科尔沁沙地土壤水分特性多尺度传递函数模拟与适用性评估

发布时间：2019-04-09 19:15

【摘要】：本文以科尔沁沙丘—坨甸交错区为研究对象,利用参数统计方法和分形理论研究构建基于土壤基本物理化学性质的不同采样尺度下土壤水分特征曲线的传递函数,为该区域土壤水、溶质的运移,以及区域水文循环提供理论支持和数据保证。主要研究结果如下：1)对研究区3种采样尺度下的不同地貌类型的土壤的物化性质以及水力参数进行统计分析。可知：研究区土壤颗粒偏粗,土壤中赋存的养分含量较低。土壤质地多为砂土,还有少量的砂质壤土以及壤质砂土。2)采用非线性规划法建立了3个不同采样尺度下土壤水分特征曲线、ran Genuchten四参模型的传递函数,表明在大采样尺度下,土壤水分特征曲线的预测值与实测值的吻合程度最高。当样本数据足够丰富,采样点布设合理时,所建立的土壤水分特征曲线传递函数可以适用于该区域(土壤成土较弱,为沙性母质幼年土,砂粒含量占主导地位的砂土以及壤砂土)或与该区域土壤成因相似的地区。3)土壤具有自相似性或分形特征。土壤颗粒分形维数D的变化范围为1.23～2.51,处于较低水平,多为风沙土。D值按照流动沙丘-半固定沙丘-固定沙丘-砂质农田-草甸农田-草甸的顺序呈逐渐增大的趋势。D与砂、粉、粘粒含量之间的关系不是简单的线性相关,而是呈明显的对数相关关系。4)土壤水分特征曲线模型的分形维数与基于体积的土壤颗粒体积分形维数有着良好的线性关系。在不同采样尺度下所建立的D与Ds方程比较接近。5)无论是哪种方法建立的传递函数,其对沙丘地带的模拟效果要优于草甸地带。利用参数统计模型建立的传递函数需要考虑尺度之间的转换关系；而分形机理模型在不同采样尺度上表现出一致性。
[Abstract]:In this paper, the transfer function of soil moisture characteristic curves under different sampling scales based on basic physical and chemical properties of soil is constructed by using parameter statistical method and fractal theory, taking Horqin Dune-Tuodian intersection area as the research object. It provides theoretical support and data guarantee for soil water, solute transport and regional hydrological cycle in the region. The main results are as follows: 1) the physical and chemical properties and hydraulic parameters of soils with different geomorphologic types under three sampling scales were statistically analyzed. It can be seen that the soil particles are thicker and the nutrient content in the soil is relatively low in the study area. The soil texture is mostly sandy soil, and there are a few sandy loam and loam sandy soil. 2) the transfer function of, ran Genuchten four-parameter model of soil water characteristic curve under three different sampling scales is established by using nonlinear programming method. The results showed that the best agreement was obtained between the predicted and measured values of soil moisture characteristic curve at large sampling scale. When the sample data is abundant and the sampling points are arranged reasonably, the transfer function of the soil water characteristic curve can be applied to this area (the soil is weak, and it is the sandy parent material juvenile soil). (3) the soil has self-similarity or fractal characteristics. 3) the soil has the characteristics of self-similarity or fractal in which the sand content is dominant and loam sand soil is similar to the soil origin in this area. The variation range of soil particle fractal dimension D is 1.23 ~ 2.51, which is at a lower level. The value of D increased gradually according to the order of moving dunes-semi-fixed dunes-sandy fields-meadows. The relationship between D and sand, powder and clay content was not a simple linear correlation. 4) there is a good linear relationship between the fractal dimension of soil moisture characteristic curve model and the fractal dimension of soil particle volume based on volume. The D obtained at different sampling scales is close to the Ds equation. 5) No matter which method is used to establish the transfer function, the simulation effect of the method is better than that of the meadow zone. The transfer function established by using the parametric statistical model needs to consider the transformation relationship between scales, while the fractal mechanism model shows consistency on different sampling scales.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152.7

【参考文献】