Quantifying ground water inputs along the Lower Jordan River.
Quantifying ground water inputs along the Lower Jordan River.
复制标题
量化约旦河下游地下水输入。
DOI：
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复制
发表时间：
2005
影响因子：
2.4
通讯作者：
A. Vengosh
中科院分区：
文献类型：
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作者：
R. Holtzman;U. Shavit;Michal Segal;I. Gavrieli;A. Marei;E. Farber;A. Vengosh
在20世纪后半叶，约旦河下游的流量发生了巨大的变化。主要天然水源的改道降低了其流量，导致了2000年和2001年干旱年的干旱事件。在这种低流量条件下，外源对河流流量和化学成分的潜在影响变得显著。我们的测量表明，河水中氯、钙和钠的浓度在前20公里段下降，而硫酸盐和镁的浓度增加。最近的一项地球化学研究解决了这些变化，表明地下水流入起了主要作用。为了进一步研究地下水的作用，我们应用了质量平衡计算，使用了详细的流量测量、水采样和沿河流北部（上游）部分的化学分析。我们的流量测量表明，2000年和2001年的河流基流量为500 ~ 1100 L s(-1)，比历史流量低约40倍。我们的测量和计算表明，地下水输入占河流水量的20%至80%，占其溶质质量流量的20%至50%。本研究独立确定了可能的端元组成。这些末端成员含有高浓度的硫酸盐，具有与农业排水沟和“含盐”的耶尔穆克河相似的化学特征。未来的区域发展计划，包括河流流速和化学应考虑河流和浅层地下水系统之间的相互作用。
The flow rate of the Lower Jordan River has changed dramatically during the second half of the 20th century. The diversion of its major natural sources reduced its flow rate and led to drying events during the drought years of 2000 and 2001. Under these conditions of low flow rates, the potential influence of external sources on the river discharge and chemical composition became significant. Our measurements show that the concentrations of chloride, calcium, and sodium in the river water decrease along the first 20-km section, while sulfate and magnesium concentrations increase. These variations were addressed by a recent geochemical study, suggesting that ground water inflow plays a major role. To further examine the role of ground water, we applied mass-balance calculations, using detailed flow rate measurements, water samplings, and chemical analyses along the northern (upstream) part of the river. Our flow-rate measurements showed that the river base-flow during 2000 and 2001 was 500 to 1100 L s(-1), which is about 40 times lower than the historical flow rates. Our measurements and calculations indicate that ground water input was 20 to 80% of the river water flow, and 20 to 50% of its solute mass flow. This study independently identifies the composition of possible end-members. These end-members contain high sulfate concentration and have similar chemical characteristics as were found in agricultural drains and in the "saline" Yarmouk River. Future regional development plans that include the river flow rate and chemistry should consider the interactions between the river and its shallow ground water system.