Profile Curvature derived from 1" SRTM DEM-S

Full description

Profile curvature is the rate of change of potential gradient down a flow line and represents the changes in flow velocity down a slope. It is significant for flow acceleration, erosion/deposition rates and geomorphology.

The profile curvature product was derived from the Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016), which was derived from the 1 arc-second resolution SRTM data acquired by NASA in February 2000. The calculation of profile curvature from DEM-S accounted for the varying spacing between grid points in the geographic projection.

This collection includes Profile Curvature data at 1 arc-second and 3 arc-second resolutions.

The 3 arc-second resolution product was generated from the 1 arc-second profile curvature product and masked by the 3” water and ocean mask datasets.
Lineage: Source data
1.\t1 arc-second SRTM-derived Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016).
2.\t1 arc-second profile curvature product
3.\t3 arc-second resolution SRTM water body and ocean mask datasets

Profile Curvature calculation
Profile curvature was calculated from DEM-S using the finite difference method (Gallant and Wilson, 2000). The different spacing in the E-W and N-S directions due to the geographic projection of the data was accounted for by using the actual spacing in metres of the grid points calculated from the latitude.

The profile curvature calculation was performed on 1° x 1° tiles, with overlaps to ensure correct values at tile edges.

The 3 arc-second resolution version was generated from the 1 arc-second profile curvature product. This was done by aggregating the 1” data over a 3 x 3 grid cell window and taking the mean of the nine values that contributed to each 3” output grid cell. The 3” profile curvature data were then masked using the SRTM 3” ocean and water body datasets.


References
Gallant, J.C. and Wilson, J.P. (2000) Primary topographic attributes, chapter 3 in Wilson, J.P. and Gallant, J.C. Terrain Analysis: Principles and Applications, John Wiley and Sons, New York.