College of Environmental Science and Engineering, Nankai University, 38, Tongyan Rd., Jinnan District, 300350, Tianijn, China.
College of Environmental Science and Engineering, Nankai University, 38, Tongyan Rd., Jinnan District, 300350, Tianijn, China.
J Environ Radioact. 2022 Oct;251-252:106959. doi: 10.1016/j.jenvrad.2022.106959. Epub 2022 Jul 10.
Glaciers, as the core part of the cryosphere, are very sensitive to climate change. As an indicator of glacier changes, the characteristics of glacier-originated rivers have profound significance to global climate change and local water resources. In this paper, the Mingyong River, a glacier-originated river replenished by groundwater, was selected to study the river hydrological cycle characteristics by integrating natural tracer radium isotopes with hydrochemical parameters. The results showed that there were significant differences in radium isotope activities and hydrochemical parameters between groundwater and river water, and the radium activities increased along the river, which reflected the fact that the river was supplied by groundwater seepage. We also found that the activity ratios of Ra/Ra in river and groundwater were less than one unit, which indicated that the groundwater and river water circulated rapidly and that the radioactive equilibrium of short-time radium isotopes had not yet been reached. According to the geochemical behavior of radium in river water body, the mass balance equation of radium was established. Ra and Ra were used to estimate the groundwater seepage of different segments of the Mingyong River. The results demonstrated that the groundwater seepage fluxes calculated by Ra and Ra were similar and increased along the river from 123.12 to 657.68 m m d. Our results have certain significance in revealing the characteristics of the local hydrological cycle and demonstrate that radium isotopes can be used as a tool to estimate the groundwater discharge of rivers in glacial environments.
冰川作为冰冻圈的核心部分，对气候变化非常敏感。作为冰川变化的指标，冰川补给河流的特征对全球气候变化和当地水资源具有深远意义。本研究选取由地下水补给的明永河为研究对象，通过整合天然示踪镭同位素与水化学参数，研究了河流水的水文循环特征。结果表明，地下水和河水中的镭同位素活度和水化学参数存在显著差异，且镭同位素活度沿河流方向增加，反映了河水主要由地下水渗漏补给的事实。我们还发现，河水和地下水中的 Ra/Ra 活度比值小于 1 个单位，表明地下水和河水循环迅速，短时间镭同位素的放射性平衡尚未达到。根据镭在河流水体中的地球化学行为，建立了镭的质量平衡方程。利用 Ra 和 Ra 估算了明永河不同河段的地下水渗漏量。结果表明，由 Ra 和 Ra 计算得到的地下水渗漏通量相似，且从 123.12 到 657.68 m m d 沿河流方向逐渐增加。本研究结果对于揭示当地水文循环特征具有一定意义，并表明镭同位素可以作为一种工具，估算冰川环境下河流的地下水排泄量。
