Longitudinal and seasonal water chemistry variations in a northern Appalachian stream.
Longitudinal and seasonal water chemistry variations in a northern Appalachian stream.
复制标题
阿巴拉契亚山脉北部溪流的纵向和季节性水化学变化。
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
K. Stewart
中科院分区：
文献类型：
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作者：
R. A. Phillips;K. Stewart
桂格溪是位于纽约州西南部的一条四级河流，其上游沿着呈现出极不寻常的化学梯度。每周的水样显示，仅沿沿着2.2公里的一段水域，年平均pH值从5.07增加到7.01。平均碱度、钙、镁、钠、钾、硝酸盐-亚硝酸盐-氮、二氧化硅和电导率在此距离上也明显增加。该研究区接收一些最高酸性的大气沉积在美国。最小的缓冲，这些酸性输入在极端的上游流域，和突然下游增加缓冲与土壤类型的变化，显然产生所观察到的河水化学梯度。相比之下，11个中游，下游和支流网站之间的比较表明，相对较小的变化，河水化学。除了明显的纵向化学变化沿着流的上部，显着的时间化学变化也观察到在所有采样点。高流量在融雪和暴雨产生更稀，酸性条件下，而溪流pH值和溶解的盐基阳离子一般最高，在低流量。这种时间上的变化在很大程度上是由于在土壤水的停留时间的季节性变化。
: Quaker Run, a fourth order stream located in southwestern New York State, exhibits a highly unusual chemical gradient along its upper reaches. Weekly water samples showed an increase in the mean annual pH from 5.07 to 7.01 along a stretch of only 2.2 km. Mean alkalinity, calcium, magnesium, sodium, potassium, nitrate-nitrite-nitrogen, silica, and conductivity also increased appreciably over this distance. The study area receives some of the most highly acidic atmospheric deposition in the United States. Minimal buffering of these acidic inputs in the extreme upper watershed, and an abrupt downstream increase in buffering associated with changes in soil type, apparently produce the observed streamwater chemistry gradient. In contrast, a comparison between 11 midstream, downstream, and tributary sites showed relatively little variation in streamwater chemistry. In addition to the pronounced longitudinal chemistry changes along the upper portion of the stream, pronounced temporal chemistry variations were also observed at all sampling sites. High flow during snowmelt and heavy rains produced more dilute, acidic conditions, while streamwater pH and dissolved base cations were generally highest during low flow. Much of this temporal variation in streamwater chemistry is attributed to seasonal variation in residence times of soil water.