浑水膜孔灌理论与技术要素试验及数值模拟研究

The project intends for the characteristics of the Yellow River irrigation area of multi- sediment characteristics of rivers muddy water irrigation and agricultural mulching. The technical route of the study is based on experimental and combines with numerical simulation and the theoretical study. We carry out muddy water infiltration and irrigation under film hole infiltration test indoor and outdoor. This study research the impact of the sand ratio of muddy water, clay content and the granule grade of mud and sand to the characteristics of single film hole infiltration from a point source and multi-point source intersection infiltration. It establishes the model that including the sand ratio of muddy water, clay content and the granule grade of mud and sand of free infiltration and intersection infiltration, simulate infiltration process of film hole irrigation, and reveal the relationship between infiltration and water distribution of wetting soil; Investigate the reduced infiltration and water saving mechanism of film hole irrigation with muddy water; Reveal the distribution characteristics of sediment along the long direction in border (furrow) of film hole irrigation and the change rule of the synthesis roughness coefficient of field surface during muddy water irrigation process, put forward the relationship between the flow characteristics on field surface and film hole irrigation with muddy water; Study the muddy water irrigation technique parameters in film hole irrigation and the best combination, and establish the optimization model of technique parameters of film hole irrigation with muddy water. The research has important scientific value and practical significance in production for the further study of film hole irrigation with muddy water.

本项目拟针对我国黄河流域灌区以多泥沙河流为水源的浑水灌溉和农业地膜栽培的特点，采用试验、理论研究和数值模拟相结合、以试验为主的技术路线，在室内外开展浑水膜孔灌入渗和灌水试验，研究浑水含沙率、粘粒含量和泥沙颗粒级配组成对膜孔灌充分供水单膜孔点源自由入渗和多膜孔点源交汇入渗特性及其减渗规律的影响，建立包括浑水含沙率、粘粒含量和泥沙颗粒级配组成在内的膜孔自由入渗和交汇入渗模型，并进行浑水膜孔灌入渗的数值模拟，揭示浑水膜孔点源入渗量与湿润体内水分分布之间的关系；探讨浑水膜孔灌减渗节水机制；揭示浑水膜孔灌泥沙沿畦（沟）长方向的分布特性和浑水灌溉过程中田面综合糙率的变化规律，提出浑水膜孔灌田面水流运动特性与浑水膜孔点源入渗的关系；研究浑水膜孔灌技术要素及其最佳组合，并建立浑水膜孔灌技术要素优化模型。以上研究为进一步研究浑水膜孔灌技术奠定科学基础，具有十分重要的科学价值和生产实际意义。

本项目针对我国黄河流域灌区以多泥沙河流为水源的浑水灌溉和农业地膜栽培的特点，采用试验、理论研究和数值模拟相结合、以试验为主的技术路线，在室内开展了浑水膜孔灌入渗和灌水试验，研究了浑水膜孔灌入渗特性及其减渗机理，分析了浑水含沙率、泥沙颗粒级配、膜孔直径、土壤容重、土壤初始含水率和膜孔间距等因素对浑水膜孔灌充分供水单膜孔点源自由入渗和多膜孔点源交汇入渗特性及其减渗规律的影响，建立了浑水膜孔灌自由入渗和交汇入渗单位膜孔面积累积入渗量入渗参数与各影响因素之间的关系，并建立了单位膜孔面积的累积入渗量模型；研究了浑水膜孔灌自由入渗和交汇入渗湿润锋运移与入渗时间之间的变化规律，建立了浑水膜孔灌自由入渗和交汇入渗自由面及交汇面湿润锋运移距离参数与各因素之间的关系，提出了自由面和交汇面垂直和水平湿润锋运移距离模型；研究了浑水膜孔灌自由入渗和交汇入渗湿润体内水分分布随时间之间的变化规律，建立了浑水膜孔灌自由入渗和单向交汇入渗灌水结束后湿润体内自由面膜孔中心垂直方向和水平方向水分分布曲线参数与各因素之间的关系，提出了灌水结束后湿润体内自由面和交汇面垂直方向和水平方向水分分布曲线模型；建立了饱和—非饱和条件下土壤水分运移的三维数学模型，研究了湿润锋运移距离、累积入渗量、土壤含水率等随时间和空间的变化规律，经模型验证和应用表明，数值模拟精度较高；基于三维Green-Ampt清水入渗模型，建立了浑水膜孔灌三维Green-Ampt入渗模型；通过多因素交互试验，建立了多因素影响下膜孔灌自由入渗累积入渗量数学模型；揭示浑水膜孔点源入渗量与湿润体内水分分布之间的关系；阐明浑水膜孔灌的节水减渗和提高灌溉质量的机制，研究了浑水膜孔灌技术要素及其最佳组合。以上研究为进一步研究浑水膜孔灌技术奠定了科学基础，具有十分重要的科学价值和生产实际意义。项目研究成果已公开发表学术论文24篇，其中SCI收录论文2篇、EI收录论文4篇；结合该项目研究，培养博士研究生3名、硕士研究生8名。