Abstract
Discharge in many rivers is Often fed by baseflow provided by drainage of the saturated zone in the shallow permeable soils. It is becoming clear that the outflow from this saturated zone is not linear proportional to storage as is commonly assumed in many algorithms. The objectives Of this study theretore, are first to explore the extent to which the assumption of linearity in storage-outflow relationships is valid and secondly to introduce an alternative approach to baseflow separation algorithms for estimating direct mnoff time series. Numerical analysis Of streamflow recessions from the semi-arid catchments of the Great Ruaha basin in Tanzania reveals a non-linear relationship between baseflow and storage. relationship is used to derive an alternative approach to estimate direct runoff. The method involves fitting an exponential reservoir model using an iteration algorithm. The study goes further to evaluate the parameter sensitivity using the methodology Of Generalized Likelihood Uncertainty Estimation (GLUE). Finally this study has found that a major difficulty in storage-outflow modelling Of streamflow recessions, irrespective of the linearity of the mtydei is the variation of model parameters from one event to the next event,
Recommended Citation
Mwakalila, S. (2001). BASEFLOW SEPARATION BASED ON STORAGE-OUTFLOW MODELLING OF STREAMFLOW RECESSIONS, WITH APPLICATION TO SEMI- ARID CATCHMENTS IN TANZANIA. Tanzania Journal of Engineering and Technology (TJET), 24(1), 54-65. https://doi.org/https://doi.org/10.52339/tjet.v24i1.305
Publisher Name
University of Dar es Salaam