摘要
为探究降水条件下水分与溶质在地表和土壤中的运动规律,分别采用二维扩散波方程和传统的三维Richards方程描述地面径流和土壤水分运动,选用双层结点法对两者进行耦合,根据达西定律和地表与土壤水中的溶质浓度,计算地面径流和土壤水分的溶质交换量,从而构建地表水土壤水运动与溶质运移全耦合数值模型。选取已发表文献中的物理模型实验进行数值模拟,算例1和算例2中地表径流数值模拟结果和模型实验结果的平均相对误差分别小于14.8%和21.5%,均方根误差分别小于0.147cm^(2)/s和0.833cm^(2)/s;算例2中径流硝态氮浓度的数值模拟结果和模型实验结果的平均相对误差小于24.7%,均方根误差小于1.334mg/L。物理实验和数值模拟所得地表径流量和溶质浓度数据的对比分析验证了模型的合理性和准确度。研究结果可为地表水土壤水水分运动与溶质运移耦合分析提供理论支持。
In order to investigate the movement of water and solute in the surface and soil under precipitation conditions,the two-dimensional diffusion wave equation and the traditional three-dimensional Richards equation were used to describe the surface runoff and soil water movement respectively,and the dual node approach was chosen to couple the two ones.According to Darcy′s law and solute concentration of surface water and soil water,solute exchange capacity of surface runoff and soil water was calculated,and a fully coupled numerical model of water movement and solute transport in surface and soil was constructed.Physical model experiments from the published literature were selected for numerical simulation tests.In Example 1 and Example 2,the average relative error between the numerical simulation results of surface runoff and the experimental results of the model were less than 14.8%and 21.5%,respectively,and the root mean square error were less than 0.147 cm^(2)/s and 0.833 cm^(2)/s,respectively.The mean relative error between the numerical simulation results and the experimental model results for runoff nitrate concentrations in Example 2 was less than 24.7%and the root mean square error was less than 1.334 mg/L.The comparative analysis of surface runoff and solute concentration data obtained from physical experiments and numerical simulations verified the reasonableness and accuracy of the model in this paper.The results of the study can provide theoretical support for the analysis of coupled water movement and solute transport in surface water and soil water.
作者
鲁舒心
万愉快
孙伯颜
农睿
朱磊
LU Shu-xin;WAN Yu-kuai;SUN Bo-yan;NONG Rui;ZHU Lei(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Key Laboratory of the Internet of Water and Digital Water Governance of the Yellow River,Ningxia University,Yinchuan 750021,China)
出处
《节水灌溉》
北大核心
2023年第8期102-109,128,共9页
Water Saving Irrigation
基金
国家自然科学基金项目(51879134)
宁夏自然科学基金项目(2020BEB04004)
宁夏自然科学基金项目(2021AAC03091)。
关键词
地表径流
土壤水分
硝态氮
溶质运移
数值模拟
全耦合
surface runoff
soil moisture
nitrate nitrogen
solute transport
numerical simulation
fully coupled
