Characterizing the recharge regime of the strongly exploited aquifers of the North China Plain by environmental tracers
Characterizing the recharge regime of the strongly exploited aquifers of the North China Plain by environmental tracers
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DOI：
10.1029/2008wr007660
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发表时间：
2010-05
影响因子：
5.4
通讯作者：
Christoph von Rohden;A. Kreuzer;Zongyu Chen;R. Kipfer;W. Aeschbach–Hertig
中科院分区：
文献类型：
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作者：
Christoph von Rohden;A. Kreuzer;Zongyu Chen;R. Kipfer;W. Aeschbach–Hertig
采用环境示踪剂（3H‐3He、惰性气体、稳定同位素18O和2H）研究了河北省会石家庄地区华北平原强开发含水层系统地下水补给和停留时间。在山前平原的非封闭部分，地下水中含有氚，深度约为100米，并显示出小于40年的3H - 3He年龄。3H - 3He年龄与采样深度的相关性较好，但与从西部山区到山前平原补给区沿样带距离的相关性较弱，表明横向流入的作用较小，而空间分布的补给作用较小。地下水年龄随着饱和带厚度的增加而增加，加上近几十年来地下水位的稳定下降，表明有效补给速率约为0.3 m/yr，主要是由于降水和灌溉水的入渗。尽管灌溉用水得到了循环利用，但水资源平衡仍然存在缺陷，导致含水层枯竭。近几十年来地下水中稳定同位素比值的增加趋势似乎反映了对自然补给机制的人为改变。
We employed environmental tracers (3H‐3He, noble gases, stable isotopes 18O and 2H) to study groundwater recharge and residence times in the strongly exploited North China Plain aquifer system in the area of Shijiazhuang, the capital of the Hebei province. Groundwater in the unconfined parts of the piedmont plain contains tritium down to depths of about 100 m and exhibits 3H‐3He ages of less than 40 years. 3H‐3He ages correlate well with sampling depth but less so with distance along a transect from the mountains in the west through the recharge area in the piedmont plain, indicating a minor role of lateral inflow compared to spatially distributed recharge. The increase of groundwater age with increasing thickness of the saturated zone combined with the steady groundwater table descent over the last decades implies an effective recharge rate of around 0.3 m/yr, mostly due to infiltration of precipitation and irrigation water. Despite the recycling of irrigation water, a water balance deficit remains, causing depletion of the aquifers. Anthropogenic modifications of the natural recharge regime appear to be reflected by a trend of increasing stable isotope ratios in groundwater of the last decades.