岸滩侧蚀崩塌速率的试验量测方法

Study on the experimental method to measure the lateral erosion rate of riverbanks

岸滩侧蚀崩塌现象普遍存在于冲积河流演变过程中,是河道治理需重点关注的问题之一,岸滩侧蚀崩塌速率的准确量测则是崩岸机理及其治理措施研究的关键基础。基于图像处理技术,建立了河岸侧蚀崩塌速率试验量测系统,通过图像追踪河岸模型上边缘示踪网格位置变迁,提出了一种河岸侧蚀崩塌速率测量方法。以试验水槽为例,对河岸侧蚀崩塌速率进行了量测,并与经验公式计算值进行了比对,两者基本吻合,可较好地反映流速、土体级配等岸滩侧蚀崩塌速率的影响因素及其变化规律。研究成果可为江河崩岸机理的深入研究提供技术支撑。

Riverbank erosion occurs frequently on fluvial rivers,which is one of the key issues for river regulations.The measurement of lateral erosion rate is critical for the investigation of bank erosion mechanism and revetment. A measurement system for bank erosion rate is developed based on the technology of image processing. A new method to measure the lateral erosion rate of riverbanks is proposed by tracking the location of tracing meshes on riverbanks. As a case study,the lateral erosion rate of riverbanks in an experimental channel is measured by the proposed method,and the measured data agreed with the calculated results by a semi-analytical method. Both measured and calculated results indicated that the lateral erosion rate depended on the flow velocity as well as the anti-scour ability of riverbanks. The proposed method is able to provide a technology for the further study on bank erosion mechanisms.