Estimating soil water content and evapotranspiration of winter wheat under deficit irrigation based on SWAP model
Estimating soil water content and evapotranspiration of winter wheat under deficit irrigation based on SWAP model
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基于SWAP模型估算亏灌冬小麦土壤含水量和蒸散量
DOI：
10.3390/su12229451
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发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Wang Xiaoyun
中科院分区：
文献类型：
--
作者：
Wang Xiaowen;Cai Huanjie;Li Liang;Wang Xiaoyun
非充分灌溉策略是干旱区农业可持续发展的关键。通过两年田间试验，研究了关中平原冬小麦非充分灌溉条件下的水分动态。在冬小麦的4个生育期分别设置了100%、80%和60%的灌水水平，并设充分灌溉处理（CK）。土壤-水-大气-植物（SWAP）农业水文模型被用来模拟农田水分收支的组成部分。SWAP参数的敏感性分析表明，饱和含水量和含水量形状因子n对SWAP参数的敏感性最高。验证结果表明，SWAP模型对土壤含水量（平均相对误差（MRE）<21.66%，均方根误差（RMSE）< 0.07 cm 3 cm−3）和蒸散量（R2 = 0.975，P < 0.01）的模拟精度较高。灌溉对实际植物蒸腾量有重要影响，但不同处理间实际土壤蒸发量变化不大。平均深层渗漏量为14.54mm，与总灌水量呈正相关。用通径分析和回归分析方法建立的ET预测模型具有较好的预测效果（R2 = 0.727，P < 0.01）。该研究为SWAP模型参数的校正提供了有效的指导，为用较少的变量准确估算蒸散量提供了一种简便的方法。
Deficit irrigation strategy is essential for sustainable agricultural development in arid regions. A two−year deficit irrigation field experiment was conducted to study the water dynamics of winter wheat under deficit irrigation in Guanzhong Plain in Northwest China. Three irrigation levels were implemented during four growth stages of winter wheat: 100%, 80% and 60% of actual evapotranspiration (ET) measured by the lysimeter with sufficient irrigation treatment (CK). The agro−hydrological model soil−water−atmosphere−plant (SWAP) was used to simulate the components of the farmland water budget. Sensitivity analysis for parameters of SWAP indicated that the saturated water content and water content shape factor n were more sensitive than the other parameters. The verification results showed that the SWAP model accurately simulated soil water content (average relative error (MRE) < 21.66%, root mean square error (RMSE) < 0.07 cm3 cm−3) and ET (R2 = 0.975, P < 0.01). Irrigation had an important impact on actual plant transpiration, but the actual soil evaporation had little change among different treatments. The average deep percolation was 14.54 mm and positively correlated with the total irrigation amount. The model established using path analysis and regression methods for estimating ET performed well (R2 = 0.727, P < 0.01). This study provided effective guidance for SWAP model parameter calibration and a convenient way to accurately estimate ET with fewer variables.