Discharge Width Research Articles

Quantifying Predictive Uncertainty and Feature Selection in River Bed Load Estimation: A Multi-Model Machine Learning Approach with Particle Swarm Optimization

This study presents a comprehensive multi-model machine learning (ML) approach to predict river bed load, addressing the challenge of quantifying predictive uncertainty in fluvial geomorphology. Six ML models—random forest (RF), categorical boosting (CAT), extra tree regression (ETR), gradient boosting machine (GBM), Bayesian regression model (BRM), and K-nearest neighbors (KNNs)—were thoroughly evaluated across several performance metrics like root mean square error (RMSE), and correlation coefficient (R). To enhance model training and optimize performance, particle swarm optimization (PSO) was employed for hyperparameter tuning across all the models, leveraging its capability to efficiently explore complex hyperparameter spaces. Our findings indicated that RF, GBM, CAT, and ETR demonstrate superior predictive performance (R score > 0.936), benefiting significantly from PSO. In contrast, BRM displayed lower performance (0.838), indicating challenges with Bayesian approaches. The feature importance analysis, including permutation feature and SHAP values, highlighted the non-linear interdependencies between the variables, with river discharge (Q), bed slope (S), and flow width (W) being the most influential. This study also examined the specific impact of individual variables on model performance by adding and excluding individual variables, which is particularly meaningful when choosing input variables for the model, especially in limited data conditions. Uncertainty quantification through Monte Carlo simulations highlighted the enhanced predictability and reliability of models with larger datasets. The correlation between increased training data and improved model precision was evident in the consistent rise in mean R scores and reduction in standard deviations as the sample size increased. This research underscored the potential of advanced ensemble methods and PSO to mitigate the limitations of single-predictor models and exploit collective model strengths, thereby improving the reliability of predictions in river bed load estimation. The insights from this study provide a valuable framework for future research directions focused on optimizing ensemble configurations for hydro-dynamic modeling.

Siting Considerations for Satellite Observation of River Discharge

AbstractWith growing global capability for satellite measurement of river discharge (flow) comes a need to understand and reduce error in satellite‐based discharge measurements. Satellite‐based discharge estimates are based on measurements of water surface width, elevation, slope, and potentially velocity. Site selection is important for reducing error and uncertainty in both conventional and satellite‐based discharge measurements because geomorphic river characteristics have strong control over the relationships between discharge and width, water surface elevation (or depth), slope, and velocity. A large ground‐truth data set of 8,445 conventional hydraulic measurements, collected by acoustic Doppler current profilers at 503 stations in the United States, was developed and quality assured to examine correlation between river discharge and water surface width, depth, velocity, and cross‐sectional area. A separate database of river surface slope and discharge time‐series was developed from paired continuous monitoring stations to examine slope‐discharge correlations. Results show that discharge correlates most strongly with velocity, cross‐sectional area, depth, width, and slope, in that order. Uncertainty of satellite discharge estimates is affected by observed hydraulic variable and reach‐specific variability in observed variable(s) characteristics including range of variability, georegistration accuracy, and stability over time of relationships between discharge and observed hydraulic variable.

Impact of Levee-Breach Width on the Channel–Levee–Floodplain: A Case Study in the Huaihe River Basin, China

Breach geometry is one essential feature for flood modelling in the channel–levee–floodplain system. It is hard to accurately predict the breach geometry because of its high uncertainty. However, due to the fact that breach geometry direct impacts the flow through the breach, the water surface profile in the channel and the flood hazard factors within the floodplain are changed with the breach geometry. To explore the impacts of breach width (one feature of the breach geometry) on the channel–levee–floodplain system, we took the Cinan Feiyou Flood Control Protection Area (CNFY-FCPA) in the middle reach of the Huaihe River Basin as the study area. We constructed a coupled 1D-2D hydrodynamic model to simulate the flooding with a series of breach-width scenarios. According to the simulation results of the models, we quantitatively analyzed the impacts of breach width on the inflow through the breach, fluvial flood process, and flood hazard factors in the CNFY-FCPA. The results indicate that (i) the relationship between the peak discharge (and inflow volume) and breach width was approximate to an S-shaped curve, while the peak discharge, inflow volume, and duration per unit width decreased with the wider breach; (ii) the breach caused a decrease in the water surface profile along the entire river sections; and (iii) while the breach width exceeded a certain width, the inundation area was nearly stable without changing with wider breach. The certain width was not the same in different rivers of 300 m in the Yinghe River and of 500 m in the Huaihe River. The research results can provide a scientific basis for flood-control and disaster-reduction decision making.

The eco-hydraulics base as flood mitigation to overcome erosion and sedimentation problems: A case study in the Lae Kombih River, Indonesia

Erosion and sedimentation have a very big influence on flooding. Floods are strongly influenced by land use and population activities that change the river’s physical condition, including erosion and sedimentation. The river upstream was very steep, and the downstream was narrowing and meandering with high rainfall recorded. This study analyses erosion, sedimentation, and its handling using the eco-hydraulic base. The method involves input rainfall data, river hydraulics, land use, watershed area, and land cover. The analysis of hydrology, hydraulics, land use, flood discharge, and eco-hydraulic, inundation height, vegetation diameter, velocity reduced, and riverbank width measured in five bridges cross-sections along the river. The eco-hydraulic compares the width of existing riverbanks and design, high inundation, and the vegetation diameter to minimise flood discharge. Erosion in the right cliff is 22.73% and the left cliff is 37.04%, land erosion was 225.83 Mg∙ha –1∙year –1. The river’s bottom is formed by rocks of 0.18–1.30 mm. The plantation land used around the Lae Kombih River grows mainly an oil palm with a diameter of 0.5–0.7 m. The riverbank design on 100 m for vegetation diameter of 0.1–1.0 m can retain flood discharge for five years return period up to 72.3%, resulting in discharge of 112.04209.43 m 3∙s –1. The largest erosion and sedimentation on the river border is Dusun Silak, so it is recommended to plant Vetiveria zizanioides, Ipomoea carnea and Bambusoideae. An inundation height of 0.9 m can be recommended to design an embankment to be used as flood mitigation.

Thermal performance of a lithium-ion battery thermal management system with vapor chamber and minichannel cold plate

An effective battery thermal management system is essential to maintain the operating temperature of lithium-ion batteries for electric vehicles in the optimum range and excellent temperature uniformity. In this work, a novel battery thermal management system based on a vapor chamber and minichannel cold plate is proposed to cool and preheat the battery module. A transient numerical simulation is developed and verified by experiments. The thermal characteristics of three battery thermal management systems are analyzed: natural convection cooling, minichannel cold plate cooling, and mixed minichannel cold plate and vapor chamber cooling. Subsequently, the effects of the discharge rate (1C, 2C, 3C), the arrangement and width of the minichannel cold plate, the coolant inlet velocity and coolant temperature on the cooling performance of the systems are investigated. The research results reveal that compared with natural convection cooling and minichannel cold plate cooling, mixed minichannel cold plate and vapor chamber cooling method exhibits lower maximum temperature and more uniform temperature distribution. When the batteries are discharged at 2C and the coolant temperature is 25 °C, the maximum temperature and temperature difference of the batteries can be maintained at 29.6 °C and 3.5 °C respectively. In addition, the preheating performance of the battery module at subzero temperature is also discussed. The results indicate that the proposed battery thermal management system with vapor chamber and minichannel cold plate also exhibits rapid heating capacity and excellent temperature uniformity.

Down‐delta hydraulic geometry and its application to the rock record

ABSTRACTPalaeodischarge estimation is largely undertaken within fluvial settings. However, there are limited palaeodischarge estimates specifically from delta deposits, despite their significance globally. Estimating water palaeodischarges for deltas using catchment‐based approaches developed using data from fluvial settings requires estimating parameters from the rock record (for example, palaeotemperature, palaeoslope and palaeorelief). These may be difficult to determine, leading to under‐estimation or over‐estimation of palaeodischarge values due to differences in process‐form relationships between alluvial rivers and deltas. When a sediment‐conveying fluvial channel enters a standing body of water, delta lobes develop through repeating mouth bar deposition due to flow deceleration, forming a deltaic morphology with distributary channel networks that differ morphologically from those developed in unidirectional flowing alluvial rivers. This study provides empirical relationships determined across five climate regions, using 3823 measurements of distributary channel width from 66 river deltas alongside the trunk river bankfull discharge that feeds into the entire delta, using a hydraulic geometry scaling approach. Empirical relationships are developed from the global delta dataset between bankfull discharge and catchment area (Qb–A), and bankfull discharge and median distributary channel width (Qb–Wmed). These empirical relationships produce very strong statistical correlations, especially between Qb and Wmed, across different climate regions (Qb = 0.34 Wmed1.48, R2 = 0.77). However, both Qb–A and Qb–Wmed relationships have outliers that may be explained by particular hydrological or geomorphic conditions. These new empirical relationships derived from modern systems are then applied to Cretaceous outcrops (Ferron Sandstone and Dunvegan Formation). The comparatively simple scaling relationships derived here produced palaeodischarge estimates within the same order of magnitude as palaeodischarge values previously obtained using existing, more complex approaches. This study contributes to source‐to‐sink investigations by enabling palaeodischarge estimates that intrinsically account for climate impacts on channel geometry at the time of deposition, using measurements of channel width or catchment area of a deltaic outcrop.

Hyporheic Exchange in a Straight Stream With Alternate Bars

AbstractHyporheic exchange (HE) is essential to riverine ecosystem, water quality, and energy cycling in a stream due to its governing role in physicochemical and biological processes in hyporheic zone (HZ). Alternate bars, characterized by a repetitive sequence of diagonal bars with a pool‐riffle bedform, are common geomorphic features that generally form in straight streams. Following similar laboratory and numerical methodology as Huang and Chui (2021, https://doi.org/10.1029/2020wr029182) who investigated the HE induced by pool‐riffle sequences, this study focused on the HE induced by alternate bars (i.e., geomorphic features on stream banks instead of streambed) where the influences of key factors were systematically examined. The results show that alternate bars strongly influence surface flow and induce significant hyporheic flows in both stream banks and streambed, whose patterns, magnitudes, and influential patterns of key factors could be similar to the HE induced by pool‐riffle sequences. The HE flowrate increases linearly with discharge, bed slope, and bar spacing. However, influential patterns of bar width on HE vary, and the bar width changes the influential patterns of discharge and bed slope on HZ scale, highlighting the influence of bar width in the complex interactions among discharge, bed slope, and bar width. All indicators of HE characteristics generally increase with bar spacing and follow exponential relationships with groundwater flow. Findings in this study lay the foundation in research on riparian ecosystems and water quality in the streams with alternate bars and help guide the design of bars during river restorations.

Effects of carbon, graphite, and graphene as propellant dopants in a laser-electric hybrid acceleration system

With the combination of laser ablation and electromagnetic acceleration, the laser–electric hybrid thruster is now perceived as an advanced propulsion system to support the precise maneuvering of microsatellites. To improve the performance of a laser–electric hybrid acceleration thruster, we used carbon, graphite, and graphene as dopants to modify the polymeric propellant fed into it. The impulse bit, consumed mass, discharge success rate, specific impulse, momentum coupling coefficient, and efficiency were measured and analyzed. Results showed that these three dopants led to higher values of impulse bit, specific impulse, discharge success rate, efficiency, and momentum coupling coefficient. The samples doped with carbon and graphene yielded better performances than those doped with graphite. Furthermore, the propellant sample made of 5% graphene and 95% polytetrafluoroethylene yielded the highest impulse bit of 394.7 μN·s, largest specific impulse of 1012.05 s, highest momentum coupling coefficient of 16.21 N/MW, and maximal efficiency of 8.21%. Furthermore, we compared the performances of the doped samples at different filling ratios and different operations. It was found that 5% was the optimal doping ratio for the dopants of carbon and graphene, and a higher discharge width could effectively improve the performances of the carbon-doped and graphene-doped samples.

Spaceborne River Discharge From a Nonparametric Stochastic Quantile Mapping Function

AbstractThe number of active gauges with open‐data policy for discharge monitoring along rivers has decreased over the last decades. Therefore, spaceborne measurements are investigated as alternatives. Among different techniques for estimating river discharge from space, developing a rating curve between the ground‐based discharge and spaceborne river water level or width is the most straightforward one. However, this does not always lead to successful results, since the river section morphology often cannot simply be modeled by a limited number of parameters. Moreover, such methods do not deliver a proper estimation of the discharge's uncertainty as a result of the mismodeling and also the coarse assumptions made for the uncertainty of inputs. Here, we propose a nonparametric model for estimating river discharge and its uncertainty from spaceborne river width measurements. The model employs a stochastic quantile mapping scheme by, iteratively: (a) generating realizations of river discharge and width time series using Monte Carlo simulation, (b) obtaining a collection of quantile mapping functions by matching all possible permutations of simulated river discharge and width quantile functions, and (c) adjusting the measurement uncertainties according to the point cloud scatter. We validate our method over 14 different river reaches along the Niger, Congo, Po Rivers, and several river reaches in the Mississippi river basin. Our results show that the proposed algorithm can mitigate the effect of measurement noise and also possible mismodeling. Moreover, the proposed algorithm delivers a meaningful uncertainty for the estimated discharge and allows us to calibrate the error bars of in situ discharge measurements.

River Extraction under Bankfull Discharge Conditions Based on Sentinel-2 Imagery and DEM Data

River discharge and width, as essential hydraulic variables and hydrological data, play a vital role in influencing the water cycle, driving the resulting river topography and supporting ecological functioning. Insights into bankfull river discharge and bankfull width at fine spatial resolutions are essential. In this study, 10-m Sentinel-2 multispectral instrument (MSI) imagery and digital elevation model (DEM) data, as well as in situ discharge and sediment data, are fused to extract bankfull river widths on the upper Yellow River. Using in situ cross-section morphology data and flood frequency estimations to calculate the bankfull discharge of 22 hydrological stations, the one-to-one correspondence relationship between the bankfull discharge data and the image cover data was determined. The machine learning (ML) method is used to extract water bodies from the Sentinel-2 images in the Google Earth Engine (GEE). The mean overall accuracy was above 0.87, and the mean kappa value was above 0.75. The research results show that (1) for rivers with high suspended sediment concentrations, the water quality index (SRMIR-Red) constitutes a higher contribution; the infrared band performs better in areas with greater amounts of vegetation coverage; and for rivers in general, the water indices perform best. (2) The effective river width of the extracted connected rivers is 30 m, which is 3 times the image resolution. The R2, root mean square error (RMSE), and mean bias error (MBE) of the estimated river width values are 0.991, 7.455 m, and −0.232 m, respectively. (3) The average river widths of the single-thread sections show linear increases along the main stream, and the R2 value is 0.801. The river width has a power function relationship with bankfull discharge and the contributing area, i.e., the downstream hydraulic geometry, with R2 values of 0.782 and 0.630, respectively. More importantly, the extracted river widths provide basic data to analyze the spatial distribution of bankfull widths along river networks and other applications in hydrology, fluvial geomorphology, and stream ecology.

Overtopping‐Induced Failure of Non–Cohesive Homogeneous Fluvial Dikes: Effect of Dike Geometry on Breach Discharge and Widening

AbstractLaboratory experiments were conducted to assess the influence of dike geometry on the breaching of non‐cohesive homogeneous fluvial dikes. Both the channel‐side and floodplain‐side dike slopes and the crest length were varied systematically. The time‐evolution of the breach discharge and breach width was monitored. Dikes having a larger volume per unit width lead to a more gradual increase in breach discharge and in breach width during the first stage of breach expansion (i.e., phase of rapid erosion). In contrast, the later stage of gradual breach widening is less influenced by the dike geometry. The breach hydrographs were observed to follow three distinct patterns, which are explained based on the relative magnitude of two characteristic time scales and of a normalized form of the dike unit volume.

Estimation of River Discharge from Satellite Observations

The role of streamflow is very important in any type of hydrologic. For very effective flood routing and hydraulic structure design, it is important to have a large dataset of past years. We now have a conceptual rainfall-runoff model that can predict streamflow based on pre-existing datasets. Because there is no or very little observed data in un-gauged basins, calibrating these models to predict daily streamflow becomes difficult. Nowadays, parameters for example river width can be observed using satellite images, and some studies show a promising associated relation between discharge and river width. The suggested study demonstrates a method for calculating streamflow from river width extracted with the help of satellite imagery. To predict streamflow, hydrological models are calibrated using river width instead of in site observed streamflow, and for estimating uncertainty Generalized Likelihood Uncertainty Estimation (GLUE) is used. For validation, the suggested method is implemented in the Kharun river basin situated in the Chhattisgarh state of India. The obtained Nash-Sutcliffe efficiency is 92.6 % for simulated river discharge in 2019-2020 at the 50% quantile, which is promising.

Comparative study of PTFE filled different dopants as propellants for laser-electric hybrid thruster

This study presents a broad comparison of samples, which are made of polytetrafluoroethylene (PTFE) filled with different dopants according to the same preparation steps, as propellants on a laser-electric hybrid thruster with a common design base. The impulse bit, specific impulse, efficiency and discharge success rate of the propellant samples were measured and analyzed under the same operation. The experimental results illustrated that the dopants of alloy could improve the impulse bit, that of salt could promote the stability of the discharge process, and the samples doped with oxide performed dramatic specific impulse and thrust efficiency. And three representative samples were adopted to investigate the dependence of propulsion characteristics on different working parameters in the respective doping ratios. It is found that the sample doped with TiO2 in lower doping rate was expected to rank maximal specific impulse and efficiency at most operations, especially under the conditions of low laser energy, long discharge width and high initial voltage. And the samples doped with Co–Cr alloy in low doping ratio appeared better performance at low discharge width and laser energy, while those in high doping ratio performed greater performance at high discharge width and laser energy.

Model-based ecological optimization of vertical slot fishways using macroinvertebrates and multispecies fish indicators

Fishway research has long focused on post-establishment assessments to optimize fish passage efficiency. Model-based optimization with the use of hydrodynamic-habitat models (HHMs) has rarely been employed to investigate passage suitability based on key hydraulic variables. In this study, a vertical slot fishway was designed, the hydraulic properties of twelve types that varied by slope, slot width and pool size were simulated using a two-dimensional HHM, and the suitability of macroinvertebrates and of seven fish groups, encompassing various guilds and size classes, was assessed for each fishway type at seven discharge scenarios, ranging from 0.1 m3/s to 1.3 m3/s. Suitability was primarily influenced by water depth. At optimal depths, suitability was fine-tuned by flow velocity to different optima per biotic group based on fixed interplays between discharge, slope and slot width: water depths were higher at high discharges, low slopes and narrow slots; flow velocities were higher at high discharges, high slopes and wide slots. Our ecologically optimal, multispecies, vertical slot fishway, had 5% slope and 30-cm wide slots, with discharges shifting between 0.15 m3/s and 0.6 m3/s to balance the needs of all species and life stages studied. Yet, even this optimal fishway could not guarantee 100% suitability for all species. The overall suitability was moderate (approx. 50–60%), higher at the pools and lower at the slots, and critically influenced by the type of substrate. We conclude that technical fishways cannot be simultaneously ideal for all species and life stages of a river reach/basin, due to the often-contrasting habitat preferences that need to be adapted to fixed interplays of hydraulic conditions. Within these limitations, however, model-based ecological pre-optimization is crucial for optimizing and deploying fishways that will guarantee suitable passage routes for a wide range of species and life stages, ultimately restoring the hydromorphological and ecological connectivity of dammed rivers.

Large wood as a confounding factor in interpreting the width of spring-fed streams

Abstract. Spring-fed streams throughout volcanic regions of the western United States exhibit larger widths than runoff-fed streams with similar discharge. Due to the distinctive damped hydrograph of spring-fed streams (as compared to large peaks visible in the hydrographs of runoff-fed streams), large wood is less mobile in spring-fed than runoff-fed stream channels, so wood is more likely to remain in place than form logjams as in runoff-fed streams. The consequent long residence time of wood in spring-fed streams allows wood to potentially have long-term impacts on channel morphology. We used high-resolution satellite imagery in combination with discharge and climate data from published reports and publicly available databases to investigate the relationship between discharge, wood length, and channel width in 38 spring-fed and 20 runoff-fed streams, additionally responding to a call for increased use of remote sensing to study wood dynamics and daylighting previously unpublished data. We identified an order of magnitude more logjams than single logs per unit length present in runoff-fed streams as compared to spring-fed streams. Histograms of log orientation in spring-fed streams additionally confirmed that single logs are immobile in the channel so that the impact of single logs on channel morphology could be pronounced in spring-fed streams. Based on these observed differences, we hypothesized that there should be a difference in channel morphology. A model for stream width in spring-fed streams based solely on length of wood is a better model than one derived from discharge or including both discharge and wood length. This study provides insights into controls on stream width in spring-fed streams.

Numerical Study of the Discharge Spatial Characteristics Influence on the KrF Laser Generation

A self-consistent two-dimensional model of the discharge KrF laser on Ne/Kr/F2 gas mixtures is described. The model predictions are compared with the experimental results for a KrF laser with an excitation pulse duration of ~ 30 ns. An agreement within 10% for the discharge current and laser energy is obtained. Evolution of the discharge width and of the radiation intensity distribution between the electrodes over the time of a radiation pulse is demonstrated. In addition, the effect of the electrode radii on laser energy is analyzed.

Study on the Discharge Characteristics of Single-Pulse Discharge in Micro-EDM.

To further study the discharge characteristics and machining mechanism of micro-electrical discharge machining (micro-EDM), the variation trends of the discharge energy and discharge crater size with actual discharge duration are discussed based on single-pulse experiments. The polarity effect of micro-EDM was analyzed according to the motion characteristics of electrons and ions in the discharge plasma channel. The results show that the discharge current and voltage of micro-EDM were independent of the discharge width and open-circuit voltage. The energy utilization rate of the short-pulse discharge was relatively high, and the energy utilization rate decreased gradually as the discharge duration increased. Even if the mass of the positive ion was much larger than that of the electron, the kinetic energy of the positive ion was still less than that of the electron when bombarding the surface of the electrode. The acceleration and speed of electrons were very high, and the number of times that electrons bombarded the surface of positive electrode was more than 600 times that of positive ions bombarding the surface of the negative electrode during the same time.

Air curtain effectiveness rating based on aerodynamics

An air curtain installed at a building entrance acts as a barrier against infiltration/exfiltration of airflow between the outdoor environment and the indoor space. Several factors may affect air curtain performance, including air discharge velocity, angle, door height and width, and indoor and outdoor conditions. The current methodological standards/codes evaluate air curtain performance based on 1). aerodynamics performance characterization through the measurements of the jet velocity distribution and degradation, and 2). the laboratory measurements of their effectiveness in terms of blocking infiltration/exfiltration rates with/without air curtains under different operating conditions, i.e. pressure difference across doors. The 1st method is easier to conduct but cannot directly evaluate the effectiveness of an air curtain in reducing infiltration/exfiltration. The 2nd method can evaluate each specific unit, though the tests are often prohibitively costly and time-consuming. This study developed a new cost-effective method to assess the aerodynamic performance of an air curtain with respect to its capability of reducing infiltration/exfiltration. This method was demonstrated by a case study and validated against previous experimental data. The new method was found to be more efficient and cost-effective for various air curtain products and installation scenarios, as compared to existing methods.

Experimental study of the local scouring around sloped piers and its estimation using statistical tools

Local scouring around sloped bridge piers in steady currents was studied both experimentally and mathematically. The effects of different inclination angles, flow intensities, flow depths, and pier size on local scouring were investigated. The experimental results show that the scouring depth increases with an increase in the values of discharge and pier width. The scouring depth for the sloped piers is smaller than the vertical piers one and the maximum scouring depth continuously decreases as the pier inclination angle increases. Prediction of the scouring depth around bridge piers using analytical models can be utilized in the feasibility studies of different models, and evaluations of the parametric analytical. Therefore, it was tried to model the scouring depth as a function of Froude number, flow intensity, and relative roughness parameters using non-dimensional analysis. The regression analysis based models were introduced to determine the scouring depth at upstream side of the pier using experimental tests data. Step-wise linear regression showed that the value of relative scouring depth has considerably good correlation only with two non-dimensionless parameters of inclination angle and normalized approaching flow depth. In this regard, some linear and nonlinear regression tools were utilized to establish functional relationships between these variables. Statistical indices and residual analyses of the models revealed the suitability of the models. Comparison of the experimental and predicted value of relative scouring depth illustrates that the suggested models can reasonably predict this parameter.

Development of Equations for Meander Movement Velocities by SCE Optimization Algorithm based on Experimental Study

Meandering rivers have a dynamic planform, which means that rivers move in radial direction with variable velocities. The movement velocities can be estimated from historical maps of specific river or using mathematical approach. There is not explicit method or suitable algebraic equation for estimation of river meander movement velocities. In this study, experiments were carried out in a laboratory flume, to develop novel equations to calculate meandering river movement velocities. We designated these empirical equations as the river resistance equations. The experiments were conducted with non-uniform, nonchosive sediment in a re-circulating flume with changeable slopes. The influence of bankfull discharge, bed slope and channel width on the meander movement velocities were discussed. Based on the experimental data, three novel empirical equations for prediction of Wx and Wexp and Wm were proposed. Moreover, the shuffled complex evolution (SCE) optimization algorithm was used to estimate the unknown parameters of the empirical equations. To validate SCE method, the result was compared with traditional multiple regression analysis. This comparison indicated that the SCE optimization algorithm outperformed the multiple regression analysis method in the empirical equations calibration.