Preliminary model for simulation of groundwater flow and seawater/freshwater interface at coastal area of Horonobe, Hokkaido

Abstract

The characteristics of seawater / freshwater interface var y locally with groundwater flow in coastal area. A repetition is needed to confirm the updated simulation result with the latest in-situ data. This study is aimed at making a model that can be modified at any point in time for the simulation of groundwater flow and seawater / freshwater interface at the coastal area of Horonobe, where geoscientific data is now being stored for future use. Preliminary simulation results indicated that the seawater / freshwater interface at the test site may be lowered into the Yuchi Formation at the depth of about 1000m. At the future survey, long term information on sea level change will be important for the chemical analysis of groundwater samples with borehole depth. The site at Horonobe is intended for the basic research development for geological disposal waste in coastal area, and the hydrogeological structure will be clarified to the depth of 1000m in several years. The result of this research will be verified at the time.