Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim

Many of the extreme rainfall events led to flash-flooding and consequent loss of life and substantial property damage. Therefore there is an urgent need to be able to forecast this event accurately Gumbel distribution is among the common probabilistic models used in hydrological extremes especially...

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Main Authors: Mohd Baki, Aminuddin, Atan, Ismail, Abd Halim, Fazzarieyyah
Format: Research Reports
Language:English
Published: Research Management Institute (RMI) 2012
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Online Access:http://ir.uitm.edu.my/id/eprint/21035/1/LP_AMINUDDIN%20MOHD%20BAKI%20RMI%2012_5.pdf
http://ir.uitm.edu.my/id/eprint/21035/
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spelling my.uitm.ir.210352018-08-21T03:35:55Z http://ir.uitm.edu.my/id/eprint/21035/ Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim Mohd Baki, Aminuddin Atan, Ismail Abd Halim, Fazzarieyyah Geomorphology. Landforms. Terrain Environmental conditions. Environmental quality. Environmental indicators. Environmental degradation Many of the extreme rainfall events led to flash-flooding and consequent loss of life and substantial property damage. Therefore there is an urgent need to be able to forecast this event accurately Gumbel distribution is among the common probabilistic models used in hydrological extremes especially in the case of modelling rainfall extremes. This has been especially the case in modeling rainfall extremes. It is a well known that an estimation of extreme rainfall is very important for major hydraulic structure designs. In this study peak over threshold extreme rainfall series have been proposed as an alternative to annual maximum rainfall series in extreme rainfall analysis. A peak over threshold series consists of all the peaks above a certain threshold, whereas an annual maximum rainfall series contains only the maximum rainfall of each year. It has been argued that peak over threshold method uses more information about extreme rainfall because it works with more elements than the annual maxima series method. In this project, the data used were obtained from Department of Irrigation and Drainage Malaysia. The area used as a case study covered a selected area of Malaysia’s highland such as Bukit Peninjau at Pahang, Ladang Boh at Cameron Highland, Gunung Brinchang at Cameron Highland, Genting Sempah at Wilayah Persekutuan and Bukit larut at Perak. The data were extracted using annual maxima and peak over threshold methods and then fitted with Gumbel and Pareto distributions. The return periods were calculated and compared. The obvious advantage of such models over an annual maxima approach is that, by making more of the data in any given time and furthermore, the precision of estimates and return levels can be greatly improved. From the analysis most of the data shows that the return period becomes smaller as the level of threshold becomes larger, i.e. reducing the number of exceedances. Besides, the parameters estimated also shows decreasing with the increasing of number of threshold Furthermore, the quantile plot obtained for each station shows a good fit for both Gumbel distribution and Pareto distribution except for Genting Sempah and Gunung Brinchang which shows a poor fit for both distributions. It can be conclude that data series for both stations are not suitable to be fitted in Gumbel and Pareto distribution. Research Management Institute (RMI) 2012 Research Reports NonPeerReviewed text en http://ir.uitm.edu.my/id/eprint/21035/1/LP_AMINUDDIN%20MOHD%20BAKI%20RMI%2012_5.pdf Mohd Baki, Aminuddin and Atan, Ismail and Abd Halim, Fazzarieyyah (2012) Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim. [Research Reports] (Unpublished)
institution Universiti Teknologi Mara
building Tun Abdul Razak Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Teknologi Mara
content_source UiTM Institutional Repository
url_provider http://ir.uitm.edu.my/
language English
topic Geomorphology. Landforms. Terrain
Environmental conditions. Environmental quality. Environmental indicators. Environmental degradation
spellingShingle Geomorphology. Landforms. Terrain
Environmental conditions. Environmental quality. Environmental indicators. Environmental degradation
Mohd Baki, Aminuddin
Atan, Ismail
Abd Halim, Fazzarieyyah
Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim
description Many of the extreme rainfall events led to flash-flooding and consequent loss of life and substantial property damage. Therefore there is an urgent need to be able to forecast this event accurately Gumbel distribution is among the common probabilistic models used in hydrological extremes especially in the case of modelling rainfall extremes. This has been especially the case in modeling rainfall extremes. It is a well known that an estimation of extreme rainfall is very important for major hydraulic structure designs. In this study peak over threshold extreme rainfall series have been proposed as an alternative to annual maximum rainfall series in extreme rainfall analysis. A peak over threshold series consists of all the peaks above a certain threshold, whereas an annual maximum rainfall series contains only the maximum rainfall of each year. It has been argued that peak over threshold method uses more information about extreme rainfall because it works with more elements than the annual maxima series method. In this project, the data used were obtained from Department of Irrigation and Drainage Malaysia. The area used as a case study covered a selected area of Malaysia’s highland such as Bukit Peninjau at Pahang, Ladang Boh at Cameron Highland, Gunung Brinchang at Cameron Highland, Genting Sempah at Wilayah Persekutuan and Bukit larut at Perak. The data were extracted using annual maxima and peak over threshold methods and then fitted with Gumbel and Pareto distributions. The return periods were calculated and compared. The obvious advantage of such models over an annual maxima approach is that, by making more of the data in any given time and furthermore, the precision of estimates and return levels can be greatly improved. From the analysis most of the data shows that the return period becomes smaller as the level of threshold becomes larger, i.e. reducing the number of exceedances. Besides, the parameters estimated also shows decreasing with the increasing of number of threshold Furthermore, the quantile plot obtained for each station shows a good fit for both Gumbel distribution and Pareto distribution except for Genting Sempah and Gunung Brinchang which shows a poor fit for both distributions. It can be conclude that data series for both stations are not suitable to be fitted in Gumbel and Pareto distribution.
format Research Reports
author Mohd Baki, Aminuddin
Atan, Ismail
Abd Halim, Fazzarieyyah
author_facet Mohd Baki, Aminuddin
Atan, Ismail
Abd Halim, Fazzarieyyah
author_sort Mohd Baki, Aminuddin
title Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim
title_short Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim
title_full Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim
title_fullStr Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim
title_full_unstemmed Extreme rainfall at Malaysia’s highlands / Aminuddin Mohd Baki, Ismail Atan and Fazzarieyyah Abd Halim
title_sort extreme rainfall at malaysia’s highlands / aminuddin mohd baki, ismail atan and fazzarieyyah abd halim
publisher Research Management Institute (RMI)
publishDate 2012
url http://ir.uitm.edu.my/id/eprint/21035/1/LP_AMINUDDIN%20MOHD%20BAKI%20RMI%2012_5.pdf
http://ir.uitm.edu.my/id/eprint/21035/
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score 13.211869