2014 Volume 25 Issue 3 Pages 159-168
Integration of multiple groundwater investigation data and precise modeling of hydrogeological structures including aquifers are indispensable to sustainable use of groundwater resources. GIS technology can be effectively applied to this purpose. This study selected the Kumamoto City area which depends on groundwater for all water supplies as a case study of such GIS application. Using the vertical geological cross-sections, the groundwater-level data at ten observation wells, digital elevation model, surface geological map, spring map, and ArcGIS (ESRI), the following hydraulic items were characterized: three-dimensional strata distribution, water-level distribution and its temporal change, correlation of the level with the precipitation, strata distribution at the water level, and the geological and topographic factors for spring formation. As the result, the general trend of annual average of water-level distribution was found to be unchanged despite the large change in precipitation. The zones with high changeability in water level were locally appeared due to the high permeability of strata along the vertical direction. Holocene Ariake clay layers and Pleistocene Aso-4 pyroclastic flow deposits were specified as main strata at the water levels in the first aquifer in the low land and terrace areas, respectively. The springs were clarified to be located at the steep change in topographic slope and at the boundaries of the surface and aquifer strata.
