Brussels, a truncated metropolis     

Christian Kesteloot  Pieter Saey 《GeoJournal》2002,58(1):53-63

This paper describes and analyses the geographical development and the governmental, budget and administrative structure of Brussels. It defines the place Brussels occupies among the cities of Europe and assesses the value of its Regional Development Plan. Brussels appears to be highly successful in international inter-city competition, but it also appears to be unable to develop a strategy for dealing with the problems of the divided city it has become in the late-20th century. Key factors in explaining this paradox are a discrepancy between the political delimitation of the Brussels Capital Region (a member state of the federal state of Belgium) and the geographical urban region, and the administrative fragmentation of the Brussels Capital Region. These factors are strongly related to the reform of the Belgian state and the forces behind this reform. In the absence of a strategy based on solidarity within the metropolitan community, one has to fear for the development towards a repressive city. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

The Co2 Lifetime Concept Should Be Banished; An Editorial Comment     

Pieter P. Tans 《Climatic change》1997,37(3):487-490

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Partnerships in forest governance     

Ingrid J. Visseren-Hamakers  Pieter Glasbergen   《Global Environmental Change》2007,17(3-4):408-419

One of the major current global environmental challenges is the conservation of forest biodiversity. Deforestation and forest degradation continue despite international governmental agreements on forest conservation. In recent years private regulation in the international forest governance system has increased. Numerous partnerships between governments, business and/or civil society have been developed. Most of them focus on a single threat to forest biodiversity. This private regulation has had a limited positive impact. The most valuable contribution has been filling the gap of lack of implementation by governments. The forest governance system can become more effective if metagovernance is strengthened.  相似文献   

Active hydrate destabilization in Lake Baikal,Siberia?   总被引：1，自引：0，他引：1  

Marc De Batist  Jan Klerkx  Pieter Van Rensbergen  Maarten Vanneste  Jeffrey Poort  Alexander Y. Golmshtok  rei A. Kremlev  Oleg M. Khlystov  Petr Krinitsky 《地学学报》2002,14(6):436-442

ABSTRACT In this paper, we present new seismic and heat-flow data that show the base of the hydrate stability zone (BHSZ) in Lake Baikal to be locally characterized by abnormal variations in depth, with distinct regions of deeper-than-normal and regions of shallower-than-normal BHSZ. These variations are related to strong lateral variations in heat flow, and occur in close association with important rift-basin faults. Areas of shallow BHSZ are also characterized by the presence of several methane seeps and mud volcanoes at the lake floor. We infer that the seeps are the surface expression of escape pathways for overpressured fluids generated by the dissociation of pre-existing hydrates, in response to a thermal pulse caused by an upward flow of hydrothermal fluids towards the BHSZ. It thus seems that present-day hydrate dissociation in Lake Baikal is modulated by the tectonic activity in the rift rather than by – climatically controlled – changes in lake level or water temperature.  相似文献   

Time Domain Electromagnetic Soundings for Mapping Sea-Water Intrusion in Monterey County, California   总被引：1，自引：0，他引：1  

Theodore Mills  Pieter Hoekstra  Mark Blohm  Lauren Evans 《Ground water》1988,26(6):771-782

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Topographic and stratification effects on shelf edge flows     

Yakun Guo  Peter A. Davies  Alessandra Cavalletti  Pieter Jacobs 《Dynamics of Atmospheres and Oceans》2000,31(1-4)

Results are presented from two sets of laboratory model experiments on the effects of an isolated seamount upon the flow of an intermediate-water slope current along a continental shelf. The experimental results for initial ambient conditions of respectively two-layer and linearly stratified fluids show that the structure of such a boundary current depends primarily on the values of the appropriate set of dimensionless dynamical parameters (namely the Burger (Bu), Ekman (Ek) and Rossby (Ro) numbers), as well as the dimensionless lateral separation of the seamount and shelf and the proportional height of the seamount relative to the distance from the bottom at which the intermediate-water flows. Comparisons of the present results with those from a previous two-layer fluid study with no obstacle present reveals that the presence of the obstacle does not alter significantly the stability of the current even when situated close to the shelf. However, for such configurations, the density, velocity and vorticity fields in the local zone of interaction between the current and the obstacle are distorted significantly by the presence of the obstacle, provided that the summit of the obstacle penetrates the level of current flow. Measurements of density, velocity and vorticity fields show no significant dependence of the flow interaction upon the detailed bathymetry of the shelf-slope. For stable intermediate-water slope currents, the nature of the interaction with the obstacle is determined primarily by (i) the lateral separation of the obstacle and the shelf edge and (ii) the Ro of the flow. For sufficiently low values of the former and high values of the latter, the interaction results in a splitting of the incident flow around the obstacle, with cyclonic and anticyclonic eddy pairs being generated in the lee. Geostrophic equilibrium is seen to be maintained in the current, even in the near wake of the obstacle. For cases in which the summit of the seamount is below the initially-undisturbed intermediate water level, no Taylor column-like division of the slope current occurs and no significant distortion of the current structure (velocity and density) occurs for the parameter ranges investigated. For linearly stratified cases, measurements show that no significant local elevation or depression of the density interfaces is observed in the interaction zone. The distributions of the local buoyancy frequencies calculated from the density profiles reveal that the minimum value of the frequency upstream of the obstacle is smaller than that downstream, indicating that the flow interactions generate local mixing downstream, with consequent erosion of the density interfaces.  相似文献   

Wisconsinan and Holocene Climate History from an Ice Core at Taylor Dome, Western Ross Embayment, Antarctica   总被引：4，自引：0，他引：4  

Eric J. Steig  David L. Morse  Edwin D. Waddington  Minze Stuiver  Pieter M. Grootes  Paul A. Mayewski  Mark S. Twickler  & Sallie I. Whitlow 《Geografiska Annaler: Series A, Physical Geography》2000,82(2-3):213-235

Geochemical data and geophysical measurements from a 554-m ice-core from Taylor Dome, East Antarctica, provide the basis for climate reconstruction in the western Ross Embayment through the entire Wisconsinan and Holocene. In comparison with ice cores from central East and West Antarctica, Taylor Dome shows greater variance of temperature, snow accumulation, and aerosol concentrations, reflecting significant variability in atmospheric circulation and air mass moisture content. Extreme aridity during the last glacial maximum at Taylor Dome reflects both colder temperatures and a shift in atmospheric circulation patterns associated with the advance of the Ross Sea ice sheet and accounts for regional alpine glacier retreats and high lake levels in the Dry Valleys. Inferred relationships between spatial accumulation gradients and ice sheet configuration indicate that advance of the Ross Sea ice sheet began in late marine isotope stage 5 or early stage 4. Precise dating of the Taylor Dome core achieved by trace-gas correlation with central Greenland ice cores shows that abrupt deglacial warming at Taylor Dome was near-synchronous with the ∼14.6 ka warming in central Greenland and lags the general warming trend in other Antarctic ice cores by at least 3000 years. Deglacial warming was following by a warm interval and transient cooling between 14.6 and 11.7 ka, synchronous with the Bølling/Allerød warming and Younger Dryas cooling events in central Greenland, and out of phase with the Antarctic Cold Reversal recorded in the Byrd (West Antarctica) ice core. Rapid climate changes during marine isotope stages 4 and 3 at Taylor Dome are similar in character to, and may be in phase with, the Northern Hemisphere stadial–interstadial (Dansgaard–Oeschger) events. Results from Taylor Dome illustrate the importance of obtaining ice cores from multiple Antarctic sites, to provide wide spatial coverage of past climate and ice dynamics.  相似文献   

Book reviews     

Fouad N. Ibrahim  G. Kunkel  David H. Miller  A. Wallner  R. O. Whyte  W. U. Ehrmann  Matthias Kuhle  Robert Giepel  Pieter Lukkes  B. K. Roy  W. R. Stanley  Paul Mosely 《GeoJournal》1986,12(4):464-469

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Volume contents     

Christian Beck  Pieter Van Rensbergen  Marc De Batist  Fernand Berthier  Serge Lallier 《Journal of Paleolimnology》2001,25(4):551-553

Volume Contents

Volume contents  相似文献   

Size-resolved characteristics of inorganic ionic species in atmospheric aerosols at a regional background site on the South African Highveld     

Andrew D. Venter  Pieter G. van Zyl  Johan P. Beukes  Jan-Stefan Swartz  Miroslav Josipovic  Ville Vakkari  Lauri Laakso  Markku Kulmala 《Journal of Atmospheric Chemistry》2018,75(3):285-304

Aerosols consist of organic and inorganic species, and the composition and concentration of these species depends on their sources, chemical transformation and sinks. In this study an assessment of major inorganic ions determined in three aerosol particle size ranges collected for 1 year at Welgegund in South Africa was conducted. SO₄^2? and ammonium (NH₄⁺) dominated the PM₁ size fraction, while SO₄^2? and nitrate (NO₃) dominated the PM_1–2.5 and PM_2.5–10 size fractions. SO₄^2? had the highest contribution in the two smaller size fractions, while NO₃^? had the highest contribution in the PM_2.5–10 size fraction. SO₄^2? and NO₃^? levels were attributed to the impacts of aged air masses passing over major anthropogenic source regions. Comparison of inorganic ion concentrations to levels thereof within a source region influencing Welgegund, indicated higher levels of most species within the source region. However, the comparative ratio of SO₄^2? was significantly lower due to SO₄^2? being formed distant from SO₂ emissions and submicron SO₄^2? having longer atmospheric residencies. The PM at Welgegund was determined to be acidic, mainly due to high concentrations of SO₄^2?. PM₁ and PM_1–2.5 fractions revealed a seasonal pattern, with higher inorganic ion concentrations measured from May to September. Higher concentrations were attributed to decreased wet removal, more pronounced inversion layers trapping pollutants, and increases in household combustion and wild fires during winter. Back trajectory analysis also revealed higher concentrations of inorganic ionic species corresponding to air mass movements over anthropogenic source regions.  相似文献