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Analysis of micro-climate on the programs of urban infrastructure regeneration in J city, Republic of Korea
Urban Forestry & Urban Greening 27 (2017) 43–49
Contents lists available at ScienceDirect
Urban Forestry & Urban Greening journal homepage: www.elsevier.com/locate/ufug
Original article
Analysis of micro-climate on the programs of urban infrastructure regeneration in J city, Republic of Korea Kiyong Parka, Daewuk Kimb, Manhyung Leea, Changkyoo Choic, a b c
MARK
⁎
Dept. of Urban Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk, 28644, Republic of Korea Future Urban Research Center, EGIS Co. Ltd., ICT Park 1, 104 Myeongdeok-ro, Nam-gu, Daegu, 42403, Republic of Korea Global Desalination Research Center, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
A R T I C L E I N F O
A B S T R A C T
Keywords: Urban infrastructure regeneration technology Micro-climate Wind flow Temperature
The purpose of this study is to simulate urban micro-climate change due to the variation of wind flow and temperature assuming situations before and after applying programs using urban infrastructure regeneration technologies (UIRTs), and to then quantitatively estimate effectiveness on the urban regeneration schems. UIRTs focus on improving the recycling efficiencies of reclaimed water and biogas produced and to enforce the linkage among all environmental infrastructures associated with water, waste, and energy in an urban block. To implement the micro-climate analyses, data such as land use, topography, building height and materials, and weather conditions were collected, and the results estimated based on fluid simulations of cold wind and temperature variation pathways. There were three programs used in the urban regeneration project in J city: river restoration, traditional market revitalization, and a primary school eco-school. The height of cold wind from the ground level was significantly elevated, and the maximum wind velocity differential between before and after increased by 0.12 m/s due to the expansion of the waterfront space and grassland through the three programs. Overall, a temperature at the ground level dropped by 1.6 °C. Based on these results, the three programs improved the urban environment at ground level, and might ultimately be capable of diminishing the urban heat island effect and mitigating the energy consumption of urban areas.
1. Introduction Urbanization in the 20th century was focused on increasing economic growth based on resource intensive consumption, which has subsequently caused rapid damage of eco-systems and deteriorated the living quality of residents. Cities release 40%–70% of the greenhouse gasses (GHG) emitted from artificially generated sources, consuming about 75% of the entire energy supply (Boone and Ganeshan, 2012). The ecological environment is important for human beings because it is directly related to our survival and provides the raw materials that are needed for human life. However, human economic and social activities have caused serious damage to nature and have threatened its sustainability. The ecological environment of citizens plays an important role, not only in terms of human survival but also in socioeconomic development. Thus, the concept of an eco-city originated from an affordable city that focuses on ecology and sustainability (Song, 2011). Much urban planning for climate change is properly to reduce and mitigate carbon dioxide emission. Nowadays, CO2 emission accelerates the severity of climate change, but there is little efficient solutions ⁎
Corresponding author. E-mail address: [email protected] (C. Choi).
http://dx.doi.org/10.1016/j.ufug.2017.06.002 Received 2 March 2017; Received in revised form 19 May 2017; Accepted 2 June 2017 Available online 28 June 2017 1618-8667/ © 2017 Elsevier GmbH. All rights reserved.
(Hulme et al., 2002). The World Wide Fund for Nature has focused on the urban warming at capital cities in Europe (WWF, 2005). The historic CO2 emissions deeply related to climate change over 40 years due to the long life of CO2 at atmosphere (Hulme et al., 2002). It means that it must have an effort to decrease the greenhouse gas emissions for preventing climate change. With regards to climate change, the ability for greenspace to contribute was significantly improved in urban areas (Healey, 1995). In the UK, climate change scenarios (UKCIP02) have warned that the average annual temperature may increase by 5 °C in the 2080s, with summer changes being more serious than winter. There would also be a change in the locality and seasonality of precipitation, with up to 30% wetter winters and up to 50% drier summers; these phenomena are dependent on the region and emissions scenario (Hulme et al., 2002). The precipitation intensity is also likely to increase, especially in winter, with increases in the number of high temperature days, especially in the summer and autumn seasons. These reports further indicate that urban hazards are likely to be more serious than in rural areas (Wilby and Perry, 2006). Recently, urban regeneration policies world-wide have focused on
Urban Forestry & Urban Greening 27 (2017) 43–49
K. Park et al.
the concept of ‘Redevelopment to Regeneration’, as suggested by Roberts and Sykes (2000), with a number of projects have since been conducted (Kim and Lee, 2012; Seo, 2006; Kye, 2010; An, 2012). To date, however, most projects have oriented on urban sustainability: increase the recycling rate of waste resources, reduce the use of natural resources, and improve the amenity in urban area. The urban micro-climate is not restricted in a traditional sense in meteorology, but the climate directly affects the urban development and renovation, especially in terms of significant factors such as wind and temperature. One of the urban problems incurred from these climate changes is the creation of an urban heat island, in which cold wind from grassland and mountain areas is seen to be important in reducing its effects. In other words, cold winds can decrease the temperature in urban centers, and ultimately resolve issues surrounding urban heat islands. Hence, the importance of cold wind from adjacent grassland and mountain areas is actively being discussed (Oke, 1987). Green infrastructure means an interconnected network of green space to conserve natural ecosystem functions and provide the benefits to human living. The urban greenspace for the micro-climate improvement and surface water runoff reduction has a potential to enhance the urban temperature. It is not known how much greenspace is needed in urban area to reduce the CO2 emission (Benedict and McMahon, 2002). The biophysical features of greenspace in urban areas, through the provision of cooler microclimates and reduction of surface water runoff, therefore offer potential to help adapt cities for climate change. However, little is known about the quantity and quality of greenspace required. The green infrastructure is ‘an interconnected network of green space that conserves natural ecosystem values and functions and provides associated benefits to human populations’ (Benedict and McMahon, 2002). The focus of this paper is to simulate micro-climate variations assuming situations before and after applying urban regeneration programs using urban infrastructure regeneration technologies (UIRTs), which are considered one of the most economical and efficient technologies for rejuvenating urban infrastructure. In particular, the ultimate goal of urban regeneration programs is to reduce carbon dioxide in urban, and to quantitatively analyze urban microclimate as an index. Therefore, this study confirms the effectiveness of urban regeneration programs to analyze and compare wind flow and thermal environments.
commercial area was about 12%, traffic way was about 20%, and grassland was about 6%. Based on this, this region was much vulnerable to micro-climate due that grassland was so small portion compared to other region in J city. Therefore, to decrease the micro-climate deterioration in this region, the urban regeneration projects related to open space, grassland, ecological networks and waterfront space was strongly recommended. 3. UIRTs ‘Reclaimed water production technology for existing wastewater treatment facilities (ReWaT)’ is a technology used to produce reclaimed water by renovating existing small-scale sewer treatment facilities in an apartment complex. The treated water can be used in small brooklets, and in gardening and cleaning, and it disembogues surplus water into rainwater pipes to use as instream water. ‘Energy production technology from organic waste (EPT)’ is on-site technology used to produce biogas from organic waste (food waste and excretions) discharged from residential and commercial areas. The effluent of EPT can be used as plant fertilizer (Park et al., 2010). ‘Reuse technology of storm water (ReTS)’ is technology used to store and reuse the rainwater after treating the high suspended solids (SS) load contained in the initial raw water. ReTS can be installed at specific locations to drain rainwater from sidewalks, outdoor parking lots, playgrounds, etc., and contributes to decreasing the pollution in the initial rainwater in a city. ‘Urban farm technology (UFT)’ is technology used to cultivate plants and vegetables using the water reclaimed from ReWaT and the biogas and manure (as fertilizer) from EPT, and can be an additional supply of renewable energy. UFT can also provide leisure and productive activities to citizens. Table 2 shows the summary for introduction of urban infrastructure regeneration technologies. 4. Urban regeneration schemes There are three programs focusing on green urban regeneration in J city: the river restoration program of Nosong stream, the traditional market revitalization program, and the eco-school program of the primary school. These programs were implemented not only to maximize the recycling of resources but also to revitalize the urban core. It has the additional advantage of creating a synergistic effect through intimate relationships with each another (Fig. 2).
2. Analysis area 4.1. River restoration program The primary area is located in the core of J city, and includes both residential and commercial regions (Fig. 1). A waterfront is close to the area, as two streams pass through. The area for this urban regeneration program includes small stores, a conventional market place, and many buildings for City Hall and business offices; however, urban decline and shrinkage in this area are accelerating due to the age of the buildings and a general population decline. Here, urban decline has led to not only a decline in the population and in environmental conditions but also economic a decline, e.g., an increase in the vacancy rate of shops and a decrease in the land prices. To quantitatively estimate the micro-climate change due to regeneration programs in this area, the eight points used to determine the present micro-climate were investigated in order to consider the wind direction, designated as Nosong stream, a primary school, and a traditional market place, which is located in center of this area. Annual average wind velocity was 1.95 m/s and maximum wind velocity was 13.6 m/s over last 10 years on this region of J city. As shown in detailed wind direction on season, summer season was southeast wind and winter was northwest wind. The status of wind velocity and direction is as Table 1. As referred to land cover classification map constructed by Ministry of Environment (2007), the residential area accounted for about 60%,
The focus of the river restoration program was to uncover and revive the dried brooklet to continuously maintain water quantity and quality by using the reclaimed water as an urban stream by refreshing the rainwater and sewage (Fig. 3). ReWaT and ReTS were applied to produce the reclaimed water for the instream water. This program can maximize the reuse rate of sewer and rainwater in an urban area (Choi et al., 2010). 4.2. Revitalization program of the traditional market place Fig. 4 shows the concept for the revitalization program of the traditional market using ReTS. Rainwater was primarily treated and stored in an underground storage tank. The treated water was then passed through and circulated throughout the artificial waterway, before eventually flowing into an adjacent stream (Park et al., 2015). This program revitalizes the marketplace and encourages customers to walk from downtown to the traditional markets. 4.3. Eco-school program of primary school The concept of the eco-school (Fig. 5) is to maximize the recycling 44
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Fig. 1. Location of area of focus.
5. Urban micro-climate management system and analysis
Table 1 Wind velocity and direction in J City (2002–2011). Source: Meteorological administration in Republic of Korea.
Average wind velocity Maximum wind velocity Main wind
5.1. UMcMS overview
Year
Spring
Summer
Fall
Winter
1.95m/s 13.6 m/s NE
2.26 m/s 13.6 m/s SSE
1.99 m/s 10.5 m/s SE
1.72 m/s 11.9 m/s WNW
1.81 m/s 10.4 m/s NW
The urban micro-climate management system (UMcMS) refers to the general technology used to maintain and operate urban conveniences that can control and manage the integrated environment of heat and wind for the entire process of urban development and urban regeneration projects. UMcMS is used to expand the liquidity of wind by predicting and analyzing the wind and heat environments as a priority among urban microclimate factors and focuses on evaluating and designating the planning techniques and other related factors necessary to lower the strength of the heat island. This system has been interlocked with a Macro-Model for wind flow analysis at a macroscopic level, Micro-Model for wind flow analysis at a microscopic level, and Thermal-Analysis Model for heat environment analysis at a microscopic level, based on a 3-dimensional virtual machine. The system has been created to allow for various thermal maps to be drawn. The File Menu consists of a Submenu, including Open and Save options, which is a common menu for most programs. The Data menu is largely divided into the creation and extraction of data, with the submenu further enabling users to create and extract the topography, image, land cover, and building data.
rate of water, waste, and energy in a primary school, and it can be used as a green education program for students. In this program, the rainwater is treated and collected by ReTS from the building rooftop and playground, and the treated water then used as a water supply for the eco-pond, green museum, and waterway in the playground. EPT treats the food-waste from the school cafeteria and produces the biogas used as the cooking gas for the cafeteria and the fertilizer for the green museum. The concept of UFT in the primary school is educational and provides a heuristic space to raise plants using reclaimed water, biogas, and fertilizer, and the place can be utilized as an eco-friendly community space for adjacent residents.
Table 2 Introduction of urban infrastructure regeneration technologies. Technology UIRT 1
Reclaimed water production technology for existing wastewater treatment facility (ReWaT)
UIRT 2
Energy production technology from organic waste (EPT)
UIRT 3 UIRT 4
Reuse technology of storm water (ReTS) Urban farming technology (UFT)
Component technologies sewer treatment facilities • Existing • Coagulation and fiber filtration systems • Diposers digestors • Anaerobic • Power generators and elastic filtration paving • Unclogged equipped with water and energy supply, and solar • Greenhouse power system
45
Products
• Reclaimed water • Biogas • Manure (as fertilizer) rainwater • Treated • Plants and vegetables • Local community
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K. Park et al.
Fig. 2. Relationship among the three programs.
Fig. 3. Concept of the river restoration program.
Fig. 4. Concept and cross-sectional design of the revitalization program for the traditional marketplace.
environment, and the status of greenhouse gas emissions, enabling users to draw specific thematic maps related to each (Kim et al., 2012).
In the Analysis menu, the submenu showing in Fig. 6 allows users to analyze the wind environment, heat environment, and greenhouse gasses emissions. Specifically, there is a submenu for the separate analyses of cold wind flow and pollution sources below the wind environment menu, a submenu for the analyses of temperature distribution below the heat environment menu, and a submenu for the analyses of green house gasses emissions. In the Display menu, we divided the analyzed results into sectors of land status, wind environment, thermal
5.2. Micro-climate analysis To implement the micro-climate analyses, data such as land use, topography, building height and materials, and weather conditions, i.e., simulation time, model status, initial temperature, wind direction, wind 46
Urban Forestry & Urban Greening 27 (2017) 43–49
K. Park et al.
Fig. 5. Concept of the eco-school program.
Fig. 6. Graphic user interface (GUI).
Fig. 7. Thermal variation analyses: (a) before and (b) after.
Fig. 8. Variations of cold wind velocity at each point: (a) A, B, C, D and (b) E, F, G.
47
Urban Forestry & Urban Greening 27 (2017) 43–49
K. Park et al.
Fig. 9. Variations of cold wind height at each point: (a) A, B, C, D and (b) E, F, G.
Fig. 10. Thermal environment variation due to river restoration program: (a) before, (b) after, and (c) difference.
Fig. 11. Thermal environmental variation due to traditional market revitalization program: (a) before, (b) after, and (c) difference. Fig. 12. Thermal variation analyses: (a) before and (b) after.
Fig. 13. Changes in cold wind velocity.
Fig. 14. Height variation of cold wind.
48
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velocity and relative humidity, were first collected and stored. In Fig. 7, the results of the micro-climate analysis were estimated from the outputs of the fluid simulation for the pathway of cold wind and thermal variation. While inputting the wind directions into the top priority target area, 7 core points were set for each micro-climate analysis before and after the urban application of the regeneration programs. According to the results of the cold wind analysis the for two programs, the river restoration program and the traditional market revitalization program, the cold wind velocity showed a significant improvement going from the South to the North (Fig. 8), whereas the cold wind thickness displayed no distinct difference (Fig. 9). The increase due to the cold wind velocity is seen by the artificial waterway created during the traditional market revitalization program, which starts at point A, and the influence becomes clear at point D. Fig. 8 also confirms that the cold wind velocity increases from points E to G due to the river restoration program. However, the rate of velocity variation was not significant, because the uncovered stream width was so narrow. Eventually, the influence due to the traditional market revitalization program became less than by the river restoration program, due to the distance of the renovated section. As shown in Fig. 10, which analyzed the thermal differences of Fig. 7 in further detail, the maximum and minimum temperatures before the river restoration program were 34.8 °C and 31.1 °C, respectively. After applying the program, the temperature dropped to 34.4 °C (max.) and 30.8 °C (min.), displaying an overall decrease of 1.6 °C (effective width: 30 m). The influence of the traditional market place revitalization is presented in Fig. 11. The maximum and minimum temperatures were 34.4 °C and 32.5 °C, respectively, before the program, which dropped to 34.2 °C and 32.4 °C after the program, resulting in an average decreased of 0.2 °C. Hence, the river restoration program more affect to drop the regional temperature than the traditional market place revitalization. Then, the area of the temperature decreased due to the urban regeneration programs was above 70%, and were deemed effective for improving the wind and thermal environment in the urban core region. As shown in Figs. 12–14, 5 points were at broad region to compare where the regeneration programe applied or not. The point J was the spot of primary school eco-school program, at that point, the wind velocity increased and the cold wind height elevated due that ecoschool program mainly build the pond, waterway in the playground. The cold wind quantity increased due to the fresh air accumulation that occurred at this spot by the creation of green land. Thus, this spot plays the role of an urban cold island. However, At points of H, I, K, and L, regions that urban regeneration programs were not applied, the cold wind velocity and height relatively decreased, because wind flowed into the regeneration region from the non-regeneration region.
the artificial waterway created by the river restoration program. The velocity variation rate was not significant because of the narrow uncovered stream width. The wind velocity and height induced by the traditional market revitalization program was less than for the river restoration program. The temperature dropped by 1.6 °C due to the river restoration program, for which the effective width was 30 m; the temperature drop due to the traditional market revitalization program was 0.2 °C. Overall, the area influenced by the temperature drop was above 70%. Point J was an eco-school; both the wind velocity and cold wind height increased due to the eco-school program, as the fresh air accumulated at this spot by the creation of green land. Eventually, waterfront program of urban regeneration is more effective to decrease the urban temperature drop, and grassland affected the broad region to enhance the micro-climate from the results of wind and thermal analysis. Therefore, it found out that program of waterfront and grassland construction help to improve the urban micro-climate and amenity, and make eco-friendly city due to low energy consumption at summer season. References An, H.S., 2012. Effect of public design on city brand image and urban regeneration. Korea Urban Manage. Assoc. 25 (2), 303–323. Benedict, M.A., McMahon, E.T., 2002. Green infrastructure: smart conservation for the 21st century. Renewable Resour. J. 20 (3), 12–17. Boone, T., Ganeshan, R., 2012. By the numbers: a visual chronicle of carbon dioxide emissions. Sustainable Supply Chains, International Series in Operations Research & Management Science. Springer Scienceþ-Business Media, New York, pp. 9–27. http://dx.doi.org/10.1007/978-1-4419-6105-1_2. Choi, C.K., Park, K., Park, W., Park, H., 2010. Development of a unified treatment system for public use of discharged water from a Korean apartment complex for urban infrastructure regeneration. WIT Trans. Ecol. Environ. 142, 227–232. http://dx.doi. org/10.2495/SW100211. Healey, P., 1995. The institutional challenge for sustainable urban regeneration. Cities 12 (4), 221–230. http://dx.doi.org/10.1016/0264-2751(95)00043-L. Hulme, M., Jenkins, G., Lu, X., Turnpenny, J., Mitchell, T., Jones, R., Lowe, J., Murphy, J., Hassell, D., Boorman, P., McDonald, R., Hill, S., 2002. Climate change scenarios for the United Kingdom. In: The UKCIP02 Scientific Report. Norwich: Tyndall Centre for Climate Change Research. School of Environmental Sciences, University of East Anglia. Kim, M.S., Lee, W.H., 2012. A study on approach system of creative city with the consideration of sustainable urban regeneration. J. Digital Interact. Des. 11 (1), 60–72. Kim, D.W., Jung, E.H., Ryu, J.W., Cha, J.G., Yun, J.S., 2012. Development and application of urban micro-climate management system for creating low-carbon and green city. International Conference on Urban Planning and Regional Development in the Information Society 201–203. Kye, K.S., 2010. A study on approach system of creative city with the consideration of sustainable urban regeneration. Korea Urban Manage. Assoc. 23 (4), 175–194. Oke, T.R., 1987. Boundary Layer Climates. Routledge, London and New York. Park, K.Y., Choi, C.K., Park, W.S., Park, H.K., 2010. Amenity enhanced apartment complex design using reclaimed water and renewable energy. Conference of International Water Week. Park, K.Y., Choi, C.K., Shin, J.S., Park, H.K., 2015. Effect of environmental infrastructure regeneration in urban region: a case study of M apartment complex in Daejeon. J. Korean Soc. Civ. Eng. 35 (2), 353–359. http://dx.doi.org/10.12652/Ksce.2015.35.2. 0353. Roberts, P., Sykes, S., 2000. Urban Regeneration: A Handbook. SAGE Publications. Seo, J.K., 2006. A study on the circulation system of urban regeneration process through cultural city strategy. Korean Assoc. Gov. 13 (1), 197–221. Song, Y., 2011. Ecological city and urban sustainable development. Procedia Eng. 21, 142–146. http://dx.doi.org/10.1016/j.proeng.2011.11.1997. WWF, 2005. Europe Feels the Heat −The Power Sector and Extreme Weather Gland. WWF International, Switzerland. Wilby, R.L., Perry, G.L.W., 2006. Climate change, biodiversity and the urban environment: a critical review based on London, UK. Prog. Phys. Geogr. 30 (1), 73–98. http://dx.doi.org/10.1191/0309133306pp470ra.
6. Conclusion The purpose of this study was to carry out micro-climate analyses before and after urban regeneration programs, to analyze the differentials in wind flow and the thermal environment, and to then quantitatively estimate their effectiveness. The cold wind velocity increased from the South to the North, though the cold wind thickness displayed no distinct difference due to
49
Contents lists available at ScienceDirect
Urban Forestry & Urban Greening journal homepage: www.elsevier.com/locate/ufug
Original article
Analysis of micro-climate on the programs of urban infrastructure regeneration in J city, Republic of Korea Kiyong Parka, Daewuk Kimb, Manhyung Leea, Changkyoo Choic, a b c
MARK
⁎
Dept. of Urban Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk, 28644, Republic of Korea Future Urban Research Center, EGIS Co. Ltd., ICT Park 1, 104 Myeongdeok-ro, Nam-gu, Daegu, 42403, Republic of Korea Global Desalination Research Center, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
A R T I C L E I N F O
A B S T R A C T
Keywords: Urban infrastructure regeneration technology Micro-climate Wind flow Temperature
The purpose of this study is to simulate urban micro-climate change due to the variation of wind flow and temperature assuming situations before and after applying programs using urban infrastructure regeneration technologies (UIRTs), and to then quantitatively estimate effectiveness on the urban regeneration schems. UIRTs focus on improving the recycling efficiencies of reclaimed water and biogas produced and to enforce the linkage among all environmental infrastructures associated with water, waste, and energy in an urban block. To implement the micro-climate analyses, data such as land use, topography, building height and materials, and weather conditions were collected, and the results estimated based on fluid simulations of cold wind and temperature variation pathways. There were three programs used in the urban regeneration project in J city: river restoration, traditional market revitalization, and a primary school eco-school. The height of cold wind from the ground level was significantly elevated, and the maximum wind velocity differential between before and after increased by 0.12 m/s due to the expansion of the waterfront space and grassland through the three programs. Overall, a temperature at the ground level dropped by 1.6 °C. Based on these results, the three programs improved the urban environment at ground level, and might ultimately be capable of diminishing the urban heat island effect and mitigating the energy consumption of urban areas.
1. Introduction Urbanization in the 20th century was focused on increasing economic growth based on resource intensive consumption, which has subsequently caused rapid damage of eco-systems and deteriorated the living quality of residents. Cities release 40%–70% of the greenhouse gasses (GHG) emitted from artificially generated sources, consuming about 75% of the entire energy supply (Boone and Ganeshan, 2012). The ecological environment is important for human beings because it is directly related to our survival and provides the raw materials that are needed for human life. However, human economic and social activities have caused serious damage to nature and have threatened its sustainability. The ecological environment of citizens plays an important role, not only in terms of human survival but also in socioeconomic development. Thus, the concept of an eco-city originated from an affordable city that focuses on ecology and sustainability (Song, 2011). Much urban planning for climate change is properly to reduce and mitigate carbon dioxide emission. Nowadays, CO2 emission accelerates the severity of climate change, but there is little efficient solutions ⁎
Corresponding author. E-mail address: [email protected] (C. Choi).
http://dx.doi.org/10.1016/j.ufug.2017.06.002 Received 2 March 2017; Received in revised form 19 May 2017; Accepted 2 June 2017 Available online 28 June 2017 1618-8667/ © 2017 Elsevier GmbH. All rights reserved.
(Hulme et al., 2002). The World Wide Fund for Nature has focused on the urban warming at capital cities in Europe (WWF, 2005). The historic CO2 emissions deeply related to climate change over 40 years due to the long life of CO2 at atmosphere (Hulme et al., 2002). It means that it must have an effort to decrease the greenhouse gas emissions for preventing climate change. With regards to climate change, the ability for greenspace to contribute was significantly improved in urban areas (Healey, 1995). In the UK, climate change scenarios (UKCIP02) have warned that the average annual temperature may increase by 5 °C in the 2080s, with summer changes being more serious than winter. There would also be a change in the locality and seasonality of precipitation, with up to 30% wetter winters and up to 50% drier summers; these phenomena are dependent on the region and emissions scenario (Hulme et al., 2002). The precipitation intensity is also likely to increase, especially in winter, with increases in the number of high temperature days, especially in the summer and autumn seasons. These reports further indicate that urban hazards are likely to be more serious than in rural areas (Wilby and Perry, 2006). Recently, urban regeneration policies world-wide have focused on
Urban Forestry & Urban Greening 27 (2017) 43–49
K. Park et al.
the concept of ‘Redevelopment to Regeneration’, as suggested by Roberts and Sykes (2000), with a number of projects have since been conducted (Kim and Lee, 2012; Seo, 2006; Kye, 2010; An, 2012). To date, however, most projects have oriented on urban sustainability: increase the recycling rate of waste resources, reduce the use of natural resources, and improve the amenity in urban area. The urban micro-climate is not restricted in a traditional sense in meteorology, but the climate directly affects the urban development and renovation, especially in terms of significant factors such as wind and temperature. One of the urban problems incurred from these climate changes is the creation of an urban heat island, in which cold wind from grassland and mountain areas is seen to be important in reducing its effects. In other words, cold winds can decrease the temperature in urban centers, and ultimately resolve issues surrounding urban heat islands. Hence, the importance of cold wind from adjacent grassland and mountain areas is actively being discussed (Oke, 1987). Green infrastructure means an interconnected network of green space to conserve natural ecosystem functions and provide the benefits to human living. The urban greenspace for the micro-climate improvement and surface water runoff reduction has a potential to enhance the urban temperature. It is not known how much greenspace is needed in urban area to reduce the CO2 emission (Benedict and McMahon, 2002). The biophysical features of greenspace in urban areas, through the provision of cooler microclimates and reduction of surface water runoff, therefore offer potential to help adapt cities for climate change. However, little is known about the quantity and quality of greenspace required. The green infrastructure is ‘an interconnected network of green space that conserves natural ecosystem values and functions and provides associated benefits to human populations’ (Benedict and McMahon, 2002). The focus of this paper is to simulate micro-climate variations assuming situations before and after applying urban regeneration programs using urban infrastructure regeneration technologies (UIRTs), which are considered one of the most economical and efficient technologies for rejuvenating urban infrastructure. In particular, the ultimate goal of urban regeneration programs is to reduce carbon dioxide in urban, and to quantitatively analyze urban microclimate as an index. Therefore, this study confirms the effectiveness of urban regeneration programs to analyze and compare wind flow and thermal environments.
commercial area was about 12%, traffic way was about 20%, and grassland was about 6%. Based on this, this region was much vulnerable to micro-climate due that grassland was so small portion compared to other region in J city. Therefore, to decrease the micro-climate deterioration in this region, the urban regeneration projects related to open space, grassland, ecological networks and waterfront space was strongly recommended. 3. UIRTs ‘Reclaimed water production technology for existing wastewater treatment facilities (ReWaT)’ is a technology used to produce reclaimed water by renovating existing small-scale sewer treatment facilities in an apartment complex. The treated water can be used in small brooklets, and in gardening and cleaning, and it disembogues surplus water into rainwater pipes to use as instream water. ‘Energy production technology from organic waste (EPT)’ is on-site technology used to produce biogas from organic waste (food waste and excretions) discharged from residential and commercial areas. The effluent of EPT can be used as plant fertilizer (Park et al., 2010). ‘Reuse technology of storm water (ReTS)’ is technology used to store and reuse the rainwater after treating the high suspended solids (SS) load contained in the initial raw water. ReTS can be installed at specific locations to drain rainwater from sidewalks, outdoor parking lots, playgrounds, etc., and contributes to decreasing the pollution in the initial rainwater in a city. ‘Urban farm technology (UFT)’ is technology used to cultivate plants and vegetables using the water reclaimed from ReWaT and the biogas and manure (as fertilizer) from EPT, and can be an additional supply of renewable energy. UFT can also provide leisure and productive activities to citizens. Table 2 shows the summary for introduction of urban infrastructure regeneration technologies. 4. Urban regeneration schemes There are three programs focusing on green urban regeneration in J city: the river restoration program of Nosong stream, the traditional market revitalization program, and the eco-school program of the primary school. These programs were implemented not only to maximize the recycling of resources but also to revitalize the urban core. It has the additional advantage of creating a synergistic effect through intimate relationships with each another (Fig. 2).
2. Analysis area 4.1. River restoration program The primary area is located in the core of J city, and includes both residential and commercial regions (Fig. 1). A waterfront is close to the area, as two streams pass through. The area for this urban regeneration program includes small stores, a conventional market place, and many buildings for City Hall and business offices; however, urban decline and shrinkage in this area are accelerating due to the age of the buildings and a general population decline. Here, urban decline has led to not only a decline in the population and in environmental conditions but also economic a decline, e.g., an increase in the vacancy rate of shops and a decrease in the land prices. To quantitatively estimate the micro-climate change due to regeneration programs in this area, the eight points used to determine the present micro-climate were investigated in order to consider the wind direction, designated as Nosong stream, a primary school, and a traditional market place, which is located in center of this area. Annual average wind velocity was 1.95 m/s and maximum wind velocity was 13.6 m/s over last 10 years on this region of J city. As shown in detailed wind direction on season, summer season was southeast wind and winter was northwest wind. The status of wind velocity and direction is as Table 1. As referred to land cover classification map constructed by Ministry of Environment (2007), the residential area accounted for about 60%,
The focus of the river restoration program was to uncover and revive the dried brooklet to continuously maintain water quantity and quality by using the reclaimed water as an urban stream by refreshing the rainwater and sewage (Fig. 3). ReWaT and ReTS were applied to produce the reclaimed water for the instream water. This program can maximize the reuse rate of sewer and rainwater in an urban area (Choi et al., 2010). 4.2. Revitalization program of the traditional market place Fig. 4 shows the concept for the revitalization program of the traditional market using ReTS. Rainwater was primarily treated and stored in an underground storage tank. The treated water was then passed through and circulated throughout the artificial waterway, before eventually flowing into an adjacent stream (Park et al., 2015). This program revitalizes the marketplace and encourages customers to walk from downtown to the traditional markets. 4.3. Eco-school program of primary school The concept of the eco-school (Fig. 5) is to maximize the recycling 44
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Fig. 1. Location of area of focus.
5. Urban micro-climate management system and analysis
Table 1 Wind velocity and direction in J City (2002–2011). Source: Meteorological administration in Republic of Korea.
Average wind velocity Maximum wind velocity Main wind
5.1. UMcMS overview
Year
Spring
Summer
Fall
Winter
1.95m/s 13.6 m/s NE
2.26 m/s 13.6 m/s SSE
1.99 m/s 10.5 m/s SE
1.72 m/s 11.9 m/s WNW
1.81 m/s 10.4 m/s NW
The urban micro-climate management system (UMcMS) refers to the general technology used to maintain and operate urban conveniences that can control and manage the integrated environment of heat and wind for the entire process of urban development and urban regeneration projects. UMcMS is used to expand the liquidity of wind by predicting and analyzing the wind and heat environments as a priority among urban microclimate factors and focuses on evaluating and designating the planning techniques and other related factors necessary to lower the strength of the heat island. This system has been interlocked with a Macro-Model for wind flow analysis at a macroscopic level, Micro-Model for wind flow analysis at a microscopic level, and Thermal-Analysis Model for heat environment analysis at a microscopic level, based on a 3-dimensional virtual machine. The system has been created to allow for various thermal maps to be drawn. The File Menu consists of a Submenu, including Open and Save options, which is a common menu for most programs. The Data menu is largely divided into the creation and extraction of data, with the submenu further enabling users to create and extract the topography, image, land cover, and building data.
rate of water, waste, and energy in a primary school, and it can be used as a green education program for students. In this program, the rainwater is treated and collected by ReTS from the building rooftop and playground, and the treated water then used as a water supply for the eco-pond, green museum, and waterway in the playground. EPT treats the food-waste from the school cafeteria and produces the biogas used as the cooking gas for the cafeteria and the fertilizer for the green museum. The concept of UFT in the primary school is educational and provides a heuristic space to raise plants using reclaimed water, biogas, and fertilizer, and the place can be utilized as an eco-friendly community space for adjacent residents.
Table 2 Introduction of urban infrastructure regeneration technologies. Technology UIRT 1
Reclaimed water production technology for existing wastewater treatment facility (ReWaT)
UIRT 2
Energy production technology from organic waste (EPT)
UIRT 3 UIRT 4
Reuse technology of storm water (ReTS) Urban farming technology (UFT)
Component technologies sewer treatment facilities • Existing • Coagulation and fiber filtration systems • Diposers digestors • Anaerobic • Power generators and elastic filtration paving • Unclogged equipped with water and energy supply, and solar • Greenhouse power system
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Products
• Reclaimed water • Biogas • Manure (as fertilizer) rainwater • Treated • Plants and vegetables • Local community
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Fig. 2. Relationship among the three programs.
Fig. 3. Concept of the river restoration program.
Fig. 4. Concept and cross-sectional design of the revitalization program for the traditional marketplace.
environment, and the status of greenhouse gas emissions, enabling users to draw specific thematic maps related to each (Kim et al., 2012).
In the Analysis menu, the submenu showing in Fig. 6 allows users to analyze the wind environment, heat environment, and greenhouse gasses emissions. Specifically, there is a submenu for the separate analyses of cold wind flow and pollution sources below the wind environment menu, a submenu for the analyses of temperature distribution below the heat environment menu, and a submenu for the analyses of green house gasses emissions. In the Display menu, we divided the analyzed results into sectors of land status, wind environment, thermal
5.2. Micro-climate analysis To implement the micro-climate analyses, data such as land use, topography, building height and materials, and weather conditions, i.e., simulation time, model status, initial temperature, wind direction, wind 46
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Fig. 5. Concept of the eco-school program.
Fig. 6. Graphic user interface (GUI).
Fig. 7. Thermal variation analyses: (a) before and (b) after.
Fig. 8. Variations of cold wind velocity at each point: (a) A, B, C, D and (b) E, F, G.
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Fig. 9. Variations of cold wind height at each point: (a) A, B, C, D and (b) E, F, G.
Fig. 10. Thermal environment variation due to river restoration program: (a) before, (b) after, and (c) difference.
Fig. 11. Thermal environmental variation due to traditional market revitalization program: (a) before, (b) after, and (c) difference. Fig. 12. Thermal variation analyses: (a) before and (b) after.
Fig. 13. Changes in cold wind velocity.
Fig. 14. Height variation of cold wind.
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velocity and relative humidity, were first collected and stored. In Fig. 7, the results of the micro-climate analysis were estimated from the outputs of the fluid simulation for the pathway of cold wind and thermal variation. While inputting the wind directions into the top priority target area, 7 core points were set for each micro-climate analysis before and after the urban application of the regeneration programs. According to the results of the cold wind analysis the for two programs, the river restoration program and the traditional market revitalization program, the cold wind velocity showed a significant improvement going from the South to the North (Fig. 8), whereas the cold wind thickness displayed no distinct difference (Fig. 9). The increase due to the cold wind velocity is seen by the artificial waterway created during the traditional market revitalization program, which starts at point A, and the influence becomes clear at point D. Fig. 8 also confirms that the cold wind velocity increases from points E to G due to the river restoration program. However, the rate of velocity variation was not significant, because the uncovered stream width was so narrow. Eventually, the influence due to the traditional market revitalization program became less than by the river restoration program, due to the distance of the renovated section. As shown in Fig. 10, which analyzed the thermal differences of Fig. 7 in further detail, the maximum and minimum temperatures before the river restoration program were 34.8 °C and 31.1 °C, respectively. After applying the program, the temperature dropped to 34.4 °C (max.) and 30.8 °C (min.), displaying an overall decrease of 1.6 °C (effective width: 30 m). The influence of the traditional market place revitalization is presented in Fig. 11. The maximum and minimum temperatures were 34.4 °C and 32.5 °C, respectively, before the program, which dropped to 34.2 °C and 32.4 °C after the program, resulting in an average decreased of 0.2 °C. Hence, the river restoration program more affect to drop the regional temperature than the traditional market place revitalization. Then, the area of the temperature decreased due to the urban regeneration programs was above 70%, and were deemed effective for improving the wind and thermal environment in the urban core region. As shown in Figs. 12–14, 5 points were at broad region to compare where the regeneration programe applied or not. The point J was the spot of primary school eco-school program, at that point, the wind velocity increased and the cold wind height elevated due that ecoschool program mainly build the pond, waterway in the playground. The cold wind quantity increased due to the fresh air accumulation that occurred at this spot by the creation of green land. Thus, this spot plays the role of an urban cold island. However, At points of H, I, K, and L, regions that urban regeneration programs were not applied, the cold wind velocity and height relatively decreased, because wind flowed into the regeneration region from the non-regeneration region.
the artificial waterway created by the river restoration program. The velocity variation rate was not significant because of the narrow uncovered stream width. The wind velocity and height induced by the traditional market revitalization program was less than for the river restoration program. The temperature dropped by 1.6 °C due to the river restoration program, for which the effective width was 30 m; the temperature drop due to the traditional market revitalization program was 0.2 °C. Overall, the area influenced by the temperature drop was above 70%. Point J was an eco-school; both the wind velocity and cold wind height increased due to the eco-school program, as the fresh air accumulated at this spot by the creation of green land. Eventually, waterfront program of urban regeneration is more effective to decrease the urban temperature drop, and grassland affected the broad region to enhance the micro-climate from the results of wind and thermal analysis. Therefore, it found out that program of waterfront and grassland construction help to improve the urban micro-climate and amenity, and make eco-friendly city due to low energy consumption at summer season. References An, H.S., 2012. Effect of public design on city brand image and urban regeneration. Korea Urban Manage. Assoc. 25 (2), 303–323. Benedict, M.A., McMahon, E.T., 2002. Green infrastructure: smart conservation for the 21st century. Renewable Resour. J. 20 (3), 12–17. Boone, T., Ganeshan, R., 2012. By the numbers: a visual chronicle of carbon dioxide emissions. Sustainable Supply Chains, International Series in Operations Research & Management Science. Springer Scienceþ-Business Media, New York, pp. 9–27. http://dx.doi.org/10.1007/978-1-4419-6105-1_2. Choi, C.K., Park, K., Park, W., Park, H., 2010. Development of a unified treatment system for public use of discharged water from a Korean apartment complex for urban infrastructure regeneration. WIT Trans. Ecol. Environ. 142, 227–232. http://dx.doi. org/10.2495/SW100211. Healey, P., 1995. The institutional challenge for sustainable urban regeneration. Cities 12 (4), 221–230. http://dx.doi.org/10.1016/0264-2751(95)00043-L. Hulme, M., Jenkins, G., Lu, X., Turnpenny, J., Mitchell, T., Jones, R., Lowe, J., Murphy, J., Hassell, D., Boorman, P., McDonald, R., Hill, S., 2002. Climate change scenarios for the United Kingdom. In: The UKCIP02 Scientific Report. Norwich: Tyndall Centre for Climate Change Research. School of Environmental Sciences, University of East Anglia. Kim, M.S., Lee, W.H., 2012. A study on approach system of creative city with the consideration of sustainable urban regeneration. J. Digital Interact. Des. 11 (1), 60–72. Kim, D.W., Jung, E.H., Ryu, J.W., Cha, J.G., Yun, J.S., 2012. Development and application of urban micro-climate management system for creating low-carbon and green city. International Conference on Urban Planning and Regional Development in the Information Society 201–203. Kye, K.S., 2010. A study on approach system of creative city with the consideration of sustainable urban regeneration. Korea Urban Manage. Assoc. 23 (4), 175–194. Oke, T.R., 1987. Boundary Layer Climates. Routledge, London and New York. Park, K.Y., Choi, C.K., Park, W.S., Park, H.K., 2010. Amenity enhanced apartment complex design using reclaimed water and renewable energy. Conference of International Water Week. Park, K.Y., Choi, C.K., Shin, J.S., Park, H.K., 2015. Effect of environmental infrastructure regeneration in urban region: a case study of M apartment complex in Daejeon. J. Korean Soc. Civ. Eng. 35 (2), 353–359. http://dx.doi.org/10.12652/Ksce.2015.35.2. 0353. Roberts, P., Sykes, S., 2000. Urban Regeneration: A Handbook. SAGE Publications. Seo, J.K., 2006. A study on the circulation system of urban regeneration process through cultural city strategy. Korean Assoc. Gov. 13 (1), 197–221. Song, Y., 2011. Ecological city and urban sustainable development. Procedia Eng. 21, 142–146. http://dx.doi.org/10.1016/j.proeng.2011.11.1997. WWF, 2005. Europe Feels the Heat −The Power Sector and Extreme Weather Gland. WWF International, Switzerland. Wilby, R.L., Perry, G.L.W., 2006. Climate change, biodiversity and the urban environment: a critical review based on London, UK. Prog. Phys. Geogr. 30 (1), 73–98. http://dx.doi.org/10.1191/0309133306pp470ra.
6. Conclusion The purpose of this study was to carry out micro-climate analyses before and after urban regeneration programs, to analyze the differentials in wind flow and the thermal environment, and to then quantitatively estimate their effectiveness. The cold wind velocity increased from the South to the North, though the cold wind thickness displayed no distinct difference due to
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