Irish Rivers Research Articles

Trends and influential factors of high ecological status mobility in Irish Rivers

The decline in high ecological water status in rivers is a significant concern in European countries. It is thus important to investigate the factors that cause sites to lose high status in order to undertake measures to protect and restore high status water quality. Analysis of 20 years of water quality data reveals strong mobility between high status and non-high status (especially good status) rivers. Associations between this mobility and socio-economic and physical environmental variables were estimated by multinomial logistic regression at national scale and regional scale. Based on reported changes in water quality status cross across 1990, 2000 and 2010, four classes of the mobility of high status were defined in this study: those sites that maintain high status (maintain), enter high status (enter), fluctuate between high and non-high status (fluctuate) and exit from high status (exit). The national results indicate that agricultural activity as indicated by variables representing intensity of livestock farming (organic nitrogen) and tillage farming (cereal share) and elevation had significant negative impacts on high status rivers. Meanwhile, significant differences in population density and septic tank density between ‘exit’, ‘maintain’, ‘fluctuate’ and ‘enter’ classes indicate that these factors played important roles in the stability of high status rivers. The regional outcomes reveal differential significant pressures across regions. For example, rainfall and elevation had positive impacts on high status rivers in the north-west region, while organic nitrogen had a negative effect in the south-west. This paper demonstrates the challenge in achieving the Water Framework Directive goal of maintaining high status rivers, given the sensitive and highly differentiated nature of areas that have lost high status or fluctuated in and out of high status. This paper also suggests the necessity for localised policies and mitigation measures.

The geochemistry of Irish rivers

Study regionIreland Study focusMultiple studies have established that catchment geology and weathering regime strongly influence surface water chemistry, and that geochemical cycling can vary due to seasonal climatic conditions. However, fewer studies have focused on the influence these controls in a holistic manner. We relate the water chemistry of a country-wide Irish river survey to atmospheric input, underlying geology, and the influence of bogs. Climatic conditions were defined by an atypically wet winter and an unusually dry summer, providing the opportunity to investigate river chemistry variation across hydrologic conditions. Sampling included 21 of Ireland’s 22 largest rivers ranked by discharge, first-order and second-order streams draining bog lands, a second-order stream draining a limestone catchment, and downstream transects along the River Shannon. All samples were analyzed for major elements, selected trace elements, and nutrients, and a subset was analyzed for δ34SSO4. New hydrological insightsMost catchments were dominated by carbonate weathering with little contribution from the weathering of aluminosilicates. River water composition also varied geographically along the prevailing wind direction due to inputs from marine aerosols, with additional weathering components important in some systems. Seasonal influences could be seen in the chemistry of the headwaters of the River Shannon, while the lower reaches of the river exhibited less variable behavior throughout seasonal changes, likely due to the influence of lakes in the River Shannon system.

Reverse flood routing in an open channel using a combined model of genetic algorithm and a numerical model

Abstract Flood impact assessment in a river system is done with the help of flood routing and this process helps to determine the status of sensitive points of the route in terms of flood entry and the resulting risks for urban and rural areas. For flood routing, a hydrodynamic numerical model should be implemented and this model needs upstream and downstream boundaries. In some cases, the upstream boundary, which is usually a hydrograph, is not available due to the lack of facilities and it is necessary to be generated for numerical model implementation. The purpose of this study is to present an integrated method comprising an optimization model and a hydrodynamic numerical model for flood modeling in order to determine the upstream hydrograph using the measured downstream hydrograph along a river. The routing procedure consists of three steps: (1) generating a hypothetical upstream hydrograph using the genetic algorithm method; (2) hydrodynamic modeling using a numerical simulation model for flood routing according to the hypothetical hydrograph, which is generated in the first step; (3) comparing the calculated and observed hydrograph in the downstream by using a fitness function. This recommended procedure was named the Reverse Flood Routing Method (RFRM) and was then applied to Karun River, the largest river in Iran. Comparison of the final generated upstream hydrograph by the RFRM model with the corresponding measured hydrograph at the upstream boundary (here Ahvaz hydrometric station was assumed as an ungauged river location) shows the high accuracy of the recommended model in this study.

Allocation of allowable pollution load by using the bankruptcy solution rules

Abstract Bankruptcy solution methods are widely used and efficient methods for conflict resolution which attract considerable attention in the area of solving conflicts related to water resources. However, most of the related studies have focused on the use of bankruptcy solution methods in solving quantitative water resources conflicts. In this study, four bankruptcy solution rules including proportional (PRO), constrained equal awards (CEA), constrained equal losses (CEL), and Talmud (TAL) rules were used to develop four models to allocate the allowable pollution loads to pollution sources. One of the novel aspects of the current study is to consider the amount of each flow discharge in addition to the pollution concentration of each pollution source. Evaluation of performances of the selected bankruptcy solution rules in a reach of Karun River in Iran showed that the CEA-based model can be considered as the most desirable option for small pollution sources whereas the CEL-based model seems to be the most appropriate option for large pollution sources. The models based on PRO and TAL rules provide results between those of CEA and CEL rules which can be considered as more probable options to reach agreement on between small and large pollution sources.

Variability effect of hydrological regime on river quality pattern and its uncertainties: case study of Zarjoob River in Iran

Abstract River water quality assessment, affected by pollution load, and river regime changes in various climate conditions, is an implementation that simplifies water resources management, and justifies terms for increases or decreases in human activities. The current paper aims to offer a water quality model of a river considering parametric, hydrologic, and pollution load uncertainty by using uncertainty indexes like Plevel, ARIL, and NUE. These indexes were used to analyze the influences of the model's parameters and the river's regime alternations on the results. A Qual2K model, calibrated with PSO algorithm, is presented and connected to GLUE algorithm to assess the model's uncertainties like effective input parameters on the modeled variations, headwater flow, and input pollutions. Zarjoob River, in the north of Iran, was chosen as the case study. The results illustrate that the interaction among parameters, hydrologic and pollutant discharge data should be considered in river water quality simulation. The presented methodology can analyze the influences of parametric uncertainty, parametric and hydrologic uncertainty, and pollution input load uncertainty according to any quantity of observations and the modeled results of any river.

A model for predicting the lateral distribution of sediment transport in river bends

ABSTRACT Distribution of lateral velocity and suspended sediment concentration in river bends is highly non-uniform. Predicting such velocity and sediment distributions is prerequisite for many applications, such as river bank protection, sediment transport, deposition pattern, pollutant transport and flood control. Due to secondary flow development, flow structure in river bends has three-dimensional feature. In this case, one-dimensional mathematical models are generally not suitable, so two- or three-dimensional mathematical models have to be used. In this paper, field measurement of lateral distributions of flow velocity and suspended sediment concentration was conducted in three bends at the Karun River in Iran (namely, Jangieh, Khabineh and Malheh), and the measured velocity data were used for calibrating the Spooner and Shiono model. Based on the lateral velocity distributions by this mathematical model, sediment transport capacities were computed using five commonly used empirical formulas of sediment transport. The results showed that in the three river bends, the sediment transports formula by Yang agrees well with the measured lateral sediment concentration. The Van Rijn formula also predicts the results with suitable accuracy. The other three formulas by Ackers-White, Engelund-Hansen, and Karim-Kennedy significantly over-predict the sediment concentration compared with the measured data.

Restorative nodes of governance in the Anthropocene: Iran's Kashaf River

AbstractThis article describes an environmental crisis in Iran that is actually a multidimensional crisis of law and policy. The article explores the restorative nodal governance response to such polycentric problems by weaving together five related ideas originating from criminologist and regulatory scholar Clifford Shearing: nodal governance; regulatory culture as a storybook (rather than a rulebook); justice as a better future; networked discovery of Awareness, Motivation, and Pathways for transformation; and a green ethic of care to guide transformation. We use an imaginary of a river to learn from a confluence of these ideas. They involve nodes of local governance organized by front‐line workers who restoried intertwined problems with an ethic of care. The challenge uncovered is that restorative microstrategies proved promising when steering powerless actors, but frayed when faced with factory owners. More aggressive strategies of nodal governance may bring forth more responsive escalation in order to confront privilege. Yet such strategies might be more creatively escalated as nodes of conversational regulation that reconfigure Shearing's five insights to transform landscapes of power. A coherence discovered inductively across these insights revolves around restorative nodal contestation of hegemony. Even lives as infused with domination as those found along the Kashaf River in Iran, where our case study is set, can be restored in counterhegemonic ways.

A comparative Study of Diatom Flora of the Taleghan River in Iran with Other Studies Around the World

A comparative Study of Diatom Flora of the Taleghan River in Iran with Other Studies Around the World

Spatial modeling of environmental vulnerability in the biggest river in Iran using geographical information systems.

The Karoon River, located in southwest Iran, has always been considered as an important water source for people in the southward areas. Khuzestan Province is one of the strategic provinces of Iran thus the development of this province is significantly affected by the water pollution of the Karoon River system. Therefore, the current study aims to assess the environmental vulnerability of the Karoon River as well as preparing a classified map of its vulnerabilities using the fuzzy logic method via the geographical information systems (GIS). In this study, the required data were gathered from the Water and Electricity Organization of Khuzestan Province. Afterward, the primary maps were created by converting the map of the study origin into a raster format. Then, fuzzy membership was performed by placing the digits in the range of zero and one using the fuzzy membership function. The primary maps were mixed, and finally, the risk map was prepared by applying the fuzzy overly function. According to the results, a clear trend of water quality deterioration exists since water moves from upstream to downstream areas. The ecological vulnerability of the Karoon basin is mostly located at a low-level (78.05 %) rank. The vulnerable areas were ranked extremely high, high, medium, and low as 2.09, 8.09, 12.08, and 78.05, respectively. Considering that 22 % of the Karoon River drainage basin in Khuzestan province is considered to have a medium to extremely high risk range, it is mandatory for the authorities to take precautions to prevent the entry of polluting sources into this precious river.

Assessment of the efficiency of river macrophytes to detect water-column nutrient levels and other environmental conditions in Irish rivers

Macrophytes are an essential biological element of freshwater aquatic ecosystems and are well known to reflect prevailing ecological conditions in rivers. Their use as bioindicators of nutrient status in river systems is widespread yet their reliability is hotly debated. The aim of this investigation was to assess whether macrophytes are reliable indicators of nutrient levels or better applied as indicators of other non-nutrient environmental conditions. The importance of two water-column nutrients; nitrates (N) and orthophosphates (P) were assessed in terms of their influence on macrophyte species richness and diversity in relation to other non-nutrient environmental factors using 395 river plots from Ireland. Then, in this context, the efficiency of macrophytes to detect nutrient levels was assessed by selecting two macrophyte-based water quality assessment tools; the Mean Trophic Rank (MTR) and the Predictions And Classification System for river macrophytes (LEAFPACS2). Finally, the ability of phytosociological communities within these rivers to reflect trophic levels was examined using the same two water quality assessment tools. It was shown that water-column nutrients N and P have a minor influence on macrophyte richness and no significant influence on macrophyte diversity and that MTR and LEAFPACS2 were only weakly correlated with N and P levels. It was concluded that macrophytes are sensitive to environmental changes but respond to a combination of ecological factors rather than N or P alone. Therefore, this study suggests that macrophytes are not the most efficient taxon group to apply when assessing trophic changes in isolation of other non-nutrient factors.

Hydro-Sedimentary Study of a Tidal River: Case Study of the Arvand River in Iran

Abstract The present field study investigated hydraulic and sediment in tidal conditions. Measurements were made for two stations at neap tide and spring tide for 13-hour periods at no-dimensional depths of 0.2, 0.6 and 0.8 of the water level each time. In these measurements, the parameters of velocity, direction of flow, electrical conductivity, temperature and depth were measured directly, and to determine the amount of suspended sediments per hour, 3 samples of one litre from the mentioned depths were measured by the instantaneous vertical sampler and taken to a laboratory. An examination of the depth charts of the suspended sediments concentration for all stations, and in both the neap tide and the spring tide, showed that, in general the suspended sediments concentration increased with increasing depth. Moreover, the deep distribution of sediments concentration showed that the values obtained in the laboratory corresponded well with the values calculated from the Rouse equation, and as the depth increases, the sediments concentration usually increases.

Estimation of total dissolved solids in Zayandehrood River using intelligent models and PCA

Artificial neural networks (ANN), adaptive neuro-fuzzy inference system (ANFIS) with subtractive clustering (ANFIS-SC) and support vector machine models were used to determine total dissolved solids (TDS) of the Zayandehrood River in Iran. In total, nine hydrochemical parameters [Ca2+, SO42−, Na+, Cl−, EC, pH, HCO3−, Mg2+ and sodium adsorption ratio (SAR)] were utilized to estimate the TDS of the river at a monthly time scale. Statistical data were categorized into low-flow and wet periods based on river discharge. Principal component analysis (PCA) was used to determine the input of the models. The results indicate that the PCA method, in both wet and low-flow periods, performed suitably based on the evaluation criteria for all models. The parameters of the first component included Ca2+, SO42−, Cl−, EC, Mg2+ and SAR in both periods. In contrast, the parameters pH and HCO3− of the second component provided unacceptable precision. The ANFIS-SC model was more precise than the other two models, with an RMSE value of 12.33 meq/l for the first component in the low-flow period. However, the ANN model was most precise in the wet period, with a calculated RMSE value of 13.87 meq/l.

Assessing the effect of emotional unit of emotional ANN (EANN) in estimation of the prediction intervals of suspended sediment load modeling

This paper presents the construction of prediction intervals (PIs) associated with the Emotional Artificial Neural Network (EANN) via the Lower Upper Bound Estimation method (LUBE) and the classic Bootstrap method for the Suspended Sediment Load (SSL) modeling. As point prediction conveys no information about modeling reliability, PIs were applied. The constructed PIs via the EANN were also compared to those of the classic feed-forward Neural Network (FFNN) model. It was attempted to construct the PIs of the SSL modeling in both daily and monthly scales for two watersheds, Upper Rio Grande River, in the United States and the Lighvanchai River in Iran. The PIs were quantified via coverage and width criteria. In the LUBE method, Genetic Algorithm (GA) constructed the PIs by minimizing the cost function of Combinational coverage Width-based Criterion (CWC). Comparison of the results indicated that the criterion of the CWC for PIs of EANN was up to 72% and 78% lower than that to the PIs of the FFNN, respectively, in the LUBE and Bootstrap methods, which showed the reliability of the EANN. In addition, obtained results via the LUBE and the Bootstrap techniques denoted the lower level of uncertainty of the LUBE method. Comparing the CWC criterion of both methods indicated that for the LUBE method, CWC was up to 39% lower than that for the Bootstrap method. Also, the PIs of the FFNN for the Lighvanchai river modeling showed reliable results with CWC of 56% lower than Upper Rio Grande River, but PIs of the EANN led to lower level of uncertainty in Upper Rio Grande River modeling.

Heavy metal pollution in surface sediments of Ghareh-Aghaj River, one of the longest perennial rivers in Iran

River heavy metal contamination (HM) is a serious growing concern across the globe. In Iran, particularly, rivers serve as the most important freshwater resource and underlie the majority of water-demanding activities, resulting in highly polluted rivers. In central Iran, the Ghareh-Aghaj River supports many industrial, municipal, and agricultural land-uses along its path to the Persian Gulf. Although there may be reciprocal HM effects, no study has yet provided supporting scientific evidence on the river’s sediment HM content that might affect the sensitive biodiversity of the river and the Persian Gulf. This study measured the concentrations of five HMs at 11 susceptible and accessible locations along the river as follows: Arsenic (41.83 mg/kg) > Nickel (38.08 mg/kg) > Zinc (24.46 mg/kg) > Copper (18.86 mg/kg) > Lead (4.97 mg/kg). The HM distributions were uniform due to insignificant correlations and high coefficient of variations. According to the results, the river was not polluted with Cu, Zn, and Pb, partly with Ni, and highly with As. The concentration of As exceeded natural values in the river midstream zone and the seawardmost station where the river is exposed to intense agriculture and extensive use of arsenical pesticides and herbicides. This study highlighted the Ghareh-Aghaj River as worthy of further HM investigation, particularly As and urged implementation of HM elimination and monitoring measures to ensure their health and well-functioning.

Research Article: Biodiversity and distribution of Garra species (Teleostei: Cyprinidae) in Iran

The genus Garra, a cyprinid fish with eleven confirmed species, is distributed in many Iranian rivers, from western to eastern and southern Iran. Materials for this study were from available published data, data bank provided by Isfahan University of Technology Ichthyological Museum (IUT-IM), and sampling during 2017-2018. Three species, G. lorestanensis, G. typhlops and G. tashanensis live in subterranean waters but other species, such as G. amirhosseini, G. gymnothorax, G. mondica, G. nudiventris, G. persica, G. rossica, G. roseae and G. rufa live in surface waters.

Electro‑crystallized NiO nanoparticles for river‑water treatment applications

There is a fundamental relationship between properties of nanoparticles and their preparation method. In this study, NiO nanoparticles were electro-crystallized in an electrochemical cell containing two nickel electrodes, and an electrolyte solution of tetramethylammonium chloride and NaOH. The optimized reaction parameters obtained for the effective electro-crystallization of NiO nanoparticles were applied potential of 10 V, electrolyte concentration of 0.075 M, bath temperature of 20 °C, and annealing temperature of 400 °C. XRD results approved the formation of cubic structure of NiO. SEM images showed the mean particle size of spherical particles ranging from 12 to 47 nm. Based on UV–visible results, the value of band gap for typical NiO nanoparticles was obtained ~ 3.56 eV. The photoluminescence spectrum of a typical NiO sample showed two peaks at 370 nm and 670 nm, related to 3d8 electron transition, recombination between electrons and holes, or defects in NiO nanoparticles. The magnetization curves showed that all samples are magnetically soft and the specific magnetization is dependent on the particle size. The electro-oxidation of Ni was particularly effective for cobalt and cadmium removal from laboratory water at high voltages. This protocol was also successful for removing cobalt and cadmium from two rivers in Iran. Based on atomic absorption spectroscopy analysis, it is possible to remove ~ 100% of cobalt and cadmium from water using obtained nanoparticles. The method could be economically scaled up to industrial capacity.

System-specific salmon louse infestation thresholds for salmon farms to minimize impacts on wild sea trout populations

Salmon lice Lepeophtheirus salmonis from aquaculture can cause negative impacts on sea trout Salmo trutta and other wild salmonids. Long-term records from 5 Irish rivers were used to explore relationships between annual sea trout runs and estimated total number of lice on nearby salmon farms. It was hypothesised that local environmental conditions may result in system-specific differences in realised louse pressure on sea trout. Louse count was thus tested as an absolute number and as a relative pressure, i.e. standardised by farm. When the standardised total number of mobile lice on a given salmon farm in April was above baseline level (50th percentile of observed annual values on that farm), there was a high probability of a below-average sea trout run in the local river. Absolute louse counts did not show an important effect on runs. This finding suggests that salmon farm louse production in spring can have a strong system-specific regulating effect on wild sea trout populations. Total number of lice on a farm was most strongly driven by changes in individual infestation rate, with a lesser effect of stocking density. Thresholds for number of mobile lice per farmed salmon required to maintain total louse count below the baseline varied with stocking density and among systems: greater density required lower infestation rate. Regulations relying on a generic louse threshold to trigger treatment are not sufficient to protect sea trout populations—stocking density and site characteristics must be considered to evaluate system-specific infestation pressure and impacts on wild salmonids.

The first record of the invasive alien freshwater amphipod Crangonyx floridanus (Bousfield, 1963) (Crustacea: Amphipoda) in two Irish river systems

The first record of the invasive alien freshwater amphipod Crangonyx floridanus (Bousfield, 1963) (Crustacea: Amphipoda) in two Irish river systems

Determination of the amount of Sanitary Water Flow from Dams based on the Quality of Drinking Water: A Case Study, Taleghan River, Iran

Introduction: Given the crisis of water shortage and the industrial development in Iran, comprehensive water-resource management, planning, and serious handling of water quality of the rivers in Iran are the critical issues to tackle with. The concentration of river pollutants is a function of both the quantity and quality of the river flow regime. In this regard, the construction of large dams leads to quantitative and qualitative changes in downstream rivers. These changes are effective in the health of the river environment for such uses as drinking, agriculture, and industry. Accordingly, it is essential to consider the quality of river water in addition to the amount of river water needs. Materials and Methods: This study examined a 22-km long section of the river at the riffle of Taleghan Dam in Alborz Province (103 km from Karaj), Iran. The average annual and monthly discharges of the river in four 6-km-apart stations were estimated. The statistics of eight hydrometric stations and a discharge-surface method were used to calculate the average annual discharge of each sub-basin downstream of Taleghan Dam. Moreover, the discharge non-dimensionalization method, along with the observational statistics of the index station, was used to calculate the average monthly discharge in the examined stations. The Hydrologic Engineering Centers River Analysis System (RAS-HEC) software was then utilized to determine the values ​​of river flow rates hydraulically. Additionally, water quality parameters were compared with the standard concentrations proposed by the World Health Organization (WHO) for drinking-water quality to examine possible changes in pollutant concentrations during the study. Correlation and regression statistical tests in SPSS software (version 24) were then used to analyze the relationship between discharge and pollutant concentration. Results: The experimental equation of Q = 0.0372A0.8641 was obtained to estimate the discharge based on the sub-basins area using the discharge-surface method. The average annual discharge at stations 2, 3, and 4 (B, C, and D) were estimated at 1.39, 2.11, and 3.39 m3/s, respectively, using this equation. Subsequently, the average monthly discharges in the studied stations in September were calculated at 0.21, 0.29, and 0.46 m3/s, respectively. Afterward, the discharge was measured using HEC-RAS software in the same month at 0.34, 0.44, 0, and 0.62 m3/s, respectively. The examination of water quality values from ​​among the 17 water quality parameters revealed that physicochemical elements, pH concentration, lead (Pb), and electrical conductivity were higher than the standard concentration of drinking water proposed by the WHO. Conclusion: A model was presented to estimate sanitary water flow by performing correlation tests and linear regression calculations between the river discharge at the dam downstream and the concentration of water quality parameters. According to the proposed model, the minimum flow of sanitary water was estimated at 1.82 m3/s to be considered to release from the dam in the driest month of the year. Therefore, the release of water as the minimum flow of sanitary water less than 1.82 m3/s was not allowed in any other month of the year.

Physicochemical and biological status of Aghlagan river, Iran: effects of seasonal changes and point source pollution.

Although the macroinvertebrates have been widely used as bio-indicator for river water quality assessment in developed countries, its application is new in Iran and data on the health status of the most ecologically important rivers in Iran is scarce. The present study aimed at monitoring and assessing the ecological quality of Aghlagan river, northwest of Iran, using integrated physicochemical-biological approaches. A total of 14,423 samplings were carried out from the headwater to downstream sites at four stations (S1, 2, 3, 4) by a Surber sampler (30 cm × 30 cm) from June 2018 to April 2019. The results obtained from macroinvertebrate biotic index revealed that the genera of Gammarus (Amphipoda) and Baetis (Ephemeroptera) were the most abundant in all seasons. The PAST software was applied to analyze the diversity indices (Shannon-Weiner diversity, Evenness, and Simpson indices). Based on the cluster analysis, S3 established the least similarity to other stations. The average frequency of each macroinvertebrate species was determined by one-factor analysis of similarities (ANOSIM). In accordance with canonical correspondence analysis (CCA), temperature and phosphate were found as the dominant factors effecting the macroinvertebrate assemblage and distribution. Moreover, the results obtained from the biological indices concluded very good quality of S4 by Helsinhoff and EPT indices and fair quality using BMWP index. The data on the macrobenthos assemblage and dynamics in the Aghlagan river across a hydraulic gradient provided useful information on water management efforts that assist us to find sustainable solutions for the enhanced quality of the river by balancing environmental and human values.