The purpose of this study was to develop a low impact development-based district unit planning (LID-DP) model and to verify the model by applying it to a test site. To develop the model, we identified various barriers to the urban planning process and examined the advantages of various LID-related techniques to determine where in the urban development process LID would provide the greatest benefit. The resulting model provides (1) a set of district unit planning processes that consider LID standards and (2) a set of evaluation methods that measure the benefits of the LID-DP model over standard urban development practices. The developed LID-DP process is composed of status analysis, comprehensive analysis, basic plan, and sectoral plans. To determine whether the LID-DP model met the proposed LID targets, we applied the model to a test site in Cheongju City, Chungcheongbuk-do Province, Republic of Korea. The test simulation showed that the LID-DP plan reduced nonpoint source pollutants (total nitrogen, 113%; total phosphorous, 193%; and biological oxygen demand, 199%); reduced rainfall runoff (infiltration volume, 102%; surface runoff, 101%); and improved the conservation rate of the natural environment area (132%). The successful application of this model also lent support for the greater importance of non-structural techniques over structural techniques in urban planning when taking ecological factors into account.

This study analyzed the characteristics of flood damages and the effects of structural and non-structural flood damage mitigation measures in Korea. First, a theoretical discussion of the structural and non-structural measures to mitigate flood damages was used to select the variables and devise the hypotheses. An analysis was conducted using the Auto-Regressive Integrated Moving-Average (ARIMA) time series methodology, Korean socioeconomic data, and damage characteristics of major flood events. The effects of flood damage mitigation measures on the extent of flood damages were assessed using an intervention time series model. The major findings were that the intervention effects of structural and non-structural measures were statistically significant from 1958 to 2013 (a period of 55 years) and that while the former were ineffective at mitigating flood damages, the latter were successful in doing so. Based on the above findings, policy suggestions for future flood damage mitigation measures in Korea were offered. For structural measures, the government should manage its existing facilities, recover ecosystems of damaged rivers, and devise mitigation measures for urban areas. For non-structural measures, the government should enhance its flood forecasting capacity, revise laws related to flood control and prevention, and update and rationalize land-use plans.

Although previous studies have posited that the high-density development of urban buildings and infrastructure contributes to urban flooding, empirical analyses and in-depth investigations into the interaction factors have remained limited. This study aims to analyze the influence and moderating effect of high-density development on urban flooding. Thus far, various land-use and interaction factors related to urban development density have been explored. Subsequently, the urban watershed was selected, utilizing panel data 2002 to 2017, and employing the Tobit model for analysis. The analysis revealed that high-density development had an adverse effect on urban flooding and that the runoff characteristics of high-density development were not limited to those of impervious surfaces. The horizontal and vertical aspects of dense buildings and structures acted as sub-watersheds that increased the time to reach peak flow. Moreover, high-density development had a moderating effect in low-lying areas. The results of this study underscore the necessity of urban disaster prevention planning to consider the direct and indirect effects, as well as the runoff characteristics, of high-density development on urban flooding.

The goal of this study is to analyze the interrelated direct and indirect impacts of urban development intensity (UDI) characteristics on carbon dioxide (CO₂) emissions in Korea. The study also compares the main arguments and analysis results of previous studies on cities that are effective in reducing CO₂ emissions. To do this, factors attributable to the UDI characteristics of Korea were selected, and CO₂ emissions were calculated. Then, the impact of UDI characteristics on CO₂ emissions was analyzed using the partial least squares structural equation model. The main results show that the physical, spatial, and socio-demographic characteristics of UDI have a direct impact on CO₂ emissions, and physical, economic, and city-type characteristics indirectly affect CO₂ emissions. As a result, we reach the following conclusions: (i) dense urban forms reduce CO₂ emissions; (ii) economic characteristics of UDI have impact on total CO₂ emissions, having both negative and positive effects; and (iii) medium and small cities have higher per capita CO₂ emissions than do large cities.