抄録
By continuous and excess pumping of a well, storage of the confined aquifer concerned decreases year by year, and the resulting form is like the decline of piestic level of ground-water. Under such a situation, the only index to evaluate the storage in decreasing may be“ Coefficient of Storage” of the aquifer, which is treated as a certain constant in Theis' Non-equilibrium Formula. Assuming the coefficient is variable, the writer proposed a practical method to analyse the yearly decrease of ground-water storage of aquifer, having been discharged for a long term counted in unit of month or year.
