AnnAGNPS Application and Evaluation in NE Indiana
AnnAGNPS Application and Evaluation in NE Indiana
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AnnAGNPS 在印第安纳州东北部的应用和评估
DOI：
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发表时间：
2008
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通讯作者：
Chi
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作者：
D. Flanagan;B. Zuercher;Chi
建立了年化农业非点源（AnnAGNPS）污染模型，用于模拟未开发农业流域的径流、沉积物、养分和农药损失。在这里，该模型应用于707平方公里的雪松溪流域（CCW）和45平方公里的马特森沟流域（MDS），这两个流域以农业为主（约85%），主要作物为玉米和大豆。阿特拉津除草剂是一个重大问题，因为圣约瑟夫河是印第安纳州韦恩堡市的饮用水源。主要目的是评估AnnAGNPS在未校准、校准和验证模式下模拟径流和阿特拉津浓度的能力。模型输入的数据来源包括USGS地形数字高程模型、NRCS空间SSURGO土壤数据和USDA-NASS农田数据层。CCW的观测流量数据来自USGS测量站，而流量和阿特拉津浓度数据来自NSERL在MDS排放点的水质采样点。在未校准模式下，AnnAGNPS的流量预测在CCW尺度上是令人满意的，但可以通过校准来改进。CCW和MDS的流量与模型校准时的观测值吻合良好，模型验证时的CCW流量也吻合良好。AnnAGNPS对径流水中阿特拉津浓度的最初预测非常差，而且不可能通过任何类型的校准来改进结果。对模型源代码的检查发现，在农药程序中使用的径流值中存在单位转换误差，修正后大大改善了结果。校正后的AnnAGNPS模型代码可以成功校准和验证用于预测MDS中的阿特拉津浓度。
The Annualized Agricultural Non-Point Source (AnnAGNPS) pollution model was developed for simulation of runoff, sediment, nutrient, and pesticide losses from ungaged agricultural watersheds. Here, the model was applied to the 707 km2 Cedar Creek Watershed (CCW) and the 45 km2 Matson Ditch Sub-Catchment (MDS), which are predominantly (>85%) agricultural, with major crops of corn and soybeans. Atrazine herbicide is of significant concern, as the St. Joseph River is the source of drinking water for the city of Fort Wayne, Indiana. Major objectives were to evaluate the ability of AnnAGNPS to simulate runoff and atrazine concentrations in uncalibrated, calibrated, and validation modes. Data sources for the model inputs included USGS Digital Elevation Model for topography, NRCS spatial SSURGO soils data, and the USDA-NASS cropland data layer. Observed flow data for CCW were available from a USGS gaging station, while flow and atrazine concentration data were available from a NSERL water quality sampling site at the discharge point of the MDS. In an uncalibrated mode, flow discharge predictions by AnnAGNPS were satisfactory at the CCW scale, but could be improved through calibration. Flow discharge for both CCW and MDS could be well matched with observed during model calibration, as could discharge for CCW during model validation. Initial AnnAGNPS predictions of atrazine concentrations in runoff water were very poor, and it was impossible to improve the results through any type of calibration. Inspection of the model source code revealed a unit conversion error in the runoff value being utilized in the pesticide routine, which when corrected greatly improved the results. The corrected AnnAGNPS model code could be successfully calibrated and validated for predictions of atrazine concentrations in the MDS.