Hello, I am modifying the LID controls from the text editor to perform a sensitivity analysis
What is the meaning of the fifth parameter assigned to infiltration trench surface layer and the fourth parameter to underdrain layer?
[LID_CONTROLS]
;; Type/Layer Parameters
;;-------------- ---------- ----------
IT-0.5% IT
IT-0.5% SURFACE 0 0 0.25 0.5 5
IT-0.5% STORAGE 2000 0.67 40 0
IT-0.5% DRAIN 0 0.5 0 6
Thank you.
Replies
Thanks, that was interesting about the canOverflow logic - it was something I missed viewing the code before. I am adding a collage image of the LID possibilities
The parameters for the Surface layer for LID modeling in SWMM 5 (the numbers are the column number on the input line):
The parameters for the Underdrain layer for LID modeling in SWMM 5 (the numbers are the column number on the input line):
Thank you very much, I found the following description on the executable file lid.c
(https://github.com/OpenWaterAnalytics/swmm/blob/master/src/lid.c)
Infiltration trench: the fifth parameter is designated as "canOverflow"
and
Underdrain: the fourth parameter represents the delay time
But it is not specifically included in the LID CONTROL EDITOR. I am using the PCSWMM Model.
Sorry for my English, thanks.
Eugenia.
//... for certain LID types, immediate overflow of excess surface water
// occurs if either the surface roughness or slope is zero
LidProcs[j].surface.canOverflow = TRUE;
switch (LidProcs[j].lidType)
{
case INFIL_TRENCH:
case POROUS_PAVEMENT:
case BIO_CELL:
case RAIN_GARDEN:
case GREEN_ROOF:
if ( LidProcs[j].surface.alpha > 0.0 )
LidProcs[j].surface.canOverflow = FALSE
Underdrain:
int readDrainData(int j, char* toks[], int ntoks)
//
// Purpose: reads underdrain data for a LID process from line of input
// data file
// Input: j = LID process index
// toks = array of string tokens
// ntoks = number of tokens
// Output: returns error code
//
// Format of data is:
// LID_ID DRAIN coeff expon offset delay
Thank you for reply , the fifth parameter is the swale side slope.
This is not available in the LID CONTROL editor. I must modify it in the text file, thanks.
/ Data Structures
//-----------------------------------------------------------------------------
// LID Surface Layer
typedef struct
{
double thickness; // depression storage or berm ht. (ft)
double voidFrac; // available fraction of storage volume
double roughness; // surface Mannings n
double surfSlope; // land surface slope (fraction)
double sideSlope; // swale side slope (run/rise)
double alpha; // slope/roughness term in Manning eqn.
char canOverflow; // 1 if immediate outflow of excess water
} TSurfaceLayer;