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Contaminants of emerging concern (CECs) can threaten aquatic ecosystems and human health. Both rural and urban areas are main sources of CECs to the environment. In rural areas, veterinary pharmaceuticals (VPs) are used to prevent diseases and protect the health of farm animals. The excrements of medicated animals are spread as manure to agricultural lands, where, after rainfall, VPs can be mobilized and reach surface waters through runoff. In urban areas, pharmaceuticals excreted by humans are collected in sewage systems and are only partially removed in wastewater treatment plants (WWTPs). Eventually, pharmaceuticals can reach surface waters through discharge of WWTP effluent. Currently, most of the predictive models only consider one source type, e.g. WWTPs or agricultural land. This limits their prediction performance since many CECs are being emitted by multiple source types. Therefore, the aim of this study is to integrate urban and rural sources of CECs in one regional water quality assessment.Here, we predicted the concentration of CECs in the Eem river basin, the Netherlands, given land-use data combined with hydrological modeling. This allows for integrated evaluation of rural and urban emissions. These emissions were predicted with models developed within the context of the SUSPECt project (https://cec-partnership.nl/web/index.php/projects/suspect). CECs exposures were predicted with the Dutch National Water Quality Model where WWTPs emissions were included as point sources and rural emissions as diffuse sources. The temporal resolution of the model hydrology is seasonal. This is key to analyze the temporal variation of concentration due to manuring of agricultural lands which mainly occurs in Spring.Predicted concentrations were successfully compared to measured concentrations taken in the SUSPECt project and from the database of the KIWK project (www.kennisimpulswaterkwaliteit.nl) for 6 compounds: carbamazepine and fipronil (only urban sources) and trimethoprim, sulfamethoxazole, permethrin and dexamethasone (urban and rural sources).

Bank erosion in riverine systems is one of the most complex, yet rampant, morphodynamic processes with significant implications for riparian activities and thereby the population. Therefore, it is an important aspect of the geomorphological evolution of a river reach that must be taken into consideration by river engineers while planning training, restoration or other engineering works of interest. Erosion of river banks are in essence a result of a combination of bank material entrainment by the river flow and mass failure.In particular, it has been found that bank accretion on one river side could play an important role in triggering erosion of the opposite bank. Such bank accretion could be a result of a natural bar formation due to morphodynamic instability or even forced by an intervention, such as a groyne. To understand this process, we conducted a computational fluid dynamics (CFD) numerical study. We set up a high-resolution 3D Large Eddy numerical model replicating data-rich experiments which have been previously conducted in a large flume with a mobile bed, where bank erosion has been observed opposite to a bar formation.The CFD hydrodynamic model takes as input the boundary conditions and the high-resolution bed topography data which had been collected during the experiment at given time intervals. The hydrodynamic simulation runs until steady-state, thus provides the flow field at that given time of the experiment, i.e., for a particular bed topography configuration. Thereafter, the next time-instances, with an updated bed topography, are simulated similarly. This provids a set of flow-field data for each time instance. The evolution of the flow field can then be related to the evolution of the opposite bank erosion. Various flow field variables and parameters such as near-bank velocities and Q-criterion, were analysed so as to determine the process driving factors. Furthermore, the large eddy simulations allowed for the identification of coherent turbulent structures and their role in driving bank erosion. Results are here presented and discussed.

The EU Water Framework Directive and Priority Substance Directive provide a framework to identify substances that potentially pose a risk to surface waters and provide a legal basis whereby member states are required to monitor and comply with environmental quality standards (EQSs) set for those substances. The cost and effort to continuously measure and analyse real world concentrations in all water bodies across Europe are high. Establishing the reliability of environmental exposure models to predict concentrations of priority substances is key, both to fill data gaps left by monitoring campaigns, and to predict the outcomes of actions that might be taken to reduce exposure. In this study, we aimed to validate the ePiE model for the pharmaceutical ibuprofen by comparing predictions made using the best possible consumption data with measured river concentrations. The results demonstrate that the ePiE model makes useful, conservative exposure predictions for ibuprofen, typically within a factor of 3 of mean measured values. This exercise was performed across a number of basins within Europe, representative of varying conditions, including consumption rates, population densities and climates. Incorporating specific information pertaining to the basin or country being assessed, such as custom WWTP removal rates, was found to improve the realism and accuracy of predictions. We found that the extrapolation of consumption data between countries should be kept to a minimum when modelling the exposure of pharmaceuticals, with the per capita consumption of ibuprofen varying by nearly a factor of 10.

The version of record os available online at: http://dx.doi.org/10.1007/s10346-020-01568-3 Time trends and their statistical significance for daily minimum, Tmin, and maximum, Tmax, temperatures recorded at the Fabra Observatory (Barcelona) along 102 years (1917–2018) permit to analyse the evolution of every one of the 365 calendar days along the recording period. Relevant changes in the daily temperature regime have been quantified not only by time trends and the Mann–Kendall test, but also by the multifractal analysis applied to consecutive segments of daily temperature data. The evolution of several multifractal parameters (the central Hölder exponent, the spectral asymmetry and spectral amplitude, the complexity index and the Hurst exponent) provides a complementary viewpoint to describe the evolution of the thermometric regime along the 102 recorded years. At monthly scale, the effects of the climate change are characterised by significant positive trends from September to December and very moderate negative trends from April to July. With respect to changes in the calendar-day structure, it is noticeable a shift of the highest minimum and maximum daily temperature from July to August (year 2018) to the beginning of September (projections for years 2030 and 2050) and the projected highest maximum calendar-day temperature exceeding 30 °C.

Human appropriation of water resources may induce water stress in freshwater ecosystems when ecosystem needs are not met. Intensive abstraction and regulation cause river ecosystems to shift towards non-natural flow regimes, which might have implications for their water quality, biological structure and functioning. We performed a meta-analysis of published studies to assess the potential effects of water stress on nutrients, microcontaminants, biological communities (bacteria, algae, invertebrates and fish), and ecosystem functions (organic matter breakdown, gross primary production and respiration). Despite the different nature of the flow regime changes, our meta-analysis showed significant effects of human-driven water stress, such as significant increases in algal biomass and metabolism and reduced invertebrate richness, abundance and density and organic matter decomposition. Water stress also significantly decreased phosphate concentration and increased the concentration of pharmaceutical compounds. The magnitude of significant effects was dependent on climate, rainfall regime, period of the year, river size and type of water stress. Among the different causes of water stress, flow regulation by dams produced the strongest effects, followed by water abstraction and channelization. © 2018, The Author(s)., This project was funded by the European Commission under the grant No. 603629 – project GLOBAQUA. VF acknowledges financial support from the Portuguese Foundation for Science and Technology (FCT) through UID/MAR/04292/2013 and IF/00129/2014. The authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (ICRA-ENV 2017 SGR 1124).

Human consumption of pharmaceuticals leads to high concentrations of pharmaceuticals in wastewater, which is usually not or insufficiently collected and treated before release into freshwater ecosystems. There, pharmaceuticals may pose a threat to aquatic biota. Unfortunately, occurrence data of pharmaceuticals in freshwaters at the global scale is scarce and unevenly distributed, thus preventing the identification of hotspots, the prediction of the impact of Global Change (particularly streamflow and population changes) on their occurrence, and the design of appropriate mitigation actions. Here, we use diclofenac (DCL) as a typical pharmaceutical contaminant, and a global model of DCL chemical fate based on wastewater sanitation, population density and hydrology to estimate current concentrations in the river network, the impact of future changes in runoff and population, and potential mitigation actions in line with the Sustainable Development Goals. Our model is calibrated against measurements available in the literature. We estimate that 2.74 ± 0.63% of global river network length has DCL concentrations exceeding the proposed EU Watch list limit (100 ng L-1). Furthermore, many rivers downstream from highly populated areas show values beyond 1000 ng L-1, particularly those associated to megacities in Asia lacking sufficient wastewater treatment. This situation will worsen with Global Change, as streamflow changes and human population growth will increase the proportion of the river network above 100 ng L-1 up to 3.10 ± 0.72%. Given this background, we assessed feasible source and end-of-pipe mitigation actions, including per capita consumption reduction through eco-directed sustainable prescribing (EDSP), the implementation of the United Nations Sustainable Development Goal (SDG) 6 of halving the proportion of population without access to safely managed sanitation services, and improvement of wastewater treatment plants up to the Swiss standards. Among the considered end-of-pipe mitigation actions, implementation of SDG 6 was the most effective, reducing the proportion of the river network above 100 ng L-1 down to 2.95 ± 0.68%. However, EDSP brought this proportion down to 2.80 ± 0.64%. Overall, our findings indicate that the sole implementation of technological improvements will be insufficient to prevent the expected increase in pharmaceuticals concentration, and that technological solution need to be combined with source mitigation actions., Authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through Consolidated Research Group (ICRA-ENV 2017 SGR 1124), as well as from the CERCA program.

The published version of this article contains error. The author noticed that there are many mistakes in the formatting and layout the paper. These include author affiliation, equations, figure resolution, open access license, Table 1 layout and some of the references.

GLOBAL-FATE is an open-source, multiplatform, and flexible contaminant fate model that links human consumption of pharmaceutical-like compounds with their concentration in the river network at the global scale. GLOBAL-FATE simulates human consumption and excretion of pharmaceuticals, the attenuation of the contaminant load in wastewater treatment plants, and runoff and contaminant routing along the river network under steady-state, including first order decay of the contaminant in rivers reaches, lakes, and reservoirs. We provide a comprehensive description of model equations and the overall structure of the model, with particular attention to input/output datasets. GLOBAL-FATE is written in C and can be compiled in any platform, and uses inputs in standard GIS format. Additionally, the model can be run inside QGIS as a plug-in. The model has no built-in working resolution, which depends on the user inputs. We exemplify the application of GLOBAL-FATE solving the global concentration of diclofenac in the river network. A comparison with a dataset of diclofenac concentration observations in rivers suggest that GLOBAL-FATE can be successfully applied in real case modelling exercises. The model is particularly sensitive to the generation of contaminant loads by human pharmaceutical consumption, and also to the processes governing contaminant attenuation in the river network.

The Lower Mara River and Wetland, Tanzania, is an important ecosystem and unique water resource for a vast semi-arid area. The river, an affluent of Lake Victoria, and the wetland are experiencing morphological and vegetation changes resulting in channel avulsions and wetland expansion. This study analyses the changes over the last 100 years and investigates natural and anthropogenic behaviors to explain the increase of the Mara Wetland area. We collated historical topographic maps and satellite images. We conducted two field surveys in low and high flow condition with an unmanned aerial vehicle, a sonar and an ADCP. We mapped selected areas as well as the bed topography in some stretches of the river, measured discharges, and collected river bed and suspended sediment samples. The analysis of the sediments shows that the wetland system, dominated by papyrus sp., is very efficient in trapping sediment, releasing clear water to the Lake Victoria. The historical reconstruction using topographic maps, satellite images and a multivariable analysis including hydrology and land cover, shows that 4 major avulsions occurred in the last 70 years due to a combination of natural behaviors, hydrological fluctuations and anthropogenic factors such as basin deforestation, farming and grazing along the river banks and in the wetland. Each avulsion led to substantial expansion of the wetland. Combined, they increased the wetland area by a factor of 3.6. Describing the Lower Mara River dynamic behavior, this work provides relevant information for sustainable future water and sediment management in order to preserve wetland habitats and natural resources.

The rapid development of GIS techniques permits the regional scale assessment for natural hazards. In this work different declared as GNU/GPL open source codes for debris flow hazard assessment have been developed for risk management and educational porpoises. The toolbox here presented manages the large amount of regional spatially distributed geographic information and includes: shallow landslide susceptibility assessment tools; an in-channel debris flow triggering mechanism evaluation tool; and the stochastic debris flow propagation tool “DebrisDice”. The tools are presented as executables in order to enhance the usability. Input/output are in ASCII grid format.

A debris flow is an erosional process that frequently occurs in areas with steep slopes. Although the initiation can be triggered in higher and inhabited altitudes, the propagation and then the deposition can endanger urbanized areas. Frequently, the zones of generation of debris flows are placed in unattainable territories complicating field observations. Moreover, the rapid vegetation’s recovery can hide the scars and tracks created by the occurrence of the flow, unlikely to be recognizable in aerial photos. As a consequence, the assessment of debris-flow susceptibility at regional scale is increasing in interest. Two main techniques can be applied for the regional susceptibility assessment: physical models and statistical models. Here, two physical models are introduced simulating the initiation of debris flow by means of shallow landslides: one based on the lateral groundwater flow and the other on vertical groundwater flow. The presented models’ algorithms are implemented in a toolbox based on GIS environment and declared as open source code. Being applied in a basin of the Spanish Pyrenees where soil properties and dataset of observations have been gathered, the two models have been evaluated. Successively, they have been compared with a statistical model based on a logistic regression. The results have been aggregated in terrain units, built as fluvio-morphological sub-catchments. Each model has been tested based on the gathered observations. It has been observed that the vertical flow-based model enhances by 18 % the performance of the lateral flow-based model in matching debris-flow susceptible areas. Furthermore, the vertical flow-based model performance is found to be similar to that of the logistic regression, having an averaged quality index of about 70 %.

Landslides falling into water bodies can generate impulsive waves, which are a type of tsunamis. The propagating wave may be highly destructive for hydraulic structures, civil infrastructure and people living along the shorelines. A facility to study this phenomenon was set up in the laboratory of the Technical University of Catalonia. The set-up consists of a new device releasing granular material at high velocity into a wave basin. A system employing laser sheets, high-speed and high-definition cameras was designed to accurately measure the high velocity and geometry of the sliding mass as well as the produced water displacement in time and space. The analysis of experimental data helped to develop empirical relationships linking the landslide parameters with the produced wave amplitude, propagation features and energy, which are useful tools for the hazard assessment. The empirical relationships were successfully tested in the case of the 2007 event that occurred in Chehalis Lake (Canada).

When a landslide or a debris-flow falls in a water body, a big wave, known as impulse wave or landslide tsunami wave, can be generated. That phenomenon can be highly destructive and unlikely predicted, involving dams and shorelines. Disastrous past events have been extensively analyzed and experimental studies have been carried out by different authors, but do not fully account for the description of the phenomenon. In the present study we introduce a new experimental set up installed in the fluvial-morphodynamic laboratory of the GITS team in the Technical University of Catalonia. The experimental device consists of a wheeled box sliding on a steep slope flume, releasing granular material, which enters a 2D basin. Defining a set of governing parameters and after several run of experiment, a description of the behavior of the waves was attempted. First results are here presented and analyzed.