Influence of catchment topography on water chemistry in southeastern Quebec Shield lakes
Influence of catchment topography on water chemistry in southeastern Quebec Shield lakes
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DOI：
10.1139/cjfas-54-10-2215
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发表时间：
1997-10-01
影响因子：
2.4
通讯作者：
Carignan, R
中科院分区：
文献类型：
--
作者：
D'Arcy, P;Carignan, R
对于魁北克东南部的30个加拿大地盾湖，流域坡度和湖泊形态学解释了叶绿素a（Chi a）、溶解有机碳（DOG）、总磷（TP）、NO3-和NH 4+变化的50-70%。溶解性有机碳、TP、Chi a、Ca和Mg与流域坡度呈负相关，而NO3-和NH 4+则随坡度增加而增加。浓度的更保守的成分（SO 42-，Na，K）的增加，随着海拔的降低，作为一个结果，较高的蒸散量和较低的降水量在低海拔。集水变量（坡度、流域面积、湿地百分比）与水化学变量（TP、Ca、Mg和pH值）一样，是Chi a（r（2）= 0.7）的良好预测因子。主要植被（落叶与针叶）对湖水化学的影响很小或没有影响。加拿大地盾的水文地质数据表明，在高径流期间，积水区的发展和饱和土壤上的地表径流的重要性与集水坡度成反比。我们建议，强烈的影响，集水区的坡度对水质是由于依赖于坡度的季节性内涝，这决定了命运（保留或出口到表面沃茨）内产生的溶解物质，并通过森林地面移动。
For 30 Canadian Shield lakes of southeastern Quebec, catchment slope and lake morphometry account for 50-70% of the variability of chlorophyll a (Chi a), dissolved organic carbon (DOG), total phosphorus (TP), NO3-, and NH4+. Dissolved organic carbon, TP, Chi a, Ca, and Mg are negatively related to catchment slope, whereas NO3- and NH4+ increase with increasing slope. Concentrations of more conservative constituents (SO42-, Na, K) increase with decreasing elevation as a result of higher evapotranspiration and lower precipitation at low elevations. Catchment variables (slope, drainage area, percent wetlands) are as good predictors of Chi a (r(2)= 0.7) as are water chemistry variables (TP, Ca, Mg, and pH). Dominant vegetation (deciduous vs. coniferous) has little or no influence on lake water chemistry. Hydrogeological data for the Canadian Shield suggest that, during periods of high runoff, the development of waterlogged areas and the importance of overland flow on saturated soils are inversely proportional to catchment slope. We propose that the strong influence of catchment slope on water quality is due to slope-dependent seasonal waterlogging, which determines the fate (retention or export to surface waters) of dissolved substances produced within and moving through the forest floor.