膜孔灌自由入渗条件下VG模型参数的敏感性分析OACSTPCD
Sensitivity analysis of the impact of soil hydraulic parameters on water infiltration from a single point source in membrane-hole irrigation
[目的]探究膜孔灌自由入渗条件下VG模型参数敏感性.[方法]基于HYDRUS-2D软件,采用单因子扰动分析方法,研究van Genuchten方程中α、n、θr对膜孔灌单点源自由入渗特性的影响.[结果]①单位膜孔面积累积入渗量与α负相关,与n正相关,θr对单位膜孔面积累积入渗量无影响.水平湿润锋运移距离与α负相关,θr对其无影响.垂直湿润锋运移距离与 θr负相关,与 n 正相关.入渗结束时高含水率湿润体面积与 θr、n 正相关,n的扰动对高含水率湿润体面积影响最大.②单位膜孔面积累积入渗量的相对灵敏度随 α 增大而逐渐减小,α 的正扰动对单位膜孔面积累积入渗量的影响程度弱于负扰动.α 负扰动时,水平湿润锋运移距离的相对灵敏度随扰动幅度的增大而逐渐增大;α正扰动时,水平湿润锋运移距离的相对灵敏度随扰动幅度的增大而逐渐减小.③n负扰动时,单位膜孔面积累积入渗量与垂直湿润锋运移距离的相对灵敏度均随扰动幅度的增大呈先增加后减小的趋势;n 正扰动时,单位膜孔面积累积入渗量的相对灵敏度随扰动幅度的增大呈先减小后增加再减小的趋势.[结论]n 发生扰动对膜孔灌自由入渗特性影响最明显,θr发生扰动对入渗特性影响最小.
[Objective]Water infiltration in soil is an important process for designing drip irrigation and is impacted by soil properties.The purpose of this paper is to investigate the effect of soil hydraulic properties on water infiltration from a single-point source in membrane-hole irrigation.[Method]The studies were based on the HYDRUS-2D software,with the soil hydraulic properties described by the van Genuchten formula.[Result]① The cumulative infiltration amount was negatively correlated with the parameter α,positively correlated with the parameter n,and was independent of the residual water content parameter θr.The horizontal advancement of the wetting front was negatively correlated to the parameter α and was independent of the parameter θr.The vertical advancement of the wetting front was negatively correlated to the parameter θr and positively correlated to the parameter n.At the end of infiltration,the volume of the wetted zone was positively correlated to the parameters θr and n.Change in the parameter n had the greatest effect on the size of the wetted zone.② The relative sensitivity of the cumulative infiltration gradually decreased with the increase in α;The positive perturbation of α affected the cumulative infiltration per unit membrane pore area to a weaker extent than the negative perturbation.α occurred in the negative perturbation,the relative sensitivity of the transport distance of the horizontal wetting front increased with the increase of the perturbation amplitude,and α occurred in the positive perturbation,the relative sensitivity of the transport distance of the horizontal wetting front decreased with the increase of the perturbation amplitude.③When n was negatively perturbed,the relative sensitivities of cumulative infiltration per unit membrane pore area and vertical wetting front transport distance both showed a tendency to increase and then decrease with the increase of perturbation amplitude;when n was positively perturbed,the relative sensitivities of cumulative infiltration per unit membrane pore area showed a tendency to decrease and then increase and then decrease with the increase of perturbation amplitude.[Conclusion]Disturbing the parameter n has the most significant effect on water infiltration from the single-point source in membrane hole irrigation,while disturbing the parameter θr had the least effect.
樊倩雯;费良军;刘念
西安理工大学 西北旱区生态水利国家重点实验室,西安 710048榆林市榆阳区水旱灾害防治中心,陕西 榆林 719000
农业工程
模型膜孔灌单点源入渗特性参数
modelmembrane hole irrigationsingle point sourceinfiltration characteristicsparameters
《灌溉排水学报》 2024 (005)
55-62 / 8
陕西省重大水利科技项目(2023SLKJ-2);国家自然科学基金项目(52079105)
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