• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.409-411
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• 2008

Water conveyance from waste water treatment plant can play a role in securing river water quantitatively in urban watershed, but it can also cause more severe contamination of river water due to lack of water quality management. Soil aquifer treatment(SAT) has been introduced to overcome the worsening water quality in the water conveyance system considering the characteristics of Korean urban watershed. The application of SAT to the water conveyance system not only improve water quality of ordinarily discharged water but also prevent accidential water pollution to the urban watershed. Since most domestic urban watersheds are consist of narrow terrace lands and surrounded by roads, SAT is estimated not to be appropriate to the urban watershed with respect to the quantitative efficiency. However, since the upstream of urban watershed in which discharge ports are located usually consists of agricultural lands, SAT can be applied near discharge ports. Therefore, combination of water conveyance and SAT is expected to supply clean and safe river water in urban watershed.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.784-794
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• 2020

In order to effectively evaluate the urban water security, the study investigates a novel system to assess factors that impact urban water security and builds an urban water poverty evaluation index system. Based on the contribution rates of Resource, Access, Capacity, Use, and Environment, the study adopts the Water Poverty Index (WPI) model to evaluate the water poverty levels of 14 cities in Gansu during 2011-2018 and uses the least variance method to evaluate water poverty space drive types. The case study results show that the water poverty space drive types of 14 cites fall into four categories. The first category is the dual factor dominant type driven by environment and resources, which includes Lanzhou, Qingyang, Jiuquan, and Jiayuguan. The second category is the three-factor dominant type driven by Access, Use, and Capability, which includes Longnan, Linxia, and Gannan. The third category is the four-factor dominant type driven by Resource, Access, Capability, and Environment, which includes Jinchang, Pingliang, Wuwei, Baiyin, and Zhangye. The fourth category is the five-factor dominant type, which includes Tianshui and Dingxi. The driven types impacting the urban water security factors reflected by the WPI and its model are clear and accurate. The divisions of the urban water security level supply a reliable theoretical and numerical basis for an urban water security early warning mechanism.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.183-183
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• 2023

Smart water cities (SWC) are urban municipalities that utilizes modern innovations in managing and preserving the urban water cycle in the city; with the purpose of securing sustainability and improving the quality of life of the urban population. Understanding the different urban water characteristics and management strategies of cities situate a baseline in the development of evaluation scheme in determining whether the city is smart and sustainable. This research herein aims to develop measurements and evaluation for SWC Key Performance Indicators (KPIs), and set up a unified global standard and certification scheme. The assessment for SWC is performed in technical, as well as governance and prospective aspects. KPI measurements under Technical Pillar assess the cities' use of technologies in providing sufficient water supply, monitoring water quality, strengthening disaster resilience, minimizing hazard vulnerability, and maintaining and protecting the urban water ecosystem. Governance and Prospective Pillar on the other hand, evaluates the social, economic and administrative systems set in place to manage the water resources, delivering water services to different levels of society. The performance assessment is composed of a variety of procedures performed in a quantitative and qualitative manner, such as computations through established equations, interviews with authorities in charge, field survey inspections, etc. The developed SWC KPI measurements are used to evaluate the urban water management practices for Busan Eco Delta city, a Semulmeori waterfront area in Gangseo district, Busan. The evaluation and scoring process was presented and established, serving as the basis for the application of the smart water city certification all over the world. The established guideline will be used to analyze future cities, providing integrated and comprehensive information on the status of their urban water cycle, gathering new techniques and proposing solutions for smarter measures.

• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.67-76
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• 2018

There are 34 mega-cities with a population of more than 10 million in the world. One of the highly populated cities in the world is Seoul in South Korea. Seoul receives $1,140million\;m^3/year$ for domestic water, $2million\;m^3/year$ for agricultural water and $6million\;m^3/year$ for industrial water from multi-purpose dams. The maintenance water used for water conservation, ecosystem protection and landscape preservation is $158million\;m^3/year$, which is supplied from natural precipitation. Recently, the use of the other water for preservation of water quality and ecosystem protection in urban areas is increasing. The objectives of this study is to develop the seasonal forecast method of environmental water in urban areas (Seoul, Daejeon, Gwangju, Busan) and to evaluate its predictability. In order to estimate the seasonal outlook information of environmental water from Land Surface Model (LSM), we used the observation weather data of Automated Synoptic Observing System (ASOS) sites, forecast and hind cast data of GloSea5. In the past 30 years (1985 ~ 2014), precipitation, natural runoff and Urban Environmental Water Index (UEI) were analyzed in the 4 urban areas. We calculated the seasonal outlook values of the UEI based on GloSea5 for 2015 year and compared it to UEI based on observed data. The seasonal outlook of UEI in urban areas presented high predictability in the spring, autumn and winter. Studies have depicted that the proposed UEI will be useful for evaluating urban environmental water and the predictability of UEI using GloSea5 forecast data is likely to be high in the order of autumn, winter, spring and summer.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.76-86
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• 2023

We are on the verge of paradigm shift for the design and operation of our urban water systems from treatment- and efficiency-based to recirculation- and sustainability-based. One of the most frequently suggested alternatives to embody this paradigm shift is to decentralize the currently highly centralized urban water infrastructure. However, claims for water infrastructure decentralization are often criticized due to poor economic feasibility, unstable performance, and unprofessional operation and maintenance. The current study critically reviews the literature to discuss the technical advancement needs to overcome such challenges. Firstly, decentralized water infrastructure was briefly defined and the rationale for the proposal of its introduction to the next-generation urban water systems was laid down. The main discussion focused on the following water technologies, which require special attention when working with decentralized water infrastructure: i) material collection, storage, and transport; ii) easily scalable water treatment; iii) sensor, information, and communications; and iv) system optimization. The principles, current development status, and challenges were discussed for each of the water technologies. The discussion on the water technologies has enabled the identification of future research needs for their application to the next-generation urban water systems which will be designed following decentralized water infrastructure. This paper will significantly improve the current understanding on water infrastructure decentralization and provides insight on future direction of water technology development.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.95-95
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• 2020

Urban flooding occurs in the form of internal-water inundation on roads and lowlands due to heavy rainfall. Unlike in the case of rivers, inundation in urban areas there is lacking in research on predicting and warning through measurement data. In order to analyze urban flood patterns and prevent damage, it is necessary to analyze flooding measurement data for various rainfalls. In this study, the pattern of urban flooding caused by rainfall was analyzed by utilizing the urban flooding measuring sensor, which is being test-run in the flood prone zone for urban flooding management. For analysis, 2019 rainfall data, surface water depth data, and water level data of a street inlet (storm water pipeline) were used. The analysis showed that the amount of rainfall that causes flooding in the target area was identified, and the timing of inundation varies depending on the rainfall pattern. The results of the analysis can be used as verification data for the urban inundation limit rainfall under development. In addition, by using rainfall intensity and rainfall patterns that affect the flooding, it can be used as data for establishing rainfall criteria of urban flooding and predicting that may occur in the future.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.4
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• pp.99-110
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• 2021

This study intends to examine the characteristics of the construction method of the urban water system in the historical cities of Korea, focusing on Gyeongju, Gyeongju, Goryeo, Hanyang, and Suwon Hwaseong, which were created as new towns in the late Joseon Dynasty. It examines the meaning of waterways in connection with the urban skeletal structure, focusing on the location of cities, roads, and arrangement of urban facilities, and analyzes the compositional form of the water system. We tried to derive the relationship with the structure. In particular, it can be seen that water and natural water systems act as key factors in determining the location of a city, and have a close relationship with the urban structure, urban development process, and urban structure. In addition to the symbolic meaning of water in harmony with the geographical concept, realistic demands in terms of water level and water retention are an important background. In order to respond to various demands related to water space, various planning and technical elements for managing water space were introduced in the process of city formation and development. The planning elements of the urban water system in the process of urban formation and development are summarized as follows through the analysis of the research site. First, in the process of building the urban water system in Gyeongju, Goryeo, Goryeo, Hanyang, and Hwaseong, Suwon, which were selected as the research destinations, the water system in consideration of drainage and disaster is common, but the water system construction method and usability are common. shows the difference. Second, water and natural water systems act as symbolic elements to secure the legitimacy of the city location, and as a key factor in determining the location of the city in harmony with the geographical concept and determining the left direction of the city. Third, the natural water system prior to the formation of a city works as a basis for determining the compositional form of the urban water system constructed in the process of urban formation and development in harmony with the topographical conditions. Fourth, the urban water system built on the basis of natural water systems is constructed by linking natural waterways and planned artificial waterways. Fifth, the urban water system is being built in a planned manner in consideration of the utility in connection with the urban structure, such as securing of urban land, arrangement of urban facilities and areas, composition of functional areas, and land division, in addition to the perspective of drainage system and flood control in consideration of disasters.

• KIEAE Journal
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• v.13 no.4
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• pp.33-41
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• 2013

The impervious area on the surface of urban area has been increased as buildings and artificial land cover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural ecosystem. There arise the environmental problems to urban area including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate flood discharge and heat reduction effect according to the green roof system and to quantify effect by analyzing through simulation water and heat cycle before and after green roof system. For the analysis, Distributed hydrologic model, WEP (Water and Energy transfer Processes) and WEP+ model were used. WEP was developed by Dr. Jia, the Public Works Research Institute in Japan (Jia et al., 2005), which can simulate water and heat cycle of an urban area with complex land uses including calculation of spatial and temporal distributions of water and heat cycle components. The WEP+ is a visualization and analysis system for the WEP model developed by Korea Institute of Construction Technology (KICT).

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.285-294
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• 2012

Current urban stream conditions and their restoration projects were investigated by surveying the urban stream management experts in 29 cities with high population density (more than 1,000person/$km^{2}$). The survey results showed that the ratio of covered urban streams decreased by 1.4% (from 14% to 12.6%) in the last 5 years through steady river restoration projects promoted by governments. Nonetheless, 36.3% of 369 urban streams surveyed still report stream depletion problems; therefore, more efforts to alleviate the problems caused by distorted water circulation of urban streams are still necessary. Water depletion in many local urban streams, unlike national rivers, is accelerated due to negligence in stream management, budget shortage, and other reasons. To prevent stream depletion, the use of reclaimed water is suggested as one of the prevention plans. When available amounts of reused sewage are estimated through actual available nationwide sewage discharges of each watershed and instream flow of stream, annual instream flow supply of 780 million $m^{3}$ is expected; 4.8% reduction in the pollution load of public sewer treatment facilities is expected; and the creation of new value through water reuse service is expected. Thus, it is important for the reviews of feasibility and alternatives of water reuse projects for flow augmentation to consider not only investment budget reductions, but also environmental aspects. Also it is necessary to provide the financial support of unified government with strict water quality management policy.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.191-201
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• 2018

Recently, the frequency of heavy rainfall is increasing due to the effects of climate change, and heavy rainfall in urban areas has an unexpected and local characteristic. Floods caused by localized heavy rains in urban areas occur rapidly and frequently, so that life and property damage is also increasing. It is crucial how fast and precise observations can be made on successful flood management in urban areas. Local heavy rainfall is predominant in low-level storms, and the present large-scale radars are vulnerable to low-level rainfall detection and observations. Therefore, it is necessary to introduce a new urban flood forecasting system to minimize urban flood damage by upgrading the urban flood response system and improving observation and forecasting accuracy by quickly observing and predicting the local storm in urban areas. Currently, the WHAP (Water Hazard Information Platform) Project is promoting the goal of securing new concept water disaster response technology by linking high resolution hydrological information with rainfall prediction and urban flood model. In the WHAP Project, local rainfall detection and prediction, urban flood prediction and operation technology are being developed based on high-resolution small radar for observing the local rainfall. This study is expected to provide more accurate and detailed urban flood warning system by enabling high-resolution observation of urban areas.