What is a Climate Change Factor (CCF)? #
CCFs are values that were first introduced by the National Hydraulic Research Institute of Malaysia (NAHRIM) to add a certain percentage to the rainfall design as an effect of the climate changes.
For Peninsular Malaysia, the factors have been summarized and categorized into five regions, with statistical values of minimum, median, mean, and maximum tabulated for the East Coast and West Coast rainfall stations. According to the guideline Hydrological Procedure 1 (Revised and Updated 2015), the values that will be utilized in the design rainfall are the median values, which is deemed to be reasonable, not too high or too low compared to the mean of the maximum values of CCF.
As for the areas in Sabah and Sarawak, the 1-day CCF for each of the rainfall were calculated for all the ARIs, ranging from 2 to 100 years and the values are presented as per the table below which can be found in the Hydrological Procedure 26 – Estimation of Design Rainstorm in Sabah and Sarawak (Revised and Updated 2018) or on the Official Website of DID Sarawak.
Steps to include CCF in software #
In our software, starting with the latest version, the CCF value is automatically included in the computation of the rainfall intensities for Drain and MSMA Detention Pond analysis for newly created projects.
For existing projects, the inclusion of the CCF needs to be enabled by the users under the Project Parameters in the latest version to prevent unintended changes in the analysis.
Kindly note that this feature can be included or excluded in the analysis.
For Drainage Module #
Options > Project Parameters > Drainage > Design > IDF > Include CCF
For MSMA Module #
Options > Project Parameters > Det. Facility > IDF > Design > Include CCF
**Note: The CCF feature is now available for MSMA Detention Pond (Rational Method and Time-Area Method) and will be implemented in other MSMA modules in future release**