A STUDY OF PEAK INSTANTANEOUS AND AVERAGE DAILY DISCHARGES FROM SMALL PRAIRIE WATERSHEDS

Abstract

This thesis is a study of watersheds on the Canadian prairies with an effective area of less than 300 sq. mi. to develop the relations between peak instantaneous discharge and average daily discharge. An empirical approach was used to develop graphical correlations between the ratio of peak instantaneous discharge to average daily discharge, Qp/Q2 ,and the effective area; between Qp/Q2 and the Qp/Q2 width of the hydrograph and between the average daily discharges on the day before, day of and day following maximum discharge with the peak ratioQp/Q2. The findings showed that there is a regional trend in the relation between the peak ratio Qp/Q2 and effective area and that there is a close correlation between the peak ratio and the width of the hydrograph for all regions. The ratios of average daily discharges before and after the day of maximum discharge can be used to estimate the value of the peak ratio for values less than 2. Seasonal differences in peaking characteristics between basins above 4000 feet and those below this altitude are discussed.