共查询到20条相似文献,搜索用时 15 毫秒
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Fatoumata Barry Duke Ophori Jeffrey Hoffman Robert Canace 《Environmental Geology》2009,56(8):1593-1603
Delineating capture zones of pumping wells is an important part of safe drinking water and well protection programs. Capture
zones or contributing areas of a groundwater extraction well are the parts of the aquifer recharge areas from which the wells
draw their water. Their extent and location depend on the hydrogeologic conditions such as groundwater recharge, pumping scenario
and the aquifer properties such as hydraulic conductivity, porosity, heterogeneity of the medium and hydraulic gradient. Different
methods of delineation can be used depending on the complexity of the hydrogeologic conditions. In this study, a 3-dimensional
transient numerical MODFLOW model was developed for the Central Passaic River Basin (CPRB), and used with a MODPATH particle
tracking code to determine 3-dimensional transient capture zones. Analytically calculated capture zones from previous studies
at the site were compared with the new numerically simulated capture zones. The study results revealed that the analytical
solution was more conservative, estimating larger capture zones than the numerical models. Of all the parameters that can
impact the size, shape and location of a capture zone, the hydraulic conductivity is one of the most critical. Capture zones
tend to be smaller in lower hydraulic conductivity areas. 相似文献
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Albrecht Steck 《Swiss Journal of Geoscience》2008,101(2):515-546
This study presents a review of published geological data, combined with original observations on the tectonics of the Simplon
massif and the Lepontine gneiss dome in the Western Alps. New observations concern the geometry of the Oligocene Vanzone back
fold, formed under amphibolite facies conditions, and of its root between Domodossola and Locarno, which is cut at an acute
angle by the Miocene, epi- to anchizonal, dextral Centovalli strike-slip fault. The structures of the Simplon massif result
from collision over 50 Ma between two plate boundaries with a different geometry: the underthrusted European plate and the
Adriatic indenter. Detailed mapping and analysis of a complex structural interference pattern, combined with observations
on the metamorphic grade of the superimposed structures and radiometric data, allow a kinematic model to be developed for
this zone of oblique continental collision. The following main Alpine tectonic phases and structures may be distinguished:
It is suggested that movements of shortening in fan shaped NW, W and SW directions accompanied the more regular NW- to WNW-directed
displacement of the Adriatic indenter during continental collision.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Editorial Handling: Stefan Bucher 相似文献
1. | NW-directed nappe emplacement, starting in the Early Eocene (~50 Ma); |
2. | W, SW and S-verging transverse folds; |
3. | transpressional movements on the dextral Simplon ductile shear zone since ~32 Ma; |
4. | formation of the Bergell – Vanzone backfolds and of the southern steep belt during the Oligocene, emplacement of the mantle derived 31–29 Ma Bergell and Biella granodiorites and porphyritic andesites as well as intrusions of 29–25 Ma crustal aplites and pegmatites; |
5. | formation of the dextral discrete Rhone-Simplon line and the Centovalli line during the Miocene, accompanied by the pull-apart development of the Lepontine gneiss dome – Dent Blanche (Valpelline) depression. |
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Editorial Handling: Stefan Bucher 相似文献
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David Hindle 《Swiss Journal of Geoscience》2008,101(2):305-310
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Eran Feitelson 《Hydrogeology Journal》2006,14(3):319-329
The reliance on aquifers which are shared by more than one country is increasing. Yet, shared aquifers are only rarely addressed in international treaties, despite the wide recognition of the desirability of comprehensive coordinated management. In order to identify the impediments to reaching agreements on the management of shared aquifers, and the factors that may assist in overcoming these impediments, the political economy of transboundary groundwater exploitation is outlined, and the Israeli-Palestinian case examined. It is argued that the main impediment to the conclusion of international agreements on groundwater is the array of domestic power structures, and particularly the power of small cohesive interest groups. The analysis of the Israeli-Palestinian 1995 interim agreement, and the negotiations leading to it, suggest that this impediment can be overcome, if the domestic interests are recognized in advance, and addressed in the agreement. It also shows that high level politics can play a positive role in forcing water negotiators to conclude an agreement.
相似文献
Eran FeitelsonEmail: Phone: +972-2-5883346Fax: +972-2-5881200 |
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The reported data present the stratigraphy of several sections across a Middle-Late Jurassic Radiolaritic Unit, well exposed
in different thrust sheets pertaining to the Maghrebian chain of Southwestern Sicily. The aim was to define the chronostratigraphical
distribution of the Jurassic biosiliceous sedimentation in the Sicanian palaeogeographical zone, a deep water basin belonging
to the Southern Tethys continental margin.
The radiolarian biostratigraphy indicates that the switching from carbonate to siliceous sedimentation in the Sicanian Basin
is referable to the Bajocian, as shown by the section of Campofiorito, near Corleone. The biostratigraphical dataset allows
the correlation between the onset of biosiliceous sedimentation and the fall of biodiversity in the Sicanian basin with the
carbonate productivity crisis, indicated by the highest eutrophication that affected Western Tethys during Middle Jurassic
times.
Editorial handling: J.-P. Billon-Bruyat & M. Chiari (Guest) 相似文献
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