Abstract
This study describes an assessment of the saltwater intrusion due to the change in groundwater flow caused by an increase in the piezometric head in Bangkok Metropolitan Area and decrease in the piezometric head in the suburban areas bordering Bangkok. Firstly, the data of the piezometric head using arc-GIS confirms the change in groundwater flow. In addition, there are reports of saltwater intrusion in the area. Furthermore, the groundwater vulnerability due to saltwater intrusion in the region is estimated using the GALDIT method. As a result, the high vulnerability areas can be located by the salt water intrusion due to the change in the groundwater flow.