Construction of Groundwater Cultivation Model for Comprehensive Management of Groundwater in Coastal City Area

本研究的研究成果如下：1)考察了大阪低地城市地下水的水文循环和地下水利用状况，指出阐明整个大阪盆地的地下水开采机制是开发地下水新利用管理系统的必要条件。2)为了建立大阪平原地下水模拟模型，需要建立大阪平原第四系三维地质结构模型。3)统一了地下水信息的数据格式，建立了与地理信息系统相连接的大阪平原数据库。4)通过基于统计简单模型的分析，明确了大阪市区降雨、潮位、抽水与地下水位的影响关系，并通过对浅层地下水溶解成分的分析，得出了大阪市区降雨、潮位、抽水与地下水位的影响关系。明确了大阪盆地的养殖流程。5)为了建立地下水可持续利用系统，保持良性的水文循环，地下水综合管理是不可或缺的系统。建立了适用于大阪平原区域地下水管理的地下水培育模型(广义地下水流分析系统)，并利用积累的信息阐明了该模型在地下水综合管理中的适用性。

The research results of this research are as follows :1)The state of a hydrological cycle and utilization of groundwater in low land city Osaka was examined, and it is pointed out that the elucidation of the groundwater cultivation mechanism for the whole Osaka basin is indispensable to develop the groundwater management system that enables new utilization of groundwater.2)In order to develop the groundwater simulation model of the Osaka plain, it is necessary to prepare the 3-dimensional geological structure model of the Quaternary layers. The plans (stripping off topographical maps) showing the distribution depth of typical layers from the information on the Quaternary layers around the Osaka plain were made, and the 3-dimensional geological structure model was built based on it.3)The data format of groundwater information was unified, and the database on the Osaka plain was built to link to GIS (Geographic Information System).4)From the analysis based on the statistical simple model, the influence relations between rain/tide-level/pumping and groundwater level were clarified in the Osaka city region, and from the analysis of dissolved components of the groundwater in the shallow aquifers, the cultivation flow paths in the Osaka basin were clarified. They are used as the basic data for the comprehensive management of groundwater.5)In order to establish sustainable groundwater utilization system, holding the wholesome hydrological cycle, a comprehensive management of groundwater is an indispensable system. The groundwater cultivation model for the regional groundwater management in the Osaka plain (broader-based groundwater flow analysis system) was developed, and the applicability to the comprehensive groundwater management of the proposed model is clarified using the accumulated information.