A thesis submitted in partial fulfillment of t he requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1980

Daily streamflow have been studied on the basis of a model involving both stochastic and deterministic aspects of the phenomenon. Alternating renewal process was applied in order to embody stochastic characteristics, in which the historical series was analyzed in terms of spells, so-called wet and dry spell. Whereas three components of flow were presumed to introduce physical properties of a catchment into the model. The component corresponding to direct flow performed as connection between stochastic and deterministic aspects. Namely, the component of direct flow analyzed in alternating renewal process leads the occurrence of other two components expressing physical properties. The model succeeded to simulate the occurrence of spells. However, difficulty was found in generation of the amount in wet spell and in evaluation of recession curve. The model was studied based on the data obtained from Mae Ping River located in northern part of Thailand.