Celso Augusto Guimarães Santos,Paula Karenina de Macedo Machado Freire,Petley de Medeiros Arruda,Sudhanshu K. Mishra, Universidade Federal da Paraíba, Engenharia Civil e Ambiental, celso@ct.ufpb.br
The difficulties involved in calibration of conceptual models have been partly attributable to the lack of robust optimization tools. This paper presents the essential concepts and application to optimize the tank model for a Japanese watershed, with a global optimization method known as Differential Evolution (DE), which grew out of Price’s attempts to solve the Chebychev Polynomial fitting Problem that had been posed to him by Rainer Storn. A breakthrough happened, when Price came up with the idea of using vector differences for perturbing the vector population. The crucial idea behind DE is a scheme for generating trial parameter vectors. The optimization technique was tested with the field data from Ishite river dam, which is the reservoir that supplies water to the city of Matsuyama, Japan. On the basis of these results, the parameter values are given, which could serve as an initial estimate for other similar Japanese watersheds.
Keywords: Optimization, tank model, Japanese watershed, differential evolution, modeling.