Preliminary Measurements of Turbulence and Environmental Parameters in a Sub-Tropical Estuary of Eastern Australia

In natural systems, mixing is driven by turbulence, but current knowledge is limited in estuarine zones where predictions of contaminant dispersion are often inaccurate. A series of detailed field studies was conducted in a small sub-tropical creek in eastern Australia. Hydrodynamic, physio-chemical and ecological measurements were conducted simultaneously to assess the complexity of the estuarine zone, notably the interactions between turbulence and environment. The measurements were typically performed at high frequency over a tidal cycle. The results provide an original data set to complement long-term monitoring and a basis for a more detailed study of mixing in sub-tropical systems. Unlike many long-term observations, velocity and water quality scalars were measured herein with sufficient spatial and temporal resolutions to determine quantities of interest in the study of turbulence, while ecological indicators were sampled systematically and simultaneously. In particular the results yielded contrasted outcomes, and the finding impacts on the selection process for key water quality indicators.     

Assessing water quality in the Ceyhan River basin (Turkey) with the use of aquatic macrophytes

As a major biotic component of many lotic ecosystems, macrophytes consist a major component of running waters are often used as indicators within the European Water Framework Directive (WFD) to establish ecological quality. In this study, we investigated macrophyte community structure (e.g. composition, abundance and diversity) in Ceyhan River Basin located in the Southeastern Anatolian Region in Turkey. Data was collected during 2014–2015 from river sites located throughout the basin to evaluate the relationship between aquatic vegetation and river physico-chemical factors. The ecological status of the river basin was also calculated based on Macrophyte Biological Index for River (IBMR). In total, 33 macrophyta taxa were observed. According to their biological classification (life form), filamentous algae (FA), free floating (FF), floating leaved (FL) and submersed (S) macrophytes reached their maximum abundance value in summer, while emergent (E) macrophytes were at their maximum abundance in both summer and autumn. The ecological status of the Ceyhan River basin ranged from moderate to bad. The values found are reasonably comparable to IBMR scores recorded in rivers of other Mediterranean countries. IBMR index may be suitable to some extent to establish a basis for ecological quality assessment in Turkish River systems.     

Comparison of environmental flow assessment methods with a case study on a runoff river–type hydropower plant using hydrological methods

This paper focuses on the environmental flow assessment (EFA) methods that maintain the river ecosystem and its integrity for hydropower plants (HPP) with their implementations on a run-off river type HPP. EFA is a crucial phenomenon in terms of electricity production and sustaining river integrity simultaneously. The novelty of this study is that it consists both a comparison of widely used preferred EFA methods and a detailed investigation of the river with pre and post-dam flow regimes. The research shows that by expanding the content and scope of the methods, their relative reliabilities increase. However, this situation requires much more expert, money, and time. Apart from most of the relevant literature, pre and post-dam situations are investigated with a flow duration curve (FDC). It is concluded that the dramatic difference between the flow characteristics of pre and post-dam situations affects long-term aquatic life. Furthermore, a case study is conducted using the selected hydrological flow assessment methods, Tennant and Tessman methods, and comparisons are made. The calculated flows are compared with monthly average flow values before dam construction, projected environmental flow data, and the current situation. Accordingly, Tennant’s “good classification” is proposed to determine the environmental flow (EF) for the considered case study.     

Modeling seasonal variations of long-term soil CO<Subscript>2</Subscript> emissions in an orchard plantation in a semiarid area,SE Turkey

Emissions of soil CO₂ under different management systems have a significant effect on the carbon balance in the atmosphere. Soil CO₂ emissions were measured from an apricot orchard at two different locations: under the crown of trees (CO₂-UC) and between tree rows (CO₂-BR). For comparison, one other measurement was performed on bare soil (CO₂-BS) located next to the orchard field. Analytical data were obtained weekly during 8 years from April 2008 to December 2016. Various environmental parameters such as air temperature, soil temperature at different depths, soil moisture, rainfall, and relative humidity were used for modeling and estimating the long-term seasonal variations in soil CO₂ emissions using two different methods: generalized linear model (GLM) and artificial neural network (ANN). Before modeling, data were randomly split into two parts, one for calibration and the second for validation, with a varying number of samples in each part. Performances of the models were compared and evaluated using means absolute of estimations (MAE), square root of mean of prediction (RMSEP), and coefficient of determination (R²) values. CO₂-UC, CO₂-BR, and CO₂-BS values ranged from 11 to 3985, from 9 to 2365, and from 8 to 1722 kg ha^?1 week^?1, respectively. Soil CO₂ emissions were significantly correlated (p?<?0.05) with some environmental variables. The results showed that GLM and ANN models provided similar accuracies in modeling and estimating soil CO₂ emissions, as the number of samples in the validation data set increased. The ANN was more advantageous than GLM models by providing a better fit between actual observations and predictions and lower RMSEP and MAE values. The results suggested that the success of environmental variables for estimations of CO₂ emissions using the two methods was moderate.     

Debriefing with teachers after the Marmara earthquake: an evaluation study1

The aim of this study was to evaluate the effectiveness of the debriefing meetings conducted after the 1999 earthquakes in Marmara, Turkey. The sample consisted of 265 teachers, 223 of whom attended the debriefing meetings. The personal satisfaction ratings of the teachers who attended the meetings revealed that they found the sessions satisfactory. The results of the comparison between those who reported that they benefited from the meetings and those who felt they did not indicated that the first group had lower scores on all of the psychopathology measures. A comparison between 42 teachers who did not attend the meetings and a randomly chosen group of 45 teachers who did attend revealed that the two groups differed significantly in terms of their post‐traumatic stress symptom scores. The findings of the study suggest that, in general, the teachers' debriefing sessions were satisfactory.     

Measurement of Traffic Related Toxic Air Pollutants in an Urban Atmosphere

Nose-level measurements of air toxics were made along a busy urban street in Ottawa, Canada for 2 hr periods during morning, noon, and afternoon rush hours in the winter and summer of 2000. Measurements were also made in a commuter car and a transit bus during morning and afternoon commutes in 2000. The main objectives of the study were to establish a database, to determine temporal and seasonal variations and to determine the contribution of motor vehicle traffic to the measured toxic substance concentrations. Ottawa is an appropriate choice of location for the measurement of motor vehicle related toxic and reactive compounds, as it has virtually no industrial sources that could be contributing to the ambient loadings. Samples were collected for a total of 165 volatile organic compounds and 25 carbonyl compounds. Sampling and analytical methodologyare discussed and results are presented. Toluene, ethylene andformaldehyde were the most abundant pollutants in Ottawa during both winter and summer. Total non-methane hydrocarbon concentrationwas measured as 100 g m^-3 at nose-level measurements in Ottawa.     

Eco-assessment of streams of Konya closed river basin (Turkey) using various ecoregional diatom indices

Ecological assessment of freshwater ecosystems based on diatom metrics is an important issue for attaining environmental sustainability. The present study aimed to evaluate differences in the diatom–stressor relationship in relatively least disturbed streams in the Konya closed river basin using multivariate analyses and to bio-assess streams by the application of different ecoregional diatom indices. Cocconeis euglypta, Cymbella excisa, Cocconeis placentula, and Achnanthidium minutissimum are the most contributing species to the dissimilarity of sampling stations between rainy (spring) and dry (summer and fall) seasons and also between altitude (A2 800- < 1600 m and A3 ≥ 1600 m) groups. The first two axes of canonical correspondence analysis revealed a significant (82.8%) relationship between diatom species and stressors. Diatom species displayed distinct responses to environmental variables (electrical conductivity, Ni, Cu, B, and altitude) playing important roles on the distribution of species. Diatom indices indicate different ecological statuses of stations, from bad to high. European diatom indices except Duero Diatom Index (DDI) and Trophic Diatom Index (TDI) showed good responses to the eco-assessment of streams and indicated high ecological status for the least disturbed sampling stations symbolized as S16, S20, S24, S25, S27-29, S37, and S39. These results were also supported by abiotic evaluation. Although TIT was more competitive in the bio-assessment of streams among diatom indices, it is necessary to increase its species list by determining their trophic weights in future studies. Therefore, the use of ecoregion-specific diatom indices is suggested along with increasing the number of used species to correctly interpret the water quality.

Graphical Abstract

     

A cost-effective screening method for pesticide residue analysis in fruits, vegetables, and cereal grains

This paper reports the results of studies performed to investigate the potential of applying thin layer chromatography (TLC) detection in combination with selected extraction and cleanup methods, for providing an alternative cost-effective analytical procedure for screening and confirmation of pesticide residues in plant commodities. The extraction was carried out with ethyl acetate and an on-line extraction method applying an acetone-dichloromethane mixture. The extracts were cleaned up with SX-3 gel, an adsorbent mixture of active carbon, magnesia, and diatomaceous earth, and on silica micro cartridges. The Rf values of 118 pesticides were tested in eleven elution systems with UV, and eight biotest methods and chemical detection reagents. Cabbage, green peas, orange, and tomatoes were selected as representative sample matrices for fruits and vegetables, while maize, rice, and wheat represented cereal grains. As an internal quality control measure, marker compounds were applied on each plate to verify the proper elution and detection conditions. The Rf values varied in the different elution systems. The best separation (widest Rf range) was achieved with silica gel (SG)--ethyl acetate (0.05-0.7), SG--benzene, (0.02-0.7) and reverse phase RP-18 F-254S layer with acetone: methanol: water/30:30:30 (v/v) (0.1-0.8). The relative standard deviation of Rf values (CV(Rf)) within laboratory reproducibility was generally less than 20%, except below 0.2 Rf, where the CVRf rapidly increased with decreasing Rf values. The fungi spore inhibition, chloroplast inhibition, and enzyme inhibition were found most suitable for detection of pesticides primarily for confirming their identity or screening for known substances. Their use for determination of pesticide residues in samples of unknown origin is not recommended.