National Ecological Framework (9 of 23)

Local Surface Form

These data are presented as a set of components within each polygon.  The following attributes are included:

Name Description
CMP Component Number (arbitrary)
Percent Percent of polygon occupied by the component
Surface Local Surface Form

Descriptions define classes of local physical surface forms (assemblage of slopes) or recurring patterns of forms which occur at the earth's surface. When applied to consolidated materials, form refers to the product of their modification by geological processes.  The following table shows the class definitions that are used.


Code Class Description
D DISSECTED A dissected (or gullied) pattern providing external drainage for an area.
H HUMMOCKY (or Irregular) A very complex sequence of slopes extending from somewhat rounded concavities (or swales) of various sizes to irregular conical knolls (or knobs) and short discontinuous ridges; there is a general lack of concordance between knolls and swales. Slopes are generally 4-70%. Examples are hummocky moraines and hummocky fluvioglacial landforms.
I INCLINED A sloping, unidirectional surface with a generally constant slope unbroken by marked irregularity or gullies; a weakly developed dissected pattern provides external drainage for the local area. Slopes are 2-70%; the form of inclined slopes is not related to the initial mode of origin of the underlying material.
L LEVEL A flat or very gently sloping, unidirectional surface with a generally constant slope unbroken by marked elevations and depressions. Slopes are generally <2%. Examples are floodplains and lake plains.
O ROLLING A very regular sequence of moderate slopes extending from rounded and, in some places, confined concave depressions to broad, rounded convexities producing a wavelike pattern of moderate relief. Slope gradients are generally >5% but may be less. The underlying bedrock usually controls this surface form.
R RIDGED A long, narrow elevation of the surface, usually sharp crested with steep sides; ridges may be parallel, subparallel, or intersecting. Examples are eskers, crevasse fillings, washboard moraines and some drumlins.
S STEEP Erosional slopes of >70%, present on both consolidated and unconsolidated materials. An example is an escarpment.
T TERRACED Scarp face and the horizontal or gently inclined surface (or tread) above it. An example is an alluvial terrace.
U UNDULATING A very regular sequence of gentle slopes that extends from rounded and, in some places, confined concavities to broad, rounded convexities producing a wave like pattern of low local relief. Slope length is generally <0.8 km and the dominant gradient of slopes is usually 2-5%. The terrain lacks an external drainage pattern. Examples are some ground moraines and lacustrine material of varying textures.


Wetland is defined as land that is saturated with water long enough to promote wetland or aquatic processes as indicated by poorly drained soils, hydrophytic vegetation. They include peatlands that are characterized by more than 40 cm of peat accumulation on which Organic soils develop. Peat consists of largely organic residues originating under more or less water-saturated conditions through the incomplete decomposition of plant and animal constituents. 

Code Class Description
B BOG A peatland with the water table at or near the surface. The bog surface, which may be raised or level with those of the surrounding wetlands, is virtually unaffected by the nutrient rich ground waters from the surrounding mineral soils and is thus generally acidic and low in nutrients. The soils are mainly Fibrisols, Meisisols, and Organic Cryosols. The bogs may be treed or treeless, and they are usually covered with sphagnum mosses, and ericaceous shrubs.
F FEN A peatland with a water table usually at or above the surface. The waters are mainly nutrient-rich, minerotrophic waters from mineral soils. The soils are mainly Mesisols, Humisols, and Organic Cryosols. The vegetation consists dominantly of sedges, grasses, reeds, and brown mosses with some shrub cover and, at times, a sparse tree layer.
M MARSH A mineral wetland or a peatland that is periodically inundated by standing or slowly moving waters. Surface waters may fluctuate seasonally, with declining levels exposing drawdown zones of matted vegetation or mudflats. The waters are nutrient rich. The substratum usually consists of mineral material. The soils are dominantly Gleysols, with some Humisols, and Meisisols. Marshes characteristically show zonal or surface patterns comprised of pools or channels interspersed with unconsolidated stands of emergent sedges, grasses, rushes, and reeds, bordering grassy meadows and peripheral bands of shrubs or trees. 
S SWAMP A peatland or mineral wetland with standing or gently flowing waters occuring in pools or channels. The water table is usually at or near the surface. There is pronounced water movement from the margin or other mineral sources, hence the waters are rich in nutrients. If peat is present, it is mainly well-decomposed forest peat, underlain at times by fen peat. The associated soils are Meisisols, Humisols, and Gleysols. Vegetation is characterized by a dense tree or shrub cover of deciduous or coniferous species, herbs, and some mosses.


Soil Landscapes of Canada (SLC) V.2.2(1996), National Soil DataBase, Canadian Soil Information System.  Available at : /cansis/nsdb/slc/v2.2/

Shields, J. A., C. Tarnocai, K.W.G. Valentine, and K. B. MacDonald. 1991. Soil Landscapes of Canada - Procedures Manual and User's Handbook. LRRC Contribution Number 88-29, Land resource Research Centre, research Branch, Agriculture Canada, Ottawa, 74 pp. This manual is superceded by the internet version available at: /cansis/nsdb/slc/

National Wetlands Working Group. 1986. Canada's Wetlands. Map Folio. Energy, Mines and Resources Canada and Environment Canada, Ottawa.