River Bed Morphology Research Articles

Analyzing natural bed‐level dynamics to mitigate the morphological impact of river interventions

AbstractLocal river interventions, such as channel narrowing or side channels, are often necessary to maintain safety, ecology, or navigation. Such interventions have different effects on the river's bed morphology during periods of high‐ and low‐discharge events. Mapping the bed‐level variations for different discharge levels and understanding these effects can provide new opportunities for the design of interventions in multifunctional rivers. At any moment, the local bed level in a river is composed of bed‐level changes that occur at various spatial and temporal scales. These changes consist of bed aggradation/degradation trends on a large scale, on an intermediate scale bed‐level variations as a result of discharge fluctuations, and on small‐scale moving river bed forms like dunes. Using the river Waal in the Netherlands as a case study, we analyze the intermediate‐term bed‐level changes resulting from discharge fluctuations (dynamic component) and propose adaptations to the design of floodplain interventions such that possible negative impact on the local bed‐level changes is minimized. Time series of bed levels along two 10 km stretches of the case study are considered for a period of 16 years (2005–2020). Using a wavelet transform, we isolate bed‐level variations resulting from discharge events. These bed‐level variations are presented based on the magnitude of the discharge event and are compiled in an interactive atlas of river morphodynamics, allowing us to mitigate the impact of interventions. This will help river managers in the design of interventions and lead to improved management, operation, and maintenance of multifunctional rivers.

Impacts of human activities on the riverbed morphological in the tidal reaches of the Yangtze River

Reservoirs and river management projects have operational impacts on the runoff, sediments, and morphologies of tidal reaches. Therefore, it is of great significance to analyze the influence of human activities on the hydrology and geomorphology of the tidal reaches of the Yangtze River (YR). We measured topographic and water–sediment flux over the past 40 and 60 years, respectively, to determine changes in the characteristics of riverbed lowering or deposition, shoal areas, and diversion ratio of branch channel (DRBC), along with the dynamics and driving mechanisms. The results indicated that cumulative scouring of the tidal reaches occurred from 1981 to 2021 (time-averaged annual riverbed lowering depth = 4.35 cm), which was mainly controlled by reductions in sediment influxes, followed by sand mining and waterway dredging. Riverbed lowering or deposition in the tidal reaches were characterized by deep channel lowering and shoal deposition from 1981 to 2001. From 2001 to 2021, lowering of both deep channel and shoal occurred, with the riverbed lowering volume of the low-flow channel accounting for 79.3 % of the total riverbed lowering volume. The shoal areas exhibited an increasing trend from 1981 to 2001, but reduced by 2.35 % in the 2001–2021 period mainly due to the operation of Three Gorges Reservoir (TGR). Moreover, the implementation of waterway improvement projects slightly increased the shoal areas since 2016. Particularly, the DRBC accounted for 15–50 % of the increase in bifurcation ratio during the 1962–1981 periods. Reductions in sediment influxes and unbalanced riverbed lowering caused by adjustments of flow processes increased the DRBC from 1981 until prior to the implementation of the river and waterway improvement projects. After the implementation, further increases in the DRBC were effectively inhibited or the ratio was decreased. In the near future, the amounts of sediment influxes in the YR Basin will remain low or even further decrease, leading to sustained or intensified scouring of the tidal reaches, and the impacts of shrinking shoal and scouring of branch channels should be focused upon. Overall, the findings of this study provide an in-depth understanding of the impacts of human activities on the riverbed morphologies of tidal reaches.

Evaluating the physical habitat of riffle‐pool design in support of river habitat protection and rehabilitation

AbstractRiffle‐pool constructions are common practice in river management and fish conservation, but insufficient science exists to guide objective design of riffle‐pool. Understanding the spatial design of a riffle‐pool in river systems has significant value because it can provide important information to ameliorate aquatic species decline. In this study, six types of riffle‐pool structures were designed to assess hydrodynamic and riverbed morphology effects on stream habitat status. A two‐dimensional ecohydraulic model was used to assess the roles of different riffle‐pool designs in river habitat conditions. The natural flow condition and three types of flood flow conditions were applied to the six types of riffle‐pool structures to evaluate the habitat quality and the sustainability of the riffle‐pool design in mountain rivers. The long‐term impacts of the hydrodynamic and hydromorphology conditions on river physical habitat status were also analysed. The results indicate substantial differences in habitat quality among six riffle‐pool structures. It was found that narrow riffle‐pool construction yielded the best performance for the fish habitat, which had the best habitat quality among six riffle‐pool designs with the smallest pool area. In the same riffle‐pool structure, the habitat suitability in the riffle‐pool sequence will primarily increase more rapidly and then decrease gradually along with the discharge increase. Under the flood discharge scenarios, low flood discharge could improve riffle‐pool habitat quality, while high flood discharge could fragment the riffle‐pool habitat quality further. The long‐term hydrodynamic conditions have the same effects on all six cases. Overall, low discharge and smaller pool design would be beneficial to the river system, which could help maintain habitat diversity of mountain rivers. This analysis could provide valuable information for river management and decision‐making, which could assist in designing better mountain river habitats to promote conservation and rehabilitation of endangered biota.

Scanning and transmission electron microscopy examinations of composite hybrid chromate and chromate phosphate conversion coatings exposed in hot 100% relative humidity environments

Conversion coatings are sine qua non in the finishing of aluminium alloys. They may be put into service without coating of paints. However, for aesthetics in architectural applications, paint overcoat is common. Chromate phosphate coatings are relatively less toxic than chromate which gained the pride of place until recently. Thus, aluminium specimens coated with hybrid chromate/phosphate conversion coatings have been subjected to 100% relative humidity for 480 h at 313K in comparison to chromate coatings and bare aluminium. Scanning electron microscopy examination revealed that initial dried river bed morphologies on coated specimens were obliterated. The friable outer coatings collapsed into the cracks/environment leaving a relatively smooth surface after exposure. Additionally, transmission electron microscopy of sections before and after exposure revealed similar texture and morphological striations nearly parallel to each other throughout the length of the coatings to the metal/coating interface. These were not disrupted as well as the metal/coating interface which remained relatively smooth with no visible corrosion products after exposure. Thus, the coatings formed effective barrier between the substrate and the relatively harsh environment. From EDS, elemental compositions were the same albeit, spectral intensities remained relatively constant after humidity exposure regimes. The coatings are made up of either Cr, O and Al for chromate and Cr, P, O and Al for chromate/phosphate. At deliberately breached regions, the coatings prevented spread of corrosion and paint delamination over the substrates. On the other hand, bare aluminium was decorated with mounds of hydrated aluminium oxide/hydroxide after exposure as revealed in the SEM/TEM.

The influence of hyporheic exchange with spur dikes: Laboratory experiments

It is important to understand heat transfer changes in the hyporheic zone of spur dikes when assessing ecological restoration and sustainability in rivers. To reveal the rule of hyporheic exchange under the action of a spur dike, the sinusoidal temperature change of surface water was set with a period of 24 h. The porous subsurface flow paths under different riverbed forms were plotted through dye tracing. In addition, the influences of surface water velocity (U), river width narrowing ratio (L/B), the number of spur dikes and riverbed shape on hyporheic exchange were also studied using the temperature tracing method. The results show that the hyporheic exchange path presents a trend of diagonal flow downstream, first conducting turbulent diffusion upstream and then sinking, with different riverbed morphologies having different path lengths. The temperature of surface water has a significant controlling effect on the temperature field of the riverbed. The sediment temperature change from the water–sediment interface to 0.3 m depth is closer to the sinusoidal trend. The change in surface water velocity (U) has the most significant effect on the temperature amplitude ratio. The temperature field below spur dikes is more susceptible to the impact of spur dikes and usually presents a “semielliptical” high-temperature area. With the increase in surface water velocity (U), river width narrowing ratio (L/B), and the number of spur dikes, the range of hyporheic exchange under the dam head also increases, which is positively related to the vertical section hyporheic exchange flux at the dam head. The local backwater area generated by spur dikes also affects pressure field distribution near spur dikes, but the changes caused by the fluctuation of the riverbed itself are greater than the impact of spur dikes on the riverbed. The water–sediment interface velocity at the spur dike increases sharply, and the upstream 1 m of the dam head gradually experiences upflow, drops sharply after reaching the maximum at the dam head, and then approaches zero after 1 m. There is no obvious upwelling and downwelling at the whole interface.

Using 1D and 2D computer models when predicting hydrodynamic and morphological parameters of a boulder block ramp: Poniczanka stream, Carpathians

When modelling flow and/or sediment transport in streams and rivers, one must frequently use the computer software of differing levels of complexity. The level of sophistication, accuracy, and quality of results are the parameters by which models can be classified as being 1D, 2D, or 3D; it seems certain that in the future, there will also be 4D and 5D models. However, the results obtained from very sophisticated models are frequently questionable, and designers in the field of hydraulic structures must have considerable experience distinguishing important information from irrelevant information. Thus, this paper aims to investigate the effect of the selected boulder block ramp hydraulic structure at Poniczanka stream on the bed-load transport. We evaluated sediment transport using the CCHE2D numerical model. We analysed several scenarios depending on the river bed type (erodible, non-erodible, rocky) and examined the rock blocks used for hydraulic structure construction. The obtained results were compared with the Hjulström and the Shields graph, which are a classic approach for identifying fluvial processes in river channels. In addition to these two methods, numerical modelling using the 1D HEC-RAS (Hydrologic Engineering Center’s River Analysis System) modelling were conducted, which included the determination of horizontal and vertical changes to the river bed morphology of the examined section of river reach as well as providing the basic hydrodynamics parameters which, from the practical point of view, designers involved in the process of designing ramps could use.

Reduction of scour around circular piers using collars

AbstractRiver dynamics and sediment transport play an important role in river bed morphology. Building a bridge pier along the river alters the cross‐section of the river and causes the change in flow processes. These changes are mainly responsible for pier scour. In this paper, the usage of collars to reduce scour around circular piers has been investigated. The collars with different diameters and depth positions have been studied using previous data and additional data collected in the present study to assess their effectiveness in reducing scour. Using a wide range of measured data, an empirical equation to compute the maximum scour depth around the circular piers in the presence of collars has been proposed. The proposed equation has been validated and proven to be applicable to a wide range of pier layouts. It has been found that the maximum efficiency can be achieved by fixing the collar at bed level and adopting a collar diameter 1.5–2.5 times of pier diameter.

Effect of opening depth of oblique weir with an opening on river bed morphology

In this study, we focused on the fact that an oblique weir with an opening activates the fluidity of the sediment compared with a conventional continuous fixed one and examined the removal function of the sediment deposited upstream of the weir. Experimental results showed that the weir with the opening increased the fluidity of the sediment deposited upstream of the weir and lowered the riverbed. The scouring section upstream of the weir was divided into a gradually varied flow section and a local flow section based on the bed topography. In the gradual flow section, the descent of water level and riverbed increases linearly as the opening depth increases. In addition, it was shown that the local scour shapes upstream and downstream of the weir were similar to each other as a result of normalization on the representative scale of vertical and transverse shapes. By creating the opening of the oblique weir, the magnitude of the downward flow generated near the left bank was reduced from 45% to 34% of the non-open weir.

Erosion irregularities resulting from series of grade control structures: The Mszanka River, Western Carpathians

Grade control structures (GCSs) are one of the most often used hydraulic structures in a river regulation in mountain catchments. The purpose of their use is to reduce the river bed gradient and prevent downcutting. The aim of this study is to evaluate the influence of GCS on changes in river bed morphology. The study was conducted in a downstream stretch (5.66 km long) of the Carpathian river – the Mszanka, regulated with 25 GCSs. Research has shown that erosion is here a predominant process despite the use of GCSs. The river bed has been cut into bedrock along approximately 40% of a studied stretch. A total of 56 scour holes were identified, which vary substantially in terms of their depth, length, and mechanism of formation. The erosion depth depends mainly on the length of reaches between GCSs and on the water surface gradient. A surprising research discovery was scour holes found upstream of the crests of the GCSs – 16 such scour holes were found. The formation of these scour holes is explained through the drawdown profile characterized by the increasing of the velocity that favored the bed erosion. The studied river is characterized by deficit of sediment. The insufficient sediment supply and imbalance between the river's load and sediment transport are two of the greatest problems affecting the most Carpathian rivers. The novelty of this research is the analysis of such a long and complex reach of mountain river engineered with GCSs in terms of variances in erosion processes. Also a new knowledge presented here is an information about scour holes located upstream of GCSs and explanation of the mechanism of their formation. Results from this research could serve geomorphologists, engineers and ecologists as well as help river managers in decision-making processes when river regulation is planned.

A seismic monitoring approach to detect and quantify river sediment mobilization by steelhead redd‐building activity

AbstractThe role of spawning salmonids in altering river bed morphology and sediment transport is significant, yet poorly understood. This is due, in large part, to limitations in monitoring the redd‐building process in a continuous and spatially extended way. A complementary approach may be provided through the use of a small seismic sensor network analysing the ground motion signals generated by the agitation of sediment during the redd‐building process. We successfully tested the viability of this approach by detecting and locating artificially generated redd signals in a reach of the Mashel River, Washington State, USA. We then utilize records of 17 seismic stations, in which we automatically detected seismic events that were subsequently manually checked, yielding a catalogue of 45 potential redd‐building events. Such redd‐building events typically lasted between 1 and 20 min and consisted of a series of clusters of 50–100 short energetic pulses in the 20–60 Hz frequency range. The majority (>90%) of these redd‐building events occurred within 11 days, predominantly during the early morning and late afternoon. The seismically derived locations of the signals were in agreement with independently mapped redds. Improved network geometry and installation conditions are required for more efficient detection, robust location and improved energetic insights into redd‐building processes in larger reaches. The passive and continuous nature of the seismic approach in detecting redds and describing fish behaviour provides a novel tool for fish biologists and fisheries managers, but also for fluvial geomorphologists, interested in quantifying the amount of sediment mobilized by this ecosystem engineer. When complemented with classic approaches, it could allow for a more holistic picture of the kinetics and temporal patterns (at scales from seconds to multiple seasons) of a key phase of salmonid life cycles. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd

ASSESSMENT OF A LOW-COST SIDE-SCAN SONAR FOR RIVER ESTUARY UNDERWATER IMAGING

River and estuary areas commonly exhibit complex and heterogeneous habitats. Thus, revealing the distribution of riverbed morphologies could promote the area management and habitats protection. Since the remote sensing method and manual survey are limited to use, side-scan sonar performs an expectant outcome in underwater habitat imaging. In shallow water and stream areas, low-cost side-scan sonar imaging has become a notable subject of study, yet its use in Indonesia is still limited. This study describes an investigation of the use of a recreational-grade side-scan sonar for stream underwater imaging. A visual inspection and interpretation were implemented using a free-cost sonar software. The result shows some underwater objects and debris could be portrayed perfectly and this indicates that the inexpensive sonar system is appropriate to be used in shallow water and stream areas with a non-rough sea surface. It is suggested that this system could provide a satisfactory product to the users who do not require high accuracy and high resolution of riverbed imagery.Keywords: estuary, river, underwater mapping, acoustic remote sensing, low-cost, side-scan sonar.

Experimental Investigation of the Debris Configurations Effects on the Scour Hole Morphology at Circular Bridge Piers

The hydraulic conditions and river bed morphology at bridge piers get extremely changed with debris accumulations. In this study, a series of tests were conducted to understand the scour hole geometry behaviour during debris accumulation at circular bridge pier. Three groups of rectangular debris were tested under clear water condition with 27 tests. The most dangerous shapes from these groups were specified and the effects of debris thickness, width and length were elaborated. The results show that the scour depth, width and length increased as the percentage of obstructed area of debris to the flow area increased. Hence, the modification factor of scour hole dimensions increased. The study concluded that the modification debris coefficient for scour hole depth, width and length increased to 2.397, 2.308 and 2.145 when the obstructed area of debris to the flow area increases from 2.07% to 26.89%, respectively. More notifications should be considered in protection work around bridge piers subjected to debris accumulation.

Response of sediment flux, bridge scouring on river bed morphology and geomorphic resilience in middle-lower part of river Chel, Eastern Himalayan foothills zone, India

Dynamism of river bed morphology is continuous and an integrated process of mountain's natural outflow in Himalayan Foothill Rivers. In-stream seasonal sediment flux, bridge establishments, bridge scouring and railway-road construction have detrimental influence over the natural flow regime of the river thereby causing channel degradation in the piedmont zone of eastern Himalaya of India, specifically near the urban areas where river management strategies are very weak. Such extreme anthropogenic events have a distinctive influence in changing river bed morphology in the middle-lower part of river Chel in Darjeeling Himalayan piedmont zone of India. Huge sediment aggradation and transportation networks historically have affected River Chel and have caused channel avulsion which poses a serious threat to the physical and ecological environment of Chel. Aggradation and lifting of sediments from the river bed are fatal for the geomorphologic character of the river, though no studies have been undertaken yet, to analyse the situation quantitatively in this regard. This paper presents evidence that suggests the changing river bed morphology, the dynamic nature of the river, the poor health of the river which is principally the impact of the seasonal sediment flux and bridge construction and thus some methods of river restoration in the middle-lower part of the river have been explained. Agglomeration of sediment, flow bifurcation, the volume of seasonal water mass, bed elevation changes and scouring are a major dynamic disposition for change of river bed morphology. Point bar, sidebar, braided active channel, ripples, and rise in the bed elevation are rapid changes in upper to lower part of bridges that are examined in the present study. In the dry season (December to February), a huge amount of sediment lifting makes incommodious man-made holes and a number of emergent channels which principally control the formation of a new active channel in the next monsoon season. The avulsion of major intra-active channels and morphological changes of the river bed for the last 85 years have also been observed in this study.

Analysing riverbed morphology as a response to changes of geological and neotectonic conditions: A case study of the oľšava river

Abstract The morphological examination of the Slovak Oľšava River channel and valley parameters is based on observation of changes in the troughs’ longitudinal profile. While the relationship between valley and channel parameters has previously been researched, establishment of the diverse conditions in trough formation enables better understanding of the basin/riverbed relationship. Our research is based on field measurements of representative sections of nine segments defined by changes in the longitudinal profile. The field measurements were performed in autumn months during a low water period to ensure the best conditions for repeated measurements. Significantly, as much as 75% asymmetry of the measured flow encourages the assumption of strong tectonic influence on the riverbed formation. While the difference between the assumed continuous changes of measured parameters and the actual measured or evaluated parameters remains a matter of interpretation, the detected anomalies enable interpretation of the parameters’ relationships. The river bed and the valley morphological parameters were evaluated on the model of The Olšava River basin which drains the eastern part of the Košická kotlina Basin (the Toryská pahorkatina Upland). The location of the basin at the foot of the Slanské vrchy Mts. is an important factor in the formation of the river network asymmetries. Both the Neogene contact between the Slanské vrchy Hills neo-volcanites and the Toryská pahorkatina Upland and the neo-tectonics influenced the change in morphological parameters in the valley’s longitudinal and transverse profile and the Oľšava river bed. Our terrain works comprised length and width measurements of the bars, their positions in the river bed, the width and depth of the channel and the type of section riffle. Available maps enabled calculation of the following; ratio of valley height to width, average gradient of the section, stream gradient index, average channel segment slope, the degree of sinuosity and the highest observed correlation between slope, river segment type (0.9576) and the width and type river reach (−0.9089). High correlation coefficient values were recorded for the valley height and width ratio, the type of river section, the water area and the total river bed width and area.

Spatio‐temporal variability of suspended sediments in rivers and ecological implications of reservoir flushing operations

AbstractHigh suspended sediment concentrations during reservoir flushing are known to be harmful to biota in downstream river stretches. Therefore, it is common practice to set legal concentration limits for upstream reservoir management operations such as flushings or controlled drawdowns. However, as shown by measurements, there is a considerable spatio‐temporal variability of suspended sediment concentrations both in the longitudinal profile of rivers and in river cross‐sections. To consider this variability in management operations, SED‐FISH—a three‐dimensional modelling approach—was developed to study this variability in a wider context by upscaling cross‐sectional measurements of suspended sediments to high‐resolution three‐dimensional information on the reach scale in an alpine river. The resulting patterns of suspended sediment concentrations were integrated over their respective time of occurrence for various scenarios in order to calculate severity of harmful impacts for target fish species. The modelling results identified refugial habitats with reduced negative impacts in near‐bank zones even for relatively high suspended sediment concentrations in the centre of the river. Moreover, a substantially larger variability of both suspended sediment concentrations and associated harmful impacts was found for a winding riverbed morphology as compared with a straight reach. Both these findings and the developed modelling tool could assist in establishing individual case‐based concentration limits for reservoir management operations in the future and should also be taken into account when planning river regulation or restoration measures.

Influences of riverbed morphology on patterns and magnitudes of hyporheic water exchange within a natural river confluence

River confluences are pivotal junctions that have vital influences on hydraulic characteristics and sediment particle distributions as well as on hyporheic water exchange. However, hyporheic water exchange is poorly understood because of the complicated river morphology within a river confluence. Therefore, the river confluence between the Juehe River and Haohe River located in arid and semi-arid areas of northwestern China was selected to evaluate the hyporheic water exchange processes, and the temperatures of different depth sediment were measured on July 11th and 12th, 2016 by an instrument equipped with five temperature sensors. The patterns and magnitudes of hyporheic water exchange were estimated using a one-dimensional heat transport model coupled with temperature data. Meanwhile, terrain points elevations and sediment particle distributions in this river confluence were collected to determine the confluence riverbed morphology. Furthermore, the river confluence morphology effects on hyporheic water exchange were investigated in this study. The different riverbed morphology and hydrodynamic zone locations were observed, which were controlled by the planform geometry with low river confluence flux momentum during the test period. Meanwhile, the upwelling flow dominated in the test area, and the downwelling occurred at three of the 23 total test points, which was induced by the complicated riverbed morphology and hydraulic characteristics. Additionally, the magnitudes of the upwelling flow were significantly influenced by the sediment heterogeneity subjected to the erosional and depositional processes. Hyporheic water exchange is a vital hydrological process in arid and semi-arid areas, where it significantly impacts the ecological environment of rivers. This study provides a valuable guideline for water quality and quantity management in arid and semi-arid areas.

Bed roughness adjustments determined from fractal measurements of river-bed morphology

The flow resistance in rivers is an old and partly unsolved problem. In this study, the bed surface fractal dimension (BSFD) is used to describe the bed morphology, and combined with the bed roughness, a general model experiment is developed. The results show that there is a positive relationship between the BSFD and the bed roughness, which can be further applied to estimate the roughness changes in rivers. These findings will also guide further studies of the mobile-bed flow resistance.

HydroSedFoam: A new parallelized two-dimensional hydrodynamic, sediment transport, and bed morphology model

Depth-averaged two-dimensional (2D) models are useful tools for understanding river morphodynamics through the computation of hydrodynamics, sediment transport, and an evolving river bed morphology. This paper presents a new parallelized 2D hydrodynamic, sediment transport, and bed morphology model, HydroSedFoam. The model uses the Message Passing Interface for code parallelization and adopts a depth-averaged k−ε turbulence model. Three different case studies, including a laboratory experiment, an analytical solution, and a field-scale river reach, show good agreement with HydroSedFoam simulations. Further development and modification of the model are relatively straightforward to accomplish within the OpenFOAM framework.

A GENETIC ALGORITHM OPTIMIZATION MODEL FOR DIRECT PUMPING WATER SUPPLY INTAKES OPERATION

An optimization model for direct water supply intakes operation was created to maximize the rate of recovery of river bed, i.e. minimizing the effects pumping on river bed morphology. The model adopted constraints such as the water volume that should be pumped daily, minimum and maximum pumping intake capacity, and maximum time of pumping per day, while the objective function maximized is the rate of recovery of the river bed . The decision variables are selected as the pumping rate to river flow ratio, and the intake operation time to time of non-operation ratio. The model combines the Genetic Algorthim and the Artificial Neural Networks techniques to find the optimum solution. The application indicated that the required number of the randomly generated solutions and the number of cross over process for a stable optimum genetic algorithm solution are (100) and (1) respectively. Sensitivity analysis of the effect of number of cycles of operation and non-operation periods of the intake per day and the river flow indicates that these variables have no effect on the objective function.

Ecological traits of water beetles in a karstic river from the Eastern Mediterranean region

This study presents new insights into ecological traits of water beetles in lotic karst habitats of the Eastern Mediterranean. The aims of the study were to investigate population aspects and ecological traits of water beetles. Data were collected monthly during one year from a large perennial river showing current anthropogenic disturbance. Altogether 11 families, 23 genera and 31 species were identified. Elmidae were the most diverse and abundant family, and the genus Elmis predominated at all sampling sites. The distribution of water beetles along the river was influenced primarily by river bed morphology and beetle substrate preference. Water beetles were more abundant in bryophytes but more diverse in angiosperms. Ecological traits of water beetles along the watercourse were defined primarily by alkalinity and current velocity. Larval stages correlated with water depth and current velocity, while the adult stage correlated only with water depth. Our results support the potential of water beetles as indicators of water quality. This report provides the most detailed investigation so far of water beetles in the Eastern Mediterranean region, providing a basis for further detailed studies of water beetles and their ecology in freshwater habitats in southeastern Europe.