Seepage rate variability in Florida Bay driven by Atlantic tidal height
Seepage rate variability in Florida Bay driven by Atlantic tidal height
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大西洋潮汐高度驱动的佛罗里达湾渗流率变化
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
M. Taniguchi
中科院分区：
文献类型：
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作者：
J. Chanton;W. Burnett;H. Dulaiova;D. Corbett;M. Taniguchi
在美国佛罗里达州基拉戈的佛罗里达州海湾和大西洋两侧的石灰岩地下浅海钻井中，大西洋潮汐波动导致了压力水头的变化。我们验证了这样的假设，即这些压力水头变化会影响地下水流量，通量变化与潮汐变化有关。我们使用自动氡监测仪对佛罗里达州海湾水域的222Rn进行了连续测量，222Rn是地下水排放的天然示踪剂。我们还部署了三种类型的渗漏仪，包括一台自动热脉冲仪，以收集沉积物的连续渗漏记录。采用4-L预充式袋式收集器，在软质沉积物中插入滚筒式渗流计，在岩石湾底粘贴玻璃纤维渗流计，并按小时进行监测。佛罗里达州海湾水域的最大Rn库存与该岛大西洋一侧的涨潮有关。对Rn变化的模拟表明，地下水排泄率不同，最大流量出现在大西洋涨潮时。佛罗里达州海湾的渗漏测量结果与222Rn模拟结果一致。佛罗里达州海湾渗漏计量率与大西洋潮汐呈正相关，1米，r = 0.63，n = 12，p <； 0.025，m 2，r = 0.67，n = 12，p <； 0.025。基拉戈大西洋一侧近海的一台渗漏仪显示的渗漏率与大西洋潮汐呈负相关(r = 0.87，n = 9，p <； 0.005)，在潮汐高涨时为负值，在潮汐低潮时为正值。总体而言，我们的结果与Reich等人的假设是一致的。(2002)，大西洋潮汐驱动的压力水头变化影响了拉戈岛附近佛罗里达州海湾的地下水渗透率变异性。有效地，如Reich等人所提议的。(2002)，Key Largo起到了分隔佛罗里达州海湾和大西洋的半透水大坝的作用。
Atlantic tidal fluctuations drive pressure head variations in shallow offshore wells drilled into the limestone subsurface on both the Florida Bay and Atlantic sides of Key Largo, Florida, USA. We tested the hypothesis that these pressure head variations influence groundwater flow and that flux rate variability is associated with tidal variability. We used an automated Rn monitor to make continuous measurements of 222Rn, a natural tracer of groundwater discharge, in Florida Bay waters. We also deployed three types of seepage meters, including an automated heat pulse meter to collect a continuous record of seepage from the sediments. Drum type seepage meters inserted into soft sediments and fiberglass meters cemented to the rocky bay floor were utilized with pre-filled 4-l bag collectors, and monitored on an hourly basis. Maximum Rn inventories in Florida Bay waters were associated with high tide on the Atlantic side of the island. Modeling of the Rn variation indicated variable groundwater discharge rates with maximum flux occurring at high Atlantic tide. Seepage meter results in Florida Bay were consistent with 222Rn modeling. Florida Bay seepage meter rates showed positive correlation with Atlantic tide, meter 1, r = 0.63, n = 12, p < 0.025 and meter 2, r = 0.67, n = 12, p < 0.025. A seepage meter offshore of the Atlantic side of Key Largo exhibited rates that were inversely correlated with Atlantic tide (r = 0.87, n = 9, p < 0.005) showing negative rates when the tide was high, and positive rates when the tide was low. Overall, our results are consistent with the hypothesis of Reich et al. (2002), that pressure head variations driven by Atlantic tide influence groundwater seepage rate variability in Florida Bay off Key Largo. Effectively, as proposed by Reich et al. (2002), Key Largo functions as a semi-permeable dam separating Florida Bay and the Atlantic Ocean.