• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.397-408
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• 2013

The purpose of this study is to analyze water cycle area ratio and spatial evaluation of water cycle in urban area of Changwon-si, Gyeongsangnam-do. Water cycle area ratio are analyzed by using spatial data of land-cover and land-use, and Hot spot analysis of GIS program was used for spatial evaluation of water cycle. The results are as below. Firstly, the high water cycle area ratio areas were forests, parks, and rivers, but urban areas covered asphalt and concrete were low under 40%. Public institutions and co-residential of urban areas were higher than others because of high area ratio of pervious land-cover. Spatial evaluation of water cycle was analyzed to vulnerable areas there are dense residential and commercial area. These areas are really occurring frequently flooding and immersion, therefore, is required water management facilities and improvement of land-cover from impervious to pervious. In the future, it will require additionally analysis of water cycle area ratio supplemented data of water management facility and ground water.

• 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.29 no.4
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• pp.447-457
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• 2015

Water cycle within the human civilization has become important with urbanization. To date, water cycle in the eco-system has been the focus in identifying the degree of water cycle in cities, but in practicality, water cycle within the human civilization system is taking on an increasing importance. While in recent years plans to reuse water have been implemented to restore water cycle in cities, the effect that such reuse has on the entire water cycle system has not been analyzed. The analysis on the effect that water reuse has on urban areas needs to be go beyond measuring the cost-savings and look at the changes brought about in the entire city's water cycle system. This study uses a SWAT model and water balance analysis to review the effects that water reuse has on changes occurring in the urban water cycle system by linking the water cycle within the eco-system with that within the human civilization system. The SWAT model to calculate the components of water cycle in the human civilization system showed that similar to measured data, the daily changes and accumulative data can be simulated. When the amount of water reuse increases in urban areas, the surface outflow, amount of sewer discharge and the discharged amount from sewage treatment plants decrease, leading to a change in water cycle within our human civilization system. The determinant coefficients for reduced surface outflow amount and reduced sewer discharge were 0.9164 and 0.9892, respectively, while the determinant coefficient for reduced discharge of sewage treatment plants was 0.9988. This indicates that with an increase in water reuse, surface flow, sewage and discharge from sewage treatment plants all saw a linear reduction.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.815-823
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• 2006

The hydrologic cycle in urban catchment has been changed due to the expansion of impervious area by rapid urban development. In this study, the SWMM 5 (Storm Water Management Model 5) model was used to simulate the hydrologic cycle of the Dorimcheon catchment which suffers from the distorted hydrologic cycle as a typical urban catchment. This study compare continuous simulation of urban runoff combining the channel and sewer system with that of channel only in the Dorimcheon catchment. Continuous simulations of urban runoff were performed for the upstream basin of Dorim bridge. The urban impervious regions were processed by the land use analysis from LANDSAT_TM images. It was performed from 1975 to 2000 for every five years. Surface, groundwater and wastewater runoffs were additionally included in the simulations one at a time. Such simulations made it possible to evaluate those components quantitatively. The result of continuous simulation of urban runoff combining the channel and sewer system is that peak flow and recession are well simulated. The analysis results of urbanization effect on runoff are as follows: the surface runoff in 2000 increases to 64% of the whole precipitation whereas the surface runoff in 1975 amounts to 46% of the precipitation; the groundwater runoff in 2000 amounts to 6% and shows 8% decrease during the period from 1975 to 2000.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.349-357
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• 2006

Nowadays, the discharges of urban streams during dry season are depleted because the hydrologic cycle in the watershed has been destroyed due to the expansion of the impermeable area, the excessive groundwater pumping, climate change, and so forth. The streamflow depletion may bring out severe water quality problems. This research are to investigate the hydrologic characteristics and to develop a technology to restore sound hydrologic cycle of Anyangcheon watershed. For the hydrological cycle analysis of the Anyangcheon watershed, continuous simulations of urban runoff were performed for the upstream basin of Gocheok bridge whose basin area covered 4/5 of the whole catchment area. The increase of impervious area by urbanization was analysed and its effect on urban runoff was evaluated. The SWMM 5 (Storm Water Management Model 5) was used for the continuous simulation of urban runoff. The analysis results of urbanization effect on runoff are as follows: the surface runoff in 2000 increases to 65% of the whole precipitation whereas the surface runoff in 1975 amounts to 50% of the precipitation; the groundwater runoff in 2000 amounts to 7% and shows 6% decrease during the period from 1975 to 2000.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1925-1928
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• 2007

Water cycle analysis was performed for Gunja basin located in metropolitan Seoul using Aquacycle model in order to assess the problems of urban water cycle. From the water cycle analysis of Gunja basin, it was found that 75% of total rainfall occurred in the form of surface runoff, and groundwater recharge only accounted for about 7%. This suggests serious distortion of water cycle which can be attributed to urbanization. Feasibility analysis of reuse scenarios such as rainwater use and wastewater reuse was then performed to examine their influences on improving the water cycle. From the analysis of water reuse options, it was shown that imported water supply savings of 13% can be achieved through rainwater use, and water supply savings of 31% through wastewater reuse.

• Land and Housing Review
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• v.3 no.3
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• pp.271-278
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• 2012

The climate change and global warming has been a world-wide issue. Also, the green growth has been a widely adopted strategy for national and regional development. In particular, after the Kyoto Protocol to United Nations Framework Convention on Climate Change was declared, the low carbon society was inevitable phenomenon. The hydrologic cycle in urban catchment has been changed due to the expansion of impervious area by rapid urban development. This paper has examined the Water cycle planning elements for green city in the scale of urban planning as well as site planning including housing site. In this study, the SWMM5-LID (Storm Water Management Model5-LID) model was used to simulate the hydrologic cycle of the test catchment as a typical urban catchment. We performed continuous simulation on urban runoff before and after the development of the test catchment and after the installation of Green city planning Elements.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.303-312
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• 2012

Water supply and sewerage systems are the large-scale urban infrastructure ejecting large amount of environmental load over the life-cycle. Therefore, it is important not only to optimize in the aspect of economical superiority and process efficiency but also to consider earth scale environmental impact. This study aimed to suggest the establishment of life cycle management(LCM) system as an integrated management solution in urban water supply and sewerage systems. As a result, the methodology for LCM system consisting of life cycle assessment(LCA), life cycle cost(LCC), life cycle $CO_{2}(LCCO_{2})$ and life cycle energy(LCE) was developed. Also, several case studies using the latest statistics data of water supply and sewerage systems were carried out to investigate the field applicability of LCM.

• 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 of Water and Wastewater
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• v.25 no.5
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• pp.699-706
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• 2011

This study has a purpose of examining technical feasibility of supplying the in-stream flow for the Gyobang cheon by using treated water from small wastewater treatment facilities as a decentralized option. To do this, the water and contaminant flow in study areas of the Gyobang cheon are defined from the context of the integrated urban water cycle, and analyzed by using the Urban Volume and Quality (UVQ) model. First, the UVQ model was built for the study areas of the Gyobang cheon and calibrated with observation data. Second, the decentralized options of the in-stream flow was explored with consideration of availability of water sources. The UVQ simulation then led to selecting the best option which would meet the criteria of water quantity and quality. It was finally concluded that using water sources out of study areas 1 and 2, adjoining the upper part of the Gyobang cheon, in the decentralized manner can be a feasible option for in-stream flow. It also seems that the UVQ model is useful to understand the water cycle in study areas of the Gyobang cheon.