The causes of land subsidence in Kawajima, Japan, have been investigated through data compilation and numerical modeling. Land subsidence has progressed despite a gradual increase in the hydraulic head in the long term. Taking into account the temporal changes and depth distribution of groundwater abstractions, the contraction of formations, and the complexity of the hydrogeological structures, it is proposed that agricultural groundwater use is one of the main triggers for land subsidence. A one-dimensional numerical simulator for coupled groundwater flow and soil deformation was developed with an evolutionary algorithm for model calibration. The calculated spatiotemporal changes in the past-maximum effective stress showed that plastic consolidation in the clayey layers progressed part by part every summer season resulting in long-term and gradual land subsidence under the same range of groundwater level fluctuations. The results also showed that the plastic deformation occurred in both the Holocene and Pleistocene sediments in the drought years, leading to significant subsidence. The model’s predictive performance showed good potential except for a structural prediction error after the Tohoku Earthquake in 2011. The scenario analysis indicated that management of the groundwater level in summer is one of the effective countermeasures in suppressing land subsidence caused by seasonal groundwater level fluctuations. These methodologies and findings can be used for groundwater management in similar cases around the world. Additional investigation is necessary on the influence of large earthquakes in deformation conditions in order to further improve the developed model.

通过数据汇编和数值模拟，研究了日本川岛地面沉降的原因。尽管从长远来看水头逐渐增加，但地面沉降仍在加剧。考虑到地下水抽取的时间变化和深度分布、地层收缩和水文地质结构的复杂性，提出农业地下水利用是地面沉降的主要诱因之一。开发了耦合地下水流和土壤变形的一维数值模拟器，并使用进化算法进行模型校准。计算的过去最大有效应力的时空变化表明，粘土层中的塑性固结在每个夏季逐个进行，导致在相同地下水位波动范围内长期和逐渐的地面沉降。结果还表明，干旱年份全新世和更新世沉积物均发生塑性变形，导致显着沉降。除了 2011 年东北地震后的结构预测误差外，该模型的预测性能显示出良好的潜力。情景分析表明，夏季地下水位管理是抑制季节性地下水位波动引起的地面沉降的有效对策之一。这些方法和发现可用于世界各地类似案例的地下水管理。有必要对变形条件下大地震的影响进行额外的调查，以进一步改进开发的模型。