Excessive groundwater withdrawal and resultant land subsidence in the Su-Xi-Chang area, China
Excessive groundwater withdrawal and resultant land subsidence in the Su-Xi-Chang area, China
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DOI：
10.1007/s12665-009-0433-6
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发表时间：
2010-01
影响因子：
2.8
通讯作者：
Yun Zhang;Yuqun Xue;Jichun Wu;Xiaoqing Shi;Jun Yu
中科院分区：
文献类型：
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作者：
Yun Zhang;Yuqun Xue;Jichun Wu;Xiaoqing Shi;Jun Yu
苏锡常地区由于地下水过量开采而引起了严重的地面沉降。自1990年代后期以来，一直在限制和禁止抽取地下水。根据最新的实测资料，分析了地下水位的变化规律和地面沉降的分布。沙三坳陷地面沉降的时空分布与第二承压含水层沉降锥的时空分布密切相关。但地面沉降与地下水位的变化并不同步。含水层和弱透水层在地下水位上升初期均表现为不断压实的蠕变材料。对含水层砂土进行了一系列室内试验，试验结果表明，砂土在初始压缩状态下的蠕变变形远大于再压缩和卸载状态下的蠕变变形，且蠕变随重复荷载循环次数的增加而迅速减小。试验结果揭示了长期地下水开采条件下砂土蠕变的机理。由于限制和禁止抽取地下水，SXC地区绝大部分地下水位已明显恢复，苏州和常州的地面沉降有所减缓，甚至出现了小幅反弹。如果连续严格限制抽水量，地下水位不会下降到历史最低值以下，而是在一定范围内波动。在这种情况下，SXC的地面沉降将不再明显发展。
Excessive groundwater withdrawal has caused severe land subsidence in the Su-Xi-Chang (SXC) area, China. The restriction and prohibition on groundwater pumping have been carried out since the late 1990s. Based on the latest updated field data, the changing pattern of groundwater level and the distribution of land subsidence are analyzed. The distribution of land subsidence in SXC is closely related to that of the cone of depression in the second confined aquifer in time and space. But land subsidence is not in synchronization with the changing groundwater level. Both aquitards and aquifers compacted continuously in the early period of groundwater level rising and behaved as creep materials. A series of laboratory tests were conducted on aquifer sands, which indicated that the creep deformation under virgin compression is much greater than that under recompression and unloading, and that the creep of sands decreases rapidly with the cycles of repeating load. The test results reveal the mechanism of sand creep under the condition of long-term groundwater pumpage. As a consequence of the restriction and prohibition on groundwater pumping, groundwater level has obviously recovered in the vast majority of the SXC area, and land subsidence has slowed down and even a little rebound has occurred in some sites in Suzhou and Changzhou. If the pumpage is strictly limited continuously, the groundwater level will not decline below the historical lowest value but fluctuate within a certain range. In such a case, land subsidence in SXC will no longer develop obviously.