Fluctuation Behaviors of the Groundwater Level in a Landslide Area

Abstract

Fluctuation behaviors of the groundwater level at Washiodake landslide area, Nagasaki Prefecture, are dealed with in this paper.
(1) The aquifers here are rich in vertical cracks caused by repeated landslides and horizontal, porous coal beds accompanied with clayey layers, which seem landslide surfaces.
(2) Seventeen piezometers (of standpipe type) were settled in different depth of 7 boreholes. This style depends on a technique recently established by the author. Water injection tests were carried out with these devices and changes of the groundwater level were observed.
(3) A new model was proposed by the author for simulating fluctuation behaviors of the groundwater level. Hence, a close agreement between the observed and calculated values can be obtained. A descending rate of the groundwater level or a half life of ascending head by injection and a permeability of the soil were calculated.