VIC-CAS导热率和未冻水算法改进及其对多年冻土水热过程模拟的实验研究  

Improvement of VIC-CAS algorithm for thermal conductivity and unfrozen water and its experimental study on simulation of hydrothermal process of permafrost

作　　者：李飞[1,2] 郭佳锴[1,2] 张世强 LI Fei;GUO Jiakai;ZHANG Shiqiang(Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Northwest University,Xi'an 710127,China;College of Urban and Environmental Sciences,Northwest University,Xi,an 710127,China)

机构地区：[1]西北大学陕西省地表系统与环境承载力重点实验室,陕西西安710127 [2]西北大学城市与环境学院,陕西西安710127

出　　处：《冰川冻土》2021年第6期1888-1903,共16页Journal of Glaciology and Geocryology

基　　金：国家重点研发计划专项(2019YFC1510503);国家自然科学基金项目(41730751)资助。

摘　　要：冻土水热过程的准确模拟对于理解和预估冰冻圈变化对水资源和生态的影响具有重要意义,其中,导热率和未冻水是多年冻土水热模拟中的两个关键参数。在VIC-CAS模型的基础上,分别尝试用EBM的导热率算法和CLM5.0的未冻水算法替换VIC-CAS模型中的导热率和未冻水算法,并利用长江源区沱沱河站的观测数据进行了数值模拟对比试验,分析了不同的导热率和未冻水算法对土壤分层温湿度模拟的影响。结果表明:EBM导热率算法对浅层土壤的温度模拟优于原算法,而在深层土壤的模拟效果变差;对浅层土壤湿度模拟改进不明显,而对深层土壤的模拟精度降低。CLM5.0未冻水算法对土壤温度模拟影响较小,对浅层土壤的湿度模拟效果变差,但在深层土壤上优于原算法。这两种算法的对比实验为进一步改进VIC-CAS模型中冻土水热过程的算法提供了借鉴。Accurate simulation of permafrost hydrothermal process is of great significance for understanding and predicting the impact of cryosphere changes on water resources and ecology,in which thermal conductivity and unfrozen water are two key parameters in permafrost hydrothermal simulation.On the basis of VIC-CAS model,this study attempts to replace the thermal conductivity and unfrozen water algorithm in VIC-CAS model with the thermal conductivity algorithm of EBM and unfrozen water algorithm of CLM 5.0,respectively,and carries out the numerical simulation contrast experiment using the observation data of Tuotuohe station in the source region of the Yangtze River,and analyzes the influence of different thermal conductivity and unfrozen water algorithms on the simulation of soil layered temperature and humidity.The results show that the EBM thermal conductivity algorithm is better than the original algorithm in simulating the temperature of shallow soil,but worse in deep soil;The improvement of the shallow soil moisture simulation is not obvious,and it becomes worse in the deep soil.CLM 5.0 unfrozen water algorithm has little influence on soil temperature simulation,and soil moisture simulation becomes worse in shallow soil,but it is better than the original algorithm in deep soil.The comparative experiments of the two algorithms in this study provide a reference for further improving the algorithm of frozen soil hydrothermal process in VIC-CAS model.

关 键 词：多年冻土 水热模拟 VIC-CAS 导热率 未冻水 

分 类 号：P642.14[天文地球—工程地质学]