3种坡面流水深测量方法比较

目的]为坡面流水深的快速、准确测量提供技术支撑。方法]采用超声波系统测量变坡试验水槽不同坡度和流量条件下坡面流水深,同时用测针法和染色法对其进行平行测量,利用平均绝对误差(MAE),平均相对误差(MRE),相对均方差误差(RRMSE)和Nash—Sultcliffe系数(NSE)4个指标比较超声波法和染色法或测针法测量数据的接近程度。结果]通过对3种方法测量结果的比较分析发现,不管以测针法还是以染色法的测量值为参照,超声波法测量的水深值与参照值更接近且相关程度更高。结论]超声波法能快速有效地测量坡面流水深,用于侵蚀静床坡面流水动力学、土壤侵蚀机理等相关的研究工作。

Comparison of Three Methods to Measure Depth of Overland Flow

Objective] To provide technical support for measuring the overland flow depth rapiclly and accurately. Methods] The overland flow depth was measured with ultrasonic method under different slope gradients and flow rates. At the same time the flow depth was measured with the digital display probe method and dye tracing method. Based on the measurement results of digital display probe method or dye tracing method, four indexes including mean absolute error(MAE), mean relative error(MRE), the relative mean square error(RRMSE ), and Nash-Sultcliffe efficiency coefficient(NSE) were calculated to analyze the similarity of the three methods. Results] The depths measured by ultrasonic method were closer to the reference values and had a high degree of correlation with other two methods. Conclusion] The ultrasonic method could be used to measure the depth of overland flow quickly and effectively in un-eroding bed experiments in laboratory for the studies of hydrodynamics properties of overland flow and soil erosion mechanism.