Global scale evaluation of coastal fresh groundwater resources     

Priyantha Ranjan  So Kazama  Masaki Sawamoto  Ahmad Sana 《Ocean & Coastal Management》2009,52(3-4):197-206

This paper presents a simplified approach to assess the effects of global warming on global coastal groundwater resources over the next century based on the smallest but necessary number of elements such as rainfall, temperature, hydraulic conductivity of the aquifers, and population changes regarding the consumption of groundwater. The positive aspect in this approach is that there is availability of the above elements in the majority of the planet. Methodology includes a sharp interface concept model and simplified estimation of groundwater recharge using limited climate data. The evaluation shows that the future climate changes would decrease fresh groundwater resources in Central American, South American, South African and Australian regions whereas most of the areas in Asia, except South-East Asia. Combinations of fresh groundwater loss and global population are considered to state the vulnerability of future fresh groundwater supply. Vulnerability assessment shows that South Asia, Central America, North Africa and the Sahara, South Africa and the Middle East countries are highly vulnerable whereas, Northern Europe, Western part of South America, New Zealand and Japan are less vulnerable with respect to future fresh groundwater supply. Further, this paper highlights the necessity Integrated Coastal Management (ICM) practices in these vulnerable coastal regions to ensure the sustainable development in coastal regions.  相似文献   

Measurement of LNAPL flow using single-well tracer dilution techniques   总被引：1，自引：0，他引：1  

Sale T  Taylor GR  Iltis G  Lyverse M 《Ground water》2007,45(5):569-578

This paper describes the use of single-well tracer dilution techniques to resolve the rate of light nonaqueous phase liquid (LNAPL) flow through wells and the adjacent geologic formation. Laboratory studies are presented in which a fluorescing tracer is added to LNAPL in wells. An in-well mixer keeps the tracer well mixed in the LNAPL. Tracer concentrations in LNAPL are measured through time using a fiber optic cable and a spectrometer. Results indicate that the rate of tracer depletion is proportional to the rate of LNAPL flow through the well and the adjacent formation. Tracer dilution methods are demonstrated for vertically averaged LNAPL Darcy velocities of 0.00048 to 0.11 m/d and LNAPL thicknesses of 9 to 24 cm. Over the range of conditions studied, results agree closely with steady-state LNAPL flow rates imposed by pumping. A key parameter for estimating LNAPL flow rates in the formation is the flow convergence factor alpha. Measured convergence factors for 0.030-inch wire wrap, 0.030-inch-slotted polyvinyl chloride (PVC), and 0.010-inch-slotted PVC are 1.7, 0.91, and 0.79, respectively. In addition, methods for using tracer dilution data to determine formation transmissivity to LNAPL are presented. Results suggest that single-well tracer dilution techniques are a viable approach for measuring in situ LNAPL flow and formation transmissivity to LNAPL.  相似文献   

Role of Hydrology in the Formation of Co-rich Mn Crusts from the Equatorial N Pacific,Equatorial S Indian Ocean and the NE Atlantic Ocean     

Geoffrey P. Glasby  Bruce Mountain  Theckethottathil C. Vineesh  Virupaxa Banakar  Ramesh Rajani  Xiangwen Ren 《Resource Geology》2010,60(2):165-177

Co-rich Mn crusts from four different locations of the world ocean have been studied to understand the role of dissolved oxygen of the ambient seawater in the formation of Co-rich Mn crusts. WOCE (World Ocean Circulation Experiment) oxygen profiles of modern seawater in the Equatorial North Pacific Ocean, Equatorial South Indian Ocean and the North East Atlantic Ocean have been evaluated with respect to the occurrence of Co-rich Mn crusts at depths ranging from 1500 to 3200 m. The oxygen content at these depths varied from ∼90–240 µmol/kg. The oxygen minimum zone (OMZ), with oxygen contents in the range ∼45–100 µmol/kg, is located in the depth range 800–900 m in these regions. The age of the ocean crust on which seamounts formed is in the range 80.3–180 Ma. Profiles of the oxygen contents of seawater with depth in the oceans are shown to be extremely useful in establishing the optimum conditions for the formation of Co-rich Mn crusts. The use of WOCE oxygen profiles to study geochemical processes in the oceans is highly recommended.  相似文献   

Incorporation of Transition and Platinum Group Elements (PGE) in Co-rich Mn Crusts at Afanasiy-Nikitin Seamount (AFS) in the Equatorial S Indian Ocean     

Geoffrey P. Glasby 《Resource Geology》2010,60(2):212-215

Of the 12 elements enriched in Co-rich Mn crusts from the Afanasiy-Nikitin Seamount in the Equatorial S Indian Ocean, Mn, Fe and Co are enriched by a factor of ~10⁹ compared to their concentrations in seawater whereas Ni and Cu are enriched by a factor of ~10⁷ and the PGE and Au by a factor of ~10⁵ to 10⁷ compared to their concentrations in seawater. The relatively high concentration of Pt in the crusts reflects its occurrence as fine-grained particles in the crusts rather than adsorption of the elements from seawater.  相似文献   

Adventive occurrence of the fouling serpulid Ficopomatus enigmaticus (Polychaeta) in New Zealand   总被引：1，自引：1，他引：0  

Geoffrey B. Read  Dennis P. Gordon 《新西兰海洋与淡水研究杂志》2013,47(3):269-273

The exotic marine‐fouling polychaete Ficopomatus enigmaticus (Fauvel) is recorded and described from New Zealand. Its sudden occurrence in New Zealand around 1967 was marked by its ecological prominence in estuaries of Whangarei and Auckland Harbours, as a nuisance species on submerged artificial structures including pleasure craft and power station intake pipes.  相似文献   

Intra-crater glacial processes in central Utopia Planitia, Mars     

Geoffrey Pearce  Gordon R. Osinski  Richard J. Soare 《Icarus》2011,212(1):86-95

We describe and interpret a series of previously unidentified glacial-like lobes (34-43°N; 107-125°E) that were discovered as part of a survey of large (D > 5 km) impact craters in Utopia Planitia, one of the great northern plains of Mars. The lobes have characteristics that are consistent with a glacial origin. Evidence includes curvilinearity of form, lineations and ridges, and surface textures that are thought to form by the sublimation of near-surface volatiles. The lobes display morphologies that range from wedge-shaped to near-circular to elongate. The flow directions are towards the northern walls in the case of craters with large single lobes, and in all directions in the case of the largest (D > 30 km) craters. Concentric crater fill is also interspersed within craters of our study region, with such craters having much higher filling rates than those with flow lobes. We suggest that the impact crater population in south-west Utopia Planitia demonstrates a spectrum of glacial modifications, from low levels of filling in the case of craters with elongate lobes at one extreme, to concentric crater fill in highly-filled craters at the other.  相似文献   

International climate policy: a “second best” solution for a “second best” world?     

Richard G. Richels  Geoffrey J. Blanford  Thomas F. Rutherford 《Climatic change》2009,97(1-2):289-296

In the current political environment, it is highly unlikely that all countries will agree to take on immediate commitments to reduce their greenhouse gas emissions. In particular, developing countries will look to their wealthier neighbors to be the “first movers.” In this paper, we assume that developing countries will eventually accede to an international emission reductions regime under two alternative scenarios. In the first, the decision on the part of developing countries to join the coalition is not made until just before accession. There is no planning to reconfigure their capital stock in advance of joining the coalition. In the second, we assume that developing countries commit to prespecified reductions beginning at an agreed upon date in the future; that is, they anticipate accession. We find that with an agreement now to future reductions, developing countries will modify their technology investment decisions in advance of accession to avoid being saddled with costly stranded assets, substantially reducing their GDP losses. Developed countries also benefit from not having to make as drastic reductions in the near-term to preserve the feasibility of stringent stabilization goals.  相似文献   

Spatial aspects of the residential adjustments of older parents moving to low-income senior housing: A longitudinal study     

Gina M. Sylvestre  Geoffrey C. Smith 《Geoforum》2009,40(5):918-929

The purpose of this paper is to determine the effects of changes in local behaviour settings and individual attributes on the adjustments of older parents moving to government-subsidized senior citizen apartment (SCA) projects. The data were elicited from a sample of 106 residents of 25 SCAs in Winnipeg, Manitoba, who participated in a longitudinal interview survey. The data analysis involved use of bivariate statistical inferential tests and multiple regression frameworks. The findings disclose that the moves had only a moderate impact on parent-child residential separation and interaction. However, statistically significant predictors of four personal state outcomes (self-rated health, morale, depression, self-esteem) of the moves include variables concerning change in the older parent’s personal resources, everyday travel, and subjective appraisals of service, social, and physical components of the local neighbourhood. The findings have important policy implications in relation to the provision of appropriate behaviour settings for senior housing.  相似文献   

Extrasolar planets around HD 196050, HD 216437 and HD 160691     

Hugh R. A. Jones  R. Paul Butler  Geoffrey W. Marcy  Chris G. Tinney  Alan J. Penny  Chris McCarthy  Brad D. Carter 《Monthly notices of the Royal Astronomical Society》2002,337(4):1170-1178

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Old continental geotherms: constraints on heat production and thickness of continental plates     

Geoffrey F. Davies  John W. Strebeck 《Geophysical Journal International》1982,69(3):623-634

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