Dual permeability modeling of tile drain management influences on hydrologic and nutrient transport characteristics in macroporous soil
Dual permeability modeling of tile drain management influences on hydrologic and nutrient transport characteristics in macroporous soil
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DOI：
10.1016/j.jhydrol.2016.01.073
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发表时间：
2016-04-01
影响因子：
6.4
通讯作者：
Lapen, David R.
中科院分区：
文献类型：
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作者：
Frey, Steven K.;Hwang, Hyoun-Tae;Lapen, David R.
瓷砖排水管理被认为是一个有益的管理实践（BMP），以减少地表水中的营养负荷。在这项研究中，2维双渗透模型被开发来模拟流动和运输液体猪粪和罗丹明WT（强吸附）示踪剂的应用大孔粘壤土控制（CD）和自由排水（FD）瓷砖管理。成功地复制了占主导地位的流量和运输特性，包括更高和更连续的瓷砖排放和较低的峰值罗丹明WT浓度在FD瓷砖流出物;在CD，其中排放是间歇性的，峰值罗丹明浓度较高，从大孔到土壤基质的质量交换更大。优先流的显式表示是必不可少的，因为大孔传输>98%的表面渗透，瓷砖流，瓷砖溶质负荷FD和CD。为了模拟CD，必须建立一个促进地下水相互作用的主动第三类下边界条件，因为较高的（相对于FD）地下水位促进了水和可溶性养分从土壤剖面向地下水深处的移动。情景分析表明，在条件下，存在轻微向上的水力梯度下瓷砖，地下水上涌可以影响FD条件下瓷砖流出物中的表面衍生溶质的浓度，而更高和更平坦的CD地下水位可以限制地下水上涌。结果表明，虽然CD可以减少瓷砖排放量，它也可以导致增加的表面应用程序派生的营养盐浓度瓷砖流出物，因此地表水受体，它可以促进NO3加载到地下水。这项研究表明，双渗透率建模作为一种工具，增加瓷砖排水BMP的概念理解。(C)© 2016 Elsevier B. V.版权所有。
Tile drainage management is considered a beneficial management practice (BMP) for reducing nutrient loads in surface water. In this study, 2-dimensional dual permeability models were developed to simulate flow and transport following liquid swine manure and rhodamine WT (strongly sorbing) tracer application on macroporous clay loam soils under controlled (CD) and free drainage (FD) tile management. Dominant flow and transport characteristics were successfully replicated, including higher and more continuous tile discharge and lower peak rhodamine WT concentrations in FD tile effluent; in relation to CD, where discharge was intermittent, peak rhodamine concentrations higher, and mass exchange from macropores into the soil matrix greater. Explicit representation of preferential flow was essential, as macropores transmitted >98% of surface infiltration, tile flow, and tile solute loads for both FD and CD. Incorporating an active 3rd type lower boundary condition that facilitated groundwater interaction was imperative for simulating CD, as the higher (relative to FD) water table enhanced water and soluble nutrient movement from the soil profile into deeper groundwater. Scenario analysis revealed that in conditions where slight upwards hydraulic gradients exist beneath tiles, groundwater upwelling can influence the concentration of surface derived solutes in tile effluent under FD conditions; whereas the higher and flatter CD water table can restrict groundwater upwelling. Results show that while CD can reduce tile discharge, it can also lead to an increase in surface-application derived nutrient concentrations in tile effluent and hence surface water receptors, and it can promote NO3 loading into groundwater. This study demonstrates dual permeability modeling as a tool for increasing the conceptual understanding of tile drainage BMPs. (C) 2016 Elsevier B.V. All rights reserved.