Rhodes>IWR>Projects>Estimation

Estimation

Student: Mr E Kapangaziwiri
Supervisor: Prof DA Hughes
Degree: MSc (Hydrology)


This research addresses the question of whether physical basin properties and the role they play in runoff generation processes could be used directly in the estimation of parameter values of the Pitman monthly
rainfall-runoff model. A physically based approach to estimating the soil moisture accounting and runoff parameters of a conceptual, monthly time-step rainfall-runoff model is proposed. The study re-investigates the
physical meaning of the model parameters, establishes linkages between parameter values and basin physical properties and develops relationships and equations for estimating the parameters taking into account the spatial and temporal scales used in typical model applications. The soil moisture accounting, runoff, recharge and infiltration parameters are investigated. The estimation methods developed are then tested in selected gauged basins in southern Africa and the results of model simulations evaluated against historical observed flows.

The results of 71 basins chosen from the southern African region suggest that it is possible to directly estimate hydrologically relevant parameters for the Pitman model from physical basin attributes. For South Africa,
simulations using the revised parameters were at least as good as the current regional sets, albeit the parameter sets being different. In the other countries where no regionalized parameter sets currently exist, simulations were equally good. The final thesis based on this research was submitted at the end of October 2007 for examination



Last Modified: Fri, 14 Aug 2015 11:23:56 SAST