基于HYDRUS的微润灌溉线源入渗数值模拟
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摘要
为探究微润灌溉在沙壤土中的入渗规律,以非饱和土壤水分运动理论为基础,建立1.0、1.5、2.0 m三种水头下微润灌溉土壤水分运动的数学模型。利用HYDRUS(2D/3D)软件对模型进行求解,求解结果表明:微润灌溉入渗流量随水头的增大而增大;湿润体沿渗灌管呈圆柱形分布,相同灌水时间下,湿润体大小随水头的增大而增大,湿润锋运移速率在灌水48 h内迅速减小,之后逐渐趋于稳定;含水率等值线为以渗灌管为中心的同心圆,平均含水率随水头的增大而增大,灌水均匀度随水头的增大而减小。为了验证软件模拟的精确性,将田间试验结果与模型模拟值进行对比,结果表明:模拟值与实测值无显著性差异,两者具有较好的一致性,说明HYDRUS软件可用于模拟微润灌溉条件下土壤水分运动及设计地下线源入渗灌水策略。
Based on the theory of unsaturated soil water movement,a mathematical model of soil water movement under three kinds of waterhead pressure(i.e.,1.0m,1.5m and 2.0m)was developed to explore the law of moisture irrigation infiltration in sandy loam. HYDRUS(2D/ 3D)software was used to solve the model. The solutions show that the moisture irrigation infiltration flow increases with the increase ofpressure. The wet body was cylindrical distribution along the moisture and its size increased with the increase of pressure under the sameirrigation time. The rate of wetting front migration decreased rapidly within 48 h of irrigation and followed by steady gradually. The moisturecontent contour maps of the wet body were concentric circles centered on moisture. The average moisture content increased with the increaseof pressure;however,irrigation uniformity decreased along with the increase of pressure. To test the accuracy of the software simulation,theresults of field experiment were compared with the simulated values. The results indicate that the simulated and measured values have nosignificant difference. Therefore,HYDRUS software can be used to simulate the soil moisture movement rule under the conditions of moistureirrigation. And it's an effective tool for designing the irrigation strategies of the underground line source infiltration.
Based on the theory of unsaturated soil water movement,a mathematical model of soil water movement under three kinds of waterhead pressure(i.e.,1.0m,1.5m and 2.0m)was developed to explore the law of moisture irrigation infiltration in sandy loam. HYDRUS(2D/ 3D)software was used to solve the model. The solutions show that the moisture irrigation infiltration flow increases with the increase ofpressure. The wet body was cylindrical distribution along the moisture and its size increased with the increase of pressure under the sameirrigation time. The rate of wetting front migration decreased rapidly within 48 h of irrigation and followed by steady gradually. The moisturecontent contour maps of the wet body were concentric circles centered on moisture. The average moisture content increased with the increaseof pressure;however,irrigation uniformity decreased along with the increase of pressure. To test the accuracy of the software simulation,theresults of field experiment were compared with the simulated values. The results indicate that the simulated and measured values have nosignificant difference. Therefore,HYDRUS software can be used to simulate the soil moisture movement rule under the conditions of moistureirrigation. And it's an effective tool for designing the irrigation strategies of the underground line source infiltration.
引文
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[10]李志新,许迪,李益农,等.畦灌施肥地表水流与非饱和土壤水流-溶质运移集成模拟Ⅰ:模型[J].水利学报,2009,40(6):673-678.
[2]李明思,康绍忠,孙海燕.点源滴灌滴头流量与湿润体关系研究[J].农业工程学报,2006,22(4):32-35.
[3]费良军,曹俊,聂卫波.涌泉根灌土壤湿润体特性试验[J].排灌机械工程学报,2011,29(3):260-265.
[4]黎朋红,汪有科,马理辉,等.涌泉根灌湿润体特征值变化规律研究[J].水土保持学报,2009,23(6):190-194.
[5]范严伟,马孝义,王波雷,等.膜孔灌土壤湿润体水分分布与入渗特性数值模拟[J].农业机械学报,2008,39(11):35-41.
[6]杨文君,田磊,杜太生,等.半透膜节水灌溉技术的研究进展[J].水资源与水工程学报,2008,19(6):60-63.
[7]李道西,彭世彰.地下滴灌灌水设计参数对土壤水分分布影响的计算机模拟[J].沈阳农业大学学报,2004,35(5):507-509.
[8]李久生,张建君,饶敏杰.滴灌施肥灌溉的水氮运移数学模拟及试验验证[J].水利学报,2005,36(8):932-938.
[9]李志新,许迪,李益农,等.畦灌施肥地表水流与非饱和土壤水流-溶质运移集成模拟Ⅲ:模型应用[J].水利学报,2011,42(3):271-277.
[10]李志新,许迪,李益农,等.畦灌施肥地表水流与非饱和土壤水流-溶质运移集成模拟Ⅰ:模型[J].水利学报,2009,40(6):673-678.