Status Of Surface Water Bodies Research Articles

Hydrological Regime Alteration Assessment in the Context of WFD 2000/60: A European and Global Review

Although the impact of hydrology on the ecological status of surface water bodies has been highly recognised, the hydrological regime alteration assessment has proven to be a challenging task. In this context, an extensive structured review analysis was used as a research method to investigate the strength and limitations of the hydrological regime alteration assessment methods as adopted by each member of the European Environment Agency and the cooperating countries, according to the Water Framework Directive 2000/60, as well as to propose future directions. The review was also widened to include the methods currently used worldwide in the hydrological alteration studies and the supporting software tools developed. The implementation of a common methodology on a European scale is not applicable, since a single approach would not be able to cope with the regional needs and conditions. The main limitation in almost all the methods developed by European countries and worldwide is the need for a flow time series of high temporal resolution, so as to also capture the systems’ extreme high and low flows. Automatic monitoring systems for rivers can provide a solution. Additionally, hydrological modelling may provide the necessary data for the definition of the reference conditions. Nevertheless, the main limitations of the methodologies reviewed and the challenge for future development are the incorporation of the groundwater contribution to the hydrological regime and the development of quantitative relationships between flow alteration and ecological response.

Assessment of trends in concentrations of chemical and physico-chemical indicators of the status of surface water bodies

Assessment of trends in concentrations of chemical and physico-chemical indicators of the status of surface water bodies

Prediction of ecological status of surface water bodies with supervised machine learning classifiers

Ensuring a good ecological status of water bodies is one of the key challenges of communities and one of the objectives of the European Water Framework Directive. Although recent works identified the most significant stressors affecting the ecological quality of rivers, the ability to predict the overall ecological status of rivers based on a limited amount of easily accessible geospatial data has not been investigated so far. Most of the analyses focus on detailed local modelling and measurements which cannot be systematically applied at regional scales for the purposes of water resources management. The aim of this work is to understand the capabilities of five supervised machine learning classifiers of predicting the ecological status of rivers based on land use, climate, morphology, and water management parameters extracted over the river catchments corresponding to the ecological monitoring stations. Moreover, the performances of machine learning classifiers are compared to the results of the canonical correlation analysis. The method is applied to 360 catchments in Tuscany (central Italy) with a median size of 33.6 km2 and a Mediterranean climate. The results show (i) a significant correlation of ecological status with summer climate (i.e., maximum temperatures and minimum precipitation), land use and water exploitation, (ii) an 80 % precision of Random Forest algorithm to predict ecological status and (iii) higher capability of all classifiers to predict at least good ecological status. In perspective, such predictive capabilities can support decision making in the land and water resources management and highlight strategies for river eco-hydrological conservation.

Evaluating the Performance of Water Quality Indices: Application in Surface Water of Lake Union, Washington State-USA

Water quality indices (WQIs) are practical and versatile instruments for assessing, organizing, and disseminating information about the overall quality status of surface water bodies. The use of these indices may be beneficial in evaluating aquatic system water quality. The CCME (Canadian Council of Ministers of the Environment) and NSF (National Science Foundation) WQIs were used for the assessment of surface water (depth = 1 m) in Lake Union, Washington State. These WQIs were used in surface water at Lake Union, Seattle. The modified versions of the applied WQIs incorporate a varied number of the investigated parameters. The two WQIs were implemented utilizing specialized, publicly accessible software tools. A comparison of their performance is offered, along with a qualitative assessment of their appropriateness for describing the quality of a surface water body. Practical conclusions were generated and addressed based on the applicability and disadvantages of the evaluated indexes. When compared to the CCME-WQI, it is found that the NSF-WQI is a more robust index that yields a categorization stricter than CCME-WQI.

Making waves: Time for chemical surface water quality monitoring to catch up with its technical potential

A comprehensive real-time evaluation of the chemical status of surface water bodies is still utopian, but in our opinion, it is time to use the momentum delivered by recent advanced technical, infrastructural, and societal developments to get significantly closer. Procedures like inline and online analysis (in situ or in a bypass) with close to real-time analysis and data provision are already available in several industrial sectors. In contrast, atline and offline analysis involving manual sampling and time-decoupled analysis in the laboratory is still common practice in aqueous environmental monitoring. Automated tools for data analysis, verification, and evaluation are changing significantly, becoming more powerful with increasing degrees of automation and the introduction of self-learning systems. In addition, the amount of available data will most likely in near future be increased by societal awareness for water quality and by citizen science. In this analysis, we highlight the significant potential of surface water monitoring techniques, showcase “lighthouse” projects from different sectors, and pin-point gaps we must overcome to strike a path to the future of chemical monitoring of inland surface waters.

A benthic invertebrates-based biotic index to assess the ecological status of West African Sahel Rivers, Burkina Faso

Conserving aquatic resources in the West African Sahel requires water management tools to assess the ecological status of surface water bodies threatened by mounting pressures from agricultural intensification and urbanization. Macroinvertebrate communities of Sahelian rivers were examined to test if a multi-metric index approach could be developed to assess the ecological quality of rivers. A total of 40 sample sites falling within a continuum ranging from “unimpaired reference sites” to “impaired sites” were assessed during this study. Macroinvertebrates were sampled with a hand net following a multi-habitat sampling approach. Key environmental parameters, both physico-chemical and hydro-morphologic, were recorded. More than 20 candidate metrics were evaluated in four categories: composition, functional feeding, diversity, and tolerance. We used detailed analysis procedures to exclude unsuitable metrics from the data set. After excluding redundant metrics, six-core metrics were selected to compose the Sahel River Multimetric Index (SRMI): Total-taxa, Shannon & Weiner index, EPT-taxa, ASPT-NEPBIOS and ASPT-SASS and Collector-filterers. The final index derived from these metrics was divided into five ecological quality classes (high, good, moderate, poor, and bad). The results showed that the SRMI responded to a set of environmental parameters associated with a gradient of human pressures affecting the ecological integrity of water bodies (R2≥|0.50|; p < 0.05; p < 0.001). This work produced a data base and analysis that confirms the usefulness of an unprecedented and promising tool for biological monitoring and decision-making in Sahelian regions' water management.

WFD Ecological Quality Indicators Are Poorly Correlated with Water Levels in River Catchments in Tuscany (Italy)

The Water Framework Directive (WFD) requires European countries to achieve a good ecological status of surface water bodies and demands that River District Authorities define ecological flows consistently. Nevertheless, the relationship between ecological and hydrological indicators is not fully understood and not straightforward to apply because ecological and hydrological indicators are monitored by different institutions, with different timings and purposes. This work examines the correlation between a set of ecological indicators monitored by environmental agencies (STAR-ICMi, LIMeco, IBMR, and TDI) and water levels with assigned durations monitored by the hydrologic service in Tuscany (central Italy). Reference water levels are derived from stage-duration curves obtained by the statistical analysis of daily levels in the same year of ecological sampling. The two datasets are paired through a geospatial association for the same river reach and the correlation is measured through Pearson’s r. The results show poor correlation (r between −0.33 and −0.42) between ecological indicators and hydrologic variables, confirming the findings observed in other Italian catchments with different hydrologic regimes, climate, and anthropogenic pressures. Nevertheless, the negative correlations show a decreasing water quality with water depths, i.e., in the lower part of the catchments more affected by anthropogenic pressures. These findings suggests that the determination of ecological flows with a purely hydrological approach is not sufficient for achieving WFD objectives in the study area.

Assessing ecological status in karstic lakes through the integration of phytoplankton functional groups, morphological approach and environmental DNA metabarcoding

Phytoplankton is one of the key Biological Quality Elements within the Water Framework Directive, used to assess the ecological status of surface water bodies. Water samples for phytoplankton identification were collected from April to September at a total of eight sampling sites in all six Croatian natural karstic lakes with an area greater than 0.5 km2. The main objective was to show the comparability of environmental DNA metabarcoding (Illumina sequencing using the hypervariable V9 region of the eukaryotic SSU rRNA gene) with morphologically based assessment and its applicability in assessing the ecological status of lakes. The value of Hungarian lake phytoplankton index (HLPI) indicating the final ecological status was calculated for both datasets using biomass and composition metrics. Chlorophyll a concentration measured using Ultra-High-Performance Liquid Chromatography and Spectrophotometer giving two biomass metrics along with the functional group approach (FG) as the composition metric for the complete taxa/operational taxonomic units (OTUs) lists as well as for the taxa/OTUs that contributed more than 5% to the total biomass/number of amplicons gave four to four HLPI values per sample. HLPI values from both approaches were highly correlated (Pearson's r > 0.92) and classified into good or high ecological status, although different compositions and proportions of FGs were recorded, thus giving the important role to the equal or similar factors assignment to different FGs with similar ecological demands and favourable habitats. In 89% of the samples, HLPI values indicate an equal range of ecological status and most differences were found due to different methods of Chlorophyll a measurement. Different composition metrics between approaches showed significant differences (p < 0.05) only in lakes Prošće and Crniševo. This study showed the applicability of the V9 region of 18S rRNA in ecological status assessment for oligotrophic and mesotrophic lakes due to the comparable results between approaches, but further development and standardization of eDNA metabarcoding are needed for the implementation in routine monitoring programs.

Hydromorphological assessment of Polish lakes: Elaborating the Lake Habitat Survey for Polish Lakes (LHS_PL) method and determining ecologically based boundary values for lake classification

AbstractThe Lake Habitat Survey for Polish Lakes (LHS_PL) is a method for the hydromorphological investigation of lakes employed for the assessment of the ecological status of surface water bodies in Poland. It was developed based on the British Lake Habitat Survey method. In 2015, after almost a decade of work on the adaptation, the LHS method was finally adjusted to Polish conditions, and since 2016, it has been implemented in the State Environmental Monitoring programme. This paper presents the assumptions and evolution of the method and the approach for determining boundary values for the high/good (H/G) and good/less than good (G/LTG) ecological status classes. The method involves the assessment of the morphological features of the lake and anthropogenic pressures at 10 observation plots as well as the analysis of hydrological alterations and anthropogenic activities within the lake basin and the entire catchment area. The data collected in the field are used to calculate the index of lake hydromorphological alteration, that is, the Lake Habitat Modification Score for Polish Lakes (LHMS_PL). The LHMS_PL values range from 0 to 144, where 0 means no modification and 144 refers to a hydromorphologically highly modified state. The boundary values for the H/G and G/LTG status classes have been determined using the quartile method based on the relationship between hydromorphological modifications of lakes and the condition of the phytoplankton and macrophyte communities therein.

Seasonal effect of land use management on gill histopathology of Barbel and Douro Nase in a Portuguese watershed

The Vilariça River (located in the northeast of Portugal) is inserted in an agricultural basin and it was chosen to replace the spawning grounds for fish, that was lost due to the construction of dams in the Sabor River. Thus, it is essential to study the effect of agricultural practices on water quality and in the health status of fish. The barbel (Luciobarbus bocagei) and Douro nase (Pseudochondrostoma duriense) were the selected species and the work was developed in two seasons (Summer 2016 and Winter 2017). For that, the histopathological changes of fish gill were used as biomarkers, through a semi-quantitative approach that considers the injuries severity. And the water quality assessment criteria followed the methodologies proposed for classifying the status of surface water bodies from Portugal. The current study showed severe histopathological changes in both species and both seasons, and the water was classified as polluted and extremely polluted in Summer and Winter respectively. The pollution in Summer was due to high temperatures, low dissolved oxygen and major concentration of As and Mn, and in Winter is due to the high concentration of Total Suspended Solids, nitrites and Cd. The increase of values of physico-chemical parameters on the water was caused by the less streamflow and excessive agricultural fertilization in Summer which arrive the river by irrigation, and by the erosion of soil particles with heavy metals associated in Winter. Also, the canonical analysis showed that physico-chemical parameters concentrations in Summer justify the major prevalence of aneurism in barbel and exudate in nase and Winter the major prevalence of hypertrophy in barbel. In conclusion, the study showed that the gill injuries of barbel and Douro nase was correlated with the water quality and it is influenced by seasonal agricultural practices and the flow regime.

EUTROPHICATION AND POLLUTION DEVELOPMENT IN THE DANUBE RIVER AND COASTAL MARINE ZONE SYSTEM

Since the 1970s, the process of anthropogenic water euthrophication and the near bottom hypoxia linked with it, have caused widespread benthos fauna mortality. In addition to this negative phenomenon a lot of contaminations and pollutants are washed out from the fields and the coastal urban agglomerations by the river flow. In the process of sedimentation, the suspended matter is accumulated in the bottom sediments. It reinforces negative changes in benthic habitat conditions. One of the main modern problem is eutrophication and pollution (waste) in rivers, lakes and coastal marine systems. It illustrates the development of eutrophication and waste in a large, deep lake, together with the impacts on the lake and marine ecosystems. The Object of investigation is the Danube mouth area. The Subject of investigation is euthrophication processes and pollution input development in aquatic system. The Danube river extends almost all over Central Europe, which means that any waste from factories located directly near the Danube will inevitably get there. Therefore, the phenomenon of "water bloom" and periodic environmental disasters on the Danube are natural consequences of human activities. The level of pollution of the bottom sediments in the Northwest shelf of the Black Sea is examined. Modern data are compared with those of the late 20th century and their variability over 20 years. Substantial increase (by two orders) of copper, lead and nickel concentration has been marked. The diverse of contamination sources in larger catchment areas usually produce a mixture of pol­lutants, which is more difficult to treat than an industrial waste. For most sediments, there are more arguments in favor of disposal rather than treatment. Mechanical separation of the less contaminated fractions could be a useful step prior to the final stor­age of the residues. To improve the status of surface water bodies in the management area, it is necessary to take into account and reduce all existing factors and risks of deterioration of water quality. Environmental issues and the science behind them are of great public concern. Water management issues are also of critical importance. Human impacts within the river – delta –sea system are environmental contamination with nutrients, heavy metals, organic compounds, etc., degrading water and sediment quality and leading to toxic impacts in biota, airborne pollution. Human impacts from outside of the wetland are lack of catchment scale management of land use upstream, leading to soil erosion and sedimentation.

Designing river water quality policy interventions with scarce data: the case of the Middle Tagus Basin, Spain

ABSTRACTAnthropic pressures deteriorate river water quality, so authorities need to identify their causes and define corrective actions. Physically based water quality models are a useful tool for addressing physicochemical pollutants, but they must be calibrated with an amount of data that is often unavailable. In this study, we explore the characterization of a model to design corrective interventions in a context of sparse data. A calibration indicator that is both simple and flexible is proposed. This approach is applied to the Middle Tagus Basin in central Spain, where the physicochemical concentration of pollutants is above legal standards. We quantify the effects of the main existing pressures (discharge from wastewater treatment plants, agricultural diffuse pollution and a major inter-basin water transfer) on the receiving waters. In particular, the study finds that wastewater treatment plant effluent concentrations should be reduced to up to 0.65 mg/L of ammonium and 0.55 mg/L of phosphate to achieve the environmental goals. We propose and prioritize a set of policy actions that would contribute to the good status of surface water bodies in the region.

Assessing the Establishment and Implementation of Environmental Flows in Spain

The alteration of natural flows due to water withdrawals and the presence of hydraulic infrastructure poses significant threats to the integrity of riverine ecosystems. The establishment of environmental flows (EF) has been conceived as a water management tool to mitigate the impact of in-stream flows alteration. To date, a large body of literature has focused on methods to define EF, but less attention has been paid to documenting and assessing their actual implementation on the ground. This article provides a framework to describe and assess the process of design, application, and monitoring of EF at a river basin level. The framework is applied to Spain, where significant efforts have been made during the past decade to define and implement EF across the country. The goal of the paper is to identify strengths and opportunities for improving the implementation of EF at country level. The Spanish legislation establishes that EF should contribute to the achievement of the good ecological status of surface water bodies as required by the European Union Water Framework Directive. Several pitfalls in the design, application, and monitoring of this important river management measure constrain the ability of the existing EF to deliver that fundamental outcome.

A methodical approach to the ecological status evaluation of water bodies using the complex index of water quality on the example of the Middle Priobye

The following paper deals with a methodical approach and experience of water quality complex index ( Iwq ) use for the evaluation of ecological status of surface water bodies by results of rivers monitoring within the Middle Ob basin during 2002-2018. This index allows to use such primary information as results of water chemistry analyses, parameters of structure of microbial community and other available data obtained for each sample site on various water bodies within the basin. The main evaluation criterion for calculating this index is a degree of a deviation of each controlled indicator from average value of this indicator for all explored water area within the basin. Water bodies (or their sites) can be classified to 5 various classes of water quality using the calculated values of the index. Such a methodical approach allows to carry out comparative estimation of an ecological condition of water bodies and their sites within the area, to map the obtained data, to analyze possible reasons of deterioration of water ecosystem state, to manage decisions on their restoration. The paper presents the results of the water quality complex index use for rivers within the Middle Ob basin, calculated on the base of indicators of the chemical composition of water and number of bacteria of various ecological and trophic groups in the structure of microbial community.

Probability of misclassifying biological elements in surface waters

Measurement uncertainties are inherent to assessment of biological indices of water bodies. The effect of these uncertainties on the probability of misclassification of ecological status is the subject of this paper. Four Monte-Carlo (M-C) models were applied to simulate the occurrence of random errors in the measurements of metrics corresponding to four biological elements of surface waters: macrophytes, phytoplankton, phytobenthos, and benthic macroinvertebrates. Long series of error-prone measurement values of these metrics, generated by M-C models, were used to identify cases in which values of any of the four biological indices lay outside of the “true” water body class, i.e., outside the class assigned from the actual physical measurements. Fraction of such cases in the M-C generated series was used to estimate the probability of misclassification. The method is particularly useful for estimating the probability of misclassification of the ecological status of surface water bodies in the case of short sequences of measurements of biological indices. The results of the Monte-Carlo simulations show a relatively high sensitivity of this probability to measurement errors of the river macrophyte index (MIR) and high robustness to measurement errors of the benthic macroinvertebrate index (MMI). The proposed method of using Monte-Carlo models to estimate the probability of misclassification has significant potential for assessing the uncertainty of water body status reported to the EC by the EU member countries according to WFD. The method can be readily applied also in risk assessment of water management decisions before adopting the status dependent corrective actions.

The assessment of the required groundwater quantity for the conservation of ecosystems and the achievement of a good ecological status of surface waters

Assessment of the available quantity of groundwater is of essential importance for its sustainable use. Modern approaches for estimation of groundwater availability take into account all potential impacts of abstractions, including impacts on groundwater dependent ecosystems and impacts on surface waters ecological status. Groundwater body is in good quantitative status if groundwater abstractions do not cause significant damages to groundwater dependent ecosystems and significant diminution in the ecological status of surface water bodies. The methodology presented in this paper was developed as an integral part of the assessment of the quantitative status of groundwater bodies in Slovenia and is tailored to the characteristics of the groundwater dependent ecosystems as well as hydrological and hydrogeological conditions in the Slovenian territory. Two different approaches were implemented; for forest habitats on alluvial aquifers, and habitats of amphibians and molluscs in karst areas. Estimates of the required quantity of groundwater for groundwater dependent ecosystems conservation were performed at the level of groundwater bodies and annual averages of temporal variables of the water balance, calculated with the regional water balance model GROWA-SI. In the areas of groundwater bodies with groundwater dependent ecosystems estimated quantity present 0.1 % - 12.4 % of the groundwater recharge. The estimated share of annual renewable quantity of groundwater to maintain the ecological status of surface waters for the entire territory of Slovenia is 23.2 %. The largest share, 30 % is in north-eastern Slovenia and the lowest in the north-west part of Slovenia with a 16.6 % average annual renewable quantity.

Aquatic risk assessment of priority and other river basin specific pesticides in surface waters of Mediterranean river basins

To meet good chemical and ecological status, Member States are required to monitor priority substances and chemicals identified as substances of concern at European Union and local/river-basin/national level, respectively, in surface water bodies, and to report exceedances of the environmental quality standards (EQSs). Therefore, standards have to be set at national level for river basin specific pollutants. Pesticides used in dominant crops of several agricultural areas within the catchment of Mediterranean river basins (‘Mondego’, ‘Sado’ and ‘Tejo’, Portugal) were selected for monitoring, in addition to the pesticides included in priority lists defined in Europe. From the 29 pesticides and metabolites selected for the study, 20 were detected in surface waters of the river basins, seven of which were priority substances: alachlor, atrazine, chlorfenvinphos, chlorpyrifos, endosulfan, simazine and terbutryn, all of which exceeded their respective EQS values. QSs for other specific pollutants were calculated using different extrapolation techniques (i.e. deterministic or probabilistic) largely based on the method described in view of the Water Framework Directive. Non-acceptable aquatic risks were revealed for molinate, oxadiazon, pendimethalin, propanil, terbuthylazine, and the metabolite desethylatrazine. Implications of these findings for the classification of the ecological status of surface water bodies in Portugal and at the European level are discussed.

Ecological Status of Rivers and Streams in Saxony (Germany) According to the Water Framework Directive and Prospects of Improvement

The Federal State of Saxony (Germany) transposed the EU Water Framework Directive into state law, identifying 617 surface water bodies (rivers and streams) for implementation of the water framework directive (WFD). Their ecological status was classified by biological quality elements (macrophytes and phytobenthos, benthic invertebrates and fish, and in large rivers, phytoplankton) and specific synthetic and non-synthetic pollutants. Hydromorphological and physico-chemical quality elements were used to identify significant anthropogenic pressures, which surface water bodies are susceptible to, and to assess the effect of these pressures on the status of surface water bodies. In 2009, the data for classification of the ecological status and the main pressures and impacts on water bodies were published in the river basin management plans (RBMP) of the Elbe and Oder rivers. To that date, only 23 (4%) streams achieved an ecological status of “good”, while the rest failed to achieve the environmental objective. The two main reasons for the failure were significant alterations to the stream morphology (81% of all streams) and nutrient enrichment (62%) caused by point (industrial and municipal waste water treatment plants) and non-point (surface run-off from arable fields, discharges from urban drainages and decentralized waste water treatment plants) sources. It was anticipated that a further 55 streams would achieve the environmental objective by 2015, but the remaining 539 need extended deadlines.

Distribución de Tetrasporidium javanicum Möbius, 1893 (Chlorophyta: Tetrasporales) en la Cuenca del río Ebro

During the implementation of the biological samplings in the CEMAS network (Control of the Status of Surface Water Bodies) in the Ebro River Basin, in application of the Water Framework Directive (period 2006-2010), the presence of the chlorophycean alga Tetrasporidium javanicum M¨obius, 1893 was detected in the middle reaches of Ebro River, in lowland reaches of the main rivers of the left margin, and in some upper reaches, gullies and also in irrigation ditches. It is a species that is distributed mainly in tropical areas that until now had been scarcely reported in Spain and Europe. In this work, the distribution and ecological preferences of the species in the River Ebro Basin is shown.

Spatial-temporal particularities of the ecological status of surface water bodies and pollution sources from Siret river basin

The ecological status of surface water bodies from Siret River Basin is monitored systematically and spatial in accordance with the requirements of European Directives in the water area. Analysis temporary and spatial of qualitative and quantitative status of surface waters (rivers, lakes) is achieved according to the specificities of each body of water resulting from physical and geographical conditions, climatic and hydromorphological regimes of river basin and from human activities.In order to know of those features, there are needed specific monitoring systems of water bodies. The parameters underlying the assessment of ecological status of rivers and lakes are monitored systematically and temporary: daily, monthly, quarterly, annually, according to these characteristics. In this context, the daily variations in environmental condition, expresses the current status of surface waters. Monthly changes are correlated with climate change and characterize the seasonal variations. On annual basis are identified the mean, minimum and maximum for each parameter and the trends (increase, decrease, regularity, periodicity, changes, etc.). Based on this information, extensive to multiannual level, it can achieve medium and long term forecasts and it might be issued the concepts and strategies for maintaining a balance and sustainable development of water resources. In this paper we have presented some issues related to the synthesis of spatial-temporal ecological status of water bodies managed by Administration of Siret Water Basin (ABAS). Results of studies on the ecological status of water bodies have been presented for the year 2009. Also, in this paper it was presented an evolution of the quantities of pollutants from wastewater discharged in surface receptors and their purification by water users from of activity of ABAS area in 1999-2009 periods.