An integrated approach to quantify groundwater transport of phosphorus to Narrow Lake, Alberta
An integrated approach to quantify groundwater transport of phosphorus to Narrow Lake, Alberta
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量化地下水磷向艾伯塔省窄湖输送的综合方法
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
E. Prepas
中科院分区：
文献类型：
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作者：
R. Shaw;J. Shaw;H. Fricker;E. Prepas
采用综合方法量化了流入窄湖（艾伯塔省中部的一个小型冰川地形湖）的地下水磷通量。来自钻探计划、主要离子浓度、环境同位素和计算机模拟的数据表明，该湖通过近岸区域从一个小型浅层地下水流系统获取水；在近海地区，水从湖泊流向地下水流系统。渗流通量通过水预算、达西方程与湖附近井的数据、达西方程与湖中微型压力计的数据以及渗流计进行量化。根据微型渗压计数据（30 mm yr-1）确定的全湖渗流通量仅为其他估计值的 10-25%（平均，221 mm yr-1；范围，分别来自渗流计和水收支数据的 133-332 mm yr-1）。地下水贡献了该湖年水负荷的 30%。湖泊沉积物孔隙水中的磷浓度[PI（平均175 mg m-‘）比湖附近井的地下水（平均2·1 mg m-3）高8倍。因此，如果用井水来估算渗流水的[P]，则会低估地下水对湖泊的P负荷率。根据平均渗流通量和平均孔隙水[P]计算，地下水对湖泊的磷负荷率为39 mg m-2 yr-I，地下水可能是湖泊表湖水磷的最大单一来源。
An integrated approach was used to quantify groundwater phosphorus flux to Narrow Lake, a smallglacial-terrain lake in central Alberta. Data from a drilling program, major ion concentrations, environmental isotopes, and computer simulations indicated that the lake gains water through the nearshore region from a small, shallow groundwater flow system; at deep offshore regions, water moves from the lake to the groundwater flow system. Seepage flux was quantified by water budget, Darcy’s equation with data from wells near the lake, Darcy’s equation with data from minipiezometers in the lake, and seepage meters. Whole-lake seepage flux determined from minipiezometer data (30 mm yr-I) was only lO-25% of the other estimates (mean, 221 mm yr-I; range, 133-332 mm yr- l from seepage meter and water budget data, respectively). Groundwater contributed - 30% of the annual water load to the lake. The P concentration, [PI, in pore water from lake sediments (mean, 175 mg m-‘) was 8 times higher than groundwater from wells near the lake (mean, 2 1 mg m-3). Thus, if well water was used to estimate the [P] of the seepage water, the rate of groundwater P loading to the lake would be underestimated. The rate of groundwater P loading to the lake computed from average seepage flux and average pore-water [P] was 39 mg m-2 yr-I, and groundwater may be the largest single source of P to epilimnetic water in the lake.