Debris flows propagating in natural environments often encounter irregular terrain features, such as bottom roughness and man-made structures like groundsills, which significantly influence their behavior dynamics. In practice, groundsills are commonly used debris flow mitigation structures. This study examines the effects of a beam-type groundsill array on sediment mixtures an inclined channel using numerical simulations. The mixtures, modeled Bingham fluids, were tested they flowed over...

Prediction of tide levels is one the important problems in determining schedule making activities or constructions coastal and oceanic area. Accurate predictions could not be obtained without a long length (about month more) measurements by conventional methods. A method using short (a few days) to predict over longer time proposed present paper. In method, harmonic level model used levels. The parameters model, that is, amplitudes components, are estimated Kalman filtering technique few-day...

Released from rest on an inclined smooth plane in a stationary fluid, sphere accelerates along the under influence of gravity and eventually reaches terminal velocity. The variations velocity with time distance, velocity, distance (the practical required for to its velocity), are investigated through laboratory experiments theoretical analysis. relationship drag coefficient Reynolds number moving is obtained compared that free fall. effect proximity sidewalls flume fluid acting steady...

To solve the equation of motion for a turbulent oscillatory boundary layer, suitable eddy viscosity model and its parameters are needed. The Businger-Arya type model, where form nearly linearly increases in lower part exponentially decays outer part, has been recognized as one most models. This three to be determined. In this paper, these calibrated by comparison with two-equation turbulence model.

A probabilistic equation of design discharge for a mountainous gully was derived in terms reliability probability. Its derivation based on the rational formula, rainfall-intensity-duration and First-Order Second-Moment method (FOSM) by considering uncertainty parameters, such as annual rainfall, runoff coefficient, watershed area, sediment concentration, length velocity overland flow, horizontal elevation difference gully, involved formulas. The also applied to debris-flow-prone Taiwan.

A two-dimensional empirical eigenfunction model is proposed to analyze and predict the variations of riverbed profile. This consists two along cross-river eigenfunctions one temporal eigenfunction. These can be generated based on a series measured profiles. The applied downstream Chou-Shui River in Taiwan. prediction also conducted by using with help Markov process model.A dimensionless effective flow discharge assigned forcing parameter predicting model, which controls changes. results show...

Stable channel design is important for conveying water among stakeholders in a safe and cost-effective manner. The current methods include the regime theory, permissible velocity method, tractive force method. Nevertheless, they are not yet conclusive, despite decades of study, because difficulties finding maximum bed sidewall shear stresses from Navier-Stokes equation. To advance stable design, we assume constant eddy viscosity apply Leighly's conformal mapping idea to equations rectangular...

This research presents investigations on the discharge coefficient of a circular orifice located at apex an inverted conical hopper attached to bottom cylindrical vortex chamber. A jet inflow tangentially enters chamber top periphery hopper. Different sizes orifices and discharges were applied in experiments investigate variation coefficient. The effect overflow upper outlet was also investigated. Based test data, empirical relations for are proposed. It is found that presence tangential...