Introduction: The role of past and present water is the current focus of the Mars Exploration Program. Athabasca Valles is widely considered to be the site of the most recent major aqueous floods on Mars [1-5]. However, the previous models used to investigate the hydraulics of this flood had significant limitations. The goal of this project is to modify and apply a cutting-edge hydraulic model ...

Three methods have been used to experimentally determine the roughness function (DU) for several rough surfaces. These include the rotating disk, the towed plate, and the velocity profile methods. The first two are indirect methods in as much as they rely on measurements of overall torque or resistance and boundary layer similarity laws to obtain DU, whereas the velocity profile method provides...

The radar backscattering coefficient of three types of soil surfaces at observation angles (10°60°) have been calculated using integral equation model (IEM) for different values of root mean square (RMS) roughness heights and correlation lengths. The surfaces are represented by isotropic autocorrelation functions (exponential, 1.5 power and Gaussian). The dielectric constant (ε) of the soil, an...

On the basis of the Manning equation and basic mass conservation principles, we derive an expression for scaling the steadystate width (W) of river channels as a function of discharge (Q), channel slope (S), roughness (n), and width-to-depth ratio (!): W " [!(! # 2)2/3]3/8Q3/8S$3/16n3/8. We propose that channel width-todepth ratio, in addition to roughness, is a function of the material in whic...

abstract ground water flow and skin is the most important phenomenon in the process streams are involved not only in the face of the whole earth, but also of the life of man on earth can. degradation of coastal erosion, lateral stability and continuity in iran and around the world each year destroys fertilized agricultural lands around the river, coastal installations, bridges, and is general h...

Simultaneous measurements of the curves for wear versus distance, wear rate versus distance, and coefficient of friction versus distance were performed in situ to distinguish the transition from severe running-in wear to mild wear. The effects of the initial surface roughness on the severe running-in wear volume were investigated. Disk-on-plate friction and wear tests were carried out with SUS3...

The effect of structured roughness on the heat transfer of water flowing through minichannels was experimentally investigated in this study. The test channels were formed by two 12.7 mm wide 94.6 mm long stainless steel strips. Eight structured roughness elements were generated using a wire electrical discharge machining (EDM) process as lateral grooves of sinusoidal profile on the channel wall...

The Manning friction coefficient as a one-dimensional (1D) openchannel flow parameter is determined from a series of two-dimensional (2D) simulations of the flow on steep slopes using a computational hydraulic solver derived from a minimal intervention strategy (MIS2D). Computations are also conducted for the oblique dam-break waves to evaluate the performance of MIS2D. The results are compared...

Soil roughness is a very important parameter affecting radar backscattering coefficient. This paper wants to introduce a new method to retrieve the combined roughness parameter 2 / Zs s l = on the condition of rough surface. To achieve this goal, two experiments are conducted: (1) Advanced Integral Equation Model (AIEM) is used to simulate backscattering coefficients; and (2) a new algorithm to...