基于HYDRUS模型低温水入渗下土壤水热运移模拟  

Simulation of Water and Heat Transfer in Soil under Low-temperature Water Infiltration based on the HYDRUS Model

作　　者：任杰[1,2] 沈振中[2] 杨杰[1] 李琛亮[3] 高金强[4] 

机构地区：[1]西安理工大学水利水电学院,陕西西安710048 [2]河海大学水利水电学院,江苏南京210098 [3]水利部海河水利委员会,天津300171 [4]水利部海河水利委员会水资源保护科学研究所,天津300171

出　　处：《干旱区研究》2016年第2期246-252,共7页Arid Zone Research

基　　金：国家自然科学基金项目(51309189)

摘　　要：为了深入研究高坝大库低温水下泄对河(渠)两岸土壤水分、温度动态变化的影响机理,构建了低温水入渗土壤水热运移的数学模型,利用HYDRUS-2D软件进行了求解,并对土壤水热运移数学模型进行参数率定与模型验证的基础上,模拟分析了不同水头低温水入渗条件下土壤水分、温度动态变化规律。经过试验验证,总体的模拟与实测温度和水分的均方根误差RMSE分别为1.074和0.01,模拟结果和实测数据均吻合较好。模拟结果表明,水头变化对土壤温度场和水分场的分布均会产生较大的影响;当模拟达到相对稳态后,土壤平均温度从上到下逐渐降低,土壤中的温度场分布较为均匀;当入渗水温相同时,随着水头增加,土壤内部平均温度降低,土壤深层低温区域逐渐扩大,温度梯度增加;土壤的深层含水率较高,达到饱和状态,含水率分布从上到下逐步增加;随着水头增加,土壤深层饱和区域逐渐扩大,并逐渐向土壤表层区域扩展。该研究揭示了不同水头下低温水入渗对土壤内部温度场、水分场影响分布的一般规律,对进一步改善水库下游河岸带生态环境,丰富土壤水动力学基本理论有着重要的理论意义和实际价值。In order to study the influence of discharge of low-temperature water from a large reservoir on the dynamic change of soil moisture content and temperature in the downstream regions,a mathematical model of simultaneous water and heat transfer was established and solved by HYDRUS-2D software,and the dynamic changes of soil moisture content and temperature under the low-temperature water infiltration at different water heads were simulated and analyzed based on the calibration of parameters and validation of the mathematical model of simultaneous water and heat transfer. By the experimental verification,the root-mean-square errors of overall simulation and the measured temperature and moisture were 1. 074 and 0. 01 respectively,and the simulated values of soil moisture content and temperature were accorded well with the observed values. According to the simulated results,the waterhead change affected significantly the distribution of soil temperature and moisture fields. When the simulation reached a relatively steady state,the average soil temperature was gradually decreased from topsoil to deep soil,and the distribution of soil temperature fields was uniform; When the temperature of infiltration water was the same,along with the increase of water head,the average soil temperature was decreased,the low-temperature area in deep soil was gradually expanded,and the temperature gradient was increased. Moreover,the deep-soil moisture content was high and to its saturation,and the soil moisture content was gradually increased from topsoil to deep soil. With the increase of water head,the saturation area in deep soil was expanded gradually towards topsoil. The study results revealed a general law that the distribution of soil temperature and moisture fields was affected by the low-temperature water infiltration at different water heads,and they were of theoretical significance and practical value for further improving the ecological environment in the downstream regions of the reservoir,and also for enriching the basic t

关 键 词：HYDRUS模型 模型参数 土壤温度 土壤水分 水热运移模拟 

分 类 号：S152.7[农业科学—土壤学]