2016 Volume 67 Issue 1 Pages 1-10
We compared the coseismic well water level rises (Cw) and the strong ground motions during the 1999 Chi-Chi, Taiwan, earthquake in the Quaternary alluvial fan near the hypocentral region using data produced by the dense networks of strong ground motion and groundwater observation. The correlation between the Cw of the shallowest aquifer (Layer 1) and the ground motion response spectra at 1 Hz (Sv(1.0)) is stronger than that at 0.1 Hz (Sv(0.1)). On the other hand, the correlation between the Cw of the deeper aquifers (Layers 2-1, 2-2, 3 and 4) and Sv(1.0) are weaker than that at 0.1 Hz. We also found the good correlation between the Cw and hydraulic conductivity in the all aquifers. It is difficult to estimate Cw only by the spectral amplitude even in a Quaternary alluvial fan, where the geological and geomorphological conditions are similar.