AS 3778.1-2009 pdf free download

AS 3778.1-2009 pdf free download.Measurement of water flow in open channels Part 1: Hydrometric determinations Vocabulary and symbols.
1.155
live storage
reservoir stoi’age which can be drawn off for users downstream
1.156
total storage
reservoir storage between the lowest bed level and the top water level
1.157
flood storage
volume of water temporarily held above the top water level of a reservoir during a flood event
NOTE Flood storage is not retained in the reservoir but Is discharged through an overflow until the normal top water level is reached.
1.158
boundary condition
condition to be satisfied by a dependent variable of a differential equation along the boundary of a model domain
NOTE Boundary conditions for the dependent variables are specified at the physical extremibes of the modelled region for the duration of the model application.
1.159
Courant condition
condition for the numerical stability of the explicit formulation of a numerical scheme which requires that the ratio (Cr) of the propagation speed of a physical disturbance to that of a numerical signal should not exceed unity, Le. Cr 1
NOTE The condition is a requirement for an explicit-finite difference formulation applied to a hyperbolic partial differential equation.
1.160
explicit finite-difference numerical scheme
scheme which converts either the characteristic equation or the governing equation into an equation from which any unknown may be evaluated directly (explicitly) without an iterative computation
NOTE 1 Dependent variables on the advanced time level are determined one point at a time from known values and conditions at the present or previous time levels.
NOTE 2 The stability of an explicit scheme Is conditional upon an error being a function of the time and distance finite- difference step sizes wtich may result in an error growing as the so’ution progresses.
NOTE 3 When the Courant condition is met, resulting in limitations in the maximum time and distance steps which can be used, generally an explicit scheme Is stable, but there can be instances of instability.
NOTE 4 If the converted equation is linear and algebraic, an iterative computation is not needed.AS 3778.1-2009 pdf free download.