Center for Agricultural and Rural Development, Iowa State University, Ames, Iowa 50011, United States.
Iowa Geological Survey, University of Iowa, Iowa City, Iowa 52242, United States.
Sci Total Environ. 2022 Sep 15;839:156302. doi: 10.1016/j.scitotenv.2022.156302. Epub 2022 May 28.
Improving food systems to address food insecurity and minimize environmental impacts is still a challenge in the 21st century. Ecohydrological models are a key tool for accurate system representation and impact measurement. We used a multi-phase testing approach to represent baseline hydrologic conditions across three agricultural basins that drain parts of north central and central Iowa, U.S.: the Des Moines River Basin (DMRB), the South Skunk River Basin (SSRB), and the North Skunk River Basin (NSRB). The Soil and Water Assessment Tool (SWAT) ecohydrological model was applied using a framework consisting of the Hydrologic and Water Quality System (HAWQS) online platform, 40 streamflow gauges, the alternative runoff curve number method, additional tile drainage and fertilizer application. In addition, ten SWAT baselines were created to analyze both the HAWQS parameters (baseline 1) and nine alternative baseline configurations (considering the framework). Most of the models achieved acceptable statistical replication of measured (close to the outlet) streamflows, with Nash-Sutcliffe (NS) values ranging up to 0.80 for baseline 9 in the DMRB and SSRB, and 0.78 for baseline 7 in the NSRB. However, water balance and other hydrologic indicators revealed that careful selection of management data and other inputs are essential for obtaining the most accurate representation of baseline conditions for the simulated stream systems. Using cumulative distribution curves as a criterion, baselines 7 to 10 showed the best fit for the SSRB and NSRB, but none of the baselines accurately represented 20% of low flows for the DMRB. Analysis of snowmelt and growing season periods showed that baselines 3 and 4 resulted in poor simulations across all three basins using four common statistical measures (NS, KGE, Pbias, and R), and that baseline 9 was characterized by the most satisfactory statistical results, followed by baselines 5, 7 and 1.
在 21 世纪，改善粮食系统以解决粮食不安全问题并将环境影响降至最低仍然是一个挑战。生态水文学模型是准确表示系统和测量影响的关键工具。我们使用多阶段测试方法来表示美国爱荷华州中北部和中部三个农业流域的基准水文条件：得梅因河流域（DMRB）、南臭鼬河流域（SSRB）和北臭鼬河流域（NSRB）。土壤和水评估工具（SWAT）生态水文学模型是使用由水文和水质系统（HAWQS）在线平台、40 个流量计、替代径流曲线数方法、额外的排水渠和肥料应用组成的框架来应用的。此外，创建了十个 SWAT 基线来分析 HAWQS 参数（基线 1）和九个替代基线配置（考虑框架）。大多数模型都实现了对测量（接近出口）流量的可接受的统计复制，纳什-苏特克里夫（NS）值高达 DMRB 和 SSRB 中的基线 9 的 0.80，以及 NSRB 中的基线 7 的 0.78。然而，水量平衡和其他水文指标表明，仔细选择管理数据和其他输入对于获得模拟溪流系统的基准条件的最准确表示至关重要。使用累积分布曲线作为标准，基线 7 到 10 显示出与 SSRB 和 NSRB 的最佳拟合，但没有一个基线准确代表 DMRB 的 20%低流量。对融雪和生长季节的分析表明，在所有三个流域中，使用四个常用统计措施（NS、KGE、Pbias 和 R），基线 3 和 4 的结果都很差，而基线 9 的结果则最令人满意，其次是基线 5、7 和 1。
