Biopores and cracks in soils act as fast transport pathways for water and solute, potentially leading to pesticide leaching shortly after application. The biopore module in the agrohydrological model Daisy was developed to simulate preferential water flow directly to drainpipes, in drain-connecting biopores, and to deeper soil layers, in matrix-terminating biopores. We tested the biopore module in Daisy against field measurements of water flow and transport of bentazone and imidacloprid after application to a cracking clay field. We generated two model concepts, drain-connecting biopores (DCB) with drain-connecting biopores and drain-connecting and matrix-terminating biopore (DCMTB) with both drain-connecting and matrix-terminating biopores. Parameters describing the biopores were estimated by inverse modeling of observations of water flow and pesticide concentrations in drains. After calibration, both models satisfactorily simulated water flow and pesticide leaching to drains (root-mean-square error (RMSE)-observations standard deviation ratio (RSR) < 0.1). Particularly, the results showed that the models were able to describe the high concentration of bentazone in drain water shortly after application. Thus, the simpler DCB model preformed just as well or better than the more complex DCMTB model (ΔAIC = 4.68 [AIC, Akaike information criteria]). Discrepancies between observations and simulations in the beginning of the drainage season were attributed to the limitations that arise when simulating dynamic DCB flow paths with a static biopore model. The pesticide distribution in the field over time was well represented, especially by the DCMTB model. We therefore conclude that Daisy can simulate fast breakthrough of pesticides in drain water and describe very well pesticide concentration in drain water throughout the drainage season.

中文翻译：

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对排水管的优先水流和农药浸出建模：排水连接和基质终止生物孔的影响

土壤中的生物孔和裂缝是水和溶质的快速运输途径，可能会在施用后不久导致农药浸出。农业水文模型 Daisy 中的生物孔模块旨在模拟优先水流直接流向排水管、排水连接生物孔和更深的土壤层、基质终止生物孔。我们测试了 Daisy 中的生物孔模块，针对水流和苯达松和吡虫啉在应用于裂化粘土田后的运输的现场测量。我们生成了两个模型概念，即具有排水连接生物孔的排水连接生物孔 (DCB) 和具有排水连接和基质终止生物孔的排水连接和基质终止生物孔 (DCMTB)。描述生物孔的参数是通过对排水管中的水流和农药浓度的观察进行逆向建模来估计的。校准后，两种模型都令人满意地模拟了水流和农药浸出到排水管（均方根误差 (RMSE)-观测标准偏差比 (RSR) < 0.1）。特别是，结果表明，该模型能够描述应用后不久的排水中苯达松的高浓度。因此，更简单的 DCB 模型与更复杂的 DCMTB 模型（ΔAIC 结果表明，这些模型能够描述应用后不久的排水中的高浓度苯达松。因此，更简单的 DCB 模型与更复杂的 DCMTB 模型（ΔAIC 结果表明，这些模型能够描述应用后不久的排水中的高浓度苯达松。因此，更简单的 DCB 模型与更复杂的 DCMTB 模型（ΔAIC =  4.68 [AIC，Akaike 信息标准]）。排水季节开始时观察和模拟之间的差异归因于使用静态生物孔模型模拟动态 DCB 流动路径时出现的限制。随着时间的推移，农药在田间的分布得到了很好的体现，尤其是 DCMTB 模型。因此，我们得出结论，Daisy 可以模拟废水中农药的快速突破，并很好地描述了整个排水季节废水中农药的浓度。