| Author | Chavalit Chaleeraktrakoon |
| Call Number | AIT Thesis no. WA-83-2 |
| Subject(s) | Hydraulics--Mathematical models
|
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, school of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The Mathematical Model for generating samples of daily flow series has been studied under the hypothesis that the daily flow series are the
superposition of periodic and dependent stochastic components which they can
be separated from each other. Based upon the hypothesis , the generation of new samples of daily flows can be carried out in the reversed procedure. The 31-year daily flow data of the Ping River at station P.1 near
Nawarath Bridge in Chiangmai province were used for investigating the performance of the mathematical model . By generating 20 samples each of 31 years of daily flow records and comparing the first three moments and the first three
serial correlation coefficients of generated samples with the corresponding statistics of the historic daily flows, the mathematical model showed good reproduction of these statistics. Furthermore, the characteristics of historic maximum annual floods could be simulated by the mathematical model . As the same set of observed daily flow data were used, the performances
in preserving some statistics of the daily flow series by the mathematical model were compared with t hose results by the Alternating Intermittent Stochastic Model as done by Arai (1979) . An important statistic namely the average daily discharge in a month during rainy season, and pattern of hydrographs were considered in the comparisons. The mathematical model showed
better results in preserving both the average daily discharges for all generated month during the rainy season and the general pattern of historic hydro
graphs. As the mathematical model could reproduce the characteristics of historic maximum annual floods, the generated samples of daily flows were considered as t he basic data for flood study. The distributions of maximum
annual floods of the three generated samples, each of 200 year in length of daily flows were tested whether they follow the Gumbel distribution the para
meter of which were derived from the parameter of the Poisson distribution of the number of exceedances and the parameter of the shifted-exponential distribution of the magnitudes of exceedances. It was found that the Gumbel distribution as the distribution of maximum annual floods could be acceptable with 1 percent significant level at exceedance rate ranging from 1 to 1.5 which
is the range of best fit.
|
| Year | 1982 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Gupta, Ashim Das ; Viraphol Taesombat
|
| Examination Committee(s) | Huynh Ngoc Phien |
| Scholarship Donor(s) | Thai Government (King' s Scholarship) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1982 |