Ministry of Land, Infrastructure and Transport

Abstract. This study developed a streamflow drought severity–duration–frequency (SDF) curve that is analogous to the well-known depth–duration–frequency (DDF) curve used for rainfall. Severity was defined as the total water deficit volume to target threshold for a given drought duration. Furthermore, this study compared the SDF curves of four threshold level methods: fixed, monthly, daily, and desired yield for water use. The fixed threshold level in this study is the 70th percentile value (Q70) of the flow duration curve (FDC), which is compiled using all available daily streamflows. The monthly threshold level is the monthly varying Q70 values of the monthly FDC. The daily variable threshold is Q70 of the FDC that was obtained from the antecedent 365 daily streamflows. The desired-yield threshold that was determined by the central government consists of domestic, industrial, and agricultural water uses and environmental in-stream flow. As a result, the durations and severities from the desired-yield threshold level were completely different from those for the fixed, monthly and daily levels. In other words, the desired-yield threshold can identify streamflow droughts using the total water deficit to the hydrological and socioeconomic targets, whereas the fixed, monthly, and daily streamflow thresholds derive the deficiencies or anomalies from the average of the historical streamflow. Based on individual frequency analyses, the SDF curves for four thresholds were developed to quantify the relation among the severities, durations, and frequencies. The SDF curves from the fixed, daily, and monthly thresholds have comparatively short durations because the annual maximum durations vary from 30 to 96 days, whereas those from the desired-yield threshold have much longer durations of up to 270 days. For the additional analysis, the return-period–duration curve was also derived to quantify the extent of the drought duration. These curves can be an effective tool to identify streamflow droughts using severities, durations, and frequencies.

Structural performance of a cementitious damper made of HPFRCC and steel bar was experimentally observed. These dampers will be applied for reducing seismic damage as well as seismic response of RC structures under performance-based engineering. Since the stiffness of RC structures is higher than that of steel structures, dampers that are stiffer than the conventional ones mainly applied for steel structures are required for drastically reducing the seismic response of RC structures. The advantage of HPFRCC dampers is selective structural performance, strength, stiffness, and ductility, obtained by varying the configuration, bar arrangements and types of materials used. Compressive resistance, which is never a feature of conventional response control dampers, is also a unique advantage of HPFRCC dampers. Thus optimum dampers that meet high performance requirements such as damage reduction for buildings in the event of large-scale earthquakes, can be easily obtained in order to minimize the reconstruction burden. The experimental results indicate that when HPFRCC is used, an extremely large capacity of more than 6N/mm2 in average shear stress and large deflection capacity of more than 10% in deflection angle can be achieved since HPFRCC contribute to the prevention of shear failure and compression failure. HPFRCC can remarkably reduce structural damage by initiating multiple fine cracks. Thus HPFRCC can be used to create small, stiffer dampers capable of high energy absorption due to large capacities in lateral resistance and lateral deflection, as well as high compressive resistance. However, the bending capacity of dampers is drastically increased by increases in axial compression force due to restriction of their elongation. Standard methods of calculating bending and shear capacities of RC columns are inadequate for predicting the capacity and failure modes of these HPFRCC dampers. Therefore, it is recommended that further investigation on evaluation methods for lateral resistance capacity, ductility, fluctuation of axial force, and hysteresis of HPFRCC dampers is essential to develop a performance-based-design method.

Geospatial information has drawn substantial attention as a means for building a common measurement and monitoring framework that can be employed across different countries all over the world for the sustainable development goals (SDGs) of the United Nations (UN). Determining the appropriate spatial units for measurements is a critical issue, particularly for the goals associated with the safety, resilience, and sustainability of cities and human settlements. Open geospatial technologies are expected to help address this issue of spatial measurement since they comply with geospatial standards and can be easily adopted by both developed and developing countries. This study evaluates the applicability of open geospatial technologies for the development of a common measurement framework for UN SDG 11. To this end, the study analyzes to what extent national urban information systems of Korea can support the measurement of the target goals and makes recommendations for how open geospatial data and technologies could fill the void that current systems cannot fill at present. The results of this study show that Korea’s urban information systems have an architecture built upon a standard-based open platform and thus can be easily extended by other open geospatial technologies for new developments. From the Korean case study findings, we concluded that open geospatial technologies could serve as an enabler for constructing a worldwide common framework for the measurement of sustainable development goals.

OBJECTIVES: In this pandemic situation caused by a novel coronavirus disease in 2019 (COVID-19), an electronic support system that can rapidly and accurately perform epidemic investigations, is needed. It would systematically secure and analyze patients' data (who have been confirmed to have the infection), location information, and credit card usage. METHODS: The "Infectious Disease Prevention and Control Act" in South Korea, established a legal basis for the securement, handling procedure, and disclosure of information required for epidemic investigations. The Epidemic Investigation Support System (EISS) was developed as an application platform on the Smart City data platform. RESULTS: The EISS performed the function of inter-institutional communication which reduced the processing period of patients' data in comparison to other methods. This system automatically marked confirmed cases' tracking data on a map and hot-spot analysis which lead to the prediction of areas where people may be vulnerable to infection. CONCLUSION: The EISS was designed and implemented for use during an epidemic investigation to prevent the spread of an infectious disease, by specifically tracking confirmed cases of infection.

Water-related damage to bituminous pavement is considered to result from penetration of liquid water from the surface and/or subsurface. However, surface courses made of bituminous material such as runway pavements are usually not permeable for liquid water. Therefore, such phenomena may be caused by moisture vapor in the air. A new moisture permeation test apparatus was developed to analyze the mass transfer. Moisture permeation tests under typical hot summer conditions suggested that atmospheric moisture permeates and accumulates in bituminous mixtures through mass transfer by vapor diffusion despite the water impermeability of bituminous surface mixtures. The moisture permeation test provides an effective approach to analyze water storage mechanisms and moisture-related phenomena such as blistering in bituminous mixtures, although the test apparatus and condition settings require some improvement.

The paper describes the possible direction of Asian EST, starting with an overview of recent trends and problems in transport systems within Asia, policy practices are also introduced. It was found that although the current situation and trend of transport in the Asian region presents a diverse picture stemming from geographical differences and levels of economic development, most Asian countries share similar concerns about transport-related problems, namely severe congestion, air and noise pollution,. Common patterns can be identified behind these problems, which include: a)large increases in traffic demand, resulting from rapid economic growth, urbanization, and motorisation, b)poor control of vehicle emissions and the absence of effective inspection and maintenance systems, c)lack of adequate and appropriate infrastructures, and d)poor coordination of transport and land-use policies. In the current situation, insufficient understanding of environmental deterioration mechanisms delay the implementation of necessary policy measures in many Asian countries. Each country should find the best way to achieve EST as fast as possible by learning from others’ experiences. Existing good examples within the region, such as intermediate public transport systems and electric road pricing, can provide a strong foundation for this purpose.

This study develops hourly water level forecasting models with lead-times of 1 to 3 h using an artificial neural network (ANN) for Anyangcheon stream, one of the major tributaries of the Han River, South Korea. To consider the backwater effect from this river, an enhanced tributary water level forecasting model is proposed by adding multiple water level data on the main river as input variables into the conventional ANN structure which often uses rainfall and upstream water level data. Four types of ANN models per each lead-time are built with increasing complexity of the input vector, and their performances are compared. The results indicate that the inclusion of multiple water level data on the main river to the network provides water level forecasts with greater accuracy at the Ogeumgyo gauging station of interest. The final best ANN models for water level forecasts with lead-times of 1 to 2 h show good performance with root mean square errors (RMSE) below 0.06 m and 0.12 m, respectively. However, the final best ANN model for forecasting 3 h ahead was unsatisfactory, showing underestimation at many rising parts of the hydrograph.

A series of fire resistance tests of aluminum alloy members was conducted. This study characterize temperature rise and collapse mechanism of the aluminum alloy members. Analytical expressions, based on lumped mass heat balance equation, have been developed to estimate the temperature rise of unprotected, protected aluminum members during fire. An evaluation method of critical temperature of aluminum alloy members was also proposed and compared to experimental data. The results of the calculations by these methods were found to be in a good agreement with the experimental results.

The scale of damage caused by drought is on the rise in South Korea. The country has been experiencing a 4–6-year cycle of extreme droughts at a nationwide scale. From 2014–2015, South Korea suffered from its worst drought in the past 50 years. This study aims to provide an effective drought management policy by analyzing the Korean government's response to the 2014–2015 drought under the National Drought Management Framework, which is composed of four stages: prevention, preparedness, response, and recovery. The findings indicate that the Korean government effectively addressed the drought, yet there are no measures currently in place to cope with megadroughts that last for more than 5 consecutive years. Immediate attention is required to conduct research and introduce policies that will help in managing megadroughts. This paper takes an interdisciplinary approach to drought preparedness research in the context of megadroughts and proposes an efficient national drought management framework that involves engagement of relevant line ministries.

One recently apparent trend in increasing traffic accidents in Japan is the increase in nighttime accidents. To address this problem, various traffic safety measures have been introduced aiming at safer road traffic environments. Among these measures, road lighting, in particular ‘local lighting’ has been introduced in an increasing number as a countermeasure against nighttime accidents. However, in terms of number of fatal accidents by road profile, the ‘at intersection’ accounts for the largest portion of the fatalities. Therefore, a more effective intersection lighting measure must be studied. This paper discusses the illuminance levels expected for intersection lighting from the viewpoint of traffic accident reduction effect and reports the review result. The means used in reviewing were accident data before and after introduction of accident countermeasure and statistical analysis. It was learned from the result of these review works that an average road surface illuminance at intersections maintained at 20 lx or higher, as a level expected for intersection lighting, can provide the effect of accident countermeasure, and that an average road surface illuminance of 30 lx can further positively develop a statistically significant result as to reduction in traffic accidents.

In the Shikoku area, it is eager to request an alternative fine aggregate in stead of natural sand, in particular sea sand, by the reason of prohibition of borrowing sea sand in Seto Island Sea. In this study, the fundamental properties of concrete using copper slag (JIS A 5011-3) or second class fly ash (JIS A 6201) as a part of fine aggregate to apply for plain concrete structure is investigated. It is concluded that the concrete of 20 mm in coarse aggregate maximum size, 50% in water-cement ratio and 40 mm in coarse aggregate maximum size, 60% in water-cement ratio and up to 30%, except in the case of 50% in water-cement ratio of fly ash concrete is possible to 20%, at in volume percentage of sand using copper slag or second class fly ash is applicable for concrete structure.

This research reaffirms a sustainable transport investment should go forward in a way that enforces consistent economic growth while maintaining environmental benefit. Society’s economic input-output relations reinvest the time saved by the transport system, of which benefit appeared as the income level’s rise. This research empirically proves that the recursive profit is possible when the infrastructure aligns accessibility enhancement with industries’ productivities. Specifically, we found that the interactions between industries and accessibilities make synergy when the industries maintain appropriate productivity. Under the same context, the measure for the socially vulnerable should start at capacity building even given transport, based on which we can build economically equitable accessibility. This research takes environmental sustainability granted as long as the incumbent Korean infrastructure investment principle exists without empirical analysis. A comparative analysis using structural equation models proved the existence of the synergy due to the accessibility-industry interactions. Besides, we captured the quantities of the synergy through groups of partial cross-sectional correlations. Authors conclude that government authority needs to pursue the best synergy between transport plan and economic development strategy, and prepare a capacity building for the socially vulnerable furthermore.

The blistering phenomenon is one of the major damages in bituminous pavement during a hot summer. The phenomenon was believed to be caused by water permeating from outside via channels of connected pores in bituminous mixtures. However, the surface course in bituminous pavement is not permeable to water, particularly near the blistering area. Therefore, permeation of liquid water is unlikely to be responsible for the water accumulation that causes the blistering phenomenon. Moisture vapor in the air is important in water intrusion into bituminous mixtures. This study examined moisture transfer mechanisms in bituminous pavements, focusing on the coefficient of permeability of pavement mixtures of both liquid water and humid air (i.e. air containing water vapor).

This paper describes a new calculation method for seismic displacement of retaining walls. A macroscopic failure surface and a plastic displacement potential in the general load space are considered in the method to evaluate the subgrade reaction force from foundation ground. The method is capable of calculating not only horizontal, vertical or rotational displacement alone, but also their combined effect. The method is validated through comparison with centrifuge test results of a gravity retaining wall with dense backfill sand subjected to strong base shaking. The calculated displacement components, that is vertical, horizontal and rotational displacement at the end of shaking, compared well with those measured. It also appeared that previously proposed conventional displacement calculation methods based on Newmark's sliding block analogy might underestimate the displacement. The assumption of the constant frictional coefficient may be responsible for this. The proposed method is limited to retaining walls resting on soils where dramatic degradation of soil strength due to the generation of excess pore pressure does not occur.

重力式岸壁の簡易的な耐震性能の評価手法を検討するため, 設計震度および地盤の液状化強度をパラメータとして, 有効応力法による有限要素解析プログラムを用いて, 200ケースを越えるパラメトリックスタディを行った. パラメトリックスタディの結果, 岸壁の変位量には岸壁直下及び背後地盤の条件が最も影響を与えることが明らかになった. パラメトリックスタディの結果をもとに, 重力式岸壁の変位量のレベルを推定する簡易的な耐震性能照査手法を提案した. また, 被災事例のデータをもとに提案手法の適用性を検討し, 数十cmから数m程度の幅広い変位レベルに対し一定の適用性を供えていることを確認した.

Click to increase image sizeClick to decrease image size Notes 1One of reasons for this is that, as Larsson (2003 Larsson, N. (2003). Adapting to climate change in Canada. Building Research & Information, 31(3–4): 231–239. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) pointed out, policy-makers might hesitate to implement an adaptation policy because it could be perceived as admitting that their mitigation policy is likely to be unsuccessful. 2This may be one of the factors that differentiate adaptation measures from mitigation measures, as was argued by Larsson (2003 Larsson, N. (2003). Adapting to climate change in Canada. Building Research & Information, 31(3–4): 231–239. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). 3It is also important to note that as Larsson (2003 Larsson, N. (2003). Adapting to climate change in Canada. Building Research & Information, 31(3–4): 231–239. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) pointed out, adaptation will be required at different times in the future to varying extents. Lowe (2003) has also referred to the need to develop and think in terms of adaptive trajectories rather than individual, once-and-for-all adaptations. This aspect will be further examined below. 4From the viewpoint of those involved in policy design, the special issue would have been more useful if it had included a paper that attempted systematically and theoretically to analyse how government policy should be developed in this area. 5One of the methods of redistribution is to introduce a nation-wide energy tax and use some part of the tax revenue to support local governments where relatively large resources are necessary to implement adaptation policies. This might be an argument that is not limited to the building sector. 6It is noteworthy that both Lisø (2003 Lisø, K.R., Aandahl, G., Eriksen, S. and Alfsen, K.H. (2003). Preparing for climate change impacts in Norway's built environment. Building Research & Information, 31(3–4): 200–209. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) and Sanders and Philipson (2003 Sanders, C.H. and Philipson, M.C. (2003). UK adaptation strategy and technical measures: the impacts of climate change on buildings. Building Research & Information, 31(3–4): 210–221. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) point to evidence that non-compliance with regulation is a significant problem. 7Although this argument could not be applied to rented buildings, which are characterized by principal and agent problems (OECD, 2003b OECD (2003b) Environmentally Sustainable Buildings: Challenges and Policies OECD Paris [Google Scholar]). 8Some papers (Hertin et al., 2003 Hertin, J., Berkhout, F., Gann, D., D.M. and Barlow, J. (2003). Climate change and the UK housebuilding sector: perceptions, future impacts and adaptive capacity. Building Research & Information, 31(3–4): 278–290. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; Mills, 2003 Mills, E. (2003). Climate change, insurance and the building sector: technological synergism between adaptation and mitigation. Building Research & Information, 31(3–4): 257–277. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; Sanders and Philipson, 2003 Sanders, C.H. and Philipson, M.C. (2003). UK adaptation strategy and technical measures: the impacts of climate change on buildings. Building Research & Information, 31(3–4): 210–221. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) reminded us that climate change is just one variant of future risk, and, for decades, buildings and building activities have been flexibly adapted to a wide variety of changes in exogenous situations, such as increased use of electric products and information technologies, changing demand of consumers, etc. The experience of the building sector in the past might suggest that some adaptation could be carried out without government policies, and it may not be appropriate to assume that government intervention is always desirable. 9For some categories of impacts, the effect of externality appears likely. For instance, in the absence of sufficient modification to the building design, a hotter summer might lead to increased use of air-conditioning, which then will worsen the urban heat island effect. 10Note that the present paper attempts to discuss how adaptive policy for the building sector should be designed, assuming that the degree of future climate change is fixed. From a broader viewpoint, upgrading mitigation measures to some extent might reduce the necessity of adaptation. In this context, externality may be the big issue. 11From the viewpoint of economists, this may still not be sufficient justification for regulatory intervention because with the provision of sufficient information about the risk of flooding, possible liability to the damage, etc., few firms may attempt to start new development, as suggested by Hertin et al. (2003 Hertin, J., Berkhout, F., Gann, D., D.M. and Barlow, J. (2003). Climate change and the UK housebuilding sector: perceptions, future impacts and adaptive capacity. Building Research & Information, 31(3–4): 278–290. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), and occupants of existing buildings may move to safer areas. 12It is also argued that the choice of economic instruments would provide incentives for innovation (e.g. OECD, 1997 OECD (1997) Evaluating Economic Instruments for Environmental Policy OECD Paris [Google Scholar]). 13Because there appears to be little room for reducing the social cost for adaptation by means of economic instruments. In other words, it is difficult theoretically to presume that the total cost for achieving a certain adaptation goal is reduced by shifting from regulatory instruments to economic instruments. 14Although in some cases regulatory instruments could be accepted more easily than other instruments depending on various contextual factors. 15Note that the effects of these soft instruments could help the introduction of regulatory instruments in the future (OECD, 2003b OECD (2003b) Environmentally Sustainable Buildings: Challenges and Policies OECD Paris [Google Scholar]). 16Economic efficiency is referred to as the total cost incurred by both businesses and households/individuals of bringing about the changes in behaviour necessary to minimize the impacts that the policy aims to achieve (OECD, 2003b OECD (2003b) Environmentally Sustainable Buildings: Challenges and Policies OECD Paris [Google Scholar]). 17Such a ‘building stock issue’ was emphasized as an important target of future efforts in both the latest European Housing Ministers Conference on Sustainable Buildings and the SB2002 Conference in Oslo. 18For further discussions about the effect of longer service life, see OECD (2003c OECD (2003c) Sustainable Use of Building Stock OECD Paris [Google Scholar]).

The Standardized Precipitation Evapotranspiration Index (SPEI) analysis was conducted using monthly precipitation data and temperature data on a 12.5 km × 12.5 km resolution based on a Representative Concentration Pathways (RCP) 8.5 climate change scenario, and the characteristics of drought were identified by the threshold. In addition, the changes in drought severity and intensity were projected using the threshold based on the run-length concept and frequency analysis. As a result of the analysis, the probability density function of the total drought and maximum drought intensity moved the upper tail for the upcoming years, and the average drought intensity was also projected to become stronger in the future than in the present to the right side. Through this, it could be projected that the drought scale and frequency and the drought intensity will become severer over South Korea because of future climate change.

Metro rail systems (MRS) currently face a serious threat from terrorist attacks – especially through use of explosives. The threat comes at a time when scores of new MRS are under construction or at the planning stage in cities across the world. Designers of these systems need to consider ways to detect explosives without an adverse impact upon passenger comfort and profitability. This paper presents a framework for designers to identify security functions in MRS, understand current methods of threat detection used in MRS and recognise their relationship with other operational requirements. Application of this framework at the planning stage can assist in designing systems where terrorist threats can be better addressed with reduced impact on passenger experience and MRS operations. The application of a framework of analysis inspired by Ekblom’s work to nine functioning MRS yields a concise representation of the major design issues architects and security specialists have to consider for effective integration of security systems in stations.

The relationship between true stress and true strain of structural steel was simply modeled considering the Bauschinger effect. This hysteresis model is composed of skeleton curve based on the material test result, Bauschinger part modeled as a function of the cumulative strain in the skeleton curve and elasticity unloading part. The analytical result of the beam which applied this hysteresis model was compared with experimental result. The analytical result and the experimental result showed the good correspondence in not only load deformation relationship but also deformation of skeleton curve as an index to the plastic deformation capacity of member, moment-curvature relationship and hysteresis of strain. Though the hysteresis model is simple, it is enough effective in order to analyze the behavior of steel member in the plastic range.