Abstract
A method for time series analysis of hydrological variables that have a response relation with an incitement variable such as precipitation has not been established yet. In this paper, we propose an analyzing method to estimate the periods of change in the relation of two variables of them based on the time series analysis of observed data such as fluctuation of ground water level in Shimabara city. Using the result, we have examined the relation between abnormality of ground water and phenomena such as volcanic activity and seismism.
