Temporal disaggregation of rainfall for Singapore

• Main Author: Ong, Kathy Yajuan.
• Other Authors: Qin, Xiaosheng
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Civil engineering::Water resources
• Online Access: http://hdl.handle.net/10356/52893
• Institution: Nanyang Technological University

This report serves as a recount on the Final Year Project the author undertook during full two semesters in her fourth year undergraduate study in Nanyang Technology University (NTU). The final year project is an integral part of an NTU student’s graduation requirement in the last year of study in the college. The author feels honoured to be able to take up this project: Temporal Disaggregation of Rainfall for Singapore, under the immediate supervision of Assistant Professor Qin Xiaosheng. Temporal disaggregation is one of the ways to obtain higher frequency data (such as hourly) from a lower frequency rainfall data (such as daily). In many statistical studies, finer rainfall data is always not widely available and not easy to obtain using the available rain gauges, thus temporal disaggregation is performed through interpolation of parameters and using benchmarking to derive the desired set of data. In this final year project report, the author had examined the degree of applicability of using the Hyetos software to derive rainfall statistics for hourly frequency from the daily rainfall frequency using the six parameters Bartlett-Lewis Rectangular Pulse Model (BLRPM). The rainfall data are obtained from Singapore Changi Climatic Station from 1980 to 2010, a total of 31 years of historical rainfall data. The objective of this project is to perform a spatial-temporal stochastic model to observe the hourly rainfall data from years 1980 to 2005 (26 years) and use the fitted model to carry out the disaggregation of 24-hr rainfall depths to obtain the desired hourly rainfall using the Hyetos software from years 2006 to 2010 (5 years) as a form of verification. After performing the disaggregation of rainfall, the author will then discuss the results obtained from the software and make comparisons of the data to discuss and analyze the extent of reliability and accuracy of the rainfall disaggregation. The author will also explain in details the software and techniques used for this disaggregation and the possible methodology involved.