Pennock et al. 1987

Pennock DJ, Zebarth BJ, De Jong E. 1987. Landform classification and soil distribution in hummocky terrain, Saskatchewan, Canada. Geoderma 40: 297-315.

These authors present a method of analysing irregular terrain for the purposes of examining important soil parameters such as soil depth and soil hydrology. Three variables (profile curvature, plan curvature, and gradient) can be calculated from a matrix of elevation data; taken together for a given point or area, these variables can be used to classify an area into one of seven landforms. These landforms are level (for summits or bottom lands), shoulders, backslopes, and footslopes; the three non-level forms come in “divergent” (convex plan) and “convergent” (concave plan) varieties. Shoulders have convex profiles, backslopes have flat profiles (i.e. constant gradient when looking up or down the slope), and footslopes are concave. Divergent landforms shed water laterally; convergent landforms tend to collect water. Where water collects and is moving slowly, rates of infiltration will be highest, and erosion will tend to deposit, rather than remove, material at these places.

The variables required to calculate profile and plan curvature and gradient are relatively easy to calculate from a matrix of elevation data, using an interpolating topographical software package and some differential calculus. The seven categories of slope elements can be estimated in the field by eye, making for a useful method for field studies.

This paper was on the recommended reading list for SLSC 834; in addition, the course instructor is Dr. Pennock, lead author of this study. The study site, near Hafford, Saskatchewan, is perhaps 1 to 1.5 hours drive away from Saskatoon, suggesting this area may be the destination of one of the day trips scheduled for the week of August 30, 2010.