A Surface Area-Volume Relationship for Prairie Wetlands in the Upper Assiniboine River Basin, Saskatchewan

The proliferation of geographical information system applications in hydrology and spatially distributed hydrologic models, all using areal input data, has created a need for a simple technique for estimating the storage volumes of wetland areas. Prompted by a hydrologic basin study in support of a Federal/Provincial study of the upper Assiniboine River basin in Saskatchewan, surface area-volume data sets for 177 wetland sites were analysed using regression analysis techniques. A composite relationship was derived, made up of two regression formulae, one for use with wetland areas under 70 hectares and a second for wetland areas between 70 and 500 hectares. A comparison was made between the composite area-volume relationship resulting from this study and similar area-volume relationships derived for two Iowa river basins in 1967. Although the two Iowa regression formulae compare reasonably well with the results of this study for wetland areas under six hectares, volumes derived by the three relationships diverge rapidly for areas greater than six hectares. Further analyses of wetland area-volume relationships using data from other areas of the prairie region could lead to the development of a suite of formulae which could eventually be consolidated and distributed into regional zones of application for use by the water resource community.