Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness.
Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness.
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DOI：
10.2134/jeq2015.02.0105
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发表时间：
2015-11
影响因子：
2.4
通讯作者：
K. Schilling;C. Wolter;T. Isenhart;R. Schultz
中科院分区：
文献类型：
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作者：
K. Schilling;C. Wolter;T. Isenhart;R. Schultz
战略，以减少硝酸盐氮（硝酸盐）污染交付流往往寻求增加地下水停留时间，以实现可测量的结果，但瓷砖排水停留时间的影响还没有得到很好的记录。在这项研究中，我们使用了地理信息系统地下水旅行时间模型来量化人工地下排水对地下水旅行时间在7443公顷熊溪流域中北部的爱荷华州的影响。我们的目标是评估如何平均地下水旅行时间随着排水强度的增加而变化，并评估排水密度如何减少地下水对河岸缓冲区的贡献。结果表明，平均地下水行程时间减少，增加瓷砖排水程度。平均地下水行程时间从5.6年下降到1.1年，排水密度范围从0.005米（7.6英里）到0.04米（62英里），分别。模型模拟表明，瓷砖排水的平均旅行时间比沉降前快150倍以上。随着密集的排水，在盆地中的地下水只有不到2%的出现流经常年流缓冲区，从而降低了这种做法的有效性，以减少流硝酸盐负荷。因此，战略，如重新连接瓷砖排水缓冲区，是很有前途的，因为它们增加了地下水在瓷砖排水流域的停留时间。
Strategies to reduce nitrate-nitrogen (nitrate) pollution delivered to streams often seek to increase groundwater residence time to achieve measureable results, yet the effects of tile drainage on residence time have not been well documented. In this study, we used a geographic information system groundwater travel time model to quantify the effects of artificial subsurface drainage on groundwater travel times in the 7443-ha Bear Creek watershed in north-central Iowa. Our objectives were to evaluate how mean groundwater travel times changed with increasing drainage intensity and to assess how tile drainage density reduces groundwater contributions to riparian buffers. Results indicate that mean groundwater travel times are reduced with increasing degrees of tile drainage. Mean groundwater travel times decreased from 5.6 to 1.1 yr, with drainage densities ranging from 0.005 m (7.6 mi) to 0.04 m (62 mi), respectively. Model simulations indicate that mean travel times with tile drainage are more than 150 times faster than those that existed before settlement. With intensive drainage, less than 2% of the groundwater in the basin appears to flow through a perennial stream buffer, thereby reducing the effectiveness of this practice to reduce stream nitrate loads. Hence, strategies, such as reconnecting tile drainage to buffers, are promising because they increase groundwater residence times in tile-drained watersheds.