Assessing groundwater coupling and vertical exchange in a meromictic mining lake with an SF6-tracer experiment
Assessing groundwater coupling and vertical exchange in a meromictic mining lake with an SF6-tracer experiment
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通过 SF6 示踪剂实验评估半积矿湖中的地下水耦合和垂直交换
DOI:
10.1016/j.jhydrol.2009.04.004
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发表时间:
2009
影响因子:
6.4
通讯作者:
B. Boehrer
中科院分区:
文献类型:
--
作者:
von Rohden;J. Ilmberger ;B. Boehrer
Groundwater–lake interaction in conjunction with surface mixing and vertical exchange were quantitatively examined for the monimolimnion in a small stratified mining lake. Although the lake is shallow (∼4.7m), it shows a strong meromixis. The permanent chemocline, which is connected with stable density stratification, separates the mixolimnion from the anoxic monimolimnion at a variable depth of only 0.6–1.9m. We conducted a tracer experiment, injecting ∼3μmol of anthropogenic gas SF6into the monimolimnion. With monthly measured vertical concentration profiles extended over 2 years we detected and quantified the groundwater coupling. An exchange time close to once per year was estimated for the monimolimnion by balancing the tracer. From CTD casts and thermistor chain data we extracted additional information about mixing. For the water and tracer balances, we included the erosion of the monimolimnion surface by strong daily convective mixing in the mixolimnion during the warm period. SF6background measurements before spiking indicate that diffusive transport through the chemocline density step must be very low, i.e., close to the molecular level. The observed seasonal variability of the chemocline depth can be considered as the result of a virtually steady inflow of groundwater, which supports the growth of the monimolimnion, and strong seasonal mixing in the mixolimnion, which acts against the stratification and erodes the monimolimnion. Over longer time scales, the chemocline is to be found at the level where erosive processes balance the recharging of the monimolimnion from groundwater.
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DOI:
--
发表时间:
2002
期刊:
影响因子:
--
作者:
D. Hongve
通讯作者:
D. Hongve
影响因子:
2.4
作者:
C. Rohden;K. Wunderle;J. Ilmberger
通讯作者:
J. Ilmberger
影响因子:
4.5
作者:
R. Jellison;J. Romero;J. Melack
通讯作者:
J. Melack
影响因子:
2.3
作者:
M. Schmid;A. Lorke;A. Wüest;M. Halbwachs;G. Tanyileke
通讯作者:
G. Tanyileke
影响因子:
1.3
作者:
A. Seebach;Severine Dietz;D. Lessmann;K. Knoeller
通讯作者:
K. Knoeller