Search

Poor land management coupled with increasing climate extremes is affecting the livelihoods of Ethiopian communities. So, evaluating the possible impact of climate change on water resource is essential for planning a sustainable water use system. As a result, this study aimed to investigate the impact of climatic variable changes on streamflow in the Borkena River Catchment, Awash Basin, Ethiopia, using projected climate data of canESM2 (Canadian Earth System Model of second generation) global climate model. Future scenario, analysis was performed for the 2020s, 2050s and 2080s for the Representative Concentration Pathway of RCP4.5 and RCP8.5. Impact assessment of climatic variable changes on streamflow was done by HBV Light hydrological models. The model was calibrated using a semi-automated method and the performance was measured by the coefficient of determination (R2), Nash–Sutcliffe efficiency (NSE) and mean difference. The performance of HBV Light hydrological model during the calibration and validation period showed a satisfactory agreement between observed and simulated flow with R2, NSE and mean difference. The value of R2, NSE and mean differences was 0.84, 0.82 and 0 for calibration and 0.83, 0.78 and 8.23 for validation periods, respectively. The downscaled precipitation and temperature result reveals decrease and increase value in all future three-time horizon for both RCP8.5 and RCP4.5 scenarios in an annual basis respectively. This condition was expected to result decreased in mean annual streamflow of Borkena River in the future three-time horizon with the value of –16.81%,–17.25% and –18.28% for RCP8.5 scenario and –6.88%, –9.89% and –10.66% for RCP4.5 scenario in the 2020s, 2050s and 2080s, respectively. Inoculation future climate variation has a significant impact on the surface water potential of the catchment. So, for sustainable development of the River catchment in water use the streamflow of the catchment should be harvested. [ABSTRACT FROM AUTHOR]

This data paper presents microplastic (MP) concentration and composition data from four campaigns in a one-year period in the Seine River within the Greater Paris area. Detailed data on MP occurrence, physical water parameters, hydrological conditions, and potential sewer point sources are presented. Initial analysis of the data set shows that MP concentrations were significant (median: 600 particles m-3 and 100 mg m-3) and MP fluxes showed variations across sampling sites and campaigns. Three polymer types (polypropylene -- PP, polyethylene -- PE, polystyrene -- PS) account for 96% of the total number of MP. This dataset provides valuable insights for understanding river MP pollution under anthropogenic pressure. [ABSTRACT FROM AUTHOR]

This data paper presents microplastic (MP) concentration and composition data from four campaigns in a one-year period in the Seine River within the Greater Paris area. Detailed data on MP occurrence, physical water parameters, hydrological conditions, and potential sewer point sources are presented. Initial analysis of the data set shows that MP concentrations were significant (median: 600 particles m−3 and 100 mg m−3) and MP fluxes showed variations across sampling sites and campaigns. Three polymer types (polypropylene - PP, polyethylene - PE, polystyrene - PS) account for 96% of the total number of MP. This dataset provides valuable insights for understanding river MP pollution under anthropogenic pressure.

The objective of this work is to demonstrate for the first time the results of hydrogeochmical studies carried out in the Steinvik River catchment, in order to provide detailed information regarding the chemical composition of groundwater in the Hornsund region, SW Spitsbergen. The water chemistry in the non-glaciated Steinvik River catchment is largely controlled by hydrological processes related to thaw of the near surface permafrost. Groundwater runoff is generated from the fast flow through well-permeable active layer. Recharge from melting snow, permafrost and rain, together with short residence time of groundwater, favors the forming of low-mineralized water, reaching 41 and 50 μS/cm for surface and groundwater, respectively, with the dominance of HCO3−, Cl−, Mg2+, Ca2+ and Na+ ions. In some water samples, increased concentrations of aluminum (up to 268 μg/L ) were found. The highest concentrations of phosphate, nitrite and ammonium in water seem to be related to the presence of bird colonies. Groundwater of active layer in the studied catchment belongs to young meteoric water with the age limited to one summer season.

Bedrock influence on river channel form is difficult to assess, with many catchments dominated by glacial erosion and with blanketing sediments from both pluvial and fluvial sources. The Scamander catchment in Tasmania lacks glacial history and features two bedrock‐confined sub‐catchments of similar area and maximum flow length, but one dominated by Mathinna Group sedimentary rocks, and the other with large areas in granite lithology. Lithology types, stream network parameters and near stream slope angles were analysed using geographical information systems, and results of stream cross sections, channel form and planforms were compared for each lithology. Results showed that granite features low gradient, shallow streams with channel slope cross sections of <10°. Granite channels are irregular and dominated by large boulders that create channel roughness and resist incision. Weathering products of coarse quartz sand provide anchorages for in‐channel vegetation. By contrast, sedimentary Mathinna Group rocks feature steeply incised trough‐like channels, with near‐channel hillslope gradients mostly between 30° and 50°. Rectangular blocks disintegrate to gravel cobbles on the channel bed, providing poor anchorage for vegetation. Mathinna lithology influences steep, low roughness channels, and stable, incised recurved meanders formed by river interaction with vertical layers of resistant rock. The resistant bedrock lithology is demonstrated in this study to influence varied river planforms, near‐channel slope gradients, channel sediments and cross sections. [ABSTRACT FROM AUTHOR]

The objective of this work is to demonstrate the results of hydrogeochmical studies carried out in the Steinvik River catchment for the first time, in order to provide detailed information regarding the chemical composition of groundwater in the Hornsund region, SW Spitsbergen. The water chemistry in the non-glaciated Steinvik River catchment is largely controlled by hydrological processes related to thaw of the near surface permafrost. Groundwater runoff is generated from the fast flow through well-permeable active layer. Recharge from melting snow, permafrost and rain, together with short residence time of groundwater, favors the forming of low-mineralized water, reaching 41 and 50 µS/cm for surface and groundwater, respectively, with the dominance of HCO3-, Cl-, Mg2+, Ca2+ and Na+ ions. In some water samples, increased concentrations of aluminum (up to 268 µg/L) were found. The highest concentrations of phosphate, nitrite and ammonium in water seem to be related to the presence of bird colonies. Groundwater of active layer in the studied catchment belongs to young meteoric water with the age limited to one summer season. [ABSTRACT FROM AUTHOR]

This paper evaluates a unique, transdisciplinary participatory research and knowledge exchange methodology developed in the Drought Risk and You (DRY) project and offers it as a transferable framework for others engaging stakeholders and systemic connections with environmental risk. Drought in the UK is a complex, diffuse and hidden risk, involving multiple stakeholders and systemic connections across diverse sectors. Historically, drought risk management has been underpinned by specialist science and technology implemented by statutory stakeholders. This paper critically evaluates the social learning from a longitudinal research process that involved co-working with seven river catchment-based, multi-stakeholder groups. The DRY project was a creative experiment in bringing drought science and stories into the same space, aiming to reveal different knowledges—specialist science, practical sector-level insight, and local knowledge—as a new evidence base to support better decision-making in UK drought risk management. An evaluative multi-method research methodology was overlaid on this process, using surveys, within meeting reflective evaluations, and summative semi-structured narrative interviews. This paper reflects on participant experiences of the 'open' scientific modelling development, 'storying' approaches, and their iterative interaction. It outlines the enablers, inhibitors and required support for this engagement process, which aimed to facilitate integration of different forms of knowledge as evidence, with social and sustainability learning among diverse stakeholders at its core. The process offered opportunity for valuable experiential learning as researchers of the nuanced impacts of intersecting factors on participatory place-based methods. It showed that similar approaches to science-narrative dialogic processes can play out locally to integrate aspects of social and sustainability learning in different ways. This sustainability learning provided a valuable platform for creative multi-stakeholder scenario-ing possible drought futures for increased local climate resilience. It then proposes a transferable research framework that promotes participatory, place-based, narrative-science knowledge exchange for building local capital for managing systemic environmental risk. [ABSTRACT FROM AUTHOR]

The Coal Province lies within the central portion of Anambra Basin and along the axis of regional water resources catchment of Southeastern Nigeria. Although this area includes a prolific aquifer, the high cost of development and treatment of the groundwater degraded by AMD has created water scarcity problems against water policy initiatives. Social and economic impacts were investigated, even as policy measures for rehabilitation purposes through water resource management were highlighted. Several geoscientific methods were integrated for the investigations. Mean resistivity up to 30 Ω-m relatively at shallow depths indicated aquitards of Enugu/Mamu Formations, whereas the aquifer reflected resistivity ≤1,000 Ω-m at depths of ≥180 m across Ajali Sandstone. Alkaline-rich seepage flushed Fe-rich AMD at aquifer-aquitard interfaces adjoining the river catchment area. The AMD-induced oxidation process produced noxious Ca-Mg-Na-HCO3-SO4-Cl facie. These results were correlated with policy related questionnaires. Plans for water security were proposed, mainly to channel groundwater directly from the regional aquifer, or the chemically degraded seeped water from the fluvial system, into constructed water reservoir (treatment) columns prior to distribution to the town-water supply. Such water resource development is cost effective; and with management policies regulated by relevant decision-making agencies, sustainable supply is assured. Highlights Poor operation, development and maintenance of water resources scheme in Nigeria, particularly around Enugu region prompted this study.; Economic losses are surpassing gains earlier accrued from coal exploitation in the studied region.; This impasse is felt via water resources against water policy standpoint.; The hazards and causative processes were identified.; The information can guide in decision making intervention.;

In this study, we present the changing trends in extreme annual streamflow at 38 gauging stations in the Godavari catchment, India, during the period 1966-2015. We have applied Mann-Kendall trend test to the time series of at least 20 years of continuous data. The results indicate an increasing trend in the peak streamflow in the northern stations located within the Wainganga, Wardha and Indravati sub-catchments. We observed a critical declining trend at the upstream, central and downstream of the Godavari main catchment. Increasing trends in annual peak streamflow may cause severe higher magnitude floods in the Godavari catchment in the near future that may affect the lives of millions of population. [ABSTRACT FROM AUTHOR]

Aim: The relationships between species and their landscape are important for understanding migration patterns. In fluvial systems, the complexity of the river network can strongly influence the dispersal and colonization rates of invading alien fishes, but habitat quality, species' biological traits and their location of introduction are also potentially important. However, understandings of how these factors interact in the wild to influence the spatial distribution of invasive species over time are limited from empirical studies. Location: "Virtual" and "real‐world" rivers from England and Wales. Method: We developed an individual‐based model (IBM) to predict how these different factors influenced the invasion dynamics and population growth rates (as abundances) of nine "virtual" alien fishes over two timeframes (10 and 30 years). The alien fishes differed in their demographic (r‐ to K‐selected) and dispersal (fast to slow) characteristics and the rivers in their network complexity. Results: Irrespective of river type, species and timeframe, the main drivers of both dispersal and population growth were the location of the introduction and the mean habitat quality of the patch into which the species were released. The introduction location determined whether dispersal was mainly passive in a downstream direction (faster) or active in an upstream direction (slower), with higher habitat quality then enabling faster population growth rates. Over 30 years, invasion rates were predicted to increase as the complexity of the river network increased, as this opened multiple invasion fronts where the invader traits favoured faster dispersal. Main conclusions: This novel IBM revealed how the complexity of the physical environment interacts with the biological traits of alien species to influence invasion outcomes, with the location of the introduction and its habitat quality being the most important factors. These results thus substantially increase understanding of the factors that influence the dispersal and colonization rates of alien freshwater fishes. [ABSTRACT FROM AUTHOR]

1. The effects of biological invasions on native biodiversity have resulted in a range of policy and management initiatives to minimize their impacts. Although management options for invasive species include eradication and population control, empirical knowledge is limited on how different management strategies affect invasion outcomes. 2. An individual-based model (IBM) was developed to predict how different removal ('culling') strategies affected the abundance and spatial distribution of a virtual, small-bodied, r-selected alien fish (based on bitterling, Rhodeus sericeus) across three types of virtual river catchments (low/intermediate/high branching tributary configurations). It was then applied to nine virtual species of varying life-history traits (r- to K-selected) and dispersal abilities (slow/intermediate/fast) to identify trade-offs between the management effort applied in the strategies (as culling rate and the number of patches it was applied to) and their predicted effects. It was also applied to a real-world example, bitterling in the River Great Ouse, England. 3. The IBM predicted that removal efforts were more effective when applied to recently colonized patches. Increasing the cull rate (proportion of individuals removed per patch), and its spatial extent was effective at controlling the invasive population; when both were relatively high, population eradication was predicted. 4. The characteristics of the nine virtual species were the main source of variation in their predicted abundance and spatial distribution. No species were eradicated at cull rates below 70%. Eradication at higher cull rates depended on dispersal ability; slow dispersers required lower rates than fast dispersers, and the latter rapidly recolonized at low cull rates. The trade-offs between management effort and the outcomes of the invasion were, generally, optimal when intermediate effort was applied to intermediate numbers of patches. In the Great Ouse, model predictions were that management interventions could restrict bitterling distribution by 2045 to 21% of the catchment (versus 90% occupancy without management). 5. Synthesis and application. This IBM predicted how management efforts can be optimized against invasive fishes, providing a strong complement to risk assessments. We demonstrated that for a range of species' characteristics, culling can control and even eradicate invasive fish, but only if consistent and relatively high effort is applied. [ABSTRACT FROM AUTHOR]

The Țiganilor River catchment covers both built areas and the green/natural areas of the Botanical Garden. As we will see, the location influences differentially the quantitative and qualitative hydric processes of the stream. Situated in a city with a particularly dynamic development, where the emphasis is on preserving a healthy natural and anthropic environment, this obliges the monitoring and evaluation of the aquatic bodies’ qualitative parameters. We assessed this through two measurement campaigns, when parameters were determined in situ and in the laboratory. The physico-chemical parameters evaluation allowed the water classification in different quality classes. At the same time, there were sections where the water quality did not comply with the national regulations, and so they require further monitoring. Such situations where identified regarding the concentration of hydrogen ions, chlorine, nitrates, sulfates, sodium, magnesium and calcium.

This study was aimed to reveal relationships between the formation of the structures of river systems and to discover the tectonic structural features of the territory. We analyzed the morphometric parameters of river catchment areas of various orders, which comprise the Kama river basin. A digital terrain model in ESRI ArcGis 10.4 geoinformation system was used. Within the identified river basin geosystems, quantitative morphometric characteristics of the terrain were calculated for comparative analysis. Multidimensional statistical analysis methods were used to group the basins with respect to their sets of geometric and morphometric characteristics. A spatial typification technique was developed to distinguish the basin geosystems by their morphometric indicators. This study pioneered in using the results of cluster analysis for identification of seven groups of basins, which reflect the spatial heterogeneity of the ancient tectonic elements and the geomorphological conditions within the entire territory of the Kama river basin. It is established that the types of the river basin geosystems with characteristic morphometric features are related to various ancient tectonic structures, which suggests a genetic relationship of endogenous processes of river channel fracturing and the diversity of geometric parameters of different river basins.

This study investigated the export of dissolved iron (DFe) from river catchments with emphasis on land use and land cover (LULC). The DFe concentrations were measured at 61 and 63 sites during summer and winter, respectively, in the Kitakami Mountain in northeast Japan. LULC was classified as broadleaf forest, conifer, grassland, paddy field, cropland, and urban area using GRASS GIS software. In the downstream areas, the riverine DFe concentrations ranged from 0.84 to 115 μg/L and from 1.5 to 103 μg/L in winter and summer, respectively, whereas the DFe in the upstream areas ranged from 0.16 to 7.6 μg/L and from 1.1 to 20.0 μg/L. Regression analysis was applied to the DFe and LULC data, and the unit load for DFe was estimated for each LULC type, the unit load values being 1.6, 139, and 439 g/km2/day for broadleaf forest, paddy fields, and urban area, respectively, in winter and 61.9, 564, and 727 g/km2/day for grassland, paddy fields, and urban area, respectively, in summer, reflecting the impact of distinct seasonality. A significant positive correlation was found between urban area and riverine DFe concentration in each season, emphasizing the influence of human activity on DFe export to river catchments. Overall, our investigation provides a series of quantitative evidence showing the importance of LULC to understand DFe export from river catchments. [ABSTRACT FROM AUTHOR]

The river catchment management is a complex problem, which requires analysis of massive amounts of mandatory monitoring data on analytical, spatial, and temporal level. The present study deals with the application of a novel water quality assessment approach combining water quality index (WQI) developed by the Canadian Council of Ministers of the Environment (CCME) and self-organizing maps of Kohonen (SOM). The study is carried out by using long-term water quality monitoring data (2008–2018) collected from 10 sampling stations located in the Mesta River catchment, Bulgaria. In the first step, the assessment of annual water quality categories of each sampling station was estimated by the calculation of CCME WQI modified according to the Bulgarian legislation. In the next step, all annual water quality categories (n = 105) characterized by the factors used for CCME WQI calculation (scope, frequency, amplitude) underwent SOM analysis. The results of implementation of the WQI factors in SOM calculations reveal similar groups of annual water quality categories with specific CCME WQI patterns among the whole river catchment. The obtained patterns represent different water quality situations, which could be treated by different management activities. Additionally, the visualization advantages of the SOM algorithm allowed for detection of the water quality temporal changes and similarity between sampling stations among river catchment. Thus, the combination between integral CCME WQI assessment and multivariate technique SOM made it possible to achieve a precise river catchment water quality assessment, which could be used by water management authorities.

Climate change is projected to cause considerable pressure on our environment and communities. In particular, an increase in flooding and extreme erosion events is foreseeable as a result of an anticipated increase in the frequency and severity of storms. In the absence of timely and strategic intervention, climate change is taking us closer to more uncertain (non-linear, stochastic) and potentially more catastrophic climatic impacts. This paper develops a state-of-the-art modelling framework to assess the economic impact of erosion hazards on critical infrastructure and evaluate their vulnerability and resilience to differing storm regimes. This framework is trialled on a UK town (Cockermouth, NW England) that has experienced significant storm-related erosion and flood damage in recent years, highlighting its ability to determine current and future erosion hazard to critical infrastructure. A hydro-sedimentary model is used to simulate fluvial and hillslope sediment erosion and deposition caused by extreme storms within river catchments (sheet, rill, gully and channel bank and bed erosion). The model is applied for current climate conditions and for two future epochs (2021–2040 & 2061–2080) to assess changing erosion hazard to critical infrastructure. Climate conditions for the two epochs are obtained using the UKCP18 high resolution realisation projections under emission scenario RCP8.5. The economic loss caused by these hazards is projected based on new, non-linear depth-cost curves derived from previous assessments. The results show that: 1) due to a warming climate, total rainfall in the Cockermouth area (and likely across the UK) may be higher for all storm durations and annual exceedance probabilities, until epoch 2061–2080 when the rainfall regime may shift towards shorter duration events with higher rainfall and longer duration events with less rainfall; 2) the total area that undergoes flooding, erosion and sediment deposition, and the magnitude of the hazard, may increase as the climate shifts; 3) the economic damage caused by erosion and deposition is positively related to rainfall total, and the highest costs are likely to be associated with damage caused to bridges (£102-130 million), followed by sediment deposition in the urban fabric (£9-82 million), and erosion damage to agricultural land (£16-26 million), buildings (£0.4-18 million) and roads (£0.4-4 million); and 4) the Estimated Annual Damage costs suggest that investment in bridges (£4-6 million) in the Cockermouth area is required now to ensure their resilience to extreme storm events, and interventions are likely to be needed within the next 20 years to prevent high economic costs associated with significant sediment deposition in the urban fabric (£0.3-4 million) and damage to roads (£0.08-0.1 million) and agricultural land (£0.6-2 million). This new framework can help support operational (immediate) and strategic (medium to long term i.e. 10+ years) erosion control decision making through the provision of an assessment of the scale and consequences of erosion.

Identification of areas susceptible to flash floods is essential to establish measures that will help the population in case of a hazard. Therefore, the purpose of the present article is to identify the areas that present a high susceptibility to flash-floods in the Vărbilău catchment. The area, located in the Prahova region, was chosen due to the complexity of the hydrological phenomena. To determine the susceptibility to flash floods, the Flash Flood Susceptibility Index (FFSI) was calculated by integrating ten factors that play an essential role in the flash floods formation. Areas located downstream and in the middle of Vărbilău basin present a low risk, while locations in the northwest (upstream of Luţu Roşu and Scurteşti) present a high risk to flash-floods due to steep slope, narrow valleys, solid rocks, and land use. [ABSTRACT FROM AUTHOR]

Aim: Hotspots of human activity are focal points for ecosystem disturbance and non‐native introduction, from which invading populations disperse and spread. As such, connectivity to locations used by humans may influence the likelihood of invasion. Moreover, connectivity in freshwater ecosystems may follow the hydrological network. Here we tested whether multiple forms of connectivity to human recreational activities promotes biological invasion of freshwater ecosystems. Location: England, UK. Time period: 1990–2018. Major taxa studied: One hundred and twenty‐six non‐native freshwater birds, crustaceans, fish, molluscs and plants. Methods: Machine learning was used to predict spatial gradients in human recreation and two high risk activities for invasion (fishing and water sports). Connectivity indices were developed for each activity, in which human influence decayed from activity hotspots according to Euclidean distance (spatial connectivity) or hydrological network distance (downstream, upstream and along‐channel connectivity). Generalized linear mixed models identified the connectivity type most associated to invasive species richness of each group, while controlling for other anthropogenic and environmental drivers. Results: Connectivity to humans generally had stronger positive effects on invasion than all other drivers except recording effort. Recreation had stronger influence than urban land cover, and for most groups high risk activities had stronger effects than general recreation. Downstream human connectivity was most important for invasion by most of the groups, potentially reflecting predominantly hydrological dispersal. An exception was birds, for which spatial connectivity was most important, possibly because of overland dispersal capacity. Main conclusions: These findings support the hypothesis that freshwater invasion is partly determined by an interaction between human activity and species dispersal in the hydrological network. By comparing alternative connectivity types for different human activities, our approach could enable robust inference of specific pathways and spread mechanisms associated with particular taxa. This would provide evidence to support better prioritization of surveillance and management for invasive non‐native species. [ABSTRACT FROM AUTHOR]

Short-distance dispersal enables introduced alien species to colonise and invade local habitats following their initial introduction, but is often poorly understood for many freshwater taxa. Knowledge gaps in range expansion of alien species can be overcome using predictive approaches such as individual based models (IBMs), especially if predictions can be improved through fitting to empirical data, but this can be challenging for models having multiple parameters. We therefore estimated the parameters of a model implemented in the RangeShifter IBM platform by approximate Bayesian computation (ABC) in order to predict the further invasion of a lowland river (Great Ouse, England) by a small-bodied invasive fish (bitterling Rhodeus sericeus). Prior estimates for parameters were obtained from the literature and expert opinion. Model fitting was conducted using a time-series (1983 to 2018) of sampling data at fixed locations and revealed that for 5 of 11 model parameters, the posterior distributions differed markedly from prior assumptions. In particular, sub-adult maximum emigration probability was substantially higher in the posteriors than priors. Simulations of bitterling range expansion predicted that following detection in 1984, their early expansion involved a relatively high population growth rate that stabilised after 5 years. The pattern of bitterling patch occupancy was sigmoidal, with 20% of the catchment occupied after 20 years, increasing to 80% after 30 years. Predictions were then for 95% occupancy after 69 years. The development of this IBM thus successfully simulated the range expansion dynamics of this small-bodied invasive fish, with ABC improving the simulation precision. This combined methodology also highlighted that sub-adult dispersal was more likely to contribute to the rapid colonisation rate than expert opinion suggested. These results emphasise the importance of time-series data for refining IBM parameters generally and increasing our understanding of dispersal behaviour and range expansion dynamics specifically. [ABSTRACT FROM AUTHOR]

Much attention regarding the environmental pollution by plastics had focused on the Oceans. More recently, contamination of freshwater ecosystems has been addressed but information from smaller rivers in moderately populated catchments is still comparatively scarce. This study explored the microplastic (MP) occurrence in the small regional river Oker, Northern Germany (catchment area 1822 km2, population of ca. 500,000, discharge approx. 12 m3 s−1). MPs (fibers and fragments in the size range 0.3–5 mm, identification by microscopy) were found in all 10 in-stream samples collected along the course of the river, ranging between 28 and 134 particles m−3 with an overall average of 63 particles m−3. This MP concentration found in the small river Oker is similar to, or higher than, that reported for larger rivers in similar environments in Central Europe. On average, higher MP concentration was found at urban (71 particles m−3) compared to rural sampling sites (51 particles m−3). Within the Oker catchment, in-stream MP concentration showed no or low correlation to the catchment-scale factors of catchment size and population. Additional samples taken from three locations directly influenced by discharges of potential MP point sources confirmed wastewater treatment plants of different capacities and an urban rainwater sewer as sources. Our results support findings that MP concentrations in small rivers are crucially influenced by local sources, superimposing linear relationships to factors of catchment size and -population. They show that even small rivers draining moderately populated catchments may exhibit comparatively high concentrations of MPs, and thereby represent underestimated pathways of MP in the environment. [Display omitted] • Microplastic concentration in small river is similar to large rivers. • Importance of point sources (WWTP, rain sewer) for microplastic (MP) in a small river. • Higher MP river concentration in urban than rural areas. • No linear correlation of MP concentration with catchment factors (size, population). • Prevalence of fibers in in-stream samples, fragments in point source discharge. [ABSTRACT FROM AUTHOR]

The Țiganilor River catchment covers both built areas and the green/natural areas of the Botanical Garden. As we will see, the location influences differentially the quantitative and qualitative hydric processes of the stream. Situated in a city with a particularly dynamic development, where the emphasis is on preserving a healthy natural and anthropic environment, this obliges the monitoring and evaluation of the aquatic bodies’ qualitative parameters. We assessed this through two measurement campaigns, when parameters were determined in situ and in the laboratory. The physico-chemical parameters evaluation allowed the water classification in different quality classes. At the same time, there were sections where the water quality did not comply with the national regulations, and so they require further monitoring. Such situations where identified regarding the concentration of hydrogen ions, chlorine, nitrates, sulfates, sodium, magnesium and calcium. [ABSTRACT FROM AUTHOR]

ABSTRAK Penelitian ini bertujuan untuk mengkaji ketelitian absolut pemodelan faktor K berbasis raster sebagai masukan dalam pemodelan erosi Universal Soil Loss Equation (USLE) di Daerah Aliran Sungai (DAS) Merawu, Banjarnegara, Provinsi Jawa Tengah.Metode yang digunakan adalah dengan mengambil 30 sampel tanah secara stratified random sampling berdasarkan bentuklahan DAS Merawu. Sampel tanah tersebut kemudian dianalisis di laboratorium sehingga diperoleh tekstur, permeabilitas, bahan organik, dan struktur yang diperlukan untuk menghitung faktor K menggunakan rumus yang sudah ada. Dari 30 sampel yang diambil, 24 sampel digunakan untuk menghitung faktor K dalam pemodelan, sedangkan 6 sampel lainnya digunakan sebagai uji model. Pengeplotan nilai K pada sampel di atas peta dilakukan sesuai dengan lokasi sampel, kemudian dilakukan digitasi dan rasterisasi dan dilakukan interpolasi spasial untuk memperoleh Peta K untuk setiap piksel dengan metode Kriging. Hasil pemodelan K tersebut (Kmodel) kemudian diuji pada 6 lokasi (Kaktual) untuk mengetahui ketelitian pemodelan. Kmodel dikatakan teliti jika memiliki nilai ≥ 80% terhadap Kaktual.Hasil penelitian menunjukkan bahwa pemodelan faktor K berbasis raster di DAS Merawu mempunyai ketelitian melebihi nilai ambang yang ditetapkan, yaitu sebesar 89,068%, yang menunjukkan bahwa peta hasil pemodelan menggunakan analisis Kriging dapat digunakan untuk analisis lebih lanjut dalam menghitung erosi. ABSTRACT The research was aimed at knowing the absolute accuracy of modeling of raster-based K factor as input for Universal Soil Loss Equation (USLE) erosion modeling at Merawu Catchment, Banjarnegara, Central Java Province. Methodology applied was by taking 30 soil samples of stratified random sampling based on landform of Merawu Catchment. Those 30 soil samples then were analised in a laboratory to get their texture, permeability, organic matter, and structure for K factor computation using the existing formula. From 30 soil samples taken, 24 samples were used to model K factor, while the other 6 soil samples were used for Model Validation. The result of computation for each sample then was plotted according to their position, digitized, transformed and spatially interpolated using Kriging technique to gain Map of K factor of the study area (Kmodel). Kmodel then was validated with 6 soil samples of the Kactual to know the accuracy of the model. Kmodel is said to be accurate when its accuracy is ≥ 80% when compared to Kactual. The research result at Merawu Catchment showed that modeling of raster-based K factor reached the accuracy of ≥ 80%, that was 89.068%, indicating that modeling of factor K by using Kriging analysis can be used further for erosion analysis.

Previous studies on environmental antibiotics resistance genes (ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms, etc. Few of them had addressed this issue in a regional scale such as river catchment. Hence, the occurrence and abundances of 23 ARGs were investigated in surface water samples collected from 38 sites which located from the river source to estuary of the Beijiang River. Among them, 11 ARGs were frequently detected in this region and 5 ARGs ( sul I, sul II, tet B, tet C, and tet W) were selected for their distribution pattern analysis. The abundances of the selected ARGs were higher in the upstream (8.70 × 10 6 copies/ng DNA) and downstream areas (3.17 × 10 6 copies/ng DNA) than those in the midstream areas (1.23 × 10 6 copies/ng DNA), which was positively correlated to the population density and number of pollution sources. Pollution sources of ARGs along the Beijiang River not only had a great impact on the abundances and diversity, but also on the distribution of specific ARGs in the water samples. Both sul I and sul II were likely originated from aquaculture farms and animal farms, tet W gene was possibly associated with the mining/metal melting industry and the electric waste disposal and tet C gene was commonly found in the area with multiple pollution sources. However, the abundance of tet B was not particularly related to anthropogenic impacts. These findings highlight the influence of pollution sources and density of population on the distribution and dissemination of ARGs at a regional scale. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Located in the north-eastern part of Romania, the Suceviţa catchment has been affected in the last decade, by the most serious known high floods in the modern period of hydrological observations. The significant amounts of rainfall (260 mm in five days in 2008 and 150 mm in four days in 2010) have led to the formation of high floods that have affected large areas of land near the river course. These torrential rainfall led to the recording of maximum flows showing an increased tendency from 214 m3/s in 2007 to 467 m3/s in 2010 (reconstituted value exceeding the probability of occurrence of 0.1%). Even if the afforestation degree, at the level of the catchment and its tributaries, in the mountainous area, is over 80%, the morphometric conditions given by the average high values of the slopes (37-55‰) and also by the circularity ratio (0,60 – 0,73) generate a fast drainage of the precipitation water to the riverbeds. At the same time, the human activity increases the impact of flooding because of the activities carried out near watercourses. Flooding associated with these high floods have highlighted the vulnerability of the communities manifested by weak capacity to absorb the effects of the phenomenon and to recover after such events. Therefore, the high floods of 2008 and 2010 have caused extensive damage to the localities situated in the Sucevița river catchment.

Erosive processes influence on several phenomena. In particular, they could influence on land depletion, on vegetation weakening, on aggradation phenomena of intermediate, and plain reaches of rivers, on waterways interruption due to overaggradation phenomena caused by floods, and on the losses of water volumes that may be stored in reservoirs. Among the models proposed in the literature for the prediction of erosion on the annual scale, one of the most widely used is the Revised Universal Soil Loss Equation (RUSLE). In the present paper, starting from the definition of the original model, the authors improved the important combined slope length and slope angle (LS-factor), taking into account the mutual interaction of solid particles, in terms of path and confluences, so as to transform the model, which was first classified on a slope scale or at most on a parcel one, into a distributed model on a basin scale. The use of a distributed approach is an integral part of the analysis of the hydrogeological risk. In this way, it is possible to obtain a map of the erodibility of any basin, from which to derive the most vulnerable areas. The proposed methodology has been tested on the Camastra Basin, located in Basilicata Region of Southern Italy.