Assessment of the spatial distribution of submarine groundwater discharge (SGD) along the Yatsushiro Inland Sea coastline, SW Japan, using 222Rn method

A towing method using 222 Rn can detect SGD signals in coastal areas. This study aims to evaluate the impact of topography and hydrology on SGD spatial distribution and the estimation of SGD patches along the coastlines. For this, we tried to determine the SGD signals in the study area and the maximum depth where the SGD rate is significant. The study conducted along the Yatsushiro Sea coastline, SW Japan. The estimated SGD distribution pattern suggests that the local topographic and geological settings govern the occurrence of SGD (recirculated seawater (RSGD) and terrestrially derived groundwater (FSGD)) as the primary deriving forces.