PhD Thesis Emmanuel Obeng Bekoe - Cranfield University

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terms of accuracy, and the benefits of using distributed rather than lumped
parameters are lost.
However, despite the wide range of model types available, Singh & Woolhiser
(2002) observed that frequently, the type of a model to be used or selected is
dictated by the availability of data.
3.2. Selection Criteria for choice of model
Hydrological models can be data intensive tools requiring much input data
(Singh & Woolhiser, 2002; & Viessman & Lewis, 2003) which often does not
exist or are not available in full (Singh & Woolhiser, 2002). However, a simple
empirical model might only require rainfall, temperature and streamflow data.
Therefore to select a model to accomplish the objectives of this research
(Chapter 1) in the Densu river basin, the following selection criteria set were
formulated against which models could be assessed for suitability.
• It must be a non-urban model that can simulate agricultural/rural areas
because the Densu basin can be classified as agricultural (Chapter 2 Section
2.4)
• The model should be one that can be applied over a range of catchment
sizes from medium to large catchments/basins (say 50km 2 up to 2600km 2 ) so
that the Densu, and other smaller catchments within the sub region of West
Africa, if found appropriate, could be modeled (i.e. catchment scale model)
• Its spatial discretization should be semi distributed to enable both modelling
in the lumped and semi-distributed modes.
• It should be able to simulate baseflow which is an important component of
the flow in perennial rivers in tropical catchments such as the Densu.
• The minimum input data requirements for the model must be easily available
i.e. meet the data gathered from a data-poor catchment such as the Densu
Basin.
Emmanuel Obeng Bekoe Phd Thesis Chapter 3 Catchment-Hydrol,& Model Selection