Characteristics of pore water quality extracted from the undisturbed boring core sampled at coastal area in Sendai City, Japan

Abstract

The water quality of observation wells, which were settled at coastal area of Sendai City, observation well of 10 m and 15 m deep was Na-Cl, and that of 30 m deep was Na-HCO₃. The influence of seawater intrusion was observed at depths of 10 to 15 m, and there were slight differences in the Na⁺ and Ca²⁺ concentrations between the 10 m and 15 m deep well. To elucidate the detailed condition of seawater intrusion and the formation process of groundwater quality, undisturbed boring cores with 30 m deep were sampled near the observation sites. Half of the boring core was cut into 5 cm depth sections, and pore water was extracted by centrifugation method to measure EC, pH, ion concentration, and oxygen and hydrogen stable isotope ratios. In this presentation, we will report on the characteristics of vertical distribution of soil moisture and EC value, and dissolved inorganic ions in the pore water.