Quality Control (QC) was undertaken prior to the data analysis. The QC procedure for data is checking the missing values of the data. The daily rainfall data is from APHRODITE data version V1101 over Thailand ( ) with resolution of latitude and longitude for the period 1951 to 2007. The figure is divided into a scale of 0 to 100. It was found that, every year of APHRODITE data over Thailand have scale 0 values. So APHRODITE data not have missing values as Figure 3.2.