void landuse_getInitBuildup(Project* project, TLandFactor* landFactor, double* initBuildup,
double area, double curb)
//
// Input: landFactor = array of land use factors
// initBuildup = total initial buildup of each pollutant
// area = subcatchment's area (ft2)
// curb = subcatchment's curb length (users units)
// Output: modifies each land use factor's initial pollutant buildup
// Purpose: determines the initial buildup of each pollutant on
// each land use for a given subcatchment.
//
// Notes: Contributions from co-pollutants to initial buildup are not
// included since the co-pollutant mechanism only applies to
// washoff.
//
{
int i, p;
double startDrySeconds; // antecedent dry period (sec)
double f; // faction of total land area
double fArea; // area of land use (ft2)
double fCurb; // curb length of land use
double buildup; // pollutant mass buildup
// --- convert antecedent dry days into seconds
startDrySeconds = project->StartDryDays*SECperDAY;
// --- examine each land use
for (i = 0; i < project->Nobjects[LANDUSE]; i++)
{
// --- initialize date when last swept
landFactor[i].lastSwept = project->StartDateTime - project->Landuse[i].sweepDays0;
// --- determine area and curb length covered by land use
f = landFactor[i].fraction;
fArea = f * area * UCF(project,LANDAREA);
fCurb = f * curb;
// --- determine buildup of each pollutant
for (p = 0; p < project->Nobjects[POLLUT]; p++)
{
// --- if an initial loading was supplied, then use it to
// find the starting buildup over the land use
buildup = 0.0;
if ( initBuildup[p] > 0.0 ) buildup = initBuildup[p] * fArea;
// --- otherwise use the land use's buildup function to
// compute a buildup over the antecedent dry period
else buildup = landuse_getBuildup(project,i, p, fArea, fCurb, buildup,
startDrySeconds);
landFactor[i].buildup[p] = buildup;
}
}
}
void subcatch_getBuildup(int j, double tStep)
//
// Input: j = subcatchment index
// tStep = time step (sec)
// Output: none
// Purpose: adds to pollutant buildup on subcatchment.
//
{
int i; // land use index
int p; // pollutant index
double f; // land use fraction
double area; // land use area (acres or hectares)
double curb; // land use curb length (user units)
double oldBuildup; // buildup at start of time step
double newBuildup; // buildup at end of time step
// --- consider each landuse
for (i = 0; i < Nobjects[LANDUSE]; i++)
{
// --- skip landuse if not in subcatch
f = Subcatch[j].landFactor[i].fraction;
if ( f == 0.0 ) continue;
// --- get land area (in acres or hectares) & curb length
area = f * Subcatch[j].area * UCF(LANDAREA);
curb = f * Subcatch[j].curbLength;
// --- examine each pollutant
for (p = 0; p < Nobjects[POLLUT]; p++)
{
// --- see if snow-only buildup is in effect
if (Pollut[p].snowOnly
&& Subcatch[j].newSnowDepth < 0.001/12.0) continue;
// --- use land use's buildup function to update buildup amount
oldBuildup = Subcatch[j].landFactor[i].buildup[p];
newBuildup = landuse_getBuildup(i, p, area, curb, oldBuildup,
tStep);
newBuildup = MAX(newBuildup, oldBuildup);
Subcatch[j].landFactor[i].buildup[p] = newBuildup;
massbal_updateLoadingTotals(BUILDUP_LOAD, p,
(newBuildup - oldBuildup));
}
}
}
