• Title/Summary/Keyword: urban effect

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The Planning of Urban Green Space System and Sustainable Development

  • Wang, Bingluo
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.1
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    • pp.37-42
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    • 2001
  • In order to answer the challenge that development gave to environment, Chinese cities are making up and putting into effect the green space system planning. The planning main keys are: set down standards and scope of green space; bring the characteristics of every types of green space in to full play and made into basic units of the system; formed powerful links of the system; make full use of the natural system of city, constituted the urban and countryside as a organic whole green space system, therefore give full play their function and ecological effect. In fact, this green space system is a complex system. It is the main body of city ecological system, a main container of the citizen activities of leisure and recreation and a leading factor for making characteristic city landscape. Therefore it is a system carrying city's environment sustainable development.

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Implementing the Urban Effect in an Interpolation Scheme for Monthly Normals of Daily Minimum Temperature (도시효과를 고려한 일 최저기온의 월별 평년값 분포 추정)

  • 최재연;윤진일
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.4
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    • pp.203-212
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    • 2002
  • This study was conducted to remove the urban heat island effects embedded in the interpolated surfaces of daily minimum temperature in the Korean Peninsula. Fifty six standard weather stations are usually used to generate the gridded temperature surface in South Korea. Since most of the weather stations are located in heavily populated and urbanized areas, the observed minimum temperature data are contaminated with the so-called urban heat island effect. Without an appropriate correction, temperature estimates over rural area or forests might deviate significantly from the actual values. We simulated the spatial pattern of population distribution within any single population reporting district (city or country) by allocating the reported population to the "urban" pixels of a land cover map with a 30 by 30 m spacing. By using this "digital population model" (DPM), we can simulate the horizontal diffusion of urban effect, which is not possible with the spatially discontinuous nature of the population statistics fer each city or county. The temperature estimation error from the existing interpolation scheme, which considers both the distance and the altitude effects, was regressed to the DPMs smoothed at 5 different scales, i.e., the radial extent of 0.5, 1.5, 2.5, 3.5 and 5.0 km. Optimum regression models were used in conjunction with the distance-altitude interpolation to predict monthly normals of daily minimum temperature in South Korea far 1971-2000 period. Cross validation showed around 50% reduction in terms of RMSE and MAE over all months compared with those by the conventional method.conventional method.

An Analysis of Urban Migration and Local Government Finance (도시의 인구이동과 지방재정에 관한 연구)

  • 김헌민
    • Korea journal of population studies
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    • v.14 no.2
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    • pp.1-17
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    • 1991
  • While various fiscal measures have been used to influence regional capital inflow or industrial location, the effect of fiscal variables on labor mobility has been little understood. Understanding the relationship between the composition of local public and urban migration would enhance the city govenment's ability to pursue an appropriate population policy. In order to examine the potential for local public finance to be utilized as a policy tool in directing urban population growth, this paper analyzes the impact of local government financial structure on urban migration. In examining the data on local government finance and the changes in population of Korean cities during the last ten years, it was found that cities with high per capita expenditure in regional development have experienced high population growth rates. In this study migration equations were constructed using various fiscal variables such as the proportion of special account expenditures which are mostly spent for local development purposes, per capita regional development expenditure, degree of local financial independence and per capita net fiscal benefit, along with other explanatory variables. The results of regression analysis showed that city government's regional development expenditure variables have a positive effect on urban net migration and a negative effect on outmigration. Fiscal independence and per capita net fiscal benefit had mixed effects on in and out migration variables, implying that local tax burden does not consistently deter inmigration or induce outmigration. Based on the results of this study some important policy implications can be found regarding local government's fiscal policies. Those cities seeking to attract higher population inflow should make a greater effort in appropriating local expenditures for regional development purposes such as infrastructure, housing, and transportation. city governments should not be too concerned about high local tax burden or necessarily seek to enhance financial independence for these factors do not exert a clear influence on urban population growth or labor supply.

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Evaluation of Urban Effects on Trends of Hydrometeorological Variables (수문기상요소 추세에 대한 도시화 영향분석)

  • Rim, Chang-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1B
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    • pp.71-80
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    • 2010
  • This study aimed to figure out the effect of urbanization on meteorological variables (air temperature, wind speed, relative humidity, solar radiation and precipitation) and reference evapotranspiration (RET). The research area of 6 urban areas and 6 rural areas near each urban area was selected. The monthly average daily data were collected from 12 ground stations operated by Korea Meteorological Administration (KMA) and the changes in climate variables were analyzed. Results of annual analysis have shown that the reference evapotranspiration (RET) tends to increase in urban areas while decreasing in rural areas. In particular, due to rising RET in urban areas and decreasing RET in rural areas, we can infer that the urbanization has affected to the RET. Results of monthly analysis showed that the urbanization has effects on the RET of July compared to other months (January, April and October). The yearly and monthly effects of urbanization on RET were closely related to solar radiation, relative humidity and change in temperature, and related to wind speed.

Factors Effect on Income-Gap Between Urban and Rural Area in China (중국 도·농 간 소득격차에 영향을 미치는 요인)

  • Nan, Xue Feng;Na, Seung-hwa
    • The Korean Journal of Franchise Management
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    • v.6 no.1
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    • pp.21-41
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    • 2015
  • The purpose of the study is to review the real situations of the income-gap between urban and rural areas which is focused on as one of the biggest issues revealed in the process of Chinese economic development and to find out which factors will alleviate or deteriorate such income-gap, also to find out such factors will effect differently on the regional characteristics. To analyze it, six factors such as industrialization-ratio, urbanization-ratio, tertiary industry-ratio, the level of both governmental educational support and agricultural support, and Chinese dual-economic structure are considered as explanatory variables, and OLS regression analysis was implemented to the factor data for the period of 1986-2007 about Chinese 31 districts(castles and cities). The results of the analysis show that both industrialization factors and urbanization factors affect significantly to alleviate income-gap between urban and rural areas, and as predicted, they also shows that dual-economic structure between urban and rural areas is the most biggest factors to enlarge the above mentioned income-gap. However, in accordance to the different level of economic development in eastern, central, and western districts the study shows that such factors will affect them differently respectively. The contents are as follows; In eastern district governmental educational support factor will affect the most great influence to alleviate the income-gap, in central district industrialization factor will affect the most great influence to alleviate the gap, and western district governmental agricultural support factor will affect the most great influence to alleviate the gap. Therefore, in solving the issue of income-gap between urban and rural areas in China we recommend that it is necessary for more differential policy in considering regional characteristics than unilateral policy to Chinese whole areas.

A Study on the Analysis of the Effect DFS installation on Urban Arterial Road (도시간선도로에서의 DFS 설치 효과 분석에 관한 연구)

  • Choi, Hyun-Seok;Kim, Hong-Sang;Lim, Geun-Ho
    • Journal of the Korean Society of Safety
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    • v.24 no.5
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    • pp.101-112
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    • 2009
  • Recently, with the existing speed-management by law enforcements and physical speed-reduction facilities, the country newly adopted Driver Feedback Sign (DFS) system, which displays driving speed in order to guide the driver to an advisable driving condition. DFS is mainly used in school zones due to reasons related to the ITS. Accordingly, because it is predictable that DFS will result in speed-reduction without legal forces and would have an effect on physical speed-reduction facilities, intersection, crosswalks, and road-alignments, this study will try to verify the efficiency of DFS by researching the vehicle speed in national highways and school zones, which have similar conditions to the urban arterial road. In consequence, on national highways, the drivers had a tendency to travel according to the road-environment such as urban arterial road and not reduce speed voluntarily. In school zones, drivers tend to reduce speed in mornings and afternoons when children travel to school or home, showing that the resulting effect is different according to the road-environment where DFS is installed, and the time slot of the DFS.

A Study on the Analysis of Temperature Reduction Effect by the Types of the Green Roof (옥상녹화의 녹화유형별 기온저감효과)

  • Lee, Chun-Woo;Kim, Soo-Bong;Moon, Hye-Shick
    • Journal of the Korean housing association
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    • v.22 no.3
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    • pp.25-33
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    • 2011
  • Recently, concerns about conserving proper size of urban green spaces and accessibility are increasing, regarding it as a solution to diverse urban environmental problems including pollution, ecosystem deterioration, urban climate change. Artificial ground greening such as green roofs is regarded as the only alternative that can conserve green spaces which are impossible to be secured on the ground. However, green roofs are not popularized yet and levels are very low in provincial cities despite of related technology development and support systems of related agencies. Based on the background, this study tries to present a theoretical basis of methods for green roofs, conducting green roof simulations Finally, it aims to offer base data which help establish policy direction for activation of green roof technology. As a result of a simulation for verifying temperature reduction effect, it was possible to affirm effect of a plot that green roofs applied. Especially, it was revealed that a green roof method using ground covers such as mixed planting was the most effective way to reduce temperature. Based on precise analysis of the users, actual study for activation of green roofs should be developed in the future, by presenting a standard model for experiments and obtaining information about examples of green roofs on private houses.

Life cycle greenhouse-gas emissions from urban area with low impact development (LID)

  • Kim, Dongwook;Park, Taehyung;Hyun, Kyounghak;Lee, Woojin
    • Advances in environmental research
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    • v.2 no.4
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    • pp.279-290
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    • 2013
  • In this study, a comprehensive model developed to estimate greenhouse gas (GHG) emissions from urban area with low impact development (LID) and its integrated management practices (IMPs). The model was applied to the actual urban area in Asan Tangjeong district (ATD) as a case study. A rainwater tank (1200 ton) among various LID IMPs generated the highest amount of GHG emissions ($3.77{\times}10^5kgCO_2eq$) and led to the utmost reducing effect ($1.49{\times}10^3kgCO_2eq/year$). In the urban area with LID IMPs, annually $1.95{\times}104kgCO_2eq$ of avoided GHG emissions were generated by a reducing effect (e.g., tap water substitution and vegetation $CO_2$ absorption) for a payback period of 162 years. A sensitivity analysis was carried out to quantitatively evaluate the significance of the factors on the overall GHG emissions in ATD, and suggested to plant alternative vegetation on LID IMPs.

Axial compression behavior of circular recycled concrete-filled steel tubular short columns reinforced by silica fume and steel fiber

  • Chen, Juan;Liu, Xuan;Liu, Hongwei;Zeng, Lei
    • Steel and Composite Structures
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    • v.27 no.2
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    • pp.193-200
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    • 2018
  • This paper presents an experimental work for short circular steel tube columns filled with normal concrete (NAC), recycled aggregate concrete (RAC), and RAC with silica fume and steel fiber. Ten specimens were tested under axial compression to research the effect of silica fume and steel fiber volume percentage on the behavior of recycled aggregate concrete-filled steel tube columns (RACFST). The failure modes, ultimate loads and axial load- strain relationships are presented. The test results indicate that silica fume and steel fiber would not change the failure mode of the RACFST column, but can increase the mechanical performances of the RACFST column because of the filling effect and pozzolanic action of silica fume and the confinement effect of steel fiber. The ultimate load, ductility and energy dissipation capacity of RACFST columns can exceed that of corresponding natural aggregate concrete-filled steel tube (NACFST) column. Design formulas EC4 for the load capacity NACFST and RACFST columns are proposed, and the predictions agree well with the experimental results from this study.

Analysis on the Mitigation Effects of Urban Heat Island through Creation of Water Space - A case study of Yeol-Mae village Apt in Daejeon's Noeun District - (수공간 조성을 통한 도시의 열섬현상 저감효과 분석 - 대전시 노은지구 열매마을아파트를 중심으로 -)

  • Park, Ki-Yong;Lee, Sun-Woo;Shim, Young-Ju;Hwang, Hee-Yun
    • KIEAE Journal
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    • v.11 no.5
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    • pp.13-18
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    • 2011
  • The overall aim of this study is to mitigate urban environmental problems. In particular, to reduce the effects of urban heat island phenomenon which is one of the urban planning perspective. This study focused on the analysis of the relationship between the urban heat island effect and the thermal and wind properties. To do this analysis, water space was virtually made at Yeol_Mae village Apt. Because it is very difficult to set up water space for the existing apartment complexes due to realistic constraints. This study, therefore has a strong sort of guidelines to create water space for newly formed city. It was based on the concept of virtual city through an in-depth analysis on reduction of urban heat island effects for the existing apartment along with creation of water space. To analysis site, Envi-Met Model developed by Michael Bruse was used. The results are as follows. The temperature went from 298.9K to 297.82K and The wind speed went from 1.42m/s to 1.43m/s. The results are slight in this study because creation of water space is planned to a small area of an apartment complex. But if the water space would be applied to a whole city, the mitigation effect of urban heat island would be bigger.