农田裂隙优先流对灌水模式/初始墒情响应机制及其模拟研究  

Response Mechanism of Preferential Flow to Irrigation Patterns/Antecedent Moisture in Agricultural Cracks and Its Simulation Study

作　　者：翟亚明[1] 王冲[1] 王策[1] 陈理政 付丽红 ZHAI Ya-ming;WANG Chong;WANG Ce;CHEN Li-zheng;FU Li-hong(College of Agricultural Science and Engineering,Hohai University,Nanjing 210098,Jiangsu Province,China;Water Conservancy Bureau of Xiangxi Tujia and Miao Autonomous Prefecture,Jishou 416000,Hunan Province,China;Water Conservancy Bureau of Xuanzhou District,Xuancheng 242000,Anhui Province,China)

机构地区：[1]河海大学农业科学与工程学院,江苏南京210098 [2]湘西土家族苗族自治州水利局,湖南吉首416000 [3]安徽省宣城市宣州区水利局,安徽宣城242000

出　　处：《中国农村水利水电》2024年第2期56-63,73,共9页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(52109053);江苏省自然科学基金青年基金项目(BK20200523);国家科技奖后备培育项目(20212AEI91011);江西省重点研发计划项目(20203BBGL73226);江西省水利科学院开放研究基金项目(2021SKTR03)。

摘　　要：农田灌溉管理过程中优先流降低水肥利用效率,加剧地下水污染风险。基于碘化钾-淀粉染色示踪试验,分析了地面灌DM、微喷灌WP1(20 mm/h)、微喷灌WP2(40 mm/h)处理下的裂隙优先流特征,验证了基于水量平衡的双域渗透模型的有效性,并采用4组初始体积含水率(0.20、0.25、0.30、0.35 cm^(3)/cm^(3))与5组灌水强度(12.0、24.0、36.0、48.0、60.0mm/h)旋转组合设计进行模拟应用分析。结果表明,WP1、WP2处理整体上水分以均匀的基质流形式入渗;DM处理下的土壤剖面染色区域在垂直方向上可明显划分为基质流区(0~6.9 cm)和优先流区(>6.9 cm)。此外,DM处理下的基质流深度、灌水均匀度显著(P<0.05)小于WP1、WP2处理,而其优先流指数及湿润锋弯曲度均极显著大于(P<0.01)WP1、WP2处理,这表明地面灌可以激活更多的优先流路径,增大优先流发育程度和空间异质性,降低灌水质量。基于水量平衡的双域渗透模型可有效预测不同灌水强度下的基质流深度和土壤剖面染色面积比变化趋势(R2≥0.9276、NSE≥0.8844、RSR≤0.0230),初始体积含水率和灌水强度旋转组合设计模拟结果表明,增加灌水强度或减小初始含水率会增加优先流的程度而降低灌水质量,故建议在农田灌溉管理过程中采用“高频少量”的灌水模式以减少优先流导致的水肥利用效率降低。该研究成果可为农田灌溉决策提供理论依据,其试验数据可为优先流模型优化与验证提供重要的数据支撑。Preferential flow during on-farm irrigation management can reduce water and fertilizer use efficiency and exacerbate the risk of groundwater contamination.Based on potassium iodide-starch dye tracing experiment,this paper analyzes the soil water distribution characteristics under surface irrigation DM,micro-sprinkler irrigation WP1(20 mm/h),irrigation WP2(40 mm/h)treatments,verifies the validity of dual-permeability model based on principle of water volume balance,and uses four levels of antecedent water content(0.20,0.25,0.30,0.35 cm^(3)/cm^(3))with five levels of irrigation intensity(12.0,24.0,36.0,48.0,60.0 mm/h)in a rotating combination design for application analysis.The results show that water infiltrated in the form of uniform matrix flow in WP1 and WP2 treatments as a whole;the soil profile staining area under DM treatment can be clearly divided into substrate flow area(0~6.9 cm)and preferential flow area(>6.9 cm)in the vertical direction.In addition,the matrix flow depth and irrigation uniformity under DM treatment are significantly(P<0.05)smaller than those under WP1 and WP2 treatments,while their the fraction of preferential flow and wetting front curvature are highly significantly larger(P<0.01)than those under WP1 and WP2 treatments,which indicates that surface irrigation can activate more preferential flow paths,increase the degree of preferential flow development and spatial heterogeneity,and reduce irrigation quality.The dual-permeability model based on principle of water volume balance can effectively predict the trends of matrix flow depth and soil profile staining area ratio under different irrigation intensities(R2≥0.9276,NSE≥0.8844,RSR≤0.0230),and the simulation results of the rotational combination design of antecedent volumetric water content and irrigation intensity show that increasing irrigation intensity or decreasing antecedent water content will increase the degree of preferential flow and reduce irrigation quality.Therefore,this paper recommend using“high-frequency,low-flow�

关 键 词：染色示踪试验 优先流 灌水强度 含水率 数值模拟 

分 类 号：TV93[水利工程—水利水电工程] S27[农业科学—农业水土工程]