Iowa Geological Survey, University of Iowa, Iowa City, IA, 52242, USA.
IIHR-Hydroscience & Engineering, University of Iowa, Iowa City, IA, 52242, USA.
Environ Monit Assess. 2019 Mar 20;191(4):231. doi: 10.1007/s10661-019-7377-4.
Baseflow is an important component of streamflow and watershed hydrologic budgets, yet quantifying the baseflow fraction of tile drainage has rarely been reported. In this study, we used two common hydrograph separation methods (local minimum method, recursive digital filter) to separate the discharge hydrographs from three drainage district tiles located in Iowa. Based on data collected from 2009 to 2013, annual baseflow ranged from 116 to 162 mm and comprised approximately 60% of the annual discharge. Baseflow was greatest during June (average of 34% of annual baseflow) and the March through August period produced 86% of the total annual baseflow. We found that the two methods of hydrograph separation produced similar results but the digital filter method was less erratic in estimating baseflow fraction. Study results can be used to better quantify hydrologic pathways in tiled landscapes and improve the design, implementation, and evaluation of nutrient reduction strategies.
基流是河流流量和流域水文预算的重要组成部分，但很少有报道量化排水渠的基流分数。在这项研究中，我们使用了两种常见的流量分割方法（局部最小值法、递归数字滤波器）来分割位于爱荷华州的三个排水区的排水渠的流量图。根据 2009 年至 2013 年收集的数据，年基流量在 116 至 162 毫米之间，约占年排放量的 60%。基流在 6 月最大（占年基流量的平均 34%），3 月至 8 月期间产生了总年基流量的 86%。我们发现，两种流量分割方法得出了相似的结果，但数字滤波器方法在估计基流分数时波动较小。研究结果可用于更好地量化排水渠景观中的水文路径，并改进养分减排策略的设计、实施和评估。
