Investigation And Analysis Of Road Greening In Guangzhou Based On Low Impact Development Model

At present,Guangzhou city is practicing a state strategy of building “Sponge city”,and applying LID(Low Impact Development)model to improve on-site hydrological cycle environment is one of the important tasks of road greening.Through field survey and data collection on 10 main roads of Guangzhou city,on the basis of consulting a great of referenced literature,the paper analyzes the regional measures of using LID idea in road greening of Guangzhou,sums up corresponding LID greening models,provides model references for the application of LID in Guangzhou when roads and greenbelts are built in new developing zones.The main outcomes are as follows:1)On the aspect of idea,LID facilities in Guangzhou are mostly adjacent to natural water,adapt to the change of terrain,use different approaches accordingly and treat rainwater ecosystem in the way of combining “green and gray”,which to a certain extent improves the hydrological cycle environment of site,thus conforms to the idea of LID.2)On the technology and application aspect,LID uses 3 types of facility in general,which are sunken greenbelt,vegetation slope and dry stream.In the application of waterfront plants,93 kinds of mesophyte and 8 kinds of hygrophyte and helophyte are being used,which accounted for 92% and 8% of total sample plant species.In the ecological treatment of rainwater,the combination of green and gray is simple and economical.3)Two regional road greening models are developed in LID application.The first model is the discharge type of traffic island with grass slope and low vegetation density,in which the rainwater is carried from grass slope to drainage.This structure can handle certa in intensity of rainfall in Guangzhou,it can slow down,filter and discharge rain water on motorway,is economical to some level,especially suitable for small and medium-sized traffic islands.The second model is the storage type of traffic island with dry stream and high vegetation density.This type of greening consists of vegetation revetment,dry stream and underground reservoir,can slow down,filter,infiltrate and collect rainwater from sidewalks and greenbelts for daily irrigation.This structure is not only able to deal with certain intensity of rainfall,but also recycle rainwater as a resource,is especially suitable for medium and large-sized roadside greenbelts and traffic islands in new developing zones.