Screening Of Typical Ecological Revetment Materials And Structures In Yongding River(Beijing Section)

Ecological revetment uses plants or combines plants with civil engineering to protect river slopes and contribute to the improvement of river water quality.The traditional non-ecological revetment blocks the connectivity between the riparian zone and the water body,making it difficult to fully exert the self-purification ability of the river bank transition zone,reducing the species diversity,not meeting the construction requirements of the“sponge city'”,and constructing the ecological revetment is the modern river channel.The inevitable trend of governance development.In this study,the ecological remediation of the river bank of the Yongding River sandy channel was taken as the goal.The simple runoff plot method was used to conduct the water flushing experiment.Under different scouring flow rates(40,60,80 mm/h),the ecological environment of different ecological revetment materials and structures The revetment type of runoff and sediment production,hydrodynamic characteristics,non-point source pollution characteristics and its interception and decontamination effects were studied.Three kinds of ecological revetment materials and two types of ecological revetment structures were found to significantly impro've the riparian site.Through the on-site investigation of the study area,this paper analyzes the ecological and hydrological status,site status,and river bank slope conditions of the study area,conducts ecological revetment suitability evaluation,and diagnoses existing revetment problems.Through reviewing the relevant materials and literatures of ecological revetment,the paper summarizes and analyzes the experience of ecological revetment at home and abroad,and combines the characteristics of the study area to determine the five materials of pebble,pine pile,three-dimensional geonet,coconut planting blanket and permeable ecological bag as ecological revetment filler.The three kinds of ecological revetment structures of tiled,stepped and fish scales were used to carry out the water discharge flushing experiment of the simple runoff plot,simulating the convergence process of the ditch and shore,and using the principal component analysis method to compare the sediment interception efficiency and water quality basic indicators of different ecological revetlents by horizontal comparison(The conditions of COD,BOD,TN,TP,ammonia nitrogen,as well as the flow rate and flow depth,finally select the ecological revetment materials and structural forms that meet the restoration objectives.The results show that both materials and structures can significantly improve the benefits of ecological revetment,and the effect of revetment materials is more obvious.The increase of ecological benefits of the two decreases with the increase of discharge flow.Finally,three kinds of ecological revetment materials such as permeable ecological bag,coconut silk planting blanket and three-dimensional geonet were screened out;two kinds of ecological revetment structures,terraced and tiled;ecological bag+grass revetment,pine pile+pebble revetment were selected.The ecological revetment combination provides some experience for the future research of ecological revetment.In this study,a simple runoff plot was used to conduct the water flushing experiment,which greatly reduced the engineering volume of the ecological revetment research.In this study,water quality indicators,flow dynamics parameters,and runoff and sediment yield status were used as variables affecting the benefits of ecological revetment,and multidimensional indicators were studied at the same level,which was innovative.In addition,it is difficult to achieve uniform water distribution for the water scouring experiment.In this study,the uniform water tank was designed to achieve uniform continuous water distribution during the experiment,which reduced the experimental error.