Application of Monte Carlo Method in Recharge Calculation of Underground Water Resources

In underground water resources evaluation, calculation of underground water recharge is the most important and preliminary work. If underground water recharge within an area comes from exclusive item, then it is easy to calculate any water volume related to each probability based on the empirical frequency curve. In most cases, underground water recharge is not a single item, but four or five items or even more items. In this case, it is necessary to find out the suitable methods to carry out underground water recharge calculation. Therefore, the paper firstly analyzed the problems existed in the recharge calculation of underground water resources, especially the problems existed in the frequency analysis and the differences between the calculation results and the actual industrial and agricultural requirement. Secondly, the Monte Carlo method was introduced, which includes the basic theory, problems existed in simulation experiment and its adaptability. Finally, taking the irrigation area of the downstream Yellow River as an example, based on the results of analysis and statistics for different recharge factors, and using the developed computer softer wale, the regional underground water recharge was calculated for multi-recharge conditions. It shows that Monte Carlo method can solve the problems existed in analytical, numerical, experiment and empirical frequency methods. Besides, Monte Carlo method has the advantages of convenience, time saving and high efficiency.