电解质示踪测量坡面薄层水流流速的改进方法

薄层水流速度测量对坡面水文和土壤侵蚀过程预测具有重要意义。电解质示踪脉冲模型在短距离测量流速的精度较低，提高短距离测量精度是开发便携测量设备的需要。该文对电解质示踪脉冲模型的边界条件进行改进，采用正态分布函数代替脉冲函数的边界，提出了电解质示踪法测量流速的正态模型。用正态边界条件和脉冲模型解的卷积作为实际电解质传输过程的解，得到更符合实际的电解质传输模型。利用正态模型与试验观测数据拟合，得到水流流速的估计值。与脉冲模型比较，正态模型不同程度地降低了不同测量位置流速预测的误差。研究结果为改进测量流速的设备开发提供了科学依据。

Advanced method for measuring velocity of shallow flow on hill-slope with an electrolyte tracer

The measurement of velocity of shallow water flow is of great importance for hill-slope hydrology and soil erosion prediction. The electrolyte tracer pulse model was found to be unable to predict the velocity correctly at short distance though it is desired for portable apparatus development. In this paper, electrolyte tracer normal distribution model was proposed by using Normal distribution function as boundary condition instead of pulse function to predict velocity of shallow water flow. An improved method for measuring the flow velocity was advanced based on the Normal Distribution Model, which uses the convolution integral of the pulse response and the normal distribution boundary as the more realistic solution to the solute transport processes. By fitting the Normal Distribution Model with the actually measured solute transport processes, the flow velocity values under different conditions were estimated. Compared with the velocity values measured with the pulse model, the Normal Distribution Model reduced the measurement errors at different locations to different degrees. The results will provide theoretical foundation for advanced apparatus development of velocity measurement.