Side Bars Research Articles

Microplastic Contamination of Fine-Grained Sediments and Its Environmental Driving Factors along a Lowland River: Three-Year Monitoring of the Tisza River and Central Europe

The hydro-geomorphological background in microplastic (MP) deposition and mobilization is often neglected, though the sampling environment is the key point in a monitoring scheme. The aim of the study was to analyze the environmental driving factors of MP transport over three years (2020–2022) along a 750 km-long section of the Tisza River, Central Europe. The mean MP content of the fresh clayey sediments was 1291 ± 618 items/kg in 2020, and then it decreased (2021: 730 ± 568 items/kg; 2022: 766 ± 437 items/kg). The upstream and downstream sections were the most polluted due to improper local sewage treatment. In 2020, 63% of the sites were hotspot (≥2000 items/kg), but their number decreased to one-third in 2021 and 2022. MP pollution is influenced by highly variable environmental factors. (1) The geomorphological setting of a site is important, as most of the hotspots are on side bars. (2) The tributaries convey MP pollution to the Tisza River. (3) The bankfull or higher flood waves effectively rearrange the MP pollution. (4) The dams and their operation influence the downstream trend of MP pollution in the reservoir. (5) Downstream of a dam, the clear-water erosion increases the proportion of the pristine sediments; thus, the MP concentration decreases.

Microplastics distribution in river side bars: The combined effects of water level and wind intensity

Rivers are the main pathway for microplastics (MP) transport toward the ocean. However, the understanding of the processes involved in the deposition and mobilization of MP in rivers, specifically in sediment side bars (SB), remains very limited. The objectives of this study were: (i) to examine the effect of hydrometric fluctuations and wind intensity on the distribution of microplastics (MP < 5 mm) in the SB of large river (the Paraná River), (ii) to determine the characteristics of MP to infer their origin and fate, and (iii) to discuss potential similarities or differences between MP suspended in the water column and MP found in sediment. The SB and water column were sampled during the autumn, winter, and spring of 2018, and the summer of 2019 at different river discharges and wind intensities. >90 % of the MP items found were fiber of polyethylene terephthalate (PET; FT-IR analysis), the most common MP color was blue, and most were in the 0.5–2 mm size range. The concentration/composition of MP varied according to the river discharge and wind intensity. During the falling limb of the hydrograph when discharge is decreasing and sediments are exposed for short periods (13–30 days), MP particles transported by the flow were deposited on temporarily exposed SB, accumulating there in high densities (309–373 items/kg). However, during the drought, when sediments remained exposed for a long time (259 days), MP were mobilized and transported by the wind. During this period (no influence of the flow), MP densities significantly decreased on SB (39–47 items/kg). In conclusion, both hydrological fluctuations and wind intensity played a significant role in MP distribution in SB.

Eccentric compression behavior of seawater and sea sand concrete columns reinforced with GFRP and stainless steel bars

Using FRP bars instead of steel bars to reinforce concrete columns in harsh environments has become an important method for solving corrosion problems. FRP bars have high tensile strength but low compressive strength and high brittleness, while stainless steel (SS) bars have high tensile and compressive strength and good ductility. Therefore, this paper studied the eccentric compression behavior of seawater and sea sand concrete (SSC) columns reinforced with GFRP and SS bars, in which GFRP bars were arranged on the tension side and SS bars were arranged on the compression side to improve the ductility and to analyze the effect of axial stiffness of reinforcement on the N-M interaction diagrams. A total of 48 SSC columns were designed, of which 20 were reinforced with GFRP and SS bars, 14 were reinforced with GFRP bars and 14 were reinforced with SS bars. To analyze the eccentric compression performance of SSC columns and propose the bearing capacity calculation equation, test variables were designed, including the reinforcement type, reinforcement ratio, and eccentricity, to ensure that the equation had certain universal applicability. The three failure modes of compression failure, combined compression-bending failure, and bending failure were found with the increase in the eccentricity for the GFRP and SS bars reinforced SSC (GFRP-SS-SSC) columns. The ductility indices of the GFRP-SS-SSC columns were approximately 1.5 times those of the GFRP bars reinforced SSC columns, which indicated that the ductility could be improved by replacing the compression GFRP bars with SS bars. Finally, the theoretical N-M interaction diagrams were established through the cross-section force analysis and compared with the experimental N-M interaction diagrams. Moreover, the failure mode is influenced by varying the axial stiffness of the longitudinal bars on both sides of the column section by analyzing the N-M interaction diagrams.

Feasibility of improving shear performance of RC pile caps using various internal reinforcement configurations: Tests and finite element modelling

The loads from columns and bridge piers are transferred to the pile foundation by reinforced concrete (RC) pile caps, which are important structural components whose behavior is significantly affected by the internal reinforcement configuration. Therefore, the current study experimentally investigates the shear response of RC pile caps by testing nine specimens have identical dimensions and various reinforcement configurations. The experimental matrix is designed to study (i) the influence of using a closed transversal reinforcement along with the presence of an upper reinforcement only or an upper and side reinforcement together. (ii) Behavior of RC pile caps internally reinforced with various closed-side bars’ area and (iii) the impact of the interaction between the longitudinal reinforcement of the piles and the column in the presence of upper reinforcement only or side closed bars solely. RC pile cap specimen internally reinforced with closed transversal reinforcement with upper reinforcement and 12 mm-diameter closed side bars can be considered the optimal reinforcement form due to the fact that this specimen achieved the highest ultimate load and toughness of 1286 kN and 1089 kN.mm, respectively. Moreover, the current research involves the development of a three-dimensional (3D) non-linear finite element model to evaluate the response of RC pile caps while taking into account concrete's tensile strength and softening behavior in either tension or compression. Results of the numerical model well agreed with the experimental data. Additionally, a parametric study is conducted using the verified model to examine the impact of utilizing bent bars positioned perpendicular to the shear crack's direction on the ultimate load, failure pattern, and toughness of the RC pile caps.

Hybrid zones of Natrix helvetica and N. natrix: Phenotype data from iNaturalist and genetics reveal concordant clines and the value of species-diagnostic morphological traits

Using georeferenced photographic records of 2944 grass snakes from Germany, Austria, and northern Italy as well as previously published mtDNA sequences (n = 1062) and microsatellite data (n = 952) for grass snakes from the same regions, we examined whether or not coloration and pattern reliably allow to differentiate between Natrix natrix and N. helvetica and if so, whether the distribution patterns revealed by phenotypes and genetics are congruent. Furthermore, we used cline analyses across hybrid zones to test whether the phenotypic transition from one species to the other parallels the steep clines unveiled by genetics. Our results suggest that the two species can be reliably differentiated using coloration and pattern. The most powerful diagnostic traits are the presence/absence of side bars on the body flanks, the number of occipital spots, and the shape of the posterior dark occipital spot. The distributions of morphologically identified N. natrix and N. helvetica match their genetically confirmed ranges. Single conflicting individuals morphologically identified as N. natrix or hybrids within the distribution range of N. helvetica either represent misidentifications or translocated snakes. For the genetic markers and phenotypes, our cline analyses revealed concordant steep clines across hybrid zones. However, the southern part of the hybrid zone in Italy, for which no sufficient genetic data are available, should be studied in more detail because the phenotypic data suggest a smooth cline in this region. The unexpected high percentage of putative hybrids with dorsal stripes in this region also calls for further research. For northwestern Germany, another region for which no genetically verified records are available, iNaturalist data suggest that the contact zone of N. natrix and N. helvetica is near the Ems River and extends from there southeastwards to the region of Höxter, North Rhine-Westphalia.

ASSESSMENT OF THE STABILITY OF MOTION OF A WHEEL SEMI-TRACK UNIT

The paper analyzes the influence of the geometric parameters of the semi-trailer unit on the stability of its movement. A mathematical model of the dynamics of the cultivator unit under the influence of disturbing forces is developed. The analysis of research results shows that in the process of movement, the wheeled semi-trailer unit is subjected to transverse forces, which arise as a result of the unevenness of the traction resistance of the side and rear beams. The main vector and the main moment cause the unit to deviate from the rectilinear movement. The differential equations obtained in the work make it possible to determine the values of the lead angles, their components, and the speed at which the lead of the unit will be the smallest. Based on the dependence of the angle of departure of the unit on the disturbing forces and speed of movement, the optimal location of the side bars of the semi-trailer unit on the tractor frame was found.

Flexural response of GFRP RC beams strengthened with side and bottom NSM GFRP bars

This study exhibits the bending performance of reinforced concrete (RC) beams with glass fiber-reinforced polymer (GFRP) rods. The beams were strengthened with the bottom or side near surface mounted (BNSM or SNSM) methods. Applying BNSM strengthening to the RC beam is difficult in some cases, so the SNSM became essential. Due to the limited research dealing with this type of beam, this study focuses on the effect of internal and NSM reinforcement areas and the NSM position on the response of the beams. Two un-strengthened and six strengthened RC beams were tested in bending. The GFRP RC beams upgraded with SNSM GFRP bars showed higher deflection, energy dissipation, ductility, and ductile failure than those upgraded with BNSM ones. On the contrary, the load-carrying capability and flexural stiffness of GFRP RC beams strengthened with BNSM GFRP rods were slightly higher than those strengthened with SNSM GFRP. Consequently, a parametric investigation relying on the verified finite element (FE) model was executed. This parametric work aimed to add additional data to the literature related to the influences of the internal and NSM reinforcement type and area on the performance of beams with ‎SNSM. According to the FE results, increasing the NSM reinforcement area improved the capacity and stiffness of the upgraded beams regardless of the combination of the internal and NSM reinforcement. The relative axial stiffness between internal and NSM materials significantly impacted the beam performance. Moreover, using GFRP with CFRP or steel with CFRP indicated higher performance than using steel with GFRP, regardless of which one was located as NSM.

Shear behavior of RC pile cap beams strengthened using ultra-high performance concrete reinforced with steel mesh fabric

Although pile cap bases of structures are the most significant element in the construction and one of the most difficult parts in strengthening applications, previous studies on this element, particularly strengthening, are quite limited. The most extensively utilized, highly efficient, and simple to implement solution is ultra-high performance concrete (UHPC). In this study, six-half scaled pile cap beams were prepared and experimentally tested. Three of them were strengthened with UHPC (one in shear with connectors only, one in shear with connectors and steel mesh fabric (SMF), and one in shear and punching with connectors and SMF), while the other three were not strengthened to explore the influence of side bars. The bottom bars of the all six beams were identical, consisting of main longitudinal tensile and secondary lateral reinforcement. The load-displacement response, ultimate carrying load, failure mechanisms, energy dissipation capacity, and shear ductility of pile cap beams were all thoroughly investigated. The results revealed that using side bar reinforcement and UHPC with various techniques significantly enhanced the shear strength and ductility of pile cap beams. Except for the specimen including additional internal side bars, there were no appreciable differences in the peak load of un-strengthened reinforced concrete (RC) pile cap beams. The gain in peak load was 59% due to use of side bars. The RC pile cap beam strengthened in shear and punching with connectors and SMF exhibited the highest peak load and the highest energy dissipation capacity among all tested specimens.

Current and paleo sources of organic material within fluvial features of the meandering Ruda River, Poland

This study aimed to identify differences in organic matter (OM) composition and origin in the main depositional subenvironments within the floodplain of a meandering river in a temperate climate zone. The study analysed organic-rich sediments found within different facies (side bars, natural levees, crevasse splays, palaeochannels, flood basins, and alluvial fans). Quantitative macrofossil analysis of the OM present in proximal floodplain sediments pointed to a dominance of amorphous OM (AOM), the average proportion of which comprised up to 60% of the total OM. During floods, the most significant phenomenon is the deposition of wood and leaf debris; however, these debris are subject to rapid decomposition in sandy layers and, as a result, do not contribute much to the total OM composition. Root and epidermis remain accumulated in situ and, with an average share of more than 10% of the total OM, are an important part of the more fine-grained alluvial layers. The other components were no more than bioindicators. The proximal floodplain is characterised by sponge spicules in the alluvia and mycelia in the epipedons. In addition, diatom remains are often recorded in the flood layers. The average AOM content in the OM found within the distal floodplain was approximately 40%, although a significantly higher proportion of this component was recorded in flood basin sediments. The accumulation of rhizodermis, epidermis, wood, and periderm (with shares ranging from 5% to 22% of the total OM) plays an important role. Less common components that are of indicative value within the distal zone include the remains of mosses, Cladocera, and sporomorphs. OM within the distal floodplain has high preservation potential, and the sediments in this zone are crucial for carbon sequestration processes in river valleys.

Microplastics Distribution in Riverine Side Bars: The Combined Effect of Wind and Current

Microplastics Distribution in Riverine Side Bars: The Combined Effect of Wind and Current

Kontaminace příbřežních sedimentárních těles řeky Odry u Bohumína organickými polutanty

The aim of this study is to investigate present-day contamination levels of selected organic pollutants (POPs) in channel side bars and identify their sources. The studied area is located on the Odra River in the north-eastern part of the Czech Republic (at the border between the Czech Republic and Poland), between the city Bohumín and Odra´s confluence with Olše River. Sediment samples were taken directly from the channel side bars and subsequently measured for grain size analysis, concentrations of total organic carbon (TOC), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and specific biomarkers (terpenoids). Three main facies were recognized in channel side bars. Grain-size analysis showed the predominance of silt fraction, followed by variable sand contents, whereas the contents of clay fraction were almost stable. No statistically significant correlation was found between grain size and the concentrations of POPs except a weak correlation between PAHs, PCBs and sand fraction. POPs including PAHs, PCBs and OCPs showed high variability. In all samples, the sum of PAHs (maximumvalue of 78.1 mg kg-1) greatly exceeded the Czech preventive limit for dry soil. The sources of PAHs were analysed by employing diagnostic ratios and plots of specific PAH compounds. The results showed a high degree of correspondence suggesting a petrogenic origin associated with direct input into the river system. Relatively high concentrations of PAHs are a consequence of the vicinity of the pollution source and location in natural river reach enabling sedimentation of polluted sediments. Concentrations of PCB, hexachlorobenzene and DDT metabolites were almost insignificant in most of the samples, except for several samples having higher PCB values (maximum value of 47.6 μg kg-1). Specific biomarker compounds were used as an indicator of the presence of fossil matter, and H29 17α(H),21β(H) hopane showed the highest concentrations. The homohopane index indicated petroleum and vehicle exhausts origin. TOC revealed a positive correlation with specific biomarkers (homo hopanes and 16 α(H)- phyllocladane, hexachlorbenzene and PCB.

Ice sheet and palaeoclimate controls on drainage network evolution: an example from Dogger Bank, North Sea

Abstract. Submerged landscapes on continental shelves archive drainage networks formed during periods of sea-level lowstand. The evolution of these postglacial drainage networks also reveals how past climate changes affected the landscape. Ice-marginal and paraglacial drainage networks on low-relief topography are susceptible to reorganisation of water supply, forced by ice-marginal rearrangement, precipitation and temperature variations, and marine inundation. A rare geological archive of climate-driven landscape evolution during the transition from ice-marginal (ca. 23 ka) to a fully submerged marine environment (ca. 8 ka) is preserved at Dogger Bank, in the southern North Sea. In this study, our analysis of high-resolution seismic reflection and cone penetration test data reveal a channel network over a 1330 km2 area that incised glacial and proglacial lake-fill sediments. The channel network sits below coastal and shallow marine sediments and is therefore interpreted to represent a terrestrial drainage network. When mapped out, the channel form morphology reveals two distinct sets. The first set comprises two low-sinuosity, wide (&gt;400 m) channels that contain macroforms of braid and side bars. These channels are interpreted to have originated as proglacial rivers, which drained the ice-sheet margin to the north. The second set of channels (75–200 m wide, with one larger, ∼400 m wide) has higher sinuosity and forms a subdendritic network of tributaries to the proglacial channels. The timing of channel formation lacks chronostratigraphic control. However, the proglacial rivers must have formed as the ice sheet was still on Dogger Bank, before 23 ka, to supply meltwater to the rivers. Ice-sheet retreat from Dogger Bank led to reorganisation of meltwater drainage and abandonment of the proglacial rivers. Palaeoclimate simulations show a cold and dry period at Dogger Bank between 23 and 17 ka. After 17 ka, precipitation increased, and drainage of precipitation formed the second set of channels. The second set of rivers remained active until marine transgression of Dogger Bank at ca. 8.5–8 ka. Overall, this study provides a detailed insight into the evolution of river networks across Dogger Bank and highlights the interplay between external (climate) and internal (local) forcings in drainage network evolution.

Using high-performance cementitious mortar and external prestressing for retrofitting of corroded reinforced concrete beams

The effect of using high-performance polypropylene fiber–reinforced cementitious mortar on reinforced concrete beam repair was presented in this article. Results of an experimental study for the flexural performance of 13 reinforced concrete beams were presented. The corrosion level, in terms of the mass loss of steel, was estimated to be 10% and 15%. Three non-strengthened specimens were tested as a reference: one control uncorroded specimen and two control specimens corroded with 10% and 15%. Ten specimens were strengthened using different techniques; replacement of the spilled concrete at the tension zone with 40-mm-thick high-performance polypropylene fiber–reinforced cementitious mortar, using external prestressing bars at the tension zone with adding 20-mm-thick high-performance polypropylene fiber–reinforced cementitious mortar at the compression zone, and a combination of these techniques. The prestressing reinforcing bars stress was chosen to be 0.25 fpy and 0.38 fpy for the corroded 10% specimens and 0.25 fpy for the corroded 15% specimens. A combination of 40-mm-thick high-performance polypropylene fiber–reinforced cementitious mortar at the tension side and external prestressing bars at the tension zone increased the specimen capacity by 15% and 34% compared with the uncorroded and 10% corroded control specimens, respectively. A comparative study was conducted to evaluate the efficiency of various strengthening techniques. An analytical model was proposed in order to give design guidelines.

Grey Oyster Mushroom Biofarm for Small-Scale Entrepreneurship

This paper reports the productivity of a small-scale pilot biofarm of grey oyster mushroom (Pleurotus sajor-caju (Fr.) Sing.). The pilot was tested in Mekelle city (Ethiopia) in a brick-walled dark room. Growing structures were constructed by erecting three wood poles and fixing them with three wooden side bars at multiple locations to make a prism-shaped rack with multiple triangular open shelves, each capable of carrying one bag of spawned substrate. Mushroom substrates were prepared from maize stalk and wheat bran supplement. Pasteurized chopped maize stalk and wheat bran were mixed at the ratio of 10:0, 9:1, 8:2, and 7:3—yielding four treatments. Five kilograms of substrate was taken from each treatment and was mixed with one kilogram of gypsum to produce a growing mass. Each mass was spawned with 200 g of inoculum under aseptic conditions and put in polyethylene bags. The treatments were replicated thrice and the bags were put on the growth racks in completely randomized design. The growing room was maintained at optimum conditions. Maize stalk substrates supplemented with 10% and 20% of wheat bran have resulted in statistically comparable productivities but statistically significantly higher than those grown on nonsupplemented and highly supplemented maize stalk substrates (p ≤ 0.05). The ingenuity of the design and the convenience of the construction of the racks, the availability of the substrates, and the simplicity of the management and maintenance of the biofarm rendered the piloted design suitable for home-based and small- and medium-scale mushroom biofarm entrepreneurship.

Compressive behavior of FRP externally wrapped R.C. column with buckling effects of longitudinal bars

In this paper, a calculation model to simulate the compressive behavior of R.C. columns with square cross-sections externally wrapped with FRP, including buckling effects of the longitudinal bars and reduction of the confinement pressure induced by the buckled compressed bars, is presented and discussed. The model distinguishes the cases of corner and side bars, calculating the different critical lengths and the critical loads. The Teng et al. (2009) model was adopted to predict the compressive behavior of FRP-confined concrete, and the Dhakal and Maekawa (2002) model was taken into account to predict the compressive behavior of longitudinal bars. The critical length and critical stress of compressed bars including interaction effects between concrete cover, stirrups and FRP wraps were calculated, distinguishing between corner and side bars. Based on the model mentioned, analytical expressions were derived to calculate the critical strain at the onset of bar buckling and the minimum thickness of FRP to prevent instability of the compressed bars. Finally, a theoretical–experimental comparison was made to validate the model.

Towards a Transferable UAV-Based Framework for River Hydromorphological Characterization.

The multiple protocols that have been developed to characterize river hydromorphology, partly in response to legislative drivers such as the European Union Water Framework Directive (EU WFD), make the comparison of results obtained in different countries challenging. Recent studies have analyzed the comparability of existing methods, with remote sensing based approaches being proposed as a potential means of harmonizing hydromorphological characterization protocols. However, the resolution achieved by remote sensing products may not be sufficient to assess some of the key hydromorphological features that are required to allow an accurate characterization. Methodologies based on high resolution aerial photography taken from Unmanned Aerial Vehicles (UAVs) have been proposed by several authors as potential approaches to overcome these limitations. Here, we explore the applicability of an existing UAV based framework for hydromorphological characterization to three different fluvial settings representing some of the distinct ecoregions defined by the WFD geographical intercalibration groups (GIGs). The framework is based on the automated recognition of hydromorphological features via tested and validated Artificial Neural Networks (ANNs). Results show that the framework is transferable to the Central-Baltic and Mediterranean GIGs with accuracies in feature identification above 70%. Accuracies of 50% are achieved when the framework is implemented in the Very Large Rivers GIG. The framework successfully identified vegetation, deep water, shallow water, riffles, side bars and shadows for the majority of the reaches. However, further algorithm development is required to ensure a wider range of features (e.g., chutes, structures and erosion) are accurately identified. This study also highlights the need to develop an objective and fit for purpose hydromorphological characterization framework to be adopted within all EU member states to facilitate comparison of results.

Design and Development of Portable Crane in Production Workshop: Case Study in BISHOPTU AUTOMOTIVE INDUSTRY, Ethiopia

This portable crane uses a hydraulic system to lift a heavy loads applying only small force. The main advantage of the project is having detail design of the mechanism in the production workshop of BISHOFTU AUTOMOTIVE INDUSTRY; Ethiopia is that it is portable, moveable, and easy for operation. In this project we designed and produced a portable crane which can lift a heavy load with a maximum capacity of 3 ton. The crane has two loaded side bars to make the base and two links (i.e. Vertical column and boom) connected each other by using pin joint. The Vertical column is secured on the cross bar that is welded to the side bars making the base using bolt connection. There are also other bars for supporting purpose which are connected to the basic link (vertical column) using bolt connection. The crane uses four wheels, of which two of them in the front are connected to the base using permanent joint and the rear wheel is connected to the base using roller. Since the crane operates hydraulically there is piston cylinder device which is connected to the vertical column and boom for lifting up and down the objects. The maximum carrying capacity 3 ton, and maximum lifting height is estimated as greater than greater than 2.96m from the ground run by using 3KW electric motor rotating 2830/3620 rpm.

AEOLIAN FORMS IN THE AMUR RIVER FLOODPLAIN

The paper presents the results of a complex study of the structure, age, genesis and evolution of riolkas – relatively high sand ridges found in the floodplain of River Amur (Russian Far East) and lower reaches of tributary valleys. Spatial distribution of riolkas and natural conditions of their development were assessed. Grainsize data pointed at fine-grained alluvia from channel side bars and levees as sources of material for riolka formation. It was shown that their development occurred during the epochs of more arid climate in the end of the Holocene when aeolian processes were more active than now. Present-day high aeolian forms are rather rare in the Amur region.

Quantifying the Effect of Aerial Imagery Resolution in Automated Hydromorphological River Characterisation

Existing regulatory frameworks aiming to improve the quality of rivers place hydromorphology as a key factor in the assessment of hydrology, morphology and river continuity. The majority of available methods for hydromorphological characterisation rely on the identification of homogeneous areas (i.e., features) of flow, vegetation and substrate. For that purpose, aerial imagery is used to identify existing features through either visual observation or automated classification techniques. There is evidence to believe that the success in feature identification relies on the resolution of the imagery used. However, little effort has yet been made to quantify the uncertainty in feature identification associated with the resolution of the aerial imagery. This paper contributes to address this gap in knowledge by contrasting results in automated hydromorphological feature identification from unmanned aerial vehicles (UAV) aerial imagery captured at three resolutions (2.5 cm, 5 cm and 10 cm) along a 1.4 km river reach. The results show that resolution plays a key role in the accuracy and variety of features identified, with larger identification errors observed for riffles and side bars. This in turn has an impact on the ecological characterisation of the river reach. The research shows that UAV technology could be essential for unbiased hydromorphological assessment.

Mathematical Modeling of Local Scour at Slender and Wide Bridge Piers

Most existing equations for predicting local scour at bridge piers suffer from overprediction of the scour depths which results in higher foundation costs. To tackle this problem, a mathematical model for predicting bridge pier scour is developed herein based on an energy balance theory. The present study equation was compared to commonly used bridge scour equations using scour field data in USA. The developed equation has several advantages among which we have the following: it adds to the understanding of the physics of bridge pier scour, is valid for slender and wide piers, does not suffer from overprediction of scour depths, addresses clear water and live bed scour, and includes the effects of various characteristics of the bed material such as specific gravity (or density), porosity, size, and angle of repose. In addition, the developed equation accounts for the debris effect and aids in the design of scour mitigation methods such as collars, side bars, slots, and pier protective piles.