天津地面沉降区地下水资源超采和涵养恢复阈值的讨论

Threshold of Groundwater Over-exploitation and Conservation-restoration in Tianjin Land Subsidence Area

天津市地面沉降属于典型的水资源短缺型地面沉降,发育范围广,沉降程度高,灾害损失大,有效防治天津市地面沉降的主要手段是严格控制地下水资源超采、涵养恢复地下水含水系统。从地下水流动系统和地面沉降的发育特点出发,综合分析讨论,认为天津沉降区整体上地下水已经超采,仅研究小区域地下水是否超采,存在"以小论大"的误区,宜以水文地质单元为单位来开展超采情况评价,地下水资源实现有效涵养恢复的阈值是要求地下水位恢复至地面沉降临界水位以上。

The land subsidence in Tianjin has been wide coverage, high degree and great danger, which mainly caused by water shortage and groundwater over - exploitation. In order to prevent the development of land subsidence, the main measures include strict controlling of over - exploitation and conservation - restoration of groundwater aquifers system. The article is based on characteristics of the groundwater flow system and the development of land subsidence, comprehensive analysis of threshold of groundwater over - exploitation and conservation - restoration, the land subsidence area in Tianjin has been over - exploitation as a whole firstly, the studies of whether over - exploitation only in a small area may result in some mistake, such as ＂ small on big＂ and so on. It has been recommended that evaluating over - exploitation of groundwater resources by hydrological geological unit as a unit. Furthermore, the groundwater table has been required grate recovery upon the critical level , which as threshold of effective conservation - restoration of groundwater resource.