The roughness coefficients are inverse proportional to Reynolds number on gentle slopes, and on the contrary,they are direct proportional to Reynolds number on steeper slopes.

• 在坡度较陡的坡面上，由于水流侵蚀作用强度的变化及重力影响作用的渐趋显著，阻力系数又会随雷诺数的增大而变大。