the manning roughness coefficient is an important parameter in the design and evaluation of furrow irrigation. despite its importance, estimation of this parameter for surface irrigation is very difficult, particularly in furrow irrigation. in this study, an evalue model was used to estimate the manning roughness coefficient in furrow irrigation. the model was based on volume balance and develo...

diffusivity equation commonly used for pressure distribution prediction in porous media results from substituting equation of state and continuity equation in navier-stokes momentum equation. from mathematical point of view this equation format shows infinite propagation speed for pressure pulse through porous media, which is physically impossible. this issue may caused by numerous assumptions ...

In this paper, we intend to solve special kind of ordinary differential equations which is called Heun equations, by converting to a corresponding stochastic differential equation(S.D.E.). So, we construct a stochastic linear equation system from this equation which its solution is based on computing fundamental matrix of this system and then, this S.D.E. is solved by numerically methods. Moreo...

Evaluation and modeling of soil water infiltration are essential to all aspects resources management the design hydraulic structures. Nonetheless, research focused on experimental studies rates in arid semi-arid regions under unknown boundary conditions remains minimal. This paper investigates characteristics spatial variability over a rural basin Algeria. The experiments were conducted using p...

won{gil park [won{gil park, j. math. anal. appl., 376 (1) (2011) 193{202] proved the hyers{ulam stability of the cauchy functional equation, the jensen functional equation and the quadraticfunctional equation in 2{banach spaces. one can easily see that all results of this paper are incorrect.hence the control functions in all theorems of this paper are not correct. in this paper, we correctthes...