CGRG Bibliography of Canadian Geomorphology
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Author : Byrne, J.M.
Date : 1990.
Title : Three-phase runoff model for small prairie rivers.
Publication : Unpublished Ph.D. dissertation. University of Alberta, Edmonton.
Issue :
Page(s) : 315 p.
Abstract
The hydrologic processes of small, low-relief watersheds on the plains in southeastern Alberta are analyzed to determine the precipitation-runoff relationships under different soil fluid states; and to test the hypothesis that the state of the soil fluid has a dominant control on runoff generation. A conceptual runoff model based on the dominant state of the soil fluid(s) is developed. The conceptual runoff model is referred to as a three phase runoff model. The three states (phrases) are frozen, saturated (liquid) and unsaturated (liquid-gaseous). The state of the dominant fluid at any time governs the water depth from snowmelt or rainfall that is available for runoff. A soil in a frozen condition has a limited infiltration capacity. The saturated (often inundated) condition has a runoff coefficient that would approach 1.0 in most cases. The unsaturated condition has the greatest potential to reduce surface runoff, both through replenishment of the available soil water and percolation of water to the groundwater system. Runoff processes are modelled for a number of years at 35 climate stations over a study area containing a number of small watersheds. The analysis includes interpolation of modelled estimates of fall soil moisture, spring snow water equivalent and snowmelt infiltration to frozen soils on a one kilometre square grid system over a watershed. These data are combined to estimate the basin spring runoff depth for the hydrologic period of record for the basin. Regression models demonstrate there is a linear relationship between the spring runoff depth and spring snowmelt runoff volume, and that the snowmelt (frozen soil) runoff contributing area and depression storage losses are constant from year to year. Analyses of the unsaturated soil system for a period of 22 years indicate there is no runoff from rainfall when the soil water is not frozen; excepting precipitation on the saturated areas of the watershed directly connected to the drainage channel system.
Bibliography of Canadian Geomorphology