International Workshop - Session 1. Green Infrastructure for Sound Urban Hydrological Cycle

Transcription

1 International Workshop - Session 1 Green Infrastructure for Sound Urban Hydrological Cycle

2 International Workshop on Eco-city and Biodiversity Session 1: Eco-city November 13, 2014; Kawasaki, Japan Green Infrastructure for Sound Urban Hydrological Cycle Taekyu KIM 1),*Seung-Hyun KIM 2) 1) National Wetland Center, NIER, Korea 2) Natural Environmental Research Division, NIER, Korea *Corresponding author Keywords: Green infrastructure; Urban hydrological cycle; Restoration The world is struggling against extreme droughts, heavy rain, and heat waves because of climate change. These abnormal climate cause urban flood, urban heat island, and water pollution and shortage and these natural disasters not only threaten citizen s health and amenity but also negatively affect cities economically, environmentally, and socially. Thus, this paper discusses about green infrastructure as the water sensitive urban landscape design strategy in terms of the restoration of sound urban hydrological cycle. To do this, this paper reviews concept, context, and current trends of green infrastructure as water sensitive urban landscape design and this paper examines relations between green infrastructure and water sensitive urban landscape design for the restoration of sound urban hydrological. And then this paper analyzes various case studies on green infrastructure as water sensitive urban landscape design, which are categorized by city-scale's case studies such as Kallang River Bishan Park and Tanner Springs Park, site and building-scale's case studies such as Mount Tabor School rain garden, Sidwell Friends School wetlands, and California Academy of Sciences green roof, and street-scale's case studies such as NE Siskiyou Green Street, SW 12th Avenue Green Street, and Taylor 28 Green Street. After analyzing these various case studies of green infrastructure as water sensitive urban landscape design, this paper draws water sensitive urban landscape design strategies for the restoration of sound urban hydrological cycle. The result of analysis is as follows. Firstly, water sensitive urban landscape design strategy for the restoration of sound urban hydrological contains various green infrastructure elements such as stormwater parks, eco-streams, constructed wetlands, green roofs, rain gardens, bio-swales, buffer strips, stormwater planters, permeable pavings, and cisterns. Secondly, these various green infrastructure elements could be applied on the various types of land-use such as buildings, roofs, roads, streets, parking lots, and grounds as well as green and water space in urban areas. Thirdly, these multi-dimensional green infrastructure could evaporate, infiltrate, filtrate, and reuse stormwater ecologically through vegetation, soil, and minerals which is applied on green infrastructure. Fourth, these biological green infrastructure could be linked and connected each other to supply more environmental benefits such as urban flood prevention, water purification, and habitat supply for plants and animals than to be applied alone on the various types of land-use. Benedict, M.A. (2000). Green infrastructure: A strategic approach to land conservation. America Planning Association PAS Memo. Benedict, M.A. and McMahon, E.T. (2003). Green infrastructure: smart conservation for the 21st century. Sprawl Watch Clearinghouse Monograph Series. Benedict, M.A. and McMahon, E.T. (2006). Green infrastructure: linking landscapes and communities. Arlington, VA: Conservation Fund. Calkins, M. (2012). the Sustainable Sites Handbook: A Complete Guide to the Principles, Strategies, and Practices for Sustainable Landscapes, John Wiley & Sons, Inc. Cook, T. W. and VanDerZanden, A. M. (2011). Sustainable Landscape Management: Design, Construction, and Maintenance, John Wiley & Sons, Inc. Hung, Y.Y., Aquino, G., Waldheim, C., and Czerniak, J. (2011) Landscape infrastructure: case studies by SWA, Birkhauser GMBH. Klaver, I.J. (2010). Reclaiming the Infrastructure: the Potential of Green Infrastructure for Urban Renewal around Stormwater Management, 3TEP Meeting, UniversityofNorth Texas. Landscape Architecture Foundation (2010a). ASLA Headquarters Green Roof, Landscape Performance Series Case Study Briefs, LAF. Landscape Architecture Foundation (2010b). ASLA Headquarters Green Roof Methodology for Landscape Performance Benefits,Landscape Performance Series Case Study Briefs, LAF. Landscape Architecture Foundation (2010c). Taylor 28, Landscape Performance Series Case Study Briefs, LAF. Landscape Architecture Foundation (2010d). Taylor 28 Methodology for Landscape Performance Benefits, Landscape Performance Series Case Study Briefs, LAF. Margolis, L. and Robinson, A. (2010).Living Systems: Innovative materials and technologies for landscape architecture, Birkhauser GmbH. OECD (2010). Cities and Climate Change, OECD Publishing. President s Council on Sustainable Development (1999). Towards a sustainable America: Advancing Prosperity, Opportunity, and a Healthy Environment for the 21st Century, PCSD. Richards, L. (2009). Managing stormwater runoff: a green infrastructure approach, Planning Commissioner s Journal, (73). U.S. Environmental Protection Agency (2010a). Low Impact Development (LID), EPA. U.S. Environmental Protection Agency (2010b). Types, applications and design approaches to manage wet weather, EPA. Venhaus, H. (2012). Designing the sustainable site: integrated design strategies for small-scale sites and residential landscapes, John Wiley & Sons, Inc. Werthmann, C. (2007). Green Roof : A Case Study, Princeton Architectural Press. Wise, S. (2008). Green Infrastructure Rising. Planning, 74(8), pp Eventually, these water sensitive urban landscape design strategies as green infrastructure could restore ecologically urban hydrological cycle which is distorted by indiscriminate urban development and could enhance urban biodiversity which is destroyed by massive urban sprawl. References: America Society of Landscape Architecture (2007). Mount Tabor Middle School Rain Garden, ASLA 2007 Professional Awards. America Society of Landscape Architecture (2006). SW 12th Avenue Green Street Project, ASLA 2006 Professional Awards. America Society of Landscape Architecture (2010). ASLA Green Roof Monitoring Results, ASLA

3 Green Infrastructure for Sound Urban Hydrological Cycle National Institue of Environmental Research Taekyu Kim, Ph.D. Seung-Hyun Kim, Ph.D

4 SEOUL, KOREA On September 21, 2010 and June 27, 2011 Seoul was severely flooded because heavy rain poured over 100mm per hour which caused landslides, river floods, and sewer overflows. Because of this, some roads and residential areas were submerged and citizen s health and amenity were threatened. 2

5 SEOUL, KOREA In 2010 and 2011, both storms caused severe property damage totally over hundreds of millions of dollars each of these years in Seoul. 3

6 SEOUL, KOREA Especially affected areas were some parts of low-lying districts where poor people live or run businesses. 4

7 SEOUL, KOREA These urban floods also cause not only property damage but also citizens distress and disamenity. 5

8 SEOUL, KOREA One of the reasons that caused urban flooding in Seoul is that the excess runoff, which cannot be handled by the existing drainage systems, quickly flows into the system through impermeable pavements. 6

9 NEW YORK, U.S.A. <Annual Precipitation for Ithaca, New York> <Extreme Precipitation Events New York State> 7

10 BEIJING, CHINA <Map of Floods Damage in China> Beijing 8

11 <Heavy rainfall increasing in Tokyo> TOKYO, JAPAN <source: Tokyo Metropolitan Construction Bureau Flood Records> A study from 117 weather station data showed that in recent years there has been an increase in the frequency of highly localized and intense rainfall events. 9

12 Dense urban development has a significant negative impact on the water that infiltrates underground. Generally urbanized areas generate over 55% runoff because that area is covered with impervious pavements which almost cannot infiltrate rainfall. In contrast, natural ground generates only 10% runoff because that area can infiltrate and evapotranspirates over 90% rainfall through the plants, trees, and soil. <source: US Army Corps of Engineers> 10

13 Green infrastructure manages rainfall through infiltration (water soaking into the ground), capture and reuse (water being stored in a rain barrel or cistern for later use), and evapotranspiration (water being used by trees and plants). These three processes - infiltration, reuse and evapotranspiration - constitute the basis of green infrastructure. <source: Southeast Tennessee Development District> 11

14 Stormwater Planters Bioponds & Wetlands Green Roofs Rain Gardens 12

15 Permeable Pavements Rain Barrels & Cisterns Curb Extensions Bio- swales 13

16 Green Infrastructure Street Landscape for Sound Urban Hydrological Cycle Stormwater Planters, Curb Extensions, Permeable Pavements Building Landscape Green Roofs, Roof Farms, Barrels, Cisterns Site Landscape Rain gardens, constructed wetlands, Bioswales, Bioponds Urban Landscape Stormwater parks, Wetlands, Eco-streams 14

17 SW 12th Avenue Green Street SITE Location: Portland, Oregon, U.S. Size: 272 square feet (25.3m 2 ) Completed: 2005 GI type: Stormwater Planters 15

18 Existing conditions of street were underused landscape areas which could not provide environmental and aesthetical benefits as urban streetscape. (photo by Kevin Perry, Bureau of Enviromental Services, City of Portland) 16

19 The new and improved Green Street converts the underutilized landscape area into a series of landscaped stormwater planters designed to capture, to slow, to purify, and to infiltrate street runoff. (photo by Kevin Perry, Bureau of Enviromental Services, City of Portland) 17

20 trench drain streets runoff curb cut During rain events, Stormwater runoff from the street flows downhill along the existing curb until it reaches the first stormwater planters. A trench drain channels the street runoff into the first stormwater planter. The native plants in water planter slows water-flow and retains pollutants. (photo by Kevin Perry, Bureau of Enviromental Services, City of Portland) 18

21 During large storm events, water may enter the planter at a rate faster than the soil can process. In that case, the runoff exits a second curb cut, flows back into the street, and enters the second downhill planter. curb cut stormwater circulation (photo by Kevin Perry, Bureau of Enviromental Services, City of Portland) 19

22 This process continues for the third and fourth planters. The system of embedded planters is designed to handle 60% of street runoff, a total of 681,374 L annually. (image courtesy of Sustainable Stormwater Management) 20

23 This project demonstrates how both new and existing streets in downtown or highly urbanized areas can be designed to provide direct environmental benefits and be aesthetically integrated into the urban streetscape. (photo by Kevin Perry, Bureau of Enviromental Services, City of Portland) 21

24 Mount Tabor Middle School Rain Garden SITE Location: Portland, Oregon, U.S. Size: 2,000 square feet (185m 2 ) Completed: 2006 GI type: rain garden 22

25 Before the Rain Garden was installed, the parking lot that dominated the south facing courtyard space created a hot and unappealing learning environment adjacent to classroom windows. (photo by Kevin Robert Perry) 23

26 This rain garden project has now completely transformed the parking lot courtyard space from a gray space into a green space that manages stormwater, helps cool the school s adjacent classrooms, and provides a canvas for environmental education for the students, staff, and overall community. (photo by Kevin Robert Perry) 24

27 rooftop stormwater runoff Runoff generated by 3,000 square meter of impervious area including the school s asphalt play area, parking lot, and rooftops, is captured and conveyed into the rain garden via a series of trench drains and concrete runnels. disconnected downspout concrete runnel pea gravel corridor trench drain (photo by Kevin Robert Perry) 25

28 concrete runnels rooftop runoff Rainwater from the school s rooftop is allowed to enter the rain garden through a series of concrete runnels. Once inside the landscape space, the water is allowed to interact with both plants and soil while soaking into the ground. (photo by Kevin Robert Perry) 26

29 The rain garden s infiltration rate varies from 5-10 mm per hour, meaning that any runoff that is retained in the rain garden is completely gone within a couple of hours. Since its completion in September 2006, all of the rainfall captured within the rain garden has infiltrated without ever overflowing into the combined sewer system. (photo by Kevin Robert Perry) 27

30 As a model for sustainable stormwater design, this School s Rain Garden s simple and cost-effective design demonstrates how stormwater management can be aesthetically integrated into urbanized space, provide direct environmental benefits, and act as a community amenity. (photo by Kevin Robert Perry) 28

31 Sidwell Friends School SITE Location: Washington, D.C., U.S. Size: 5 acres (20,234 m 2 ) Completed: 2007 GI types: Constructed Wetland, Rain Garden, Habitat Pond, Green Roof, Organic Garden, Cisterns 29

32 In 2007, School renovated its urban campus. An enlarged school building now includes an outdoor living laboratory that features a green roof, terraced wetland, rain garden, and habitat pond. This space functions as an extension of the classroom where students can learn about sustainable practices. (photo by Andropogon Associates) 30

33 The landscape and building function as a single integrated system that is designed to capture, clean, and re-use wastewater and stromwater from the school. (c 2010 Andropogon Associates) 31

34 Terraced wetlands step down the hill of the courtyard as they act as the primary filtration mechanism for building wastewater. Below the surface, waste water from the kitchen and bathrooms flows through the soil and sand to remove contaminants. 1. RESTROOM/LAVATORY 2. STORAGE 3. FLOW SPLITTER 4. WETLANDS 5. EXIT WETLAND 6. TRICKILING FILTER 7. EXIT TRICKLING FILTER 8. SAND FILTER 9. ENTER BUILDING (c 2010 Andropogon Associates) 32

35 Because the water never breaches the surface, students in the courtyard cannot smell odor nor contact the water directly. Terraced wetlands rain garden habitat pond (photo by Andropogon Associates) 33

36 The green roof on top of the new school building adds another layer to the school s stormwater management system. Rather than diverting rain water to gutters and storm drains, the living roof absorbs water into its soils where it is stored and taken up by resident native plants. (photo by Andropogon Associates) 34

37 In large storms, clean water overflows into a drain pipe that leads to the habitat pond. Some of the runoff gets in an underground cistern. During dry weather, this storage tank provides water to the pond. (c 2010 Andropogon Associates) 35

38 During heavy rains, excess water flows from the pond into the rain garden, simulating the hydrological dynamics of a floodplain environment. Water seeps through the soil and gets naturally filtered. (c 2010 Andropogon Associates) 36

39 The habitat pond, filled with stormwater and located at the bottom of the sunken courtyard, acts as a center for learning and recovery. Science classes experience the benefits of water management systems by comparing water quality before and after it enters the filtration system. (photo by Andropogon Associates) 37

40 Two Innovative GI Projects in Seoul Seoul city government was instrumental in creating Seonyudo Park and restoring the Cheonggyecheon stream Seonyudo Park is an award-winning urban ecological park, created by the conversion of a former water treatment plant. The Cheonggyecheon Restoration Project has created a green pathway that runs through the city alongside the Cheonggyecheon stream. 38

41 Seonyudo park, which covers over 100,000 square meters, sits on a island in the Hangang River which runs Seoul. It contains four ecological zones which each incorporate existing sewage treatment infrastructure into their design. Seonyudo is South Korea s first urban ecological park. It is part of the New Seoul initiative introduced by the city s planning authority, which aims to provide the city with more green space and to diversify cultural programming. (c PUB/Atelier Dreiseitl) 39

42 The park incorporates industrial landmarks and infrastructure from the treatment plant into its design. 40

43 Water channels from the old water purification plant have been reused to move water around the site 41

44 A series of pools full of different plant species clean the water used around the park. 42

45 The Cheonggyecheon Restoration Project required the dismantling and demolition of an elevated highway, and the uncovering of the historic 5.8 km waterway that ran underneath. This was transformed into an ecologically sensitive green pedestrian corridor. The restoration of the Cheonggyecheon stream became a vehicle for revitalisation, urban renewal and economic development. It also signified a shift in Korean planning priorities. Whereas the decades after the Korean War championed accelerated industrialisation and modernisation, there is now a different emphasis from both city authorities and residents on health, sustainability and social responsibility. 43

46 The Cheonggyecheon Restoration Project created a 5.8km green pathway (c PUB/Atelier Dreiseitl) 44

47 This project is an inspiring example of how a city park can function as green infrastructure, a smart combination of water source, flood management, biodiversity, and recreation. (c PUB/Atelier Dreiseitl) 45

48 Students have access to a valuable educational resource 46

49 Green Infrastructure for Sound Urban Hydrological Cycle Multidimensional approach Interconnected system Green Infrastructure Restoring nature Ecological process 47

50 1. Multidemensional approach Multidimensional approach means green infrastructure can apply to buildings, sites, streets, and open spaces in urban areas by multidimensional scaling such as green roofs, rain gardens, cisterns, wetlands, greenways, eco-streams, and urban stormwater parks. building landscape street landscape site landscape (c 2010 UACDC, Fayetteville, Arkansas) urban landscape 48

51 2. Interconnected system Interconnected system means that it can create more effectively environmental benefits when multidimensional green infrastructure components, such as rain gardens, wetlands, stormwater planters, green roofs, and cisterns, mutually linked and interconnected even though each of them can evapotranspirate, absorb, filtrate, and infiltrate stormwater runoff. (c 2010 UACDC, Fayetteville, Arkansas) 49

52 3. Ecological process Ecological process means green infrastructure can apply biological processes to evapotranspirate, absorb, filtrate, and infiltrate stromwater runoff by using various trees, plants, and soils as well as mechanical engineering. + (c 2010 UACDC, Fayetteville, Arkansas) 50

53 4. Restoring nature Restoring nature means that green infrastructure conserves and restores natural hydrologic process and increases biodiversity in urban areas that is distorted by impact of indiscriminate development. (c 2010 UACDC, Fayetteville, Arkansas) 51

54 Thank you 52