Impact of impoundment on groundwater seepage in the Three Gorges Dam in China based on CFCs and stable isotopes
Impact of impoundment on groundwater seepage in the Three Gorges Dam in China based on CFCs and stable isotopes
复制标题
DOI：
10.1007/s12665-014-3349-8
复制
发表时间：
2014
影响因子：
2.8
通讯作者：
Lei Zhang;Duoxing Yang;Yaowei Liu;Yong-tai Che;D. Qin
中科院分区：
文献类型：
--
作者：
Lei Zhang;Duoxing Yang;Yaowei Liu;Yong-tai Che;D. Qin
三峡大坝建成后引起的地下水流场变化对区域地震活动和环境的影响是人们普遍关注的问题。利用基于氯氟烃（CFC）的地下水年龄分析技术，可以有效地反映渗流区的变化。利用三峡水库蓄水过程中地下水、库水和泉水中的CFCs、稳定同位素和水位，研究了水库蓄水对地下水和水库渗流区边界的影响。结果表明，地下水补给的水年龄较大，而水库和泉水补给的水年龄较小。随着库水位的升高，位于库首区副坝的W3井由于库水加载作用而老化，而W4井由于库水侧向渗流而老化。这一发现表明，位于水库上游的威尔斯W3、W4井地下水渗流区均受到三峡水库的影响。相比之下，仙女山断裂带北方段距离大坝较远，地下水和水库水之间没有任何直接的水力联系，因此，水库渗流效应可能不会影响仙女山断裂带的北方部分。这些研究成果为分析三峡水库蓄水对区域环境的影响提供了重要的参考数据。
It is a common concern that the groundwater flow field caused by the Three Gorges Dam changes the regional seismic activity and environment. The changes in the seepage region could be effectively reflected through the analysis of the groundwater age using chlorofluorocarbons (CFC)-based techniques. In this study, the influences of the reservoir water on groundwater and the seepage region boundary of the reservoir were investigated using CFCs, stable isotopes, and water level in groundwater, reservoir water, and spring water during the water storage process of the Three Gorges Reservoir. The results show that the water supplied by the groundwater is older, whereas the water supplied by the reservoir and the springs is younger. With an increase in the water level of the reservoir, the water in well W3, which is located at the vice dam of the head region, becomes older due to the reservoir loading effect, whereas the water in well W4 become younger due to the lateral seepage of reservoir water. This finding indicates that the groundwater seepage regions in wells W3 and W4, which are located at upstream of the reservoir, are all influenced by the Three Gorges Reservoir. In contrast, the sampling points in the northern section of the Xiannvshan fault zone, which is farther from the dam, did not exhibit any direct hydraulic connection between the groundwater and the reservoir water; thus, the reservoir seepage effects may not affect the northern part of the Xiannvshan fault zone. These research results provide important reference data that can be used to analyze the effects of the Three Gorges reservoir storage on the regional environment.