基于SHAW模型高寒区冻融土壤水热耦合过程数值模拟  

Numerical simulation of coupled process of freeze-thaw soil water and heat in alpine regions based on SHAW model

作　　者：郑丽萍 甘永德 魏加华[1,2] 李润杰 吴玉帅[1] 王冠楠 ZHENG Liping;GAN Yongde;WEI Jiahua;LI Runjie;WU Yushuai;WANG Guannan(School of Water Conservancy and Electric Power,Qinghai University,Xining 810016,Qinghai,China;State Key Laboratory of Water and Sediment Science and Water Conservancy and Hydropower Engineering,Tsinghua University,Beijing 115003,China)

机构地区：[1]青海大学水利电力学院,青海西宁810016 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京115003

出　　处：《水利水电技术（中英文）》2022年第6期194-204,共11页Water Resources and Hydropower Engineering

基　　金：青海省重大科技专项(2019-SF-A4);国家自然科学基金项目(51379215,50939006)。

摘　　要：针对青海省这类高寒地区对其冻融土壤的水热耦合过程开展科学合理的研究,有利于水土流失的防治和生态环境的建设。试验于青海省德令哈市怀头他拉试验基地开展,采用TDR水分温度自动监测系统进行冻融土壤含水量和温度进行监测与记录。从2020年7月至2021年3月长达八个多月对土壤含水量和温度进行动态监测试验,结果表明:土壤在冻融阶段,其温度与空气温度具有同步变化的规律;外界环境变化对表层土壤含水量产生的影响较大,且土层越深影响越小;土壤含水量与温度具有相似的波动规律,都经历了一个下降、稳定、回升的过程。根据试验数据,利用SHAW模型进行该试验基地冻融土壤水热耦合过程的数值模拟,并对模拟结果展开分析,最后,根据Nash效率系数、标准差、平均偏差等指标对模型的模拟结果进行评价。模拟结果显示:地表下不同深度处土层温度的Nash效率系数(NSE)皆大于0.95,标准差(RMSE)在0.121~2.350之间,平均偏差(MBE)在0.001~0.678之间;不同土层含水量的Nash效率系数(NSE)都在0.83以上,标准差(RMSE)在0.001~0.0111之间,平均偏差(MBE)在0.001~0.006之间;根据模型模拟效率,可以认为土壤温度和含水量的模拟效果都是较为良好的,模拟结果都具有一定的可信度,能够较为真实地反映土壤各节点温度和含水量的动态运动规律和实际分布情况。Scientific and reasonable research on the hydrothermal coupling process of freezing and thawing soil in alpine regions such as Qinghai Province is conducive to the prevention and control of soil erosion and the protection and construction of the ecological environment. In this article, the experiment is carried out at the Huaitutara test base located in the Delingha City of Qinghai Province, the TDR moisture and temperature automatic monitoring system is used to monitor and record the moisture content and temperature of the freezing and thawing soil. According to the dynamic monitoring experiment on soil moisture content and temperature for more than eight months from July 2020 to March 2021, the results show that during the freezing and thawing phase of soil, its temperature and the atmospheric temperature have a synchronous change law, changes in the external environment have a greater impact on the surface soil moisture content, and the deeper the soil layer is, the smaller the impact is;the soil moisture content and temperature have a similar fluctuation, and both have experienced a process of decline, stability, and recovery. According to the experimental data, the SHAW model is used to carry out the numerical simulation of the coupled process of freezing and thawing soil water and heat in the test base, and the simulation results are analyzed. Finally, the simulation results of the model are evaluated and tested according to the model evaluation indicators such as Nash-Sutcliffe efficiency coefficient, root mean square error, and mean bisa error. The simulation results are as follows: below the surface, the Nash-Sutcliffe efficiency coefficients(NSE) of the simulation results of soil temperature at different depths are greater than 0.95, the root mean square error(RMSE) is between 0.121 and 2.350, and the mean bisa error(MBE) is between 0.001 and 0.678, the Nash-Sutcliffe efficiency coefficient(NSE) between the simulated and measured values of soil moisture content at different depths is above 0.83, the roo

关 键 词：冻融土壤 土壤含水量 土壤温度 水热耦合 SHAW模型 

分 类 号：S152[农业科学—土壤学]