Evaluation of Groundwater Risk due to Anthropogenic Activities in a Coastal Plain of the Seto Inland Sea, Japan

Anthropogenic activities have exerted increasingly large-scale influences on terrestrial ecological systems from the past century, primarily through agriculture; however, the impact of such changes on the groundwater risk is poorly understood. As the main source of water in the Dogo Plain, Japan, groundwater plays an important role in providing people with fresh water and contributing to stream base flow. The purpose of this study is to quantify the alterations in the land use regime as well as to assess the changes in groundwater risk. A conceptual hydrologic model was developed to simulate groundwater and water balance in the study basin under different land use scenarios. The simulated results illustrated different groundwater level evolution and risk in the typical hydrologic years of 2003 (normal flow year), 2001 (high flow year), and 2002 (drought year) in different land use cases that are influenced by anthropogenic activities. The produced groundwater risk simulation results can be used by the local management authorities to enhance sustainable socio-economic planning and environmental management.