Analysis of rainfall datasets for major Asian cities

• Main Author: Teo, Jing Xiong.
• Other Authors: Lo Yat-Man, Edmond
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Environmental engineering
• Online Access: http://hdl.handle.net/10356/52762
• Institution: Nanyang Technological University

This study evaluates the accuracy and reliability of a gridded rain-gauged based dataset, APHRODITE (v1011) and a satellite-based dataset, TRMM (3B42) with the actual rain-gauge data provided by Changi Meteorological Station, Singapore. A series of software were used to download and extract the required data for the comparison process. The two datasets were then evaluated against the local data from 1998 – 2006 with six parameters in terms of intensity, duration and extreme events. Both APHRODITE and TRMM have underestimated the rainfall intensity parameters although APHRODITE has consistently performed better than TRMM with an underestimation of 0.5% - 29.1%. TRMM however, outperformed APHRODITE, which consistently overestimated in terms of duration, when detecting the number of wet days at a range of -21.1% - 14.9% of the actual data. The overestimation by APHRODITE has also caused it to overestimate the mean wet spell length as compared with TRMM. APHRODITE has shown better overall performance than TRMM in detecting identical days with extreme events to the local data. Both datasets are effective and limited relatively in their own ways. For the purpose of modeling and forecasting of floods in Singapore, APHRODITE is suggested to be the potential dataset.