ll Number: AIT Thesis no.EV-85 creator Kreeta Sroikeeree creator Orth, H.M. Chairperson Lohani, B.N. Examination Committee Huynh, Ngoc Phien Examination Committee Chongrak Polprasert Examination Committee US-ASEAN Scholarship Donor text th Bangkok Asian Institute of Technology 1985 continuing eng 51, (39) p. Drainage systems can be efficiently designed for minimum cost by Dynamic Programing. Present models generally use a one-dimensional state variable with the pipe level as parameter. Although the theoretical need for at least a two-dimensional state variable is recognised, more dimensional state variables are still considered as impracticable due to computational requirements. In this study one-, two-, and three-dimensional models were developed. The parameters are the pipe elevation, the pipe diameter, and the time of flow as in the Rational Method. The model has been implemented on a IBM personal computer. Three test examples show the operationability of the developed program. It has been found for the test examples that introducing the time of flow into the state variable reduces the least cost between 0 and 7.2%. Depending on topography, introducing the diameter in some certain cases reduces the least cost more than 17% {u2022} A thesis submitted in partial fulfillment of requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Eng.) - Asian Institute of Technology, 1985 Flocculation Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B20014 http://203.159.5.9/ait-thesis/detail.php?q=B20014 011298 20260818145356.0