HOW MANY RESERVOIRS - AN ANALYSIS OF FLOW RECESSIONS FROM A GLACIER BASIN

Analysis of hydrograph-recession curves from temperate catchments has frequently been directed towards identifying a linear-storage element with mean residence time K which characterizes the delayed-flow compon ent. This paper presents the results of applying such an analysis to r ecession curves from 11 years of discharge records from a glacier basi n. Four reservoirs are identified but their estimated recession coeffi cients (K values) are found to vary with discharge and with time in th e ablation season. This implies that the reservoirs are non-linear. Wh ilst it may be helpful for the interpretation of glacier-hydrological processes to identify several reservoirs, it appears that a single non -linear reservoir may provide an adequate representation of the glacie r for operational forecasting purposes.