Long-term changes in water mineral concentrations and their influence on sediment water content in a shallow lake
Long-term changes in water mineral concentrations and their influence on sediment water content in a shallow lake
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DOI：
10.1007/s42452-020-3119-z
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发表时间：
2020-07
影响因子：
2.6
通讯作者：
T. Fukushima;Shunsuke Komuro;T. Kitamura;Y. Nagahama;B. Matsushita
中科院分区：
文献类型：
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作者：
T. Fukushima;Shunsuke Komuro;T. Kitamura;Y. Nagahama;B. Matsushita
在过去的四十年中，已观察到的实质性变化，不仅在特里普浓度，但也在其他湖沼参数在霞浦湖，浅富营养化湖泊。前人的研究表明，特里普顿浓度与沉积物含水量（WC）呈正相关，与沉积物灼烧失重呈负相关。为了解释沉积物WC的变化，我们对1979-2016年期间矿物浓度和沉积物WC的变化进行了分析，以确定它们之间的关系。整个湖泊中的水矿物浓度高，观察到在20世纪90年代后半期和沉积物中的WC较高，随后的几年的时间滞后，导致显着的相关性。它们之间的关系在实验室实验中得到证实，实验表明，在水-沉积物系统中加入NaCl会使沉积物膨胀（沉积物压实减慢）。相比之下，显着较低的SS浓度在上覆的沃茨中观察到较高的矿物条件下，类似于以前的研究。在1994-1997年期间的显着较低的年降水量可能导致高Na+和Cl-的浓度在湖泊沃茨在20世纪90年代后半期。海洋喷雾气溶胶和蒸发的综合影响被怀疑是高盐浓度的原因。盐水通过下游闸门和/或周围建筑结构侵入是另一种可能性。
During the last four decades, substantial changes have been observed not only in tripton concentrations but also in other limnological parameters in Lake Kasumigaura, a shallow eutrophic lake. A previous study reported that tripton concentration showed a positive correlation with sediment water content (WC) and a negative one with sediment ignition loss. To explain the changes in sediment WC, we conducted an analysis of the changes in mineral concentrations and sediment WC during 1979–2016 to determine their relationship. High mineral concentrations in water throughout the lake were observed in the latter half of the 1990s and higher WC in sediments followed with a time lag of a few years, resulting in significant correlations. The relationship between them was confirmed in laboratory experiments that indicated swelling of sediments (slowdown of sediment compaction) by the addition of NaCl into the water-sediment system. In contrast, significantly lower SS concentrations in overlying waters observed in higher mineral conditions were similar to previous studies. The significantly low annual precipitation during 1994–1997 probably caused high Na+and Cl-concentrations in the lake waters in the latter half of the 1990s. The combined influence of sea-spray aerosol and evaporation was suspected to be the cause of high salt concentrations. The intrusion of salty water through the downstream gate and/or surrounding construction structures was another possibility.