径流小区集流桶（池）搅拌取样测量含沙量误差校正

发布时间：2018-02-28 14:50

本文关键词： 径流小区含沙量测量搅拌取样误差校正　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：水土流失监测是我国水土保持工作的重中之中,其中径流小区法是水土保持监测中一种重要且应用广泛的方法。径流小区集流桶(池)中含沙量的测量是准确计算土壤侵蚀量的关键。在径流小区泥沙监测中搅拌取样测量法是含沙量测量的传统方法,此前的研究已表明这种方法可能因为搅拌不均匀和取样过程中泥沙沉降影响含沙量测量精度,搅拌取样法测量含沙量存在较大误差。另外,我国各地不同的地形条件、降雨条件和土壤类型造就径流小区监测的径流量、泥沙量存在较大差异,这也将影响径流小区的建设和含沙量测量方法的精度。我国现有的行业规范并没有全面反映径流小区的技术要素,在含沙量测量方法的具体操作上规定不明确。虽有新的含沙量测量方法提出,但未能在全国范围内得到推广应用,径流桶(池)含沙量的测量误差问题仍未得到解决。因此,本研究通过四种土壤模拟集流桶(池)搅拌取样测量含沙量误差实验得出误差校正公式,提出一种较为简便的搅拌取样测量含沙量的误差校正方法,以期快速应用于全国各地的径流小区监测中。本研究以紫色土、黄绵土、X土、黑土四种土壤为研究对象,按照设计的13个含沙量水平,分为50 L和100 L的总体积,制备不同含沙量的泥沙水样,由从事径流小区测量的专业人员进行搅拌取样,采用烘干称重法测量含沙量,并与设计含沙量进行对比,计算得到搅拌取样法的测量误差,再通过回归分析得出实际含沙里与测量含沙量之间的误差校正公式,最后总结出误差校正法应用于径流小区监测的一般方法,结果表明:1)搅拌取样法测量含沙量存在较大误差,测得的含沙量整体结果均偏低。低含沙量时,紫色土、X土、黄绵土的平均相对误差在-30%~-40%,黑土的平均相对误差在-60%~-70%,在这个含沙量段误差随含沙量升高变化不大,围绕平均相对误差上下波动;含沙量升高到超高含沙量时,测量误差会发生陡变,四种土壤平均相对误差均减小到-20%以下,此时绝对误差仍然较大,但相对标准偏差减小,测量结果更稳定。2)搅拌取样测量法的含沙量测量误差与体积成负相关,50 L泥沙水样测量含沙量的相对误差较100 L泥沙水样的相对误差小。低含沙量时紫色土、X土、黑土100 L泥沙水样含沙量测量误差比50 L泥沙水样高-7%左右,超高含沙量时紫色土、X土、黑土100 L泥沙水样含沙量测量误差比50 L泥沙水样高-3%左右,黄绵土的测量误差总体上受体积影响较小。3)通过方差分析和回归分析得到四种土壤关于体积、含沙量的测量误差的线性回归方程:δ=j+aC0+bV;推导出测量含沙量与实际含沙量之间的误差校正公式:将四种土壤的测量含沙量代入误差校正公式进行检验,结果显示校正含沙量更接近实际含沙量,误差校正提高了集流桶(池)内含沙量测量的精度。4)将本研究通过模拟实验得出含沙量误差校正公式的过程总结成应用于径流小区泥沙监测的误差校正法,包括样品制备、搅拌取样过程和误差校正公式的建立三部分内容。各径流小区可通过此误差校正方法,建立不同工况下搅拌取样测量含沙量与实际含沙量的关系,用于校正测量误差,提高集流桶(池)内含沙量测量精度,为水土保持监测提供更可靠的基础数据。
[Abstract]:The monitoring of soil erosion is China's soil and water conservation work in, the runoff plot method is one of the most important and widely used method in monitoring of soil and water conservation. Runoff plots (pool) in the measurement of sediment concentration is the key to accurately calculate the amount of soil erosion. In the runoff sediment monitoring mixed sampling method is the traditional method for measuring sediment concentration, previous studies have shown that this method may affect the sediment measurement accuracy because of uneven mixing and sediment deposition in the sampling process, measurement of sediment sampling volume mixing has larger errors. In addition, different terrain conditions in our country, rainfall and soil types make runoff plots monitoring there is a big difference, the amount of sediment, which will also affect the construction and method of measuring sediment concentration in runoff plots. The accuracy of our existing industry standard does not fully reflect the runoff The technical elements, the specific operation in the measurement of sediment concentration on the provisions are not clear. Although the proposed new method of measuring sediment concentration, but has not been applied in the national scope, runoff barrels (pool) not errors in sediment are solved. Therefore, this research through four kinds of simulated soil collecting tank (pool) mixing sediment sampling and measurement error experiment error correction formula, put forward a correction method of simple mixing sampling and measurement of sediment concentration in runoff monitoring error and rapid application throughout the country. In this study, purple soil, loessial soil, soil X, soil four kinds of soil as the research object. According to the 13 concentration level of design, is divided into a total volume of 50 L and 100 L, the sediment water preparation of different sediment concentration, stirring by sampling measurement professionals engaged in runoff, sediment concentration by the method of drying and weighing measurement, And compared with the design of sediment concentration, the calculated error mixing sampling method, then the regression analysis showed that the error between the actual measurement of sediment concentration and sand containing correction formula, finally summarizes the general method of error correction is applied to runoff monitoring, the results showed that: 1) mixing sediment sampling amount of measurement the error of the measured sediment concentration, the overall results were low. Low concentration, purple soil, X soil, the average relative error of Loessal Soil in the -30%~-40%, the average relative error of black soil in -60%~-70%, in the sediment concentration increased with the error period changed little, on average relative error of the fluctuation of sediment concentration increased; to the ultra high sediment concentration, the measurement error will occur suddenly, four kinds of soil average relative error was reduced to below -20%, the absolute error is still large, but the relative standard deviation is reduced, the measurement results more stable .2) mixing sampling method the sediment volume measurement error and negatively related to the relative error of 50 L sediment samples measurement of sediment concentration is 100 L sediment samples. Low sand content in purple soil, soil X, soil water content of 100 L sediment measurement error than 50 L sediment water with high -7% about super high sand content in purple soil, soil X, soil water content of 100 L sediment measurement error than 50 L sediment water about -3% high volume, less affected by the overall measurement error of.3 in loessial soil) on the analysis of variance and regression analysis in four kinds of soil on the volume, concentration of linear measurement error the regression equation: =j+aC0+bV value; error is deduced and the actual measurement of sediment concentration correction formula: measurement of sediment into the error of four kinds of soil test results show that the correction formula, correction of sediment is more close to the actual content, error Differential correction improves the accuracy of.4 collecting tank (pool) sediment measurement) will be through the study of simulation experiment show the error correction process Sedimentconcentration error correction formula summarized as applied to runoff sediment monitoring, including sample preparation, mixing process and sampling error correction formula is established. The content of the three part the runoff through this error correction method, relationship between sampling and measurement of sediment concentration and stirring actual sediment is established under different working conditions, for the correction of measurement error, improve the accuracy of collecting tank (pool) sediment measurement, and provide basic data for more reliable monitoring of soil and water conservation.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157.1

【参考文献】