山区小流域坡面、沟道床面粗糙度与糙率测量方法探讨

在山区小流域中,坡面流糙率、沟道和山溪等的糙率由于缺乏天然水流实测资料,无法进行糙率率定,使得山洪爆发后,坡面流、沟道和山溪水流计算难以符合实际.根据分形理论和投影覆盖法的原理,建立了山区河流坡面流、沟道和山溪水流糙率直接测量方法.为了验证该方法的有效性,运用三维激光扫描仪,对山区河流河床粗糙度进行了精细测量.根据测量的卵石河床表面粗糙度的数据,建立分维方法与传统方法确定的床面面积之比与扫描间距之间的关系,进而运用本方法确定了该河道的糙率.结果表明,实测结果和实际符合良好.

Roughness of slope surface and gully bed and its measurement method in a small watershred of mountainous areas

In a small watershed of mountainous areas,it is difficult to calibrate roughness of slope surface,gully and stream due to laking measured data of natural flow movement.As a result,when flash flood occurs,the flow pridiciton of slope surface,gully and streams alwayes disagrees with the acutal case.Based on the fractal theory and the projective covering method,this paper develped a method for measureing roughness coefficeint of overland flow,gully and stream flows directly.In order to verify the method,the bed roughness of mountain rivers was measured by means of 3-D Laser Scanner.Applying the measured data,the roughness of the river was determined using the method proposed in the paper.It is shown that there is a good agreement with the computed and acutal values.