GroMoPo Metadata for Kyushu Island model

Groundwater is an important resource for water use in the alluvial coastal lowland plain. In the Shiroishi lowland plain, southwestern Kyushu Island of Japan, land subsidence and salinity intrusion due to intense withdrawals of groundwater have become the main environmental issues for public concern. In this study, an integrated surface and groundwater model was established and applied to the Shiroishi site to simulate groundwater flow hydraulics, aquifer compaction and solute transport in the alluvial lowland plain. Moreover, a groundwater optimization model was also formulated to search for an optimal safe yield of groundwater extraction without violating salinity intrusion and other constraints. The simulated results show that groundwater levels in the aquifer greatly vary in response to varying climatic and pumping conditions. Consequently, land subsidence has rapidly occurred throughout the area with the central prone in Shiroishi basin. As a result of pumping and land subsidence, seawater has been intruded along the coast. in case of relative sea level rise, seawater intrusion appears to extend much farther in land from the coast. From the viewpoint of agricultural water management, pumping for irrigation with an optimal pumping amount that is a new finding from the optimization model will sustain groundwater quality in the study area. (c) 2006 Elsevier B.V. All rights reserved.地下水是冲积沿海低地平原用水的重要资源。位于日本九州岛西南部的白石低地平原，因高强度地下水开采引发的地面沉降与咸水入侵，已成为公众关注的核心环境问题。本研究构建并应用了地表-地下水耦合模型（integrated surface and groundwater model），对该冲积低地平原的地下水水动力、含水层压密与溶质运移过程开展模拟。此外，本研究还建立了地下水优化模型，用于求解不突破咸水入侵约束及其他限制条件的地下水最优允许开采量。模拟结果表明，含水层地下水位会随气候与抽水条件的变化产生显著波动。受此影响，全区快速出现地面沉降，其中以白石盆地（Shiroishi basin）中部为沉降敏感核心区。抽水活动与地面沉降共同作用下，海水沿海岸带发生入侵；当出现相对海平面上升（relative sea level rise）时，海水入侵范围将向内陆大幅扩展。从农业用水管理的角度而言，基于优化模型得到的最优灌溉抽水量，可维持研究区内的地下水水质。©2006 Elsevier B.V. 保留所有权利。