국토개발사업의 지속가능성 평가

Abstract

Abstract Sustainability Assessment on Land Development Projects -Developing and pilot testing an assessment system in the view of greenspace volume Measuring the sustainability level of Environmentally Sound and Sustainable Development (ESSD) is required in order to set the goals, directions, and guidelines for ESSD. The indices created to evaluate the sustainability of development planning are usually applied to nations, cities, and regions. However, for macro-scale and higher level planning, the indices do not provide goals and standards regarding the sustainability of smaller developmental plans. This study looks at ways to achieve the sustainability of urban development planning in two cases; an apartment complex and in a medium-sized city. For this sustainability assessment, we coined a sustainability indicator which is expressed by a combination of the environmental pressure (P) and the environmental response (R). The equation used to quantify sustainability is R/(P+R). If P is equal to R, it is calculated at 0.5, which means the required minimum for sustainable development. Using the carbon dioxide cycle, we positioned the amount of carbon dioxide emitted by urban development as P, whereas the amount of carbon dioxide assimilated by the vegetation and soils of a greenspace as R. The indicator used is named the Carbon Greenspace Sustainability Indicator, or ‘CGSI’. This study applied CGSI to 57 apartment complexes. As a result, 30.17% of the total CO2 emissions at the apartment complex developments can be compensated. If the present greenspace at the apartment complexes is kept, it is estimated that at least 18 years is needed to absorb the total amount of CO2 emissions. If the annual growth rate of the vegetation is considered, an average of 44 years is needed to reach CGSI 0.5. Moreover, if we want to reach CGSI 0.5 in only ten years under the same assumption that CO2 emissions are stable but assimilation grows annually, we will have to modify urban planning, including a 31.3% decrease in building capacity or a 65.21% increase in greenspace. Therefore, to improve the sustainability with regard to CGSI, decreasing development density is more practical than increasing the amount of greenspace. In order to find out whether CGSI is effective at the city level, the study also applied CGSI to two cities. The annual CO2 emissions in City A were 549,470 tons and its CO2 assimilation was 2,774,289 tons. Thus CGSI for City A is 0.8346. CO2 emissions from City B were 1,189,356 tons and its CO2 assimilation was 167,689 tons. City B’s CGSI is 0.1236. Considering that, City A (CGSI 0.5) is sustainable but City B (CGSI 0.5) is unsustainable. To make City B sustainable, the CGSI must be changed from 0.1236 to 0.5 by increasing the amount of greenspace and by reducing the use of fossil energy. Apparently, the sustainability indicator proposed in this study is capable of measuring the sustainability of city scale. For prior environmental reviews or environment impact assessments, the CGSI could have been used to suggest the quantity goal. CGSI could provide guidance when setting the amount of green area. It can also be used to contribute to establishing local environmental plans. Because this research lacks various greenspace measurements, including the differences in the CO2 cycle between natural vegetation and urban landscapes, follow-up research needs to be applied to pilot projects in order to increase the applicability of the indicator. Nonetheless, we hope the idea of CGSI will benefit other research and help to design more indicators for sustainable development.