Rainfall is a major source for groundwater recharge. The response of groundwater level to rainfall is divided into quick and slow parts. This article presents a method to analyze the rainfall-induced quick groundwater-level (QGL) response. In the method, a technique of recursive digital filter was applied to splitting the rainfall-induced QGL response from a residual groundwater hydrograph in which the effects of both earth tide and barometric pressure were removed. The response of QGL to rain was simplified as a linear function and described by using a convolution of a rainfall sequence and a discrete Kernel function. Based on data of rainfall and corresponding QGL variations, the discrete Kernel function was determined via a linear system analysis. The method was applied to determining the discrete Kernel function and simulating the variation of QGL to rain at the station of Naba well in southwestern Taiwan. Comparison between the results of simulations and measurements of QGL variations shows that our proposed method can simulate the QGL response to rain with a value of root mean square error less than 4. 26 mm. Based on the discrete Kernel function, an empirical, continue Kernel function was also proposed.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Agronomy and Crop Science
- Water Science and Technology