Transcript Nugget

Hypsometry of canyons and gullies in the central US Atlantic slope
Dina Vachtman and Neil C. Mitchell, The University of Manchester, UK
Hypsometric curves represent the distribution of area with elevation in landscapea. Such curves calculated for
the Atlantic slope are treated as cumulative probability functions so that gross canyon shapes can be
parameterised in terms of simple statistics (skewness, kurtosis and integral).
Based on such statistical attributes, we have
identified four hypsometric curve types: toeless
concave, S-shaped, flattened-J-shaped and convex.
Toeless concave
S-shaped
1
Convex
These types turn out to correspond remarkably well to network
geometries in plan-view. Narrow networks (straight trellis
patterns - types I, II) correspond to toeless concave and Sshaped hypsometric curves. In contrast, networks with smaller
aspect ratios and more highly branched (types III, IV)
correspond with flattened-J-shaped and convex curves.
These linkages have been surprising and may suggest an
underlying control of erosion process on large-scale form,
presently being investigated.
DIF
FUS
IVE
-LIK
E
0.8
Relative elevation
J-shaped
SKEWNESS SMALL
INTEGRAL LARGE
0.6
0.4
0.2
0.0
0.0
AD
VEC
TIV
E-L
IKE
SKEWNESS LARGE
INTEGRAL SMALL
0.2
0.4
0.6
0.8
1
Relative area
Type I
Type II
Type III
Type IV