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Eerstelijnsrapportage Westerschelde 2018 : meetgegevens van 1996 t/m 2018
Deze rapportage bevat de beschikbare hydrodynamische, fysisch-chemische en biologische data in de periode 1996 tot en met 2018 voor de Westerschelde en de monding. Het is een eerste weergave van de beschikbare data en beschrijft enkel 'wat men in de meetresultaten ziet'. Het bevat een interpretatie van de gegevens op basis van een eenvoudige analyse. De rapportage is opgesteld in het kader van de OntwikkelingsSchets 2010 en vormt een van de bouwstenen voor de vergunningverlening van de derde verdieping van het Scheldeestuarium.
Achteroever Wieringermeer : verkenning van effecten van het achteroever concept op het regionaal waterbeheer
In dit rapport wordt beschreven hoe en in welke situatie het in de Wieringermeer pilot onderzochte concept in een opgeschaalde vorm baten kan opleveren voor het regionale waterbeheer, waar onder het omgaan met voortschrijdende verzilting.
Field measurements and hydrodynamic modelling to evaluate the importance of factors controlling overwash
Overwash hydrodynamic datasets are mixed in quality and scope, being difficult to obtain due to fieldwork experimental limitations. Nevertheless, these measurements are crucial to develop reliable models to predict overwash. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was undertaken on Barreta Island (Portugal) in December 2013, during neap tides and under energetic conditions, with significant wave height reaching 2.6 m. During approximately 4 h, more than 120 shallow overwash events were measured with a video-camera, a pressure transducer and a current-meter. This high-frequency fieldwork dataset includes runup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to implement XBeach model in non-hydrostatic mode (wave-resolving). The baseline model was tested for six verification cases; and the model was able to predict overwash in five. Based in performance metrics and the verification cases, it was considered that the Barreta baseline overwash model is a reliable tool for the prediction of overwash hydrodynamics. The baseline model was then forced to simulate overwash under different hydrodynamic conditions (waves and lagoon water level) and morpho-sedimentary settings (nearshore topography and beach grain-size), within the characteristic range of values for the study area. According to the results, the order of importance of factors controlling overwash predictability in the study area are: 1. wave height (more than wave period) can promote overwash 3–4 times more intense than the one recorded during fieldwork ; 2. nearshore bathymetry, particularly shallow submerged bars, can promote an average decrease of about 30% in overwash ; 3. grain-size, finer sediment produced an 11% increase in overwash due to reduced infiltration ; 4. lagoon water level, only negligible differences were evidenced by changes in the lagoon level. This implies that for model predictions to be reliable, accurate wave forecasts are necessary and topo-bathymetric configuration needs to be monitored frequently.
Innovation in climate adaptation
Scientists, policy makers and entrepreneurs worked together in the Knowledge for Climate programme to research ways in which the Netherlands can be climate proofed. This book presents the overall design of the programme and the results for each of the eight research themes within the programme and discusses lessons learned.
Generation of a global synthetic tropical cyclone hazard dataset using STORM
Over the past few decades, the world has seen substantial tropical cyclone (TC) damages, with the 2017 Hurricanes Harvey, Irma and Maria entering the top-5 costliest Atlantic hurricanes ever. Calculating TC risk at a global scale, however, has proven difficult given the limited temporal and spatial information on TCs across much of the global coastline. Here, we present a novel database on TC characteristics on a global scale using a newly developed synthetic resampling algorithm we call STORM (Synthetic Tropical cyclOne geneRation Model). STORM can be applied to any meteorological dataset to statistically resample and model TC tracks and intensities. We apply STORM to extracted TCs from 38 years of historical data from IBTrACS to statistically extend this dataset to 10,000 years of TC activity. We show that STORM preserves the TC statistics as found in the original dataset. The STORM dataset can be used for TC hazard assessments and risk modeling in TC-prone regions.
Distance to forest, mammal and bird dispersal drive natural regeneration on degraded tropical peatland
Restoration of peat swamp forest (PSF) on degraded Southeast Asian peatlands could reduce global carbon emissions and biodiversity loss. However, multiple ecological barriers are believed to hinder natural regeneration of native trees on degraded peatland and make restoration expensive. We evaluated if natural PSF regeneration occurs and what factors may influence it on eight different land use and land cover (LULC) classes with different types of disturbance, including drainage and fire, in a retired Acacia crassicarpa Benth. (Acacia) plantation landscape. The study involved 42 plots inside five PSF LULCs – intact, logged, burnt (1997, 2015), remnant and 212 plots at distances up to 2 km from the PSF edge in three Acacia plantation LULCs – unharvested, harvested, and burnt. The number of species per plot were similar between intact PSF (25 ± 6 (SD) per 20 m × 10 m plot), logged forest (30 ± 6) and 1997 burnt forest (30 ± 13) but lower in 2015 burnt forest (11 ± 10) and remnant forest (18 ± 11). Regeneration away from the PSF across all degraded LULCs varied from fern dominated areas with no regeneration to clusters with high stem densities. The plantation LULCs, unharvested (94 species) and harvested Acacia (71 species), had similar overall species diversity after 3–4 years of regeneration to the intact and logged PSF (90 species). In unharvested Acacia, total species diversity, species per plot and stem density decreased with distance from forest edge (1–300 m – 87 species; 9 ± 6 (SD) species per 20 m × 10 m plot; 1,056 stems/ha; 301–500 m – 33; 5 ± 2; 511 and >500 m – 38; 6 ± 3; 683). In harvested Acacia, there was low plot species diversity irrespective of distance from the forest (1–300 m – 51; 4 ± 2; 578; 301–500 m – 17; 4 ± 2; 1,100; >500 m – 48; 4 ± 2; 780). Factors which may influence regeneration differed between different LULCs, but there was a clear influence of distance from forest edge and dispersal mechanism – i.e. whether a tree was bird or mammal dispersed and the interaction between these two factors. While our study suggests that if not further disturbed by logging, drainage and/or fire, degraded PSF could regenerate naturally to a similar species diversity as intact PSF, the lower levels of natural regeneration further away from the forest may warrant selective planting of species which do not disperse over long distances. More study is needed on the factors facilitating natural regeneration, whether it leads to restoration of PSF ecosystem functioning and the role of Acacia as a potential regeneration catalyst.
On the need for a new generation of coastal change models for the 21st century
The combination of climate change impacts, declining fluvial sediment supply, and heavy human utilization of the coastal zone, arguably the most populated and developed land zone in the world, will very likely lead to massive socio-economic and environmental losses in the coming decades. Effective coastal planning/management strategies that can help circumvent such losses require reliable local scale (<~10 km) projections of coastal change resulting from the integrated effect of climate change driven variations in mean sea level, storm surge, waves, and riverflows. Presently available numerical models are unable to adequately fulfill this need. A new generation of multi-scale, probabilistic coastal change models is urgently needed to comprehensively assess and optimise coastal risk at local scale, enabling risk informed, climate proof adaptation measures that strike a good balance between risk and reward.
Oogst van de toekomst
Zeewier is een potentieel belangrijke bron voor voedsel en duurzame energie in de toekomst. Maar boeren op zee vereist grote investeringen in infrastructuur. Vooraf is het belangrijk om te weten: wat kunnen we nu eigenlijk maken van zeewier? En hoe makkelijk is het te kweken? Onderzoekers van MARIN, ECN, TNO, Deltares en Wageningen Researchgingen aan de slag met zeewierkaas en -zoetstof.
Wind en water bundelen krachten
Om de transitie naar groene energie op grote schaal mogelijk te maken, kunnen windturbines ver op zee uitkomst bieden. Onderzoek is nodig om efficiënte en betrouwbare drijvende turbines te ontwikkelen en zo de kosten van offshore windenergie te verlagen. MARIN, Deltares, NLR en ECN hebben twee projecten uitgevoerd voor wind op zee: "floating wind turbines" en "safe helicopter movements".
In de circulaire stad heeft elke boom een functie
In het gezamenlijke onderzoeksproject Adaptive Circular Cities werken Deltares, TNO, Wageningen Research en ECN aan innovatieve oplossingen voor grote stedelijke opgaven, daarbij gebruikmakend van de kennis, instrumenten en modellen van de deelnemende instituten.