河岸刚性植被缓冲带对水流阻力的影响

河床糙度尺度特征在评价明渠淹没植被引起的阻力作用时具有重要意义,通过重新定义水力半径,提出植被密度刚性植被缓冲带糙度系数,用以量化沉水植被对河道表面层水流阻力特性的影响程度。研究表明,沉水植被缓冲带粗糙度与植被茎粗和植被密度有关,并通过试验数据拟合出缓冲带表面层摩擦系数,进而提出一种用于估算植被缓冲带上平均流速和阻力系数的计算方法。

Influence of Rigid Vegetation Buffer Zone on Flow Resistance

Roughness length scale is important in evaluation of resistance caused by submerged vegetation in open channel flows. By transforming the concept of hydraulic radius, a roughness coefficient of rigid vegetation density buffer zone is proposed for quantifying the impact of submerged vegetation on flow resistance in the river surface layer. The study demonstrates that the buffer zone roughness of submerged vegetation is related to the stem diameter and vegetation density. The frictional coefficient of surface layer in buffer zone is fitted by experiment data. Thus, an approach is developed for estimation of the average flow velocity and resistance coefficients of vegetation buffer zone.