西藏林芝地区土壤水分特征曲线适用性研究

发布时间：2018-07-07 23:23

本文选题：土壤水分特征曲线 + 高原土壤　；参考：《灌溉排水学报》2017年10期

【摘要】：西藏地区自然气候特征、成土母质和成土条件有着显著的地区特性,了解西藏高原地区土壤水动力学特性对于研究高原地区水文和水循环过程具有重要的意义。2015年分别在林芝地区米林县(海拔2 905 m),八一镇(海拔3 240 m)和林芝县(海拔3 879 m)3个青稞种植区田间取样,在原状土土壤水分特征曲线测试的基础上,研究了西藏林芝地区土壤基质势和土壤含水率之间的关系,并建立了参数的微分求解方程,发展了土壤水分特征曲线非线性函数的参数估计方法;基于实测值构建Jacobi矩阵,采用全局性最优方法确定了van Genuchten模型和Gardner-Russo模型的参数。结果表明,-11.0~-4.0、-42.0~-11.0 k Pa以及-54.0~-42.0 k Pa基质势区段的单位基质势平均含水率变化量分别为5.4×10-3、11.2×10-3和6.7×10-3cm~3/(cm~3·k Pa),最大差异性发生在-54.0~-42.0 k Pa之间,西藏地区的土壤水分特征曲线形状主要决定于黏粒质量分数,而砂粒质量分数则主要影响土壤水分特征曲线的变异性。van Genuchten模型和模拟6组试验数据的相对误差平均值和最大值分别为0.04和0.09。采用Gardner-Russo模型模拟6组试验数据的相对误差的平均值和最大值分别为0.06和0.14。van Genuchten模型模拟西藏林芝地区的土壤水分特征曲线的精度及有效性显著超过Gardner-Russo模型。
[Abstract]:The natural climatic characteristics, the parent material and the conditions of soil-forming in Tibet have remarkable regional characteristics. Understanding the characteristics of soil hydrodynamics in the Tibetan Plateau is of great significance for the study of hydrology and water cycle processes in the plateau region. In 2015, Milin County (2 905 m),) and Linzhi County (3 240 m above sea level) were located in Milin County, Linzhi Prefecture, respectively. (3 879 m above sea level) field sampling in 3 highland barley planting areas, Based on the test of soil moisture characteristic curve of undisturbed soil, the relationship between soil matrix potential and soil moisture content in Linzhi region, Tibet, was studied, and the differential solution equation of parameters was established. The parameter estimation method of nonlinear function of soil moisture characteristic curve was developed, and the parameters of van Genuchten model and Gardner-Russo model were determined by using global optimal method to construct Jacobi matrix based on measured values. The results show that the average moisture content per unit matrix potential in the substrates potential range of -11.0 ~ 4.0 ~ 42.0 KPA and -54.0 ~ 42.0 KPA is 5.4 脳 10-3 脳 10-3 and 6.7 脳 10-3cm~3/ (cm~3 KPA), respectively. The maximum difference occurs between -54.0 KPA and 42.0 KPA, the results show that the average moisture content per unit matrix potential varies from -54.0 KPA to 42.0 KPA, and the variation of average moisture content per unit matrix potential is 5.4 脳 10-3 脳 10-3 and 6.7 脳 10-3cm~3/ (cm~3 KPA) respectively. The shape of soil water characteristic curve in Tibet is mainly determined by clay mass fraction. The relative error average and maximum value of the van Genuchten model and the six groups of simulated test data were 0.04 and 0.09, respectively. The accuracy and validity of the Gardner-Russo model for simulating the soil moisture characteristic curves in Linzhi region of Tibet were significantly higher than that of the Gardner-Russo model. The average and maximum values of the relative errors of the six groups of experimental data were 0.06 and 0.06, respectively, and the 0.14.van Genuchten model was much more accurate and effective than the Gardner-Russo model.
【作者单位】：西藏农牧学院;
【基金】：西藏自治区科技厅农牧业科技成果转化与示范项目;西藏自治区科技厅科技重大专项(Z2016C01G01/07) 国家重点研发项目(2016YFC0402405) 国家自然科学基金项目(51379152,91647109,51679257)
【分类号】：S152.7

【相似文献】