Feature analysis of groundwater discharge points in coastal regions around Mt. Chokaisan using ALOS AVNIR‐2 Data

Abstract

AbstractThe flow of fresh water into the sea, called submarine groundwater discharge, is a key factor for understanding the hydrologic cycle in both sea and land regions. The numerous positions from which fresh water is discharged and the variations in its quantity impede the understanding of its properties. In a previous study, we detected groundwater discharge points expressed by differences in fresh water and seawater by using multispectral Landsat Enhanced Thematic Mapper Plus (ETM+) signals with 30‐m spatial resolution. Details of seawater surface information regarding the submarine groundwater discharge have not yet been obtained. Therefore, this paper analyzes the features of water properties around groundwater discharge points by using Advanced Land Observing Satellite (ALOS) Advanced Visible and Near Infrared Radiometer type 2 (AVNIR‐2) outputs, which provide 10‐m spatial resolution. Classification maps obtained by k‐means clustering are compared with measurements in ground surveys, geologic maps, and estimation maps of relative salinity. The experimental results obtained from the AVNIR‐2 data are in considerable agreement with the realities in the study area. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(7): 1–9, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11398