Evaluation of the hydrological performance of grassed swales usually needs long-term monitoring data. At present, suitable techniques for simulating the hydrological performance using limited monitoring data are not available. Therefore, current study aims to investigate the relationship between saturated hydraulic conductivity (Ks) fitting results and rainfall characteristics of various events series length. Data from a full-scale grassed swale (Enschede, the Netherlands) were utilized as long-term rainfall event series length (95 rainfall events) on the fitting outcomes. Short-term rainfall event series were extracted from these long-term series and used as input in fitting into a multivariate nonlinear model between Ks and its influencing rainfall indicators (antecedent dry days, temperature, rainfall, rainfall duration, total rainfall, and seasonal factor (spring, summer, autumn, and winter, herein refer as 1, 2, 3, and 4). Comparison of short-term and long-term rainfall event series fitting results allowed to obtain a representative short-term series that leads to similar results with those using long-term series. A cluster analysis was conducted based on the fitting results of the representative rainfall event series with their rainfall event characteristics using average values of influencing rainfall indicators. The seasonal index (average value of seasonal factors) was found to be the most representative short rainfall event series indicator. Furthermore, a Bayesian network was proposed in the current study to predict if a given short-term rainfall event series is representative. It was validated by a data series (58 rainfall events) from another full-scale grassed swale located in Utrecht, the Netherlands. Results revealed that it is quite promising and useful to evaluate the representativeness of short-term rainfall event series used for long-term hydrological performance evaluation of grassed swales.
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The stability of upstream deposited tailings dams is dependent on maintaining a drawn down phreatic surface and unsaturated profile in its outer edge. However, it has been speculated that intense rainfall events could induce unexpected translation of pore air and water pressures into the tailings profile and thus compromise the effective stress in the unsaturated zone or result in a sudden rise in the phreatic surface. This phenomenon, known as the Lisse effect, has been observed and studied in hydrological sciences to explain the rapid delivery of antecedent hillslope groundwater during storm events. However, the phenomenon has not been comprehensively applied to evaluating tailings dam slope stability. In this paper, the outcomes of controlled observations of the phenomenon in column and analytical experiments, are assembled and evaluated in terms of the surface water application volumes and rate, the properties of the porous media and the resultant nature of pore pressure and phreatic surface responses. In addition, application of applied theories to evaluate the rapid transmission of pore pressures through a profile in response to an advancing wetting front, leads to the development of a methodology that could be applied to tailings materials of a range of hydraulic conductivities and water retention characteristics. The theory is applied to a series of profiles of different tailings porous media, using varied water application rates. Resultant perturbations in phreatic surface elevation and changes to pore pressures in the unsaturated zone are used to evaluate changes in effective stress distribution in the unsaturated outer wedge and subsequent stability criteria. A possible evaluation algorithm for assessing stability criteria is suggested.
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Swales are widely used Sustainable Urban Drainage Systems (SuDS) that can reduce peak flow, collect and retain water and improve groundwater recharge. Most previous research has focused on the unsaturated infiltration rates of swales without considering the variation in infiltration rates under extreme climate events, such as multiple stormwater events after a long drought period. Therefore, fieldwork was carried out to collect hydraulic data of three swales under drought conditions followed by high precipitation. For this simulation, a new full-scale infiltration method was used to simulate five rainfall events filling up the total storage volume of the swales under drought conditions. The results were then compared to earlier research under regular circumstances. The results of this study show that three swales situated in the same street show a variation in initial infiltration capacity of 1.6 to 11.9 m/d and show higher infiltration rates under drought conditions. The saturated infiltration rate is up to a factor 4 lower than the initial unsaturated rate with a minimal rate of 0.5 m/d, close to the minimum required infiltration rate. Significant spatial and time variable infiltration rates are also found at similar research locations with multiple green infrastructures in close range. If the unsaturated infiltration capacity is used as the design input for computer models, the infiltration capacity may be significantly overestimated. The innovative method and the results of this study should help stormwater managers to test, model, plan and schedule maintenance requirements with more confidence, so that they will continue to perform satisfactorily over their intended design lifespan.
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Abstract: Climate change is related with weather extremes, which may cause damages to infrastructure used by freight transport services. Heavy rainfall may lead to flooding and damage to railway lines, roads and inland waterways. Extreme drought may lead to extremely low water levels, which prevent safe navigation by inland barges. Wet and dry periods may alternate, leaving little time to repair damages. In some Western and Middle-European countries, barges have a large share in freight transport. If a main waterway is out of service, then alternatives are called for. Volume- and price-wise, trucking is not a viable alternative. Could railways be that alternative? The paper was written after the unusually long dry summer period in Europe in 2022. It deals with the question: If the Rhine, a major European waterway becomes locally inaccessible, could railways (temporarily) play a larger role in freight transport? It is a continuation of our earlier research. It contains a case study, the data of which was fed into a simulation model. The model deals with technical details like service specification route length, energy consumption and emissions. The study points to interesting rail services to keep Europe’s freight on the move. Their realization may be complex especially in terms of logistics and infrastructure, but is there an alternative?
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Er is wereldwijd een groeiende groep milieuvluchtelingen. Voor deze mensen, die vluchten als gevolg van bijvoorbeeld een tsunami, dijkdoorbraak, hoge concentraties vrijkomende giftige stoffen bij een industrieel ongeval, verwoestijning, uitputting van de bodem of langdurige regenval, bestaat nog geen adequaat internationaal beschermingsregime. Ons vorige artikel in Applied Research Today (april 2013) bracht in kaart welke soorten milieuvluchtelingen bestaan, en betoogde dat de bescherming van deze groep plaats kan vinden onder het VN-principe The Responsibility to Protect (R2P). R2P omvat onder andere een integrale aanpak die gericht is op het voorkomen, reageren en opbouwen, waarbij de verantwoordelijkheid is ondergebracht in drie pijlers: 1) een staat is zelf verantwoordelijk voor de bescherming van milieuvluchtelingen, 2) de internationale gemeenschap heeft een verantwoordelijkheid een staat hierbij te assisteren, en 3) de internationale gemeenschap heeft de verantwoordelijkheid om collectief snel en beslissend te reageren indien een staat zelf zijn milieuvluchtelingen niet kan of wil beschermen. Dit vervolgartikel formuleert hoe de integrale aanpak van The Responsibility to Protect kan worden geoperationaliseerd voor de bescherming van milieuvluchtelingen. ABSTRACT The number of environmental refugees is growing. An adequate international legal protection regime is lacking for people who, for example, flee as a result of a tsunami or levee breach; high concentrations of toxic substances from industrial accidents; desertification; soil depletion or prolonged rainfall. Our previous article in Applied Research Today (April 2013) described eight different groups of environmental refugees and argued that the protection of these groups can be ensured under the UN principle the Responsibility to Protect (R2P). R2P offers an integral approach that focuses on prevention, reaction and rebuilding. In first instance, the responsibility to take protective measures lies with the state itself. Secondly, the international community has a responsibility to assist. Lastly, when a state is not able or willing to protect its environmental refugees, the international community has the responsibility to respond in a swift and decisive manner. This follow-up article formulates how the Responsibility to Protect concept could be operationalised to protect environmental refugees.
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Saturated hydraulic conductivity (Ks) of the filler layer in grassed swales are varying in the changing environment. In most of the hydrological models, Ks is assumed as constant or decrease with a clogging factor. However, the Ks measured on site cannot be the input of the hydrological model directly. Therefore, in this study, an Ensemble Kalman Filter (EnKF) based approach was carried out to estimate the Ks of the whole systems in two monitored grassed swales at Enschede and Utrecht, the Netherlands. The relationship between Ks and possible influencing factors (antecedent dry period, temperature, rainfall, rainfall duration, total rainfall and seasonal factors) were studied and a Multivariate nonlinear function was established to optimize the hydrological model. The results revealed that the EnKF method was satisfying in the Ks estimation, which showed a notable decrease after long-term operation, but revealed a recovery in summer and winter. After the addition of Multivariate nonlinear function of the Ks into hydrological model, 63.8% of the predicted results were optimized among the validation events, and compared with constant Ks. A sensitivity analysis revealed that the effect of each influencing factors on the Ks varies depending on the type of grassed swale. However, these findings require further investigation and data support.
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Natural disasters are a growing concern around the globe. In the Netherlands, water has always played an important role as both friend and enemy. To quickly analyze and visualise possible disaster outcomes has been really difficult. In collaboration with engineering company Tauw we improved this modellingwith an interdisciplinary team of GIS experts, High performance computing and real time visualisation. In a pilot for the city center of Groningen we developed a 3D version of flooding landscape maps (RUG, 2014) after modelling extreme rainfall. With a flooding landscape map you can see at a glance where water isgoing and where problem areas arise in case of extreme rainfall. Any municipality or county can thus quickly determine which measures are to be taken to prevent for example disruption to traffic or flooding damage tobuildings.
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Understanding how horses interact with landscapes is key to designing environments that support welfare and biodiversity. Yet, little is known about how domestic horses use specific elements within a landscape. This study examined the behavioral interactions of seven Swedish warmblood mares (1–3 years old) with naturally occurring landscape features in the Kumlan Nature Reserve (Sweden) during July and August 2021. HoofStep® sensors continuously recorded equine behaviors, categorized as highly active, active, resting, or eating. Manly Selection Ratios (MSRs) were used to assess landscape feature selection (LFS) relative to availability. A generalized linear model (Gamma distribution, log link) tested the effects of horse, behavior, landscape feature, time of day, temperature, rainfall, and month on LFS. Significant main effects included horse, landscape feature, month, rainfall, and temperature (p < .001). Two-way interactions showed that behavior was linked to LFS and that selection was influenced by weather. For instance, tree rows and hedges were preferred during rainfall (Exp(B) = 1.17, p = 0.01), but avoided as temperatures rose (Exp(B) = -0.51, p < 0.001). Three-way interactions highlighted individual preferences, i.e., Horse A preferred resting on a sandbank (Exp(B) = 42.48, p < 0.05), and Horse B in a blackberry patch (Exp(B) = 25.22, p < 0.05). Horse C was active on a sandbank with vegetation (Exp(B) = 22.57, p = 0.01), while Horse D preferred the pool (Exp(B) = 90.44, p < 0.001). Findings suggest that both landscape and weather shape equine behavior, with notable individual variation. Landscape design should incorporate diverse features to meet the behavioral needs of individual horses and to support welfare and biodiversity goals.
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Although in 2019 the local government of Tegal city Indonesia had constructed a retention basin at drainage system of Siwatu, Tegal Barat, Tegal city with a catchment area of 226 ha, the areas around the system still experienced flood and inundation. This study belonged to a descriptive qualitative research aimed to evaluate the performances of Siwatu drainage system and Tegalsari retention basin. Data of the study included field data and technical data from institutions. Based on the 15-year rainfall data (2014 – 2018) from Pemali - Comal PSDA Office, Central Java Province, Indonesia, the statistical parameters of Cs: 0.0027, Ck: 1.904, Sd: 15.91, Cv: 0.144 were obtained and so Gumbel method distribution was applied in the study, the return period rainfall of 10 years was 138 mm, the flood discharge for Qr.10 years was 9.63 m3/sec., the addition of long storage was 8×2,50×500 m, and the combination of pump addition was of 1 m3/sec. with the long storage of 8×2.00×500 m. By implementing one of the alternative choices, either flood or inundation could be resolved.
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Global society is confronted with various challenges: climate change should be mitigated, and society should adapt to the impacts of climate change, resources will become scarcer and hence resources should be used more efficiently and recovered after use, the growing world population and its growing wealth create unprecedented emissions of pollutants, threatening public health, wildlife and biodiversity. This paper provides an overview of the challenges and risks for sewage systems, next to some opportunities and chances that these developments pose. Some of the challenges are emerging from climate change and resource scarcity, others come from the challenges emerging from stricter regulation of emissions. It also presents risks and threats from within the system, next to external influences which may affect the surroundings of the sewage systems. It finally reflects on barriers to respond to these challenges. http://dx.doi.org/10.13044/j.sdewes.d6.0231 LinkedIn: https://www.linkedin.com/in/sabineeijlander/ https://www.linkedin.com/in/karel-mulder-163aa96/
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