采砂活动影响下的河道水面比降变化

受河道无序采砂的影响, 局部河段水流流态变得复杂, 从而影响船舶通航条件。根据实测河道地形资料及水 文资料, 分析了赣江下游樟树至外洲河道采砂后局部河床最大比降的历年变化, 并运用一维水流数学模型计算了历 年不同流量的河道水面线变化, 分析了水面线局部最大比降与河床比降的关系。结果表明, 受河道采砂影响, 局部 水面比降明显增加; 局部水面最大比降与河床比降密切相关; 随着流量的增加, 水面最大比降减小, 水面比降受河床 的影响程度减弱。 Due to the uno rder ed sand ex traction, the lo cal flow pat tern becomes mo re complex and the navigation conditions ar e effected. Acco rding t o the measur ed river terr ain data and hydro lo gical data, the annual var iations of max imum r iver bed slope hav e been analy zed fo r the r iver r each betw een Zhang shu to Waizhou in the downstr eam of Ganjiang River after sand ex tr action. The river w ater sur face var iation is calculated using the one2dimensio nal mathematical flow mo del under different flow discharg e co nditions, and the relatio nship betw een the local max imum w ater sur face slo pe and riv erbed slo pe is analyzed. The r esult s show that local water sur face slope incr eases sig nificant ly and lo ca l max imum water surface slo pe is closely r elated to r iv erbed slope due to the effects o f sand ext raction, and the maximum water surface slope decr eases and t he effects of riv erbed on w ater sur face slope weaken wit h the increasing of r iver flow dischar ge. 国家重点基础研究发展计划( 973) 项目( 2011CB403303)