A study was made to estimate the values of aquifer increasing or decreasing two consecutive months and to find their characteristics by means of a time series analysis. The results that were obtained are as follows:
1) The values of aquifer increasing or decreasing during consecutive months, dV, were obtained by Eq. (1), and the results showed that the values of dVvaried from 158.95× 104m3 to 186.49× 104m3as listed in Table 1.
2) To see the variation of dVduring the period (March to February), the term of γ was defined by Eq. (2), and the results are shown in Figs. lA to 1D. To show mathematically variation of γ (the curves show the variation of γ ), Eqs. (3) and (4) were constructed by applying the FOURIER series. The theoretical values of γ, γ, were obtained by these equations as shown in Figs.1A ot 1D. As shown in these figures, the theoretical values coincided with the observed ones.
3) The values of the cumulative γ in the positive values, γ t+, were obtained by Eq. (6) that was constructed by applying the GOMPERTZ curve. Also the cumulative values ofγ in the negative, values, Rt-, were obtained by using Eq. (7) that was constructed by applying the LOGISTIC curve. The theoretical values obtained by these equations (the open circles) coincided with the observed ones (the solid circles and the crosses) as shown in Figs.2A to 2D. References
JAPANESE ASSOCIATION OF GROUNDWATER HYDROLOGY