Estimation of Reservoir Volumes at Drafts of 40% - 90%: Drought Magnitude Method Applied on Monthly River Flows from Canadian Prairies

The draft ratios for sizing the reservoirs can vary within a wide range (40% - 90% of mean annual flow, MAF), depending upon demands water by various users, and environmental ecological considerations. reservoir volumes based on drought magnitude (DM) method were assessed at aforesaid using monthly-standardized hydrological index (SHI) sequences 10 Canadian rivers located in prairies northwestern Ontario. These are typified high level persistence lag-1 autocorrelation, ρ1m ≥ 0.50 up to 0.94) coefficient variation (cvo) 0.42 1.48. moving average (MA) smoothing monthly SHI formed basis DM estimating volumes. truncation or cutoff was found as SHIx [=(α 1)μo/σo], [(α 1)μo/σmax], 1)μo/σav], where α (=0.40 0.90) is ratio i.e. proportion MAF, μo σo overall standard deviation flows, σmax maximum value deviations σav 12 values. failure probability levels (PF) fixed 5%, 2.5% 0% (corresponding reliability 95%, 97.5% 100%). study revealed that most important parameter influences size while role autocorrelation (ρ1m) appears more pronounced ratios, such 0.90, 0.80 0.70 increasing size. be regarded an alternative Behavior analysis desired level.