Temporal Subsurface Flow Patterns from Fifteen Years in North-Central Iowa
Temporal Subsurface Flow Patterns from Fifteen Years in North-Central Iowa
复制标题
爱荷华州中北部十五年的时间地下流动模式
DOI：
10.13031/2013.19040
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发表时间：
2005
影响因子：
1.5
通讯作者：
D. Lemke
中科院分区：
文献类型：
--
作者：
M. Helmers;P. A. Lawlor;J. Baker;S. Melvin;D. Lemke
上中西部的地下排水对农业生产具有重要意义。但正当
需要通过现场管理、排水管理或现场实践的边缘来管理这些系统，
限制对环境的负面影响，特别是硝酸盐氮的沥滤损失。一种管理做法是
考虑的是排水管理，其中对地下排水的流出进行管理以节约用水，
减少地下排水的总流出量。了解如何以及何时使用排水管理
在上中西部，重要的是要审查长期的排水数据，以了解时间，持续时间和数量的
在这种气候下的地下排水系统一项正在进行的爱荷华州中北部的排水研究允许对15个
多年的地下排水，包括一系列气候条件。此信息已被审查，
目的是了解时间、持续时间和排水量，考虑时间排水流量模式。在
特别是，每月和季节的流量模式进行了调查，使用这个长期的排水记录。On this
场地排水间距相对较窄，为7.6 m，排水量约为降水量的40%。的时间
从4月到6月的这段时间大约有50%的平均年降水量和大约70%的
年平均排水量。此外，每年8月1日之后发生的排水量仅占7%左右。
这些地区地下水流的时间，特别是在春季，与种植，作物发芽，
在考虑排水管理措施和
这些做法限制了流动，因此也限制了硝酸盐氮的沥滤损失。为减少排水流失，
排水管理系统需要有足够的灵活性，以确保作物生产，同时有效地
管理地下排水流，以潜在地最小化水的流出。
Subsurface drainage in the Upper Midwest is of importance to agricultural production. However, proper
management of these systems through in-field management, drainage management, or edge of field practices is needed to
limit negative environmental impacts particularly from nitrate-nitrogen leaching losses. One management practice being
considered is drainage management where the outflow of subsurface drainage is managed to conserve water and
decrease the overall outflow of subsurface drainage. To understand how and when drainage management may be utilized
in the upper Midwest it is important to review long-term drainage data to understand the timing, duration, and volumes of
subsurface drainage in these climates. An on-going drainage study from north-central Iowa allows for reviewing fifteen
years of subsurface drainage which encompasses a range of climatic conditions. This information has been reviewed with
the objective of understanding the timing, duration, and drainage volumes considering temporal drainage flow patterns. In
particular, the monthly and seasonal flow patterns have been investigated using this long-term drainage record. On this
site with a relatively narrow drain spacing of 7.6 m, drainage volume was approximately 40% of the precipitation. The time
period from April through June had approximately 50% of the average annual precipitation and approximately 70% of the
average annual drainage. In addition, the percent of annual drainage occurring after August 1 was only approximately 7%.
The timing of subsurface flow in these areas specifically during the spring coincides with time of planting, crop germination,
and early crop development has implications when considering drainage management practices and the effectiveness of
these practices to limit flow and therefore nitrate-nitrogen leaching losses. To minimize outflow of drainage water, these
drainage management systems would need to allow for adequate flexibility to ensure crop production while effectively
managing subsurface drainage flow to potentially minimize the outflow of water.