The characteristics and measurement of winter precipitation in basins of internal drainage in Saskatchewan: a case study of Big Quill Lake
Whiting, J. M.
The main objective of this thesis is to find an acceptable method with which to measure the winter precipitation in the major internal drainage basins in Saskatchewan. These internal basins constitute twenty per cent of the settled land area of the province. Using stochastic hydrological information, precipitation was demonstrated to be the controlling factor in the level of four-closed lakes within four of the five major drainage basins (Old Wives Lake Complex, Quill Lakes and Assiniboine Plain Complex, Snipe Lake Plain Complex and Moose Mountain Complex). For the fifth basin (Great Sand Hills Complex) data were insufficient to permit a valid analysis. A case study showed that the winter precipitation data for Big Quill Lake could be used to predict the water balance for the lake plain section of the basin. With this understanding, it was possible to design a new technique for measuring winter precipitation using the recorded hydrostatic pressure from beneath the ice surface of a closed lake. The new technique is necessary because the present network is either too sparse in these basins or extension too expensive to be used to give areal snow cover information. The hydrostatic pressure data provided a single value for winter precipitation which was accurate for ninety per cent of the Big Quill Lake drainage basin. The parameters necessary for the calibration equation were then drawn up as a conceptual model which would permit the snow cover of the remaining three major internal drainage basins (Old Wives, Snipe Lake Plain and Moose Mountain Complexes) to be analysed given the necessary data. The conceptual model provides an estimate of the precipitation resulting from a single storm. Another model was developed from which it was possible to forecast winter precipitation for any of the five basins studied from information derived from one of the basins. At the present time the model developed is not capable of dealing with the comlexities of the duration and direction of the storm movement. Thus the application of the present model is limited to single basins. The technique is, however, not limited to the internal basins described but could be used in any closed lake where ice forms during the winter months.