Response to the Commentary of Wolf Tietze     

Herman van der Wusten 《GeoJournal》2002,57(4):341-341

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National sovereignty & transboundary protected areas in Southern Africa     

Marloes van Amerom 《GeoJournal》2002,58(4):265-273

The notion that Transboundary Protected Areas (TBPAs) will act as `Peace Parks' has become an important argument in their promotion in post-Apartheid Southern Africa. This `Peace Parks Concept' is implicitly based upon the assumption that national sovereignty will not become a constraining factor in the creation and management of TBPAs. However, this assumption is problematic. TBPAs introduce various changes in the landscape with consequences for the ways in which a state can exercise its sovereignty over its borderland and citizens. This situation might evoke state action that could endanger the various environmental, socio-economic and political objectives of TBPAs. A state's behaviour with regard to TBPAs is not just informed by its interests in TBPAs, but also by its strategic and other interests in the wider borderland area. These are not necessarily compatible with the environmental and economic objectives of TBPAs. The ways in which these interests are mediated are highly complex and non-linear. Because of the inter-dependency that TBPAs create, the extent to which a state can pursue certain interests by means of TBPAs will be (partially) constrained by the wishes of the other states involved. In addition, power has to be shared with a wide range of non-state actors. The operation of sovereignty in TBPAs is therefore highly unpredictable and cannot be captured in static zero-sum terms. Actor Network Theory is identified as a possible starting-point to unravel and evaluate these complex political processes in TBPAs and their subsequent outcomes for state sovereignty.  相似文献   

Paleolimnological evidence for increased landslide activity due to forest clearing and land-use since 3600 cal BP in the western Swiss Alps     

Florence Dapples  André F. Lotter  Jacqueline F.N. van Leeuwen  Willem O. van der Knaap  Sophia Dimitriadis  Daniel Oswald 《Journal of Paleolimnology》2002,27(2):239-248

Schwarzsee is located in the western Swiss Alps, in a region that has been affected by numerous landslides during the Holocene, as evidenced by geological surveys. Lacustrine sediments were cored to a depth of 13 m. The vegetation history of the lake's catchment was reconstructed and investigated to identify possible impacts on slope stability. The pollen analyses record development of forest cover during the middle and late Holocene, and provide strong evidence for regional anthropogenic influence such as forest clearing and agricultural activity. Vegetation change is characterized by continuous landscape denudation that begins at ca. 4300 cal. yrs BP, with five distinct pulses of increased deforestation, at 3650, 2700, 1500, 900, and 450 cal. yrs BP. Each pulse can be attributed to increased human impact, recorded by the appearance or increase of specific anthropogenic indicator plant taxa. These periods of intensified deforestation also appear to be correlated with increased landslide activity in the lake's catchment and increased turbidite frequency in the sediment record. Therefore, this study gives new evidence for a strong influence of vegetation changes on slope stability during the middle and late Holocene in the western Swiss Alps, and may be used as a case study for anthropogenically induced landslide activity.  相似文献   

Rapid and rhythmic ice sheet fluctuations in western Scandinavia 15-40 Kya–a review     

Lars Olsen  Harald Sveian  Klaas van der  Borg  Bjørn Bergstram  Maarten Broekmans 《Polar research》2002,21(2):235-242

The onshore record of Middle to Late Weichselian sediments and glacial history in Norway indicates a succession of four major ice advances alternating with rapid, considerable ice recessions and interstadial conditions. During all the glacial advances the ice sheet expanded from onshore/inland positions to the shelf areas. The basis for visualizing these variations in glaciation curves constructed along nine transects from inland to shelf, and for interpretation of the palaeoclimatic history, is the regional Quaternary stratigraphy, more than 300 datings, fossil content and some palaeomagnetic data. The methods applied in recent years for AMS radiocarbon dating of glacial sediments with low organic carbon content have given promising results with respect to accuracy and precision, and the results of such datings were an important tool for our reconstructions and for timing of the ice oscillations. The rapid and rhythmic ice fluctuations, as reconstructed in our new model, have been fairly synchronous in most parts of Norway. Ice advances commenced and culminated at 40, 30-28, 24-21 and 18-15 (¹⁴C) Kya. We describe three intervening interstadials from inland sites: Hattfjelldal I, Hattfjelldal II and Trofors. Our stratigraphical record also includes many indications of high, pre-Holocene, relative sea levels, suggesting a considerable glacioisostatic depression of western Scandinavia during the interstadials. In our glaciation model we suggest that, in addition to precipitation, the mountainous fjord and valley topography, glacial isostasy and relative sea level changes were probably more important for the size of the glacial fluctuations than were air temperature changes.  相似文献   

Isotope (O-Sr-Nd-Pb) and Fluid Inclusion Distributions in the CCSD Main Hole     

XIAO Yi-lin  Jochen Hoefs  Rolf L. Romer  ZHANG Ze-ming  Alfons van den Kerkhof 《矿物岩石地球化学通报》2008,27(Z1)

1. Introduction The main-hole of the Chinese Continental Scientific Drilling Project (CCSD) in Donghai of the Dabie-Sulu UHP metamorphic belt in East China has reached its final depth of 5118 m in March 2005. As shown in Fig.  相似文献   

Evaluation of CADISSE a regional storage capacity model     

B. van der Wateren‐De Hoog 《水文研究》1999,13(6):847-863

In this paper the validity of CADISSE, a regional storage capacity model developed to assess the sensitivity of catchment hydrology to climate variability, is examined. In CADISSE, catchment discharge sensitivity is expressed as the ratio of present maximum reservoir storage to catchment storage capacity. Present maximum storage should be interpreted as the maximum amount of water stored in a catchment at present. Catchment storage capacity is defined as the absolute amount of water that can be stored, given the catchment's dimensions and lithological characteristics. With CADISSE, catchment sensitivity can be quantified regionally using limited discharge data and topographic information. Furthermore, storage capacities can be assessed. CADISSE was successfully applied to 15 catchments in the Upper Loire Basin. However, successful application does not necessarily mean that the variables (present maximum storage and storage capacity) represent real world values. Therefore, a two‐step evaluation procedure is presented in this paper. To evaluate CADISSE, (1) the accurate assessment of regionally determined storage capacity, and (2) the importance of present maximum storage for catchment discharge sensitivity is examined with a daily discharge model by comparing observed and simulated catchment storage behaviour for dry and wet periods. The evaluation was carried out using the probability distributed daily discharge model, PDM, and a weather generator for three catchments with different storage capacities and storage behaviour. Results indicate that catchment storage capacity can be correctly quantified with CADISSE and that differences in storage behaviour are indeed important for analyses of catchment sensitivity. Hence, CADISSE has great potential as it can be used to identify flood‐ and drought‐prone catchments under present and future conditions. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

The importance of sediments in the transformation and turnover of nutrients and organic matter in the Wadden Sea and German Bight     

J. E. E. van Beusekom  U. H. Brockmann  K. -J. Hesse  W. Hickel  K. Poremba  U. Tillmann 《Ocean Dynamics》1999,51(2-3):245-266

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SPM concentrations in the German Bight: comparison between a model simulation and measurements     

W. Puls  J. van Beusekom  U. Brockmann  R. Doerffer  U. Hentschke  P. König  D. Murphy  B. Mayer  A. Müller  Th. Pohlmann  A. Reimer  R. Schmidt-Nia  J. Sündermann 《Ocean Dynamics》1999,51(2-3):221-244

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Extreme storm surge modelling in the North Sea     

Nina Ridder  Hylke de Vries  Sybren Drijfhout  Henk van den Brink  Erik van Meijgaard  Hans de Vries 《Ocean Dynamics》2018,68(2):255-272

This study shows that storm surge model performance in the North Sea is mostly unaffected by the application of temporal variations of surface drag due to changes in sea state provided the choice of a suitable constant Charnock parameter in the sea-state-independent case. Including essential meteorological features on smaller scales and minimising interpolation errors by increasing forcing data resolution are shown to be more important for the improvement of model performance particularly at the high tail of the probability distribution. This is found in a modelling study using WAQUA/DCSMv5 by evaluating the influence of a realistic air-sea momentum transfer parameterization and comparing it to the influence of changes in the spatial and temporal resolution of the applied forcing fields in an effort to support the improvement of impact and climate analysis studies. Particular attention is given to the representation of extreme water levels over the past decades based on the example of the Netherlands. For this, WAQUA/DCSMv5 is forced with ERA-Interim reanalysis data. Model results are obtained from a set of different forcing fields, which either (i) include a wave-state-dependent Charnock parameter or (ii) apply a constant Charnock parameter (α _{C h} =?0.032) tuned for young sea states in the North Sea, but differ in their spatial and/or temporal resolution. Increasing forcing field resolution from roughly 79 to 12 km through dynamically downscaling can reduce the modelled low bias, depending on coastal station, by up to 0.25 m for the modelled extreme water levels with a 1-year return period and between 0.1 m and 0.5 m for extreme surge heights.  相似文献   

Why and when it is useful to publish and share inconclusive results and failures: reply to “Reporting negative results to stimulate experimental hydrology”*     

Theresa Blume  Ilja van Meerveld  Markus Weiler 《水文科学杂志》2018,63(8):1273-1274

We thank van Emmerik et al. for their discussion of our opinion paper. We do not fully agree that publication of negative results will be very effective in promoting experimental hydrology. Instead, we think that experimental hydrology is considered to be more risky than modelling studies because of difficulties in publishing inconclusive results and the potential for failure.  相似文献