• Title/Summary/Keyword: Urban water

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Assessing the resilience of urban water management to climate change

  • James A. Griffiths
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.32-32
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    • 2023
  • Incidences of urban flood and extreme heat waves (due to the urban heat island effect) are expected to increase in New Zealand under future climate change (IPCC 2022; MfE 2020). Increasingly, the mitigation of such events will depend on the resilience of a range Nature-Based Solutions (NBS) used in Sustainable Urban Drainage Schemes (SUDS), or Water Sensitive Urban Design (WSUD) (Jamei and Tapper 2019; Johnson et al 2021). Understanding the impact of changing precipitation and temperature regimes due climate change is therefore critical to the long-term resilience of such urban infrastructure and design. Cuthbert et al (2022) have assessed the trade-offs between the water retention and cooling benefits of different urban greening methods (such as WSUD) relative to global location and climate. Using the Budyko water-energy balance framework (Budyko 1974), they demonstrated that the potential for water infiltration and storage (thus flood mitigation) was greater where potential evaporation is high relative to precipitation. Similarly, they found that the potential for mitigation of drought conditions was greater in cooler environments. Subsequently, Jaramillo et al. (2022) have illustrated the locations worldwide that will deviate from their current Budyko curve characteristic under climate change scenarios, as the relationship between actual evapotranspiration (AET) and potential evapotranspiration (PET) changes relative to precipitation. Using the above approach we assess the impact of future climate change on the urban water-energy balance in three contrasting New Zealand cities (Auckland, Wellington, Christchurch and Invercargill). The variation in Budyko curve characteristics is then used to describe expected changes in water storage and cooling potential in each urban area as a result of climate change. The implications of the results are then considered with respect to existing WSUD guidelines according to both the current and future climate in each location. It was concluded that calculation of Budyko curve deviation due to climate change could be calculated for any location and land-use type combination in New Zealand and could therefore be used to advance the general understanding of climate change impacts. Moreover, the approach could be used to better define the concept of urban infrastructure resilience and contribute to a better understanding of Budyko curve dynamics under climate change (questions raised by Berghuijs et al 2020)). Whilst this knowledge will assist in implementation of national climate change adaptation (MfE, 2022; UNEP, 2022) and improve climate resilience in urban areas in New Zealand, the approach could be repeated for any global location for which present and future mean precipitation and temperature conditions are known.

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Butyric Acid Fermentation of Sodium Hydroxide Pretreated Rice Straw with Undefined Mixed Culture

  • Ai, Binling;Li, Jianzheng;Chi, Xue;Meng, Jia;Liu, Chong;Shi, En
    • Journal of Microbiology and Biotechnology
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    • v.24 no.5
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    • pp.629-638
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    • 2014
  • This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

Hydrologic Cycle Simulation of Urban river for Rehabilitation of Water Environment (I) - Anyangcheon Basin - (물 환경 건전화를 위한 도시하천의 물 순환 모의 (I) - 안양천 유역 -)

  • Lee, Jung-Min;Lee, Sang-Ho;Lee, Kil-Seong
    • 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.

Analysis on the Mitigation Effects of Urban Heat Island through Creation of Water Space - A case study of Yeol-Mae village Apt in Daejeon's Noeun District - (수공간 조성을 통한 도시의 열섬현상 저감효과 분석 - 대전시 노은지구 열매마을아파트를 중심으로 -)

  • Park, Ki-Yong;Lee, Sun-Woo;Shim, Young-Ju;Hwang, Hee-Yun
    • KIEAE Journal
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    • v.11 no.5
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    • pp.13-18
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    • 2011
  • The overall aim of this study is to mitigate urban environmental problems. In particular, to reduce the effects of urban heat island phenomenon which is one of the urban planning perspective. This study focused on the analysis of the relationship between the urban heat island effect and the thermal and wind properties. To do this analysis, water space was virtually made at Yeol_Mae village Apt. Because it is very difficult to set up water space for the existing apartment complexes due to realistic constraints. This study, therefore has a strong sort of guidelines to create water space for newly formed city. It was based on the concept of virtual city through an in-depth analysis on reduction of urban heat island effects for the existing apartment along with creation of water space. To analysis site, Envi-Met Model developed by Michael Bruse was used. The results are as follows. The temperature went from 298.9K to 297.82K and The wind speed went from 1.42m/s to 1.43m/s. The results are slight in this study because creation of water space is planned to a small area of an apartment complex. But if the water space would be applied to a whole city, the mitigation effect of urban heat island would be bigger.

Profiling Total Viable Bacteria in a Hemodialysis Water Treatment System

  • Chen, Lihua;Zhu, Xuan;Zhang, Menglu;Wang, Yuxin;Lv, Tianyu;Zhang, Shenghua;Yu, Xin
    • Journal of Microbiology and Biotechnology
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    • v.27 no.5
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    • pp.995-1004
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    • 2017
  • Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

Analysis of Application Cases of Living Lab for Urban Water Resources: Focusing on Sam-bang Water Living Lab (도시 수자원 리빙랩 적용사례 분석: 김해시 삼방워터 리빙랩을 중심으로)

  • Lee, Nam Jung;Lee, Jung Hoon;Kum, Ah Ro
    • Journal of Information Technology Services
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    • v.20 no.6
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    • pp.141-150
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    • 2021
  • With the recent spread of the concept of Smart Cities which is to solve urban problems with ICT technology, Living Lab, which identifies the demands of citizens who dwell in the city and verifies the acceptability of the services being introduced, has become an important topic. Living Lab is an open innovation platform introduced in consideration of the user's perspective in real life and is a new approach in that service developers use collective intelligence in the process of Co-creation with users. Living Lab is operated on topics which is close to citizens' daily lives such as energy, housing, transportation, and education. In particular, as energy and environmental-focused Living Lab emerges in accordance with the 'Korean New Deal Policy', interest and importance in the field are increasing. The paper derives the characteristics of water resource Living Lab through case analysis of several Living Lab practices. Water resource Living Lab in Daejeon and Chuncheon, which are located in Korea, and water resource Living Lab in Romania and Indonesia are covered in this paper as the reference. The paper finally analyzes the case of Sambang Water Living Lab in Gimhae, which is the city located in southern part of Korea. As a result of case analysis, the urban water resource Living Lab focuses on the raw water of urban water resource and should respond sensitively to the safety of citizens. And for the success of this urban water resource Living Lab, it is essential to ensure that citizens participating in the Living Lab clearly understand the concept of water resources, and citizens' opinions to be implemented as services.