in 3D. Spatial & Terrain Analysis. Nigel Trodd Coventry University. Aim & objectives. To understand the application of 2D+ terrain analysis in GIS. to review methods of 2D spatial analysis to identify 1st and 2nd order derivatives of DEM data
… improves communication & interaction
… is essential for environmental modelling
… drives new methods of data capture & management
without some basic
points, lines, areas
not a problem
2D + above, below
DEM, TIN, voxel
Point – none!
Line - length, mid-point
Area - perimeter, area, centroid, shape
Surface – mean, min, max, range, variance
Volume – volume, centroid
Berry, J.K., 1987, Fundamental operations in computer-assisted map analysis, International Journal of GIS1 119-36.
Reclassify & then merge adjacent areas with the same attribute i.e. change geometry
e.g., to determine areas impacted by a proposed highway
Which states share a border with Missouri?
output at a location calculated from the values at locations in a window
1st order derivative
2nd order derivative