e.g. for computation interval, base on what “ras-help” has said, i choose 5min.
Is it ok to choose 20min for Hydrogragh output interval & 1hour for Detailed output interval?or these 2 components have specific way to choose?
In Ras help it’s just said “The Hydrograph Output Interval is used to define at what interval the computed stage and flow hydrographs will be written to HEC-DSS. This interval should be selected to give an adequate number of points to define the shape of the computed hydrographs without losing information about the peak or volume of the hydrographs. This interval must be equal to or larger than the selected computation interval.”
But,in fact i don’t get the point.would you plz explain it easier or whit an example?
tnx
i checked example applications and all of them,the unsteady ones, had used 0.1 and 0.3 for the coefficients.
where is that separate table for unsteady contraction and expansion coefficients, thad you mentioned?
In fact i wanna rout the flood hydrograph in downstream of a river with a constant triangle cross section.i have the river’s slope and the geometry of cross section but i don’t know whether the slope is necessary or not? and where in hec-ras should i enter it?
tnx but i don’t understand!
forexample for a river i just have a constant triangle cross section,whit the length of the river.
how hec-ras estimate & calculate the slope??