Extreme rainfall patterns for sg. Sarawak and Samarahan river basins

Rainfall patterns and frequency analysis are carried out based on rainfall data extracted from 23 rainfall stations in Sg. Sarawak and 7 rainfall stations in Samarahan basin. In this study, Daily Maximum Rainfall (DMR) and Monthly Mean Rainfall (MMR) data has been used for rainfall pattern analys...

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Bibliographic Details
Main Author: Wan Ahmad, W.F
Format: Final Year Project Report / IMRAD
Language:English
English
Published: Universiti Malaysia Sarawak, UNIMAS 2009
Subjects:
Online Access:http://ir.unimas.my/id/eprint/4539/
http://ir.unimas.my/id/eprint/4539/1/Wan%20Ahmad%2824pgs%29.pdf
http://ir.unimas.my/id/eprint/4539/2/Wan%20Ahmad.pdf
Description
Summary:Rainfall patterns and frequency analysis are carried out based on rainfall data extracted from 23 rainfall stations in Sg. Sarawak and 7 rainfall stations in Samarahan basin. In this study, Daily Maximum Rainfall (DMR) and Monthly Mean Rainfall (MMR) data has been used for rainfall pattern analysis whereas rainfall frequency analysis procedure is applied only for DMR data. The objectives of this study are to constructing the extreme rainfall region map based on frequency analysis reduced variate curves which is the better plotting formula fit to Extreme Value Type I (EVI) distribution either plotting position formulae Gringorten and Weibull formula using Geographic Information System (GIS) application. Besides, these study also to determine the factors influencing the rainfall distribution in Sg. Sarawak basin and Samarahan basin. From the results and analysis, the rainfall distribution in coastal areas of Sg Sarawak basin is influencing by prevailing wind during northeast monsoon season where a regime of one maximum and minimum rainfall distribution can be observed. Meanwhile, those inland is less likely influenced where the rainfall is distributed quite evenly throughout the year. The results obtained from rainfall frequency analysis showed that the Gringorten formula gives least ratio than Weibull formula which is in accordance to previous study and literature review. From this result, frequency analyses in reduced variate graph are plotted for both basins and then the extreme rainfall region map are constructed using Geographic Information System (GIS) based on the graph.