The vertical percolation of soil water under different rainfall inputs is calculated using a semi-empirical analytical equation and the numerical solution from HYDRUS-1D model.Results from both methods are compared to assess the relative accuracy of the analytical equation.It is found that both methods can capture the response of soil water leakage to the rainfall conditions.The soil water percolation rate is highly correlated to rainfall intensity.The analytical solution of soil water percolation is a little greater than the numerical solution for low rainfall intensity and the result is the opposite for high rainfall intensity.Major differences from the two methods are shown in terms of the time when the peak percolation rate occurs and the time when the water initially starts to occur at the bottom of soil column.It is also found that the accuracy of the analytical solution is improved with the decrease in the thickness of soil column.Therefore

it is suggested that soil column be divided into sub-columns when the analytical solution is used to achieve a better accuracy in the calculation.