Lessons Learned From Modeling Irrigation From Field to Regional Scales
Lessons Learned From Modeling Irrigation From Field to Regional Scales
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DOI：
10.1029/2018ms001595
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发表时间：
2019-08
影响因子：
6.8
通讯作者：
Xiaoyu Xu;Fei Chen;M. Barlage;D. Gochis;Shiguang Miao;S. Shen
中科院分区：
文献类型：
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作者：
Xiaoyu Xu;Fei Chen;M. Barlage;D. Gochis;Shiguang Miao;S. Shen
正确计算作物灌溉的时间和数量对于捕获灌溉对地表水和能量收支以及土地-大气相互作用的影响至关重要。本研究将一个动态灌溉方案与诺亚多参数陆面模式相结合，探讨了利用农业管理资料确定作物生长季长度的三种方法。灌溉计划进行了评估，在现场规模使用观察两个对比（灌溉和灌溉）AmeriFlux网站附近米德，内布拉斯加州。结果表明，作物特定的生长季节长度有助于捕获第一次施用时间和总灌溉量，特别是对于大豆。使用校准的土壤水分触发阈值（IRR_CRI），仅使用种植和收获日期可以合理地预测玉米的首次施用。对于大豆，需要对生长季节进行额外的限制，以纠正第一个建模应用程序中的早期偏差。真实的叶面积指数输入对于确定基于叶面积指数的生长季节至关重要。当从田间尺度过渡到区域尺度时，县级校准的IRR_CRI有助于缓解内布拉斯加州东南部（密西西比河下游流域）高估（低估）的总灌溉量。在这两个重灌溉区，灌溉产生了0.8-1.4 K的冷却效应，1.2-2.4 g/kg的增湿效应，显热通量减少60-105 W/m2，潜热通量增加75-120 W/m2。灌溉水主要用于增加土壤水分和蒸发，而不是径流。缺乏区域尺度的灌溉时间和作物特定参数使得评估和参数约束方法难以从田间转移到区域尺度。
Correctly calculating the timing and amount of crop irrigation is crucial for capturing irrigation effects on surface water and energy budgets and land‐atmosphere interactions. This study incorporated a dynamic irrigation scheme into the Noah with multiparameterization land surface model and investigated three methods of determining crop growing season length by agriculture management data. The irrigation scheme was assessed at field scales using observations from two contrasting (irrigated and rainfed) AmeriFlux sites near Mead, Nebraska. Results show that crop‐specific growing‐season length helped capture the first application timing and total irrigation amount, especially for soybeans. With a calibrated soil‐moisture triggering threshold (IRR_CRI), using planting and harvesting dates alone could reasonably predict the first application for maize. For soybeans, additional constraints on growing season were required to correct an early bias in the first modeled application. Realistic leaf area index input was essential for identifying the leaf area index‐based growing season. When transitioning from field to regional scales, the county‐level calibrated IRR_CRI helped mitigate overestimated (underestimated) total irrigation amount in southeastern Nebraska (lower Mississippi River Basin). In these two heavily irrigated regions, irrigation produced a cooling effect of 0.8–1.4 K, a moistening effect of 1.2–2.4 g/kg, a reduction in sensible heat flux by 60–105 W/m2, and an increase in latent heat flux by 75–120 W/m2. Most of irrigation water was used to increase soil moisture and evaporation, rather than runoff. Lacking regional‐scale irrigation timing and crop‐specific parameters makes transferring the evaluation and parameter‐constraint methods from field to regional scales difficult.