Liu, Jiahong

Luan, Yong

Shao, Weiwei

Xiang, Chenyao

English

Hydraulic Engineering Repository

Article, Published VersionLiu, Jiahong; Xiang, Chenyao; Shao, Weiwei; Luan, YongSponge city construction in Xiamen, ChinaHydrolinkVerfügbar unter/Available at: https://hdl.handle.net/20.500.11970/109350Vorgeschlagene Zitierweise/Suggested citation:Liu, Jiahong; Xiang, Chenyao; Shao, Weiwei; Luan, Yong (2016): Sponge city construction inXiamen, China. In: Hydrolink 2016/4. Madrid: International Association for Hydro-Environment Engineering and Research (IAHR). S. 103-105. https://iahr.oss-accelerate.aliyuncs.com/library/HydroLink/HydroLink2016_04_Sponge_Cities.pdf.Standardnutzungsbedingungen/Terms of Use:Die Dokumente in HENRY stehen unter der Creative Commons Lizenz CC BY 4.0, sofern keine abweichendenNutzungsbedingungen getroffen wurden. Damit ist sowohl die kommerzielle Nutzung als auch das Teilen, dieWeiterbearbeitung und Speicherung erlaubt. Das Verwenden und das Bearbeiten stehen unter der Bedingung derNamensnennung. Im Einzelfall kann eine restriktivere Lizenz gelten; dann gelten abweichend von den obigenNutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte.Documents in HENRY are made available under the Creative Commons License CC BY 4.0, if no other license isapplicable. Under CC BY 4.0 commercial use and sharing, remixing, transforming, and building upon the materialof the work is permitted. In some cases a different, more restrictive license may apply; if applicable the terms ofthe restrictive license will be binding.103hydrolink number 4/2016IAHROn September 19th, 2016, with the landing ofTyphoon Meranti, Xiamen suffered winds of upto force 17 in the Beaufort scale, a short-timerainstorm, and severe waterlogging. Meanwhile,Xiamen’s aquatic environment is facing greatchallenges. In recent years, water quality in over80% of local streams is below Class V, the worstcategory in the national surface water qualitystandards.In 2014, Xiamen initiated the sponge cityconstruction project which contains 4 majorparts: (1) controlling surface runoff through LowImpact Development (LID) implementation; (2)extending the storage capacity of the local river-lake system to contain stormwater throughwater body renovation and ecologicalrestoration; (3) controlling pollution sources byrebuilding combined sewer systems, raisinginterception ratio and wastewater treatmentcapacity, so as to improve the local aquaticenvironment; and (4) building basic stormwaterdraining infrastructure to prevent urban floodingand waterlogging.Sponge city implementation inXiamenAccording to the design of the Xiamen spongecity construction project, the built-up area of thecity is divided into 16 drainage districts. Spongecommunity, sponge roads, eco-river systems,pollution management infrastructure anddrainage installations are constructed accordingto each district’s feature. The overall objective isto accommodate 70% of the annual rainfall inthe built-up region.Low Impact Development (LID) of communities and roadsLID for residential communities and roads arealso called “sponge community construction”and “sponge road construction”. CurrentlyXiamen has launched sponge communityprojects in Guoyun-Maluan Bay and SouthernXiangan districts. These 2 projects cover anarea of 41.76 km2, 12.9% of the city’s total built-up area. Sponge community constructionfocuses more on vertical design. Green roofs,interception devices, high parterres, rain barrels,sunken green belt, permeable surface areintegrated vertically so that rainfall would beabsorbed level by level. The remaining rainfallpartly infiltrates into soils, while the rest flowsinto bio-retention ponds or rain drainage systemas runoff, and is further stored in rain pools orscenic ponds, then treated for watering andlandscape water use, as well as road sprinkling.Sponge community construction also favorsmore green spaces in the plazas and parkinglots, less impermeable pavements made ofconcrete, asphalt, etc. The sponge communitywould become a low-temperature region for LIDmeasures, which should help strengthen localair circulation and weaken the surrounding heatisland effect. Another key aspect of spongecommunity is green space system construction,including “green planes” and “green lines.” Agreen plane is a park or greenbelt of consid-erable area, of which the surface storagecapacity can be increased by sunken greenbeltconstruction. While green lines mainly includenon-motorized traffic system (pavements,bikeways, multifunctional non-motorized roads,etc.). By remoulding non-motorized roads intopermeable surfaces, and connecting them togreen spaces in buffer zone, an urban “greenweb” could be built to filter first flush pollutionand reduce runoff peak volume. So far, XiamenSPONGE CITY CONSTRUCTIONIN XIAMEN, CHINABY JIAHONG LIU, CHENYAO XIANG, WEIWEI SHAO, YONG LUANSponge city construction is a key mission of urban development plan in China’s 13th Five Year Plan,and Xiamen is in the group of 16 pilot sponge cities in China. Xiamen is located in the southeasterncoastal region in China, with a subtropical maritime monsoon climate and an urban population ofover 4 million. The local water resources are very unevenly distributed during the year, resulting indouble threats of urban flooding and water shortage. Figure 1. The drainage districts of Xiamen sponge citySPECIAL ISSUE ONrivers (Guoyun Stream, Shenqing Stream,Yaoshan Stream, Hou Stream, GuanxunStream, Daitou Stream, Dongxi Stream,Longdong Stream, Jiuxi Stream and XianganEcological Rivers) and 3 lakes (Yundang Lake,Maluan Bay and the Nose Canal). Engineeringmeasures adopted includes ecologicalembankment (natural slope revetment, stone-mesh revetment, vegetated block slopeprotection, ecological geofabriform revetment),riverbank buffers (tree belts or grassland builtalong riverbanks and valleys), river dredging,and ecological water supplementation with rainwater or recycled water. In the Xiang’anecological water replenishment project, storedrain water and recycled water are pumped to ascenic lake with high elevation by solar PVpower, and then flow into streams by gravity. Inthis way, the system is able to replenish riversystem automatically in sunny days, and stop inrainy days when rivers are supplemented byrainfall; in a word, the system is complementarywith weather.Pollution controlXiamen is suffering from severe water pollutioninduced by wastewater discharge, non-pointsource pollution of runoff, and waste dumpingalong rivers. The sponge city project appliesinterception infrastructures and ecologicalrestoration techniques to solve the problem. has finished 5 green lines and is constructing 2 more. According to the plan, Xiamen’s percapita green area ought to exceed 12 m2 during2014-2016. During 2017-2020, the city’s greenspace system structure should be generallyformed. The per capita green area shouldsurpass 15 m2 by 2020.Sponge road construction refers to transformroads and greenbelts into sponge construc-tions. The primary is slope landscaping andground slope aspect design. Curbs arelessened to only necessity, and designed to beno higher than the road, avoiding blocking therainwater. Greenbelts along roads are combinedwith sunken greenbelt, bio-retention infrastruc-tures, grassed swales and so on, while largergreen spaces, such as traffic islands and flyoversurroundings, are altered to rain gardens, rainwater wetlands, ponds, regulation pools orsunken green spaces. Runoff over pavementsis drained through underground sewers intostorage devices in greenbelts.Ecological river system constructionEcological river system construction includesrecovering water body damaged by landfill, riverdredging, altering river morphology, andresuming aquatic ecological conditions,biomes, and ecological functions. By far Xiamenhas initiated ecological recovery projects for 10Prof. Jiahong Liu isworking as the SectionChief of Urban Hydrology,Department of WaterResources, ChinaInstitute of WaterResources & Hydropower Research (IWHR),Beijing, China. Dr. Jiahong Liu has presidedmore than 40 researches and consultantprojects on water resources, sponge cities’planning as well as ecological restoration.He was supported by the Natural ScienceFoundation of China as one of theOutstanding Young Scientists, and wasselected as one of the Young Talents byMinistry of Science and Technology. Chenyao Xiang is agraduate student in UrbanHydrology Group,Department of WaterResources, ChinaInstitute of WaterResources & Hydropower Research (IWHR),Beijing, China. Chenyao graduated fromTsinghua University in 2015, and is currentlyconcentrating on urban rainfall-runoffmechanism study and simulations, andsponge city related issues.Dr. Weiwei Shao is asenior engineer ofDepartment of WaterResources in ChinaInstitute of WaterResources & HydropowerResearch(IWHR), Beijing, China. Dr. WeiweiShao has presided more than 10 researchand consultant projects on water resources,sponge cities’ planning as well asecological restoration.Yong Luan is a graduatestudent in the Departmentof Water Resources,IWHR, supervised byAcademician Hao Wangand Professor JiahongLiu. He is currently majoring on urbanhydrology. and participated in 4 water-resource planning projects, including oneon sponge city.  104 hydrolink number 4/2016Figure 2. Stone-mesh revetment         Figure 3. Vegetated block slope protection105hydrolink number 4/2016IAHRTo control point-source pollution, rain-sewageseparated sewers are built and wastewatertreatment plants are extended. For regions notreached by the sewer system yet, distributedwastewater treatment plants are built to controlwastewater discharges. Non-point sourcepollution is reduced by constructing greenroofs, rain barrels, permeable pavements, plantfilters, grassed swales, infiltration swales, sandfilters, bio-retention pools and other similarfeatures. Ecological floating beds, whichconsume nitrogen and phosphorus, are set inrivers and lakes, to purify eutrophic waters andrestrain overgrowth of planktonic algae.Waterfalls, fountains, jet currents, and othermethods are adopted to increase dissolvedoxygen. In the open area of lake entrances,artificial wetlands are built to purify enteringwater. Sediments of closed- and semi-closedlakes are cleaned regularly. Rubbish recycling iscontrolled more strictly, so that any waste isforbidden into river-lake systems. Measures asabove would alleviate urban water pollution aswell as improve the urban landscape and livingenvironment.Waterlogging prevention constructionWaterlogging prevention construction consistsof rain-sewage diversion projects, flooddischarge trenches and open channelsextension, and the installation of additionaldrainage pumps in waterlogged lowlands.Presently projects under construction include 2large pumping stations (Yundang Lakedrainage pumping station and Xinglin Baydrainage pumping station), and 44 drainageinfrastructures on sites that are particularlyprone to waterlogging. Moreover, the rain-sewage diversion project of Haicang District isin the planning phase at present, planned to becompleted by 2020.Lessons for sponge city constructionin XiamenOne of the most prominent issues thatXiamen’s sponge city construction faces iswater pollution. To solve this problem Xiamenexplores 3 distinct engineering methods:(1) Distributed wastewater treatmentdevicesDue to the high cost and long duration ofdrainage system construction in some recentlybuilt-up regions, Xiamen applies distributedwastewater treatment devices (such as HighFiber Reinforced Plastic Tank (HFRPT) fordigestion). This solution overcomes difficultiesof collection, discharge, treatment and recyclingin traditional centralized wastewater treatmentmethods. It costs less, gathers wastewatermore efficiently and reuses recycled water moreconveniently. Also the devices fit right intosurroundings, requiring little groundconstruction area and less gathering-deliverysewers, producing no outlet discharges orpollution.(2) Ecological drainage channels renovationTo reduce water pollution, drainers are installedunderneath flood-drainage channels to collectwastewater, which is then conveyed to thenearest underground wastewater treatmentdevices through sewers, and diverted to thesurrounding water body after having beentreated to Class IV in the national surface waterquality standard. On the channel beds, suitableplants are planted, so that flood flowing wouldbe unaffected in rainy seasons while thelandscape is more appealing in dry seasons.(3)Comprehensive management in the Nose CanalThe Nose Canal is in the mid-north region inXiamen Island. Presently, the canal is almost aculvert. Backwash water from nearby waterplants and domestic wastewater from in-cityvillages are discharged directly into the canal,forcing the natural waterway into local wastedrainage channel. To improve local waterquality, local government has initiated acomprehensive management project into thesponge city construction. Firstly, a sewage inter-cepting pump station is constructed to managethe first flush pollution. Then the culvertstretches are transformed into open canals,ensuring the flood discharge capacity of thecanal. Meanwhile, the ecological functions ofthe canal are restored to ensure living condi-tions of fishes, amphibians and birds.Landscape design is also valued in the project.Elevation differences are managed with water-falls. Banks are built into gentle slopes, andpavements or recreation spaces are built along.AcknowledgementThe researchers would like to extend theirthanks to the Chinese National Natural ScienceFoundation (No. 51522907, No. 51279208). Thestudy was also supported by the ResearchFund of the State Key Laboratory of Simulationand Regulation of Water Cycle in River Basin,China Institute of Water Resources andHydropower Research (No. 2016ZY02). nFigure 4. Ecological geotexitile revetmentFigure 5. Installation site of one of the distributedwastewater treatment devicesFigure 6. Demonstration of a completedecological drainage channel

Sponge city construction in Xiamen, China

http://henry.baw.de/bitstream/20.500.11970/109350/1/HydroLink_2016_04_Sponge%20city%20construction%20in%20Xiamen%2c%20China.pdf

Sponge city construction in Xiamen, China

Abstract

Similar works

Full text

Available Versions

Hydraulic Engineering Repository