MODFLOW and its stream package, and was successfully calibrated for a historical irrigation season.
Modeling results indicate that drainage through streams is significantly higher than drainage through artificial drains. The
stream/aquifer relationship proved very responsive to water table rises caused by irrigation. This response manifested as
changes in the gaining/losing character of stream reaches. A synthetic run aimed at isolating the effect of streamflow changes
on groundwater levels showed that the effect of higher streamflows dissipates toward the interior of the island, disappearing
completely at the island center. Even though some results were qualitative, the model helped to provide a better understanding
of the coupled system to elucidate some of the causes of a rising water table on the island.
相似文献
| Leticia B. RodríguezEmail: |
5.
The morphology, colour, fluorescence, cathodoluminescence, nitrogen content and aggregation state, internal structure and mineral inclusions have been studied for 69 alluvial diamonds from the Rio Soriso (Juina area, Mato Grosso State, Brazil). Nitrogen in most diamonds (53%) is fully aggregated as B centres, but there is also a large proportion of N-free stones (38%). A strong positive correlation between nitrogen and IR-active hydrogen concentrations is observed. The diamonds contain (in order of decreasing abundance) ferropericlase, CaSi-perovskite, magnetite, MgSi-perovskite, pyrrhotite, olivine, SiO2, perovskite, tetragonal almandine-pyrope phase and some other minerals represented by single grains. The Rio Soriso diamond suite is subdivided into several subpopulations that originated in upper and lower mantle of ultramafic and mafic compositions, with the largest subgroup forming in the ultramafic lower mantle. Analysed ferropericlase grains are enriched in Fe (Mg#=0.43–0.89), which is ascribed to their origin in the lowermost mantle. The Juina kimberlites may be unique in sampling the material from depths below 1,700 km that ascended in a plume formed at the core–mantle boundary.Electronic Supplementary Material Supplementary material is available for this article at
相似文献
| Maya G. KopylovaEmail: Phone: +1-604-8220865Fax: +1-604-8226088 |
6.
Anthony John Christopher 《GeoJournal》2006,67(2):123-136
The pattern of Church of England dioceses has evolved over a period of 1,400 years. It reflects the practical response of
the Church to the changing political and demographic patterns of the country. No ideal size and form of diocese was ever devised
and few systematic attempts were made to achieve a degree of equity between them. The constitutional link between state and
church has inhibited change for the last 80 years, although society has changed significantly. Nevertheless, rapid constitutional
reforms, especially in the House of Lords, may be reflected in ecclesiastical reorganisation of the dioceses.
相似文献
| Anthony John ChristopherEmail: |
7.
Spatial and temporal knowledge representation 总被引：1，自引：1，他引：0
Antony Galton 《Earth Science Informatics》2009,2(3):169-187
Knowledge Representation (KR) originated as a discipline within Artificial Intelligence, and is concerned with the representation
of knowledge in symbolic form so that it can be stored and manipulated on a computer. This article surveys that part of KR
that is concerned with the representation of space and time, with particular reference to the use of such representations
in geographical information science.
相似文献
| Antony GaltonEmail: |
8.
Remote sensing and GIS based determination of groundwater dependent ecosystems in the Western Cape, South Africa 总被引：4，自引：0，他引：4
Finding the location of groundwater dependent ecosystems (GDEs) is important in determining the extent of restrictions that
need to be placed upon the abstraction of groundwater. Remote sensing was combined with geographical information system (GIS)
modelling to produce a GDE probability rating map for the Sandveld region, South Africa. Landsat TM imagery identified the
areas indicating the probable presence of GDEs and GIS assisted in their delineation. Three GIS models were generated: a GIS
model predicting landscape wetness potential (LWP model) based on terrain morphological features; the LWP model was modified
to highlight groundwater generated landscape wetness potential (the resulting GglWP model); and a groundwater elevation model
was interpolated, combining groundwater level measurements in boreholes in the region with digital elevation model data. Biomass
indicators generated from Landsat were classified and combined with the GIS models, followed by field verification of riverine
and wetland GDEs. The LWP model provided the most accurate results of the three models tested for GDEs in this region.
相似文献
| Zahn MünchEmail: |
9.
Igor Vojnovic 《GeoJournal》2007,69(4):271-300
Throughout the 20th century, government in the U.S. has gone through significant changes; initially responding to the disorder
of early capitalism, and later, to the economic crisis of the 1970s. This article will explore the changes in the U.S. political
landscape over the last century, as well as the recent rise of neo-liberalism. In addition, with the analysis of the model
laissez-faire municipal government, the City of Houston, the article will illustrate how the basic weaknesses of neoliberalism
at the national level are also evident at the local scale of government.
相似文献
| Igor VojnovicEmail: |
10.
Dorian Speakman 《Natural Hazards》2008,44(1):111-127
A vulnerability index for the Fire Service in the UK has been designed to identify vulnerable locations during episodes of
severe floods. Taking recent case studies with the UK Fire Service, the patterns of vulnerability, in terms of demand on time
and resources, can be explained by investigating the environmental causes and their interaction with the adaptive capacity
of the response agencies.
相似文献
| Dorian SpeakmanEmail: |
11.
Giorgio Hadi Curti 《GeoJournal》2009,74(3):201-208
Ostensibly, subtitles in films serve as linguistic approximations of meaning. Expectedly then, much of the debate surrounding
subtitling has been concerned with representational accuracy, fidelity and authenticity. In this article I argue that by encountering
subtitles as affective bodily expressions, as opposed to approximate representations of pre-existent meanings or intentions,
filmic experiences may be(come) transformed and differently transformational. As a result, meaning and accuracy in subtitles
as superimposed signifiers or static representations become secondary to subtitles as spatially affective- and expressive-movements
intimately part of filmic scapes. The creative use of subtitling in Bekmambetov’s Russian language film Night Watch (Nochnoy dozor; 2006 [2004]) is discussed.
相似文献
| Giorgio Hadi CurtiEmail: |
12.
This paper describes an application of the geographic information system (GIS) technology to a ground stability assessment
in the karst area of Dzerzhinsk, Russia. In the stability analysis, the groundwater level changes in the karst aquifer could
cause suffosion sinkholes when the gravitational force was greater than the soil strength. The GIS technology was used to
combine various data and to delineate the zones of potential gravitational collapse and suffosion collapse in the area.
相似文献
| V. V. TolmachevEmail: |
13.
Space Physics Interactive Data Resource—SPIDR 总被引：1，自引：0，他引：1
Mikhail Zhizhin Eric Kihn Rob Redmon Dmitry Medvedev Dmitry Mishin 《Earth Science Informatics》2008,1(2):79-91
SPIDR (Space Physics Interactive Data Resource) is a standard data source for solar-terrestrial physics, functioning within
the framework of the ICSU World Data Centers. It is a distributed database and application server network, built to select,
visualize and model historical space weather data distributed across the Internet. SPIDR can work as a fully-functional web-application
(portal) or as a grid of web-services, providing functions for other applications to access its data holdings.
相似文献
| Mikhail ZhizhinEmail: |
14.
With the global container population exceeding 25 million TEU (Twenty-foot Equivalent Unit) and the annual production of new
boxes exceeding 3 million TEU it is estimated that around 1.5 million TEU of empty containers are sitting in yards and depots
around the world waiting for use. Although utilization rates have improved since 2004, container utilization depends on the
very dynamic nature of container transportation, and the container building and leasing industries. Owing primarily to the
chronic trend of increasing trade imbalances across the oceans, and despite recent trends along some trade routes, the empty
container management problem has become a major issue for the container shipping industry during the last decade. This paper
examines and analyzes empty container logistics at a global, interregional, regional and local level. Special consideration
is given to key factors affecting the empty container logistics management and strategies implemented by ocean carriers and
other stakeholders to better manage empty containers.
相似文献
| Maria BoileEmail: |
15.
Indigenous people often exclusively depend on the natural resources available within the ecosystems where they live, and commonly
manage their resources sustainably. They have developed, and continue to develop indigenous knowledge systems which encompass
sustainable management of natural resources. This study compares indigenous knowledge of natural resource management developed
by two different communities in two different environments—Maori in the temperate environment in New Zealand and Dusun in
the tropical environment in Brunei Darussalam, and comparatively evaluates the role of indigenous knowledge in sustainable
resource management in three categories of knowledge such as spatial and seasonal distribution of natural resources, sustainable
harvesting, and habitat management. The comparison reveals that despite the differences in environment and the great geographical
distance between the two communities, there are remarkable similarities between the two knowledge systems in concepts, principles,
strategies and technologies used in natural resource management.
相似文献
| Rohana UlluwishewaEmail: |
16.
Predicting environmental conditions to minimise salt damage at the Tower of London: a comparison of two approaches 总被引：1，自引：0，他引：1
Clifford A. Price 《Environmental Geology》2007,52(2):369-374
The paper compares the results of two studies of salt damage at the Wakefield Tower, Tower of London. The first, in 1993,
was based on semi-quantitative salt analysis and hygroscopicity measurements. The second was based on quantitative analysis
and a thermodynamic model, ECOS. Both studies aimed to predict environmental conditions that would minimise salt damage to
the interior stonework. Their predictions are markedly different, and this paper examines the reasons for the differences.
It is shown that hygroscopicity alone is not a reliable indicator of crystallisation from mixed salt solutions.
相似文献
| Clifford A. PriceEmail: |
17.
Sex offenders are currently a major focus of crime control policies at the local, regional, state and federal levels throughout
the United States. In part, the perceived threat of offender recidivism has motivated legislators to launch stringent community
notification programs and to establish spatial restriction zones (SRZs) around schools, daycare facilities and public parks.
The purpose of these restriction zones is to help protect children and minimize their exposure to convicted sex offenders
living in the community. In addition to the concern that the implementation of SRZs dramatically reduces viable housing options
for registered sex offenders, there are concerns that offenders will be forced to reside in socially disorganized areas that
may encourage recidivism. The purpose of this paper is to explore the demographic and socioeconomic differences between areas
inside and outside SRZs. Implications of these results for sex offender policies are discussed.
相似文献
| Tony H. GrubesicEmail: |
18.
Summary The question of alternative technologies for high-speed Internet access lies at the heart of rural development problems. In
this paper, we focus on one of those technologies, the system combining satellite technologies and Wi-Fi. Based on an empirical
study carried out in three rural areas, we analyze the dynamics of the use and appropriation of that technology by the companies
and organizations participating in the experiment. Considered both from a technical and social standpoint, the technology
‘in use’ appears here in its structuring dimensions.
相似文献
| Valérie FautreroEmail: |
19.
The future of the dolomitic springs after mine closure on the Far West Rand,Gauteng, RSA 总被引：1，自引：0，他引：1
Approximately 1.2 km of dolomitic limestone overlies the Far West Rand gold reefs southwest of Johannesburg, South Africa. This karst aquifer is partitioned into several groundwater compartments by predominantly north–south trending syenite dykes. Prior to mining, the primary water flow was westwards, decanting over dyke boundaries as a succession of springs along the Lower Wonderfontein Spruit. Dewatering of the overlying dolomitic aquifer for safety and economic reasons by deep gold mining operations, caused the water levels of four compartments to drop and their respective springs to dry up. By perforating dykes, formerly separated aquifers were hydraulically interconnected by mining. Using historical and recent data of water flow—surface and groundwater—and pumping rates, a geohydrological model is presented. The results suggest that the water tables will rise to their pre-mining levels within 30 years after mining ceases and that the dry springs will flow again, despite the compartments being connected by the extensive mining operations.
相似文献
| C. J. U. SwartEmail: Phone: +27-18-7874435Fax: +27-18-7875972 |
20.
Sarah F. Ives 《GeoJournal》2009,74(3):245-255
Using a discussion of South African soap operas, I will place the idea of visuality in a discourse analysis that incorporates
a feminist epistemological lens, or an epistemology that integrates reflexivity and an acknowledgment of the dialogic nature
of visual media. Through this discussion, I will examine the possibilities that dialogism provides for unpacking and exploring
the politics of imperfect translation between the visual and the textual. These methodological interventions, I argue, will
help enrich discussions of the visual’s role in the contested realm of geographic imaginations and move beyond the distanced
position of the masculine gaze.
相似文献
| Sarah F. IvesEmail: |