TopWidth Function

private function TopWidth(y, B0, alpha) result(b)

returns the topwidth of a triangular, rectangular or trapezoidal cross section

Reference:

Todini, E. (2007) A mass conservative and water storage consistent variable parameter Muskingum-Cunge approach, Hydrol. Earth Syst. Sci.,1645-1659.

Arguments

Type IntentOptional Attributes Name
real(kind=float), intent(in) :: y

water stage (m)
real(kind=float), intent(in) :: B0

bottom width, = 0 for triangular section (m)
real(kind=float), intent(in) :: alpha

angle formed by dykes over a horizontal plane (deg)

Return Value real(kind=float)


Variables

Type Visibility Attributes Name Initial
real(kind=float), public :: calpha

cotangent of angle alpha

Source Code

FUNCTION TopWidth &
( y, B0, alpha ) &
RESULT (b)


IMPLICIT NONE

! Function arguments
! Scalar arguments with intent(in):
REAL (KIND = float), INTENT (IN) :: y !!water stage (m)
REAL (KIND = float), INTENT (IN) :: B0 !!bottom width, = 0 for  triangular  section (m)
REAL (KIND = float), INTENT (IN) :: alpha !!angle formed by dykes over a horizontal plane (deg)

! Scalar arguments with intent(OUT):
REAL (KIND = float) :: b
REAL (KIND = float) :: calpha !!cotangent of angle alpha

!------------end of declaration------------------------------------------------
calpha = 1. / TAN(alpha*degToRad)

b = B0 + 2 * y * calpha

RETURN
END FUNCTION TopWidth