## Point Classification (Ridges and valleys)

Now also includes:

• Pennnock Landform Classification (Pennock,D.J., Zebarth,B.J., and De Jong,E., 1987. Landform Classification and Soil Distribution in Hummocky Terrain, Saskatchewan, Canada. Geoderma, 40: 297-315.), using WhiteBox.
• Iwashashi and Pike Classification

### Draw Ridge/valley Map

Wood (1996) algorithm Simple algorithm Simple 2 algorithm  (tolerance 5)

### Draw Simple 2 Ridge/valley Map

Simple 2 algorithm (tolerance 7) Simple 2 algorithm  (tolerance 6) Simple 2 algorithm (tolerance 5, same as above)

 Ridge Mask Wood (1996) algorithm Simple algorithm Simple 2 algorithm

Simple:

if (z < znw) and (z < zn) and (z < zne) and  (z < zsw) and (z < zs) and (z < zse) and (z < zw) and (z < ze) then Result := PitPoint
else if (z = znw) and (z = zn) and (z = zne) and (z = zsw) and (z = zs) and (z = zse) and (z = zw) and (z = ze) then Result := FlatPoint
else if (z > znw) and (z > zn) and (z > zne) and (z > zsw) and (z > zs) and (z > zse) and (z > zw) and (z > ze) then Result := PeakPoint
else if ((zn > znw) and (zn > zne)) and ((z > zw) and (z > ze)) and ((zs > zsw) and (zs > zse)) then Result := RidgePoint {NS trend}
else if ((zw > znw) and (zw > zsw)) and ((z > zn) and (z > zs)) and ((ze > zne) and (ze > zse)) then Result := RidgePoint {WE trend}
else if ((zn < znw) and (zn < zne)) and ((z < zw) and (z < ze)) and ((zs < zsw) and (zs < zse)) then Result := ValleyPoint {NS trend}
else if ((zw < znw) and (zw < zsw)) and ((z < zn) and (z < zs)) and ((ze < zne) and (ze < zse)) then Result := ValleyPoint {WE trend}
else Result := OtherPoint;

Simple 2:

Of 8 neighbors, count those higher and lower

if Higher = 8 then Result := PitPoint
else if Lower = 8 then Result := PeakPoint
else if (Higher = 0) and (Lower = 0) then Result := FlatPoint
else if (Higher >= RidgeValleyTolerance) then Result := ValleyPoint
else if (Lower >= RidgeValleyTolerance) then Result := RidgePoint
else Result := OtherPoint;

### Compare to:

Last revision 3/2/2023