Department of Land, Air, and Water Resources, University of California, Davis, CA 95616, USA.
Environ Pollut. 2010 May;158(5):1629-37. doi: 10.1016/j.envpol.2009.12.008. Epub 2009 Dec 29.
Field runoff is an important transport mechanism by which pesticides move into the hydrologic environment of intensive agricultural regions such as California's Central Valley. This study presents a spatially explicit modeling approach to extend Pesticide Root Zone Model (PRZM), a field-scale pesticide transport model, into basin level. The approach was applied to simulate chlorpyrifos use in the Central Valley during 2003-2007. The average value of loading as percent of use (LAPU) is 0.031%. Results of this study provide strong evidence that surface runoff generation and pesticide application timing are the two influencing factors on the spatial and temporal variability of chlorpyrifos sources from agricultural fields. This is one of the first studies in coupling GIS and field-scale models and providing simulations for the dynamics of pesticides over an agriculturally dominated landscape. The demonstrated modeling approach may be useful for implementations of best management practice (BMP) and total maximum daily load (TMDL).
田间径流是农药进入加利福尼亚州中央谷地等集约化农业区水文环境的重要迁移机制。本研究提出了一种空间显式建模方法，将农药根区模型（PRZM）扩展到流域尺度，这是一种用于模拟田间尺度农药迁移的模型。该方法应用于模拟 2003-2007 年中央谷地氯吡硫磷的使用情况。使用量的负载百分率（LAPU）平均值为 0.031%。本研究结果提供了有力的证据，表明地表径流的产生和农药施用时间是影响农业用地中氯吡硫磷来源时空变异性的两个关键因素。这是首次将 GIS 和田间尺度模型相结合并对农业为主的景观中农药动态进行模拟的研究之一。所展示的建模方法对于最佳管理实践（BMP）和最大日负荷总量（TMDL）的实施可能是有用的。
