/* -------------------------------------------------------------
HeadSlopeAspect
This computes slope and aspect using the water table elevation.
Comment: rewritten to fill the sinks (Ning, 2013)
------------------------------------------------------------- */
void HeadSlopeAspect(MAPSIZE * Map, TOPOPIX ** TopoMap, SOILPIX ** SoilMap,
float **FlowGrad, unsigned char ***Dir, unsigned int **TotalDir)
{
int x;
int y;
int n;
float neighbor_elev[NNEIGHBORS];
/* let's assume for now that WaterLevel is the SOILPIX map is
computed elsewhere */
for (x = 0; x < Map->NX; x++) {
for (y = 0; y < Map->NY; y++) {
if (INBASIN(TopoMap[y][x].Mask)) {
float slope, aspect;
for (n = 0; n < NNEIGHBORS; n++) {
int xn = x + xneighbor[n];
int yn = y + yneighbor[n];
if (valid_cell(Map, xn, yn)) {
neighbor_elev[n] =
((TopoMap[yn][xn].Mask) ? SoilMap[yn][xn].WaterLevel : (float) OUTSIDEBASIN);
}
else {
neighbor_elev[n] = (float) OUTSIDEBASIN;
}
}
slope_aspect(Map->DX, Map->DY, SoilMap[y][x].WaterLevel, neighbor_elev,
&slope, &aspect);
flow_fractions(Map->DX, Map->DY, slope, aspect, neighbor_elev,
&(FlowGrad[y][x]), Dir[y][x], &(TotalDir[y][x]));
}
}
}
return;
}
/* -------------------------------------------------------------
ElevationSlopeAspect
------------------------------------------------------------- */
void ElevationSlopeAspect(MAPSIZE * Map, TOPOPIX ** TopoMap)
{
const char *Routine = "ElevationSlopeAspect";
int x;
int y;
int n;
int k;
float neighbor_elev[NNEIGHBORS];
int tempdir[NDIRS];
int steepestdirection;
unsigned int sum;
float min;
int xn, yn;
/* fill neighbor array */
for (x = 0; x < Map->NX; x++) {
for (y = 0; y < Map->NY; y++) {
if (INBASIN(TopoMap[y][x].Mask)) {
/* Count the number of cells in the basin.
Need this to allocate memory for
the new, smaller Elev[] and Coords[][]. */
Map->NumCells++;
for (n = 0; n < NNEIGHBORS; n++) {
xn = x + xneighbor[n];
yn = y + yneighbor[n];
if (valid_cell(Map, xn, yn)) {
neighbor_elev[n] = ((TopoMap[yn][xn].Mask) ? TopoMap[yn][xn].Dem : (float) OUTSIDEBASIN);
}
else {
neighbor_elev[n] = (float) OUTSIDEBASIN;
}
}
slope_aspect(Map->DX, Map->DY, TopoMap[y][x].Dem, neighbor_elev,
&(TopoMap[y][x].Slope), &(TopoMap[y][x].Aspect));
/* fill Dirs in TopoMap too */
flow_fractions(Map->DX, Map->DY, TopoMap[y][x].Slope,
TopoMap[y][x].Aspect,
neighbor_elev, &(TopoMap[y][x].FlowGrad),
TopoMap[y][x].Dir, &(TopoMap[y][x].TotalDir));
/* Check that upslope neighbors && outsidebasin Dir = 0. */
for (n = 0; n < NDIRS; n++)
tempdir[n] = 0; /* initialize */
sum = 0;
for (n = 0; n < NDIRS; n++) {
xn = x + xdirection[n];
yn = y + ydirection[n];
if ((TopoMap[y][x].Dir[n] > 0) && valid_cell(Map, xn, yn)) {
if (!INBASIN(TopoMap[yn][xn].Mask)) {
/* Can never have flow in this direction.*/
(TopoMap[y][x].TotalDir) -= TopoMap[y][x].Dir[n];
TopoMap[y][x].Dir[n] = 0;
}
else if(TopoMap[yn][xn].Dem >= TopoMap[y][x].Dem) {
/* Will put flow in this direction if no other choice to
preserve water balance. */
(TopoMap[y][x].TotalDir) -= TopoMap[y][x].Dir[n];
tempdir[n]=TopoMap[y][x].Dir[n];
TopoMap[y][x].Dir[n] = 0;
}
}
else if((TopoMap[y][x].Dir[n] > 0) && valid_cell(Map, xn, yn)) {
/* Can never have flow in this direction, should not be
possible to get here. */
(TopoMap[y][x].TotalDir) -= TopoMap[y][x].Dir[n];
TopoMap[y][x].Dir[n] = 0;
}
sum+=TopoMap[y][x].Dir[n];
}
/* If there is a sink, check again to see if there
is a direction of steepest descent. Does not account
for ties.*/
steepestdirection = -99;
if(sum==0) {
min = DHSVM_HUGE;
for (n = 0; n < NDIRS; n++) {
xn = x + xdirection[n];
yn = y + ydirection[n];
if (valid_cell(Map, xn, yn)) {
if (INBASIN(TopoMap[yn][xn].Mask)) {
if(TopoMap[yn][xn].Dem < min)
{
min = TopoMap[yn][xn].Dem;
steepestdirection = n;
}}
}
}
if(min < TopoMap[y][x].Dem) {
TopoMap[y][x].Dir[steepestdirection] = (int)(255.0 + 0.5);
TopoMap[y][x].TotalDir = (int)(255.0 + 0.5);
}
else {
/* Last resort: set the Dir of the cell to the cell that is
closest in elevation. This should only happen for the
basin outlet, unless the Dem wasn't filled. */
TopoMap[y][x].Dir[steepestdirection] = (int)(255.0 + 0.5);
TopoMap[y][x].TotalDir = (int)(255.0 + 0.5);
xn = x + xdirection[steepestdirection];
yn = y + ydirection[steepestdirection];
}
}
} // end if (INBASIN(TopoMap[y][x].Mask)) {
}
} // end of for loops
/* Create a structure to hold elevations of only those cells
within the basin and the y,x of those cells.*/
if (!(Map->OrderedCells = (ITEM *) calloc(Map->NumCells, sizeof(ITEM))))
ReportError((char *) Routine, 1);
k = 0;
for (y = 0; y < Map->NY; y++) {
for (x = 0; x < Map->NX; x++) {
/* Save the elevation, y, and x in the ITEM structure. */
if (INBASIN(TopoMap[y][x].Mask)) {
Map->OrderedCells[k].Rank = TopoMap[y][x].Dem;
Map->OrderedCells[k].y = y;
Map->OrderedCells[k].x = x;
k++;
}
}
}
/* Sort Elev in descending order-- Elev.x and Elev.y hold indices. */
quick(Map->OrderedCells, Map->NumCells);
/* End of modifications to create ordered cell coordinates. SRW 10/02, LCB 03/03 */
return;
}