Obviously, securing water resources is going to be an important global issue in the near future. Groundwater is an excellent water resource as it provides a steadier supply than surface water in terms of both quantity and quality. In our country, tap water of most households is supplied by water other than groundwater, and only 20% of the areas are supplied by groundwater as the main water source, whereas in many European countries, some metropolitan cities in Asia, and many other regions, groundwater supports the local populations. Conflicts over water which arise in many areas in the world demonstrate the increasing importance of groundwater, and water is destined to be used as strategic resource in some countries and regions.
Kumamoto has a unique groundwater circulation system. One hundred percent of tap water in Kumamoto City is supplied by groundwater, and 80% of drinking water in Kumamoto Prefecture is supplied purely by groundwater. It is not an exaggeration to say that groundwater is a treasure of Kumamoto. Furthermore, in the water circulation system, a combination of both surface water from the river systems including the Shira River and the groundwater yields rich agriculture products, and the farming activities in paddy fields boost the rich groundwater resource. These two resources, agriculture and water, help each other and create the remarkable foundation to support various products in Kumamoto.
Our laboratory elucidates the mechanism of the water circulation system based on groundwater that Kumamoto boasts, and through the achievement of research on conservation of groundwater, we establish a groundwater circulation model and ground design of basin areas, which ensure sustainable and strategic usage of water resources. Through such efforts, we will make contributions to societies in many areas in Japan and in many Asian monsoon countries which may have similar issues.