土壤圆锥指数、水分与容重耦合模型的试验比较研究--Ⅱ.水分与深度的影响

Experimental Comparison of Various Models Related Soil Water Content and Bulk Density to Cone Index——Ⅱ.Components Effect of Water Content and Depth

在对4种模型统计性能的水平检验与容重预测精度评价的基础上,分析与检验了各模型中水分与行进深度的影响作用.为分解水分对圆锥指数的单因数影响,采用定义水分影响指数(的方法.对于圆锥传感器行进深度的影响作用,借助于da与ead两种独立的深度影响因子,结合各模型与试验数据进行了计算与比较.结果表明:(1)只有Ayers模型能够较好地刻画土壤圆锥指数与水分间的耦合关系;(2)根据Ayers模型与Upadhyaya模型,圆锥传感器行进深度对圆锥指数的影响作用可以忽略;(3)根据Busscher模型,圆锥传感器行进深度显著影响圆锥指数的数值,但与此同时水分影响却可忽略不计,这显然与事实不符.由此看来,应用Ayers模型解析土壤圆锥指数、水分与容重的耦合关系,优于其它模型,但它作为隐函数,寻求最优迭代算法有待进一步研究.

Based on the statistical analysis for each model in the part I, this part focused on investigating the components effect of water content and penetration depths on CI. In order to separate the influence of water content from each model, an index in terms of 7/was defined as the ratio of CI to bulk density. For the same purpose of studying the effect of the penetration depths, two impact factors, i.e. d^a and e^ad, were used to combine with each model. As a comprehensive consequence, three conclusions can be drawn： （1） only Ayers-model can satisfactory characterize the relation between CI and water content; （2） According to the computation results from Ayers- and Upadhyaya-model, CI seems independently of the penetration depths; （3） Contrary to Ayers- and Upadhyaya-model, the computational results of Busscher- and Hernanz-model show that CI should be strongly rely on the penetration depths and the influence of water content be negligible if impact factor of the penetration depth is considered. Nevertheless, the computation results of Busscher- and Hernanz-model are in contradiction with the experiment results. Thus, it can be speculated that Ayers Model is preferred among four models although it is an implicit function associated volumetric water content and bulk density with CI.