Land/water classification : a review of water classifications and proposals for water integration into ecological land classification

Abstract

Apart from its value to nearly all human activity and settlement, water is one of the major land cover types in Canada. Sound planning of an area and its natural resources therefore requires basic data on landforms, soils, vegetation, wildlife, climate and water. However, while many ecological land surveys have been conducted in Canada, few include water information in their data bases. I propose that this omission be rectified, following the principles outlined in this paper. Ecological land survey uses a hierarchy of levels of generalization in order to portray land resources. The internal logic of this hierarchy, which is mostly functional, is marred by one level, the so-called Land System, which has a morphological definition. Land/Water Integration would be difficult in such an inconsistent hierarchy, and so a revised unit is defined with the name of land section (ecosection). The term land system (ecosystem) is reserved for any tract of land which has the properties of a general system appropriate to its size. Classifications of lakes, rivers and shorelines are discussed. Lakes are generally classified according to (1) the surrounding land environment, (2) the morphometry of the lake itself, (3) water quality, or (4) water regime. The selection of properties for river classification is scale dependent, ranging from (1) small plot runoff, through (2) bedforms (hydraulics) (3) channel morphology, (4) habitat, (5) valley form, (6) drainage networks and (7) patterns to (8) river basin regime at continental scales. Most classifications of rivers and lakes have been for research, In contrast, shorelines are notably classified for planning and management purposes. They are generally quite detailed, use one or a combination of topographic, geologic or botanic features, and map either separate components of each site (offshore, beach, backshore, etc.) or characteristic assemblages.