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 climate change.

For Peninsular Malaysia, the factors have been summarised and categorised 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 utilised 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, the CCF value is automatically included in the computation of the rainfall intensities for Drain analysis for newly created projects.

As for the MSMA analysis, similarly to the existing projects, the inclusion of the CCF needs to be enabled by the users under the Project Parameters.

Kindly note that this feature can be included or excluded in the analysis.

For StormSync (Drain & Pond) Module #

Options > Project Settings > Expand Storm Design > Expand Design Guideline > Malaysia > CCF Inclusion

Changing or Updating the CCF value #

To change or update the value, users may do so at the RHS Properties tab or under the Project Settings, as the steps provided here.

For HydroCalc (MSMA) Module #

Options > Project Parameters > Det. Facility > IDF > Design > Include CCF