Study On The Vegetation Buffer Zone Repair Design Strategy

Vegetation buffer strip is an important part of the land-water boundary of the river bank,which is of great significance for river water quality protection and has always been considered as one of the "best management measures" to control agricultural non-point source pollution.The phenomenon of waterfront habitat destruction,deterioration of water quality,degradation of aquatic ecosystems is becoming increasingly serious,and the habitat and ecological functions of vegetation buffer strip are also deteriorating in different degrees.It is of practical significance to carry out research on restoration design strategies.On the basis of extensive reading of domestic and foreign related literatures,this paper sorts out and summarizes research progress related to vegetation buffer strip;using a combination of graphic and textual methods to systematically construct restoration strategies for vegetation buffer strip;A comprehensive analysis of the status of the vegetation buffer strip within 60 m along the Yangliu river section of the XinJin Baihe Tan wetland park was conducted by field investigation,on the base of the comprehensive analysis,the restoration design of the vegetation buffer strip was carried out and provided theoretical and practical references for the river habitat protection.The conclusions are as follows:(1)Four different vegetation buffer strip types were proposed.Including natural prototype(N),near-natural ecological type(E),comprehensive type(C),and artificial reanimation type(A).The quantified features were summarized from the aspects of the purpose or function of the restoration and construction of the vegetation buffer strip,vegetation structure and type,vegetation originality,form of river bank,construction rate of landscape facilities,and ecological vulnerability.(2)Put forward pretreatment measures for agricultural non-point source pollution.Take emission reduction and resource utilization as the key points,select pesticide spraying and irrigation time control technologies,use of organic fertilizers and environmental protection pesticides to dispose pollution sources in agricultural production,and select garbage sorting,biological treatment technologies and constructed wetlands for the treatment of pollution sources in daily life and livestock and poultry farming.(3)Put forward the suitable types of vegetation buffer strip and determination methodto the spatial layouts.The appropriate types were determined on the base of non-point source pollution,vegetation buffer strip structure,plant communities,etc.,as well as the analysis of vegetation buffer strip types and ecological fragility.The spatial layout of vegetation buffer strip was determined according to the river line types,river contour lines and the reservation and optimization of existing vegetation buffers.(4)Take deceleration shunting,osmotic absorption,soil fixing and purifying,and effect enhancement as functional entry points,and consider the vegetation type,river bank topography(slope,width),revetment,and near-shore waters as the major factors,the optimized technology system for vegetation buffer strip structure was constructed from the four spatial levels,which consisted of the front,middle,end,and near-shore waters of the vegetative buffer strip.The front diffused structure includes Grassland filter,Fascine,Shrub hedge,and Stone weir.The middle osmosis system is made of three kinds of optimization techniques: plant selection techniques in three soil environments(clay,loam and sand),micro-basins,and step-topography;The terminal revetment is consist of three types of optimization technologies: " Grass+Shrub "," Live Fascine + Brush Mattress " and "Vegetation+Stone ".The near-shore water assist device are various types of ecological floating islands.(5)Proposed the optimization strategy of vegetation buffer strip plant community.The vegetation reference systems for different types of vegetation buffer strips were constructed according to common plant species in the study area and natural or near-natural plant communities with good growth conditions.The reference systems were also combined with structural optimization techniques.(6)The design scope of Vegetation Restoration in the Yangliu river section of XinJin Baihe Tan wetland park was used as the vegetation buffer strip.Frist a status survey was conducted,which indicated that vegetation buffer strips were at greater risk of agricultural non-point source pollution and the vegetation buffer strips were degraded by habitats.There were 9 types of vegetation buffer strips in the current status,51 species of common plant species,4 species of typical natural and near-natural terrestrial plant communities,and 6species of aquatic plant communities included.(7)The restoration design of appropriate natural prototypes(N),near-natural ecological(E)and comprehensive(C)vegetation buffer strips in the study area was accomplished for the reference of vegetation buffer strip structure optimization technical system after site investigation.At the same time,agricultural non-point source pollution was proposed.The pre-treatment measures and the planning and design of the scientific research monitoring system,road facilities,identification system,basic service facility system,and lighting system within the design scope were carried out.