3831 resultaten

  • Water supply network model for sustainable industrial resource use a case study of Zeeuws-Vlaanderen in the Netherlands

    Auteurs: Willet, J.; King, J.; Wetser, K.; Dijkstra, J.E.; Oude Essink, G.H.P.; Rijnaarts, H.H.M. (2020)

    Matching the regional water supply and demand can be improved by allocating local renewable water resources through decentralized water supply networks (WSNs). The feasibility of decentralized WSNs depends on the costs for the required pipeline infrastructure. The lowest cost for pipeline infrastructure depends on the local landscape characteristics. We present a model that designs decentralized WSNs to supply water with regional supply sources. The objective of the model is to include the effects of landscape characteristics on infrastructure costs and to minimize overall WSN costs. We tested the model on a case study in the fresh-water scarce region of Zeeuws-Vlaanderen in the southwestern part of The Netherlands with known (hydro)geological, geographical and climate data. The model was tested to supply a large industrial water user with groundwater resources operated within sustainable yields. The generated WSNs cover a demand between 0.5 and 5.5 million m3 year−1. Between 1 and 12 supply locations are needed to cover the demand. The pipeline infrastructure needed ranges from 25.1 to 114.5 km. The model determines the optimal pipeline route, the amount of water flowing over each pipeline segment, and reveals if a small increase in demand causes a relatively large increase in costs. The results can be used to determine if water transport is preferred over other options, such as wastewater re-use or desalination of saline water resources.

  • Panorama New Netherlands

    Auteurs: Timmermans, J.; Storms, J.; Pleijster, E.J.; Meulen, G. van der; Alphen, J. van; Haasnoot, M.; Diermanse, F.L.M.; Cohen, K.; Minderhoud, P. (2020)

    How can the Netherlands adapt to sea level rise on the long term: maintain, advance or retreat? This article compares the results of seven plans and designs from a diverse group of scholars and professionals that offer very different answers to this question. This diversity broadens the options, which is vital in this stage. Both problem solving and design approaches are shown to be worthwhile, when grounded in coastal, landscape, and ecological dynamics as well as visions of the Netherlands in the far future.

  • Yield stress measurements of mud sediments using different rheological methods and geometries: an evidence of two-step yielding

    Auteurs: Shakeel, A.; Kirichek, A.; Chassagne, C. (2020)
    Gepubliceerd in: Marine Geology, volume 427 (2020)

    Yield stress materials have a wide range of commercial applications. Yet, the suitable way of determining the yield stress values of a given material has been the subject of many studies and debates. Yield stresses are dependent on the material (shear) history and composition, which implies that robust protocols should be developed to study the yield stress dependence on a given parameter. In this study, three natural mud samples from a port having different densities were chosen for analysis. Four different geometries including concentric cylinders (Couette), cone and plate, parallel plates, and vane geometries were used. Our aim was to find the geometry and measurement protocol that best adapted to natural mud samples: the measurement should be reasonably fast and the major changes in sample structure (two-step yielding) should be recorded within the same measurement. Various rheological experiments such as stress sweep, oscillatory amplitude sweep, creep and stress growth tests were tested. Two-step yielding behavior was observed for the mud samples in stress sweep and amplitude sweep tests. The first yield point was linked with the breakage of interconnected network of aggregates/flocs while the second one was attributed to the collapse of aggregates into the smaller flocs or individual particles. Stress sweep tests proved to be practical, time efficient, and reliable tests for measuring yield stress values. Our study showed that Couette and parallel plate geometries are the most suitable geometries for analyzing the two yield stresses of the samples. Vane geometry is appropriate to study consolidated (solidlike) systems as for these samples a Couette geometry cannot be used because the bob could get stuck during the experiment.

  • Numerical verification of the Concentric Arches Model for geosynthetic-reinforced pile-supported embankments : applicability and limitations

    Auteurs: Lee, T.; Eekelen, S.J.M. van; Jung, Y.H. (2020)
    Gepubliceerd in: Canadian geotechnical journal (2020), pagina 1-51

    In this study, a series of 3D FE simulations of a geosynthetic-reinforced pile-supported embankment (GRPE) design were conducted. The effect of the subsoil stiffness, friction and dilation angles of the fill, the fill height, the pile spacing, the surcharge load on the embankment, and the anisotropic tensile stiffness of the GR, the ground reaction curve (GRC), and the interfacial responses between the fill material and geosynthetic reinforcement (GR) were scrutinized. The numerical results showed how transfer of the vertical load towards the piles (load part A) and the related soil arches change with the subsoil stiffness, geometric parameters, and the vertical pressure on the embankment. Furthermore, the vertical load transferred through the GR (load part B) is reduced significantly with increasing subsoil stiffness, while the load part carried by the subsoil increases (load part C). The numerical results showed that the vertical stress distribution on the GR changes from an inverse-triangular shape for low subsoil stiffness to a uniform shape for high subsoil stiffness. This matches perfectly with the Concentric Arches model. For low subsoil stiffness, the tensile strains of the GR are concentrated at the corner of a square pile cap.

  • Handbook for the implementation of nature-based solutions for water security : guidelines for designing an implementation and financing arrangement

    Auteurs: Altamirano, M.A.; Benitez-Avila, C. (2020)

    Following the Financing Framework for Water Security (Altamirano, 2017) principles we have further tailored and developed additional elements to fit the innovative nature of NBS projects for which there are important evidence and information gaps, like expected and typical cash and risk profiles of green and hybrid (green-grey) projects and more importantly which levels of water and water risk mitigation service(s) they can guarantee over time. To fill in this knowledge gaps we make use of collaborative modelling techniques that allow for transdisciplinary collaboration and enable the development of the full business case for investments in NBS for water security, even if at a conceptual and semiquantitative level to start with. In this deliverable we present the basic methodological elements of our approach and the process it involves, as well as the results of the three demonstration cases we have supported to develop an implementation strategy beyond our NAIAD project, pioneer examples of implementation and financing arrangements from around the world and our conclusions and recommendations about what is needed to move ahead towards implementation at scale of NBS for water security in Europe. The three demos we have supported directly are Rotterdam in the Netherlands, Medina del Campo in Spain and Potelu in the lower Danube in Romania.

  • An Automatic procedure for dune foot position detection : application to the Dutch coast

    Auteurs: Diamantidou, E.; Santinelli, G.; Giardino, A.; Stronkhorst, J.; Vries, S. de (2020)
    Gepubliceerd in: Journal of coastal research (JCR) : an international forum for the littoral sciences, volume 36 (2020) nummer 3, pagina 668-675

    Coastal indicators are a useful proxy in coastal zone management to describe the status of a physical system and to assess the effectiveness of possible interventions. They can be used as a basis to implement and evaluate coastal erosion policies, as it is done, for example, in The Netherlands. One often used coastal indicator is the position of the dune foot. In the current definition used in The Netherlands to describe the dune foot position, the actual geometry of the profile is, however, not accounted for, but this is simply based on one reference value for the entire coastline. In the present study, an automatic procedure for the detection of the dune foot position is proposed based on the actual shape of the cross-shore profile and on the evaluation of the first and second derivatives of the cross-shore topography. The methodology is compared to visual observations as well as satellite images for case studies in The Netherlands and Portugal, hence showing that the methodology is generally applicable. The algorithm to derive the dune foot position in a cross-shore profile and the database derived from this study are publicly available.

  • Mapping deep peat carbon stock from a LiDAR based DTM and field measurements, with application to eastern Sumatra

    Auteurs: Vernimmen, R.R.E.; Hooijer, A.A.; Akmalia, R.; Fitranatanegara, N.; Mulyadi, D.; Yuherdha, A.; Andreas, H.; Page, S. (2020)

    Within the SE Asia region, areas of deeper peat present the greatest carbon stocks, and therefore the greatest potential for future carbon emissions from degradation and fire. They also support most of the remaining lowland swamp forest and its associated biodiversity. Accurate maps of deep peat are central to providing correct estimates of peat carbon stocks and to facilitating appropriate management interventions. We present a rapid and cost-effective approach to peat thickness mapping in raised peat bogs that applies a model of peat bottom elevation based on field measurements subtracted from a surface elevation model created from airborne LiDAR data. We discuss how the deep peat map may be used to identify priority areas for peat and forest conservation and thereby help prevent major potential future carbon emissions and support the safeguarding of the remaining forest and biodiversity. We propose rapid application of this method to other coastal raised bog peatland areas in SE Asia in support of improved peatland zoning and management. We demonstrate that the upcoming global ICESat-2 and GEDI satellite LiDAR coverage will likely result in a global DTM that, within a few years, will be sufficiently accurate for this application.

  • Portable XRF quick-scan mapping for potential toxic elements pollutants in sustainable urban drainage systems : a methodological approach

    Auteurs: Venvik, G.; Boogaard, F.C. (2020)

    Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle-bound Potential Toxic Elements (PTE), which are known to often accumulate in the topsoil. A portable XRF instrument (pXRF) is used to provide in situ spatial characterization of soil pollutants, specifically lead (Pb), zink (Zn) and copper (Cu). The method uses pXRF measurements of PTE along profiles with set intervals (1 m) to cover the swale with cross-sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In-Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost-efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long-term functioning of the soil-based SuDS facilities.

  • Innovative water quality and ecology monitoring using underwater unmanned vehicles: field applications, challenges and feedback from water managers

    Auteurs: Pedroso de Lima, R.L.; Boogaard, F.C.; Graaf-van Dinther, R.E. de (2020)
    Gepubliceerd in: Water, volume 12 (2020) nummer 4

    With climate change and urban development, water systems are changing faster than ever. Currently, the ecological status of water systems is still judged based on single point measurements, without taking into account the spatial and temporal variability of water quality and ecology. There is a need for better and more dynamic monitoring methods and technologies. Aquatic drones are becoming accessible and intuitive tools that may have an important role in water management. This paper describes the outcomes, field experiences and feedback gathered from the use of underwater drones equipped with sensors and video cameras in various pilot applications in The Netherlands, in collaboration with local water managers. It was observed that, in many situations, the use of underwater drones allows one to obtain information that would be costly and even impossible to obtain with other methods and provides a unique combination of three-dimensional data and underwater footage/images. From data collected with drones, it was possible to map different areas with contrasting vegetation, to establish connections between fauna/flora species and local water quality conditions, or to observe variations of water quality parameters with water depth. This study identifies opportunities for the application of this technology, discusses their limitations and obstacles, and proposes recommendation guidelines for new technical designs.

  • De kwaliteit van afstromend hemelwater in Nederland

    Auteurs: Boogaard, F.; Liefting, E.; Langeveld, J.; Palsma, B. (2020)
    Gepubliceerd in: H2O : tijdschrift voor drinkwatervoorziening en afvalwaterbehandeling (2020)

    Ten behoeve van beleidsvorming stelt STOWA samen met stichting RIONED al sinds 2007 een Database Hemelwaterkwaliteit ter beschikking. In 2020 verschijnt een flink herziene versie van deze database. Dit artikel beschrijft de belangrijkste bevindingen op basis van deze nieuwe database.

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