A comparison of recharge rates in aquifers of the United States based on groundwater-age data
A comparison of recharge rates in aquifers of the United States based on groundwater-age data
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DOI：
10.1007/s10040-011-0722-5
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发表时间：
2011-06-01
影响因子：
2.8
通讯作者：
Hinkle, S. R.
中科院分区：
文献类型：
--
作者：
McMahon, P. B.;Plummer, L. N.;Hinkle, S. R.
概述了现有的地下水年龄数据及其对评估美国选定的非承压含水层系统的补给率和时间尺度的影响。表观年龄分布在含水层确定从氯氟烃，六氟化硫，氚/氦-3，45个网络中的565口威尔斯和放射性碳测量用于计算地下水补给率。补给的时间尺度是由来自27个井网的1，873个分布式氚测量和102个放射性碳测量确定的。根据测得的垂直年龄分布并假设指数年龄梯度，选定含水层的补给率在10毫米/年至1 200毫米/年之间。在区域的基础上，补给率的基础上示踪剂的年轻的地下水表现出显着的负相关性与年均气温和显着的正相关性与年均降水量。补给来自地下水年龄与补给来自河流基流评价的比较表明，类似的整体格局，但大量的地方差异。本汇编的结果表明，基于年龄的补给估计可以提供有益的见解空间和时间的变化，在全国范围内的补给和控制因素的变化。当地年龄为基础的补给估计提供了经验数据和过程信息，需要测试和改进更空间完整的模型为基础的方法。
An overview is presented of existing groundwater-age data and their implications for assessing rates and timescales of recharge in selected unconfined aquifer systems of the United States. Apparent age distributions in aquifers determined from chlorofluorocarbon, sulfur hexafluoride, tritium/helium-3, and radiocarbon measurements from 565 wells in 45 networks were used to calculate groundwater recharge rates. Timescales of recharge were defined by 1,873 distributed tritium measurements and 102 radiocarbon measurements from 27 well networks. Recharge rates ranged from < 10 to 1,200 mm/yr in selected aquifers on the basis of measured vertical age distributions and assuming exponential age gradients. On a regional basis, recharge rates based on tracers of young groundwater exhibited a significant inverse correlation with mean annual air temperature and a significant positive correlation with mean annual precipitation. Comparison of recharge derived from groundwater ages with recharge derived from stream base-flow evaluation showed similar overall patterns but substantial local differences. Results from this compilation demonstrate that age-based recharge estimates can provide useful insights into spatial and temporal variability in recharge at a national scale and factors controlling that variability. Local age-based recharge estimates provide empirical data and process information that are needed for testing and improving more spatially complete model-based methods.