中文摘要：

细沟和细沟水流参数的准确测量可为深化坡面土壤侵蚀过程研究提供重要理论依据。基于立体摄影测量技术，以坡度为15°和20°的黄土坡面为研究对象，采用人工模拟径流冲刷的方法，对比不同时刻坡面的高精度数字高程模型DEN，提出了动床条件下坡面细沟宽度、深度以及细沟水流宽度、深度的测量和计算方法，分析了2个坡度处理下坡面细沟形态、细沟水流特征及其变化规律，探讨了立体摄影测量技术与其他测量技术在细沟形态及径流特征参数测量方面的异同。结果表明：经过比例尺的校正，可以在垂直拍摄的立体摄影照片上直接准确测量细沟宽度和细沟水流宽度；运用内插法，立体摄影测量技术能较准确地测量细沟深度和细沟水流深度的实时动态变化。随坡长的增加，细沟深度逐渐增大，而细沟水流深度则无明显变化趋势；细沟宽度随坡长的增加呈先增大后减小的变化趋势，而细沟水流宽度逐渐减小；20°坡度下细沟宽度和深度的增加速率分别是15。坡度下的1．7倍和1．3倍；同20°坡度相比，15°坡度条件下的细沟水流的宽度增加了1．7％-13．1％，而2个试验坡度下的细沟水流深度无明显差异。

英文摘要：

Accurate measurements of rill geometry and flow parameters provide theoretical basis for erosion processes on hillslopes. Rill width and depth are basic rill morphological characteristics. Rill flow width and depth are the foundation for calculating hydraulic and hydrodynamic parameters. A soil box （2.0 m long, 0.3 m wide and 0.5 m deep） was subjected to a 140 s movable-bed scouring test under a surface inflow rate of 1 L/rain with slope gradients of 15° and 20°. Based on photogrammetry, point cloud and high-precision DEMs of the soil bed at different times were extracted. Measurements of rill depth and width, and rill flow depth and width were made. Variation trends of rill morphology and rill flow characteristics were analyzed and differences between photogrammetry and other measurement methods were discussed. The results showed that rill width and rill flow width could be measured directly from perpendicularly shot photographs after proportional scale calibration. Based on interpolation principal, dynamic variations of rill depth and rill flow depth could be measured. With increasing slope length, rill depth was increased while rill flow depth showed no significant trend. Rill width was increased and then decreased while rill flow width was decreased gradually along the soil bed. Increasing rates of rill widths and depths with slope gradient of 20~ were 1.7 and 1.3 times as those with slope gradient of 15°. Rill flow widths in different cross-sections with slope gradient of 15° were 1.7% -13. 1% larger than those with slope gradient of 20~, while rill flow depths showed little difference between these two slope gradients. Rill depths and rill flow depths obtained by manual measurements with a steel ruler were 3.3 % - 5.1% and 91.0% -178.5% higher than those obtained by photogrammetry. Compared with traditional methods and 3D laser scanning technique, photogrammetry had speed, resolution and non-contact advantages and it can also overcome rill wall shield and prevent the occurrence of point cloud ＂bla