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Rijswijk, Netherlands

van der Meulen F.,Frank van der Meulen Consultancy | van der Valk B.,Deltares | Vertegaal K.,Vertegaal Ecologisch Advies en Onderzoek | van Eerden M.,Rijkswaterstaat Water
Journal of Coastal Conservation | Year: 2015

A new dune area was constructed using beach and foreshore nourishment along the Dutch dune coast in the delta area. The new area is intended as a compensation for losses of existing high quality dune habitat as a result of the use of Maasvlakte 2 (MV-2), the new extension of Rotterdam harbour. Compensation was required under international EU Community regulations because the existing dune areas that could potentially be affected are protected under the EU Natura2000. The paper discusses the political and management aspects at EU- and regional levels. In The Netherlands, the construction of a compensation area along the coast, due to the extension of an international harbour, has been a procedure without precedence. The knowledge-based design and construction of the area and the set up of monitoring and evaluation programs in the context of policy and management are described. We believe that they provide innovative ideas for coastal management worldwide. Aspects of construction and landscape ecological developments of the same area have been reported in an earlier paper (van der Meulen et al. 2014). © 2015, Springer Science+Business Media Dordrecht. Source

Hamers T.,VU University Amsterdam | Kamstra J.H.,VU University Amsterdam | Kamstra J.H.,Norwegian University of Life Sciences | van Gils J.,Deltares | And 2 more authors.
Environmental Research | Year: 2015

As a consequence of climate change, increased precipitation in winter and longer periods of decreased precipitation in summer are expected to cause more frequent episodes of very high or very low river discharge in the Netherlands. To study the impact of such extreme river discharge conditions on water quality, toxicity profiles and pollutant profiles were determined of suspended particulate matter (SPM) collected from Rivers Meuse and Rhine. Archived (1993-2003) and fresh (2009-2011) SPM samples were selected from the Dutch annual monitoring program of the national water bodies (MWTL), representing episodes with river discharge conditions ranging from very low to regular to very high. SPM extracts were tested in a battery of in vitro bioassays for their potency to interact with the androgen receptor (AR), the estrogen receptor (ER), the arylhydrocarbon receptor (AhR), and the thyroid hormone transporter protein transthyretin (TTR). SPM extracts were further tested for their mutagenic potency (Ames assay) and their potency to inhibit bacterial respiration (Vibrio fischeri bioluminescence assay). Target-analyzed pollutant concentrations of the SPM samples and additional sample information were retrieved from a public database of MWTL results. In vitro toxicity profiles and pollutant profiles were analyzed in relation to discharge conditions and in relation to each other using correlation analysis and multivariate statistics. Compared to regular discharge conditions, composition of SPM during very high River Meuse and Rhine discharges shifted to more coarse, sandy, organic carbon (OC) poor particles. On the contrary, very low discharge led to a shift to more fine, OC rich material, probably dominated by algae. This shift was most evident in River Meuse, which is characterized by almost stagnant water conditions during episodes of drought. During such episodes, SPM extracts from River Meuse demonstrated increased potencies to inhibit bacterial respiration and to compete with thyroid hormone to bind to TTR, possibly due to the presence of fycotoxins. Meanwhile concentrations of polychlorobiphenyls (PCBs) in SPM were also increased. Very high River Meuse discharges on the other hand corresponded to increased androgenic and AhR agoniztic responses, which coincided with increased PAH levels and PAH-related in vivo risk estimates (i.e. multi-substance potentially affected fraction of species; msPAF). In River Rhine, very high discharges also corresponded to increasing androgenic potencies in SPM. Concentrations and corresponding msPAF values of PAHs (and metals), however, decreased with very high discharges in River Rhine in contrast to River Meuse. Mutagenicity was observed for SPM extracts from River Rhine collected during all discharge conditions, except during regular discharge. Aggregated toxicity index values, which were useful to identify toxicity profiles deviating from the generally observed pattern, did not correlate with river discharges, probably due to opposite effects of discharge conditions on different bioassay responses. In conclusion, SPM quality and related in vivo risk estimates changed during very low or very high discharge conditions but the changes were specific for the different toxic endpoints and pollutants in the different rivers. Moreover, bioassay responses to a series of consecutively collected samples from River Rhine during the Christmas flood of 1993 indicated that SPM quality is variable within a single episode of extreme discharge. © 2015 Elsevier Inc. Source

Hoogendoorn S.P.,Technical University of Delft | Landman R.L.,Technical University of Delft | Van Kooten J.,Arane Adviseurs in Verkeer en Vervoer | Schreuder M.,Rijkswaterstaat Water | Adams R.,Praktijkproef Amsterdam
Transportation Research Record | Year: 2015

Praktijkproef Amsterdam (Field Operational Test Integrated Network Management Amsterdam) is a project focused on the design and implementation of an innovative system for the coordinated deployment of traffic management measures in the regional network around the city of Amsterdam, Netherlands. On the basis of the generic functional architecture described in previous publications, monitoring and control functions were specified, implemented, tested, and tuned, both in a model environment and in practice. The focus here is on the controller design, which adapts and generalizes the master-slave structure used in the well-known HERO algorithm. It is shown how the principles are applied to use the urban arterials as storage locations for freeway metered traffic as well as to solve problems occurring on the urban arterials themselves-for example, in the case of spillback or gridlock. The key control principles are explained and the resulting feedback controller is analyzed to show how to choose its parameters to ensure stability and minimize the time needed to achieve the target value. To this end, a new methodology is proposed to analyze the dynamics of the controller in relation to the control parameters for different controller designs. Finally, the implementation of the system is discussed, and preliminary tuning and evaluation results from the field tests are provided. Source

De Lange W.J.,Deltares | Prinsen G.F.,Deltares | Hoogewoud J.C.,Deltares | Veldhuizen A.A.,Wageningen University | And 8 more authors.
Environmental Modelling and Software | Year: 2014

Water management in the Netherlands applies to a dense network of surface waters for discharge, storage and distribution, serving highly valuable land-use. National and regional water authorities develop long-term plans for sustainable water use and safety under changing climate conditions. The decisions about investments on adaptive measures are based on analysis supported by the Netherlands Hydrological Instrument NHI based on the best available data and state-of-the-art technology and developed through collaboration between national research institutes. The NHI consists of various physical models at appropriate temporal and spatial scales for all parts of the water system. Intelligent connectors provide transfer between different scales and fast computation, by coupling model codes at a deep level in software. A workflow and version management system guarantees consistency in the data, software, computations and results. The NHI is freely available to hydrologists via an open web interface that enables exchange of all data and tools. © 2014 The Authors. Source

Cornelissen P.,Rijkswaterstaat Water | Bokdam J.,Wageningen University | Sykora K.,Wageningen University | Berendse F.,Wageningen University
Basic and Applied Ecology | Year: 2014

Whether self-regulating large herbivores play a key role in the development of wood-pasture landscapes remains a crucial unanswered question for both ecological theory and nature conservation. We describe and analyse how a 'partly self-regulating' population of cattle, horses and red deer affected the development of the woody vegetation in the Oostvaardersplassen nature reserve (Netherlands). Using aerial photographs from 1980 to 2011, we analysed the development of shrubs and trees. Before the large herbivores were introduced in the Oostvaardersplassen in 1983, the woody vegetation increased and vegetation type significantly affected the number of establishments. Cover of woody species increased further from 1983 to 1996, not only by canopy expansion but also by new establishments. After 1996, cover of the woody vegetation decreased from 30% to <1% in 2011 and no new establishments were seen on the photographs. Survival of Sambucus nigra and Salix spp. increased with increasing distance to grassland, which is the preferred foraging habitat of the herbivores. These results support the hypothesis of Associational Palatability. In addition, our results show that the relative decline in cover of S. nigra and Salix spp. over a certain period was negatively correlated with the cover of S. nigra in the beginning of this period, presenting some evidence for the Associational Resistance and Aggregational Resistance hypothesis. Our research shows aspects necessary for the woodland-grassland cycle, such as a strong decline of woody vegetation at high numbers of large herbivores and regeneration of shrubs and trees at low densities. Thorny shrubs, which are important for the cycle, have not yet established in the grasslands. It seems that a temporary decline in herbivore numbers is necessary to create a window of opportunity for the establishment of these woody species. © 2014 Gesellschaft für Ökologie. Source

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