论文部分内容阅读
在壤土和砂土条件下分别采用碘-淀粉染色示踪方法和亮蓝染色示踪方法各开展了2个染色示踪试验,分别采用活动流场模型和二域模型模拟计算了各试验入渗后染色区内的土壤含水率和溶质浓度分布,通过相对均方根误差分析评价了两个模型模拟预测优先流发展的有效性;此外,通过敏感性分析研究了不同入渗条件(土壤质地、入渗水量和土壤初始含水率)下活动流场模型模拟预测结果(入渗深度)对活动流场模型分形特征参数变化的敏感度。模型检验分析结果显示活动流场模型对土壤水入渗深度、入渗后染色区内土壤含水率和溶质浓度分布的预测精度要明显高于二域模型的模拟预测精度;活动流场模型较好的捕捉到了优先流运动整体的非均匀特征。敏感性分析结果显示,当降雨入渗水量和土壤初始含水率相同时,入渗深度对活动流场模型分形特征参数(γ)的敏感度随着γ的增大而增大;相同活动流场模型分形特征参数(γ)值条件下(即流动非均匀程度相同),入渗深度对活动流场模型分形特征参数(γ)的敏感度随着入渗水量的增大和土壤初始含水率的升高而减小。
Under the condition of loam and sand, two dyeing tracing experiments were carried out by iodine-starch staining and bright blue staining respectively. The infiltration of each experiment was calculated by using the flow field model and two-domain model respectively The soil moisture content and the distribution of solute concentration in the post-dyeing zone, the relative RMSE analysis was used to evaluate the effectiveness of the two models in predicting the development of the preferential flow. In addition, the sensitivity of the model to different infiltration conditions (soil texture, Infiltration capacity and soil initial moisture content), the sensitivity of the predicted results (infiltration depth) to the change of fractal characteristic parameters of the active flow field model is predicted. The results of model test and analysis show that the prediction accuracy of the active flow field model for soil water infiltration depth, infiltration soil water content and solute concentration distribution is obviously higher than that of the two-domain model. The active flow field model is better The capture captures the non-uniform features of the overall flow of preferential flow. Sensitivity analysis results show that the sensitivity of infiltration depth to the fractal characteristic parameter (γ) of the active flow field model increases with the increase of γ when the rainfall infiltration and the initial soil water content are the same. The sensitivity of the infiltration depth to the fractal characteristic parameter (γ) of the active flow field model with the fractal characteristic parameter (γ) of the model (ie, the same degree of flow inhomogeneity) increases with the increase of the infiltration water amount and the increase of the initial soil water content High and decrease.