| Author | Saravuth Wachirasuntornpoj |
| Call Number | AIT Thesis no.WA-86-25 |
| Subject(s) | Rain and rainfall--Mathematical models
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| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WA-86-25 |
| Abstract | This study deals with the generation of daily rainfall at multiple stations in an area by a stochastic simulation model. The model of areal rainfall used in this study is based on a multivariate normal distribution. Due to a large number of zero values, it is not applicable to treat the distribution of daily rainfall at a station as a continuous distribution. The truncated normal distribution of daily rainfall proposed by RICHARDSON (1977) for describing the probabilities of occurrence and nonoccurrence of daily rainfall is used in the study. The square roots of daily rainfall at a point are found to approximate to a sample from a univariate normal distribution that has been truncated at zero. A method of maximum likelihood is used for estimating daily means and standard deviations of the truncated sample in terms of monthly average values. When the periodic means and standard deviations are removed from daily rainfall data, the remaining stationary stochastic components are approximately time independent. Therefore, the multivariate model for generating new data with time independence in sequences proposed by FIERING (1964) is applicable for this study. Regionalizations of the parameters, namely means, standard deviations and l ag-zero cross correlations, are carried out in order to use the regional parameters as the model parameters for generating new sequences. The described model is applied to generate daily rainfall of the Mananga River Basin in the Philippines. Daily rainfall data from eight stations in the area are used to evaluate the regional parameters and used to test the model. The parameters are investigated by generating new sequences and comparing them to the observed sequences. The applied model gives reasonable results. |
| Year | 1986 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WA-86-25 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Nielsen, Steen Asger ;Huynh Ngoc Phien ; |
| Examination Committee(s) | Gupta, Ashim Das ;Bogardi, Janos J. ; |
| Scholarship Donor(s) | The Government of France ; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1986 |