Development of isohyet map for Kuantan river basin using kriging and radial basis functions methods

• Main Author: Ng, Hui Ping
• Format: Undergraduates Project Papers
• Language: English
• Published: 2018
• Subjects: TC Hydraulic engineering. Ocean engineering
• Online Access: http://umpir.ump.edu.my/id/eprint/26257/1/Development%20of%20isohyet%20map%20for%20Kuantan%20river%20basin%20using%20kriging%20and%20radial%20basis%20functions%20methods.pdf; http://umpir.ump.edu.my/id/eprint/26257/; https://efind.ump.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=7993

Precipitation is an important climatic parameter and the studies on rainfall such as identification of rainfall pattern are commonly hampered due to limited rain-gauge network in the field and cause lack of continuous data and occurrence of systematic and random errors. To obtain missing observations in data, several spatial interpolation methods are currently used. However, the lack of knowledge on the suitability of these methods for Kuantan River Basin is a practical problem. In view of this problem, one of the objectives of this study is comparing two selected methods used for the estimation of missing rainfall data to determine their suitability in Kuantan River Basin. The methods studied were Kriging and Radial Basis Functions (RBFs) methods. In this approach, 8 rainfall stations from Kuantan River Basin which are most or less evenly distributed in the basin and with the most extensive data were chosen. The rainfall data was obtained from the Department of Irrigation and Drainage Malaysia (DID) from years 1970 until 2016. Subsequently, monthly and annually rainfall data of each station were estimated based on the above selected methods so that actual data and the estimated data can be compared by using cross-validation method with two common diagnostic statistics, include Mean Absolute Error (MAE) and Root-Mean-Square-Error (RMSE). Results in overall of the study show that the RBFs method is the most common spatial interpolation method to analyse monthly and annually rainfall pattern maps for the impact of climate change over Kuantan River Basin. In term of seasonal rainfall distribution, the rainfall pattern maps show that from November to March received higher precipitation which may due to the Northeast monsoon effect. Meanwhile, in term of regional distribution, the areas which high altitudes and near to the open sea usually are projected to receive more precipitation compared to the lowlands and inlands. For the impact of climate change, the rainfall intensity and the areal extent of higher precipitation has also increased significantly over years. The rainfall distributed more evenly over the Kuantan region. The difference of rainfall depth between year 1970 until 1999 and year 2000 until 2016 recorded highest is in the Northeast Monsoon season where extreme precipitation events occur resulting in major floods.