• Title/Summary/Keyword: Artificial urban canal

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Assessment of water quality in an artificial urban canal: A case study of Songdo City in South Korea

  • Ahn, Jungkyu;Na, Yeji;Park, Sung Won
    • Environmental Engineering Research
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    • v.24 no.4
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    • pp.582-590
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    • 2019
  • Currently, the waterfront facility was constructed in New Songdo City, South Korea. It has the various water leisure areas and especially an artificial urban canal with filtered seawater by re-circulating flow system. However, due to excessive amount of nutrients from seawater combined with complicated geometry, it is highly vulnerable to deterioration of water quality. In this study, flow characteristics and pollutant transport were analyzed with comprehensive numerical models, MIKE 3 FM and ECO-lab. Based on these numerical results, notable sampling points were selected for field measurements and comparison between modeling and measured results were conducted. In addition, the integrated water quality evaluation index, Water Quality Index was applied to analyze various water quality issues. We also set up scenarios to control the two kinds of water quality factors, dissolved oxygen (DO), and total phosphorus (TP). As a result, the effect of 20% reduction of TP was less than 10% and it was almost ineffective for a year but it was reduced by up to 40% in case of scenario which DO is increased by 20%. Therefore, it was recommended to control the DO concentration, usually by applying re-aeration facility, rather than TP in artificial urban canal with seawater.

An Experimental Study on Debris Reduction System for Culvert (암거의 유송잡물 저감시설에 관한 실험 연구)

  • Kim, Sung-Joong;Kang, Joon-Gu;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.696-706
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    • 2017
  • The purpose of this study was to verify experimentally debris reduction facilities for culverts installed in small rivers. A culvert is defined as a structure laid under a road or a railroad that passes through an inner urban area or downtown area to make an artificial canal. Culverts are generally categorized into road culverts or waterway culverts, among which the latter are artificial structures designed to discharge running water into a river. At the time of floods, the structural safety of waterway culverts can be undermined by the accumulation of debris, such as soil, boughs and weeds, and they may be at risk of overflowing due to blockages. Debris reduction facilities are necessary to prevent such damage. In this study, the effects of the three existing types of debris reduction facilities were examined through hydraulic experiments. The results of the experiments showed that vertical separation to divert debris reduced the accumulation rate by 27.65 to 31.39 percent. The two types of screen designed to block and divert debris, respectively, were found to have excellent debris blocking abilities. However, when the effects of the rising water level are considered simultaneously, the screen to divert debris was found to show superior effects. The screen to block debris can be considered to have excellent debris blocking ability, but requires the continuous collection of the debris, due to the high risk of rising water levels caused by its accumulation.

A Study on the Characteristics of Humanistic Landscape in Pyongyang Castle through Pictorial Maps in the Late Joseon Dynasty (조선후기 회화식 고지도를 통해 본 평양성의 인문경관 특성)

  • Kim, Mi-Jung;So, Hyun-Su
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.38 no.2
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    • pp.14-30
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    • 2020
  • This study focuses on the fact that pictorial maps in the late Joseon Dynasty were conceptual diagrams with the place names perceived by the people at the time of their production. In this regard, targeting on five pictorial maps, the humanistic landscape characteristics of Pyongyang, which had cultural identities such as a historically old, commercial, and Pungnyu(appreciation for the arts) city, were derived as follows. First, the historic legitimacy of Pyongyang Castle was represented by ritual and religious facilities. They include 'Dangunjeon' and 'Gijagung' related to the nation founder, 'Munmujeong': the remains of Goguryeo, 'Sajikdan' & 'Pyongyanggangdan': the place of the national rites, Hyanggyo and Seowon: education & rite functions, Buddhism and Taoist facilities, 'Yongsindang', 'Sanshindang', and 'Jesindan': folk religion facilities. Gija-related facilities, which became symbols of Pyongyang due to the importance of Small-Sinocentrism and Gija dignity tendency, were distributed throughout Pyongyang Castle though, the facilities related to King Dongmyeong of Goguryeo and the spaces of religion praying for blessings are spread in Bukseong and on the riverside of Daedonggang each. Second, as a Pyongando Province's economic center, Pyongyang's commercial landscape was represented by logistics and transportation facilities. The Daedonggang River, which was in charge of transportation functions, had many decks such as 'Yangmyeongpo', 'Cheongryongpo' and 'Waeseongjin' and bridges, such as 'Yeongjegyo' and 'Gangdonggyo', which connected major transportation routes. The road network was created in Oeseong area to facilitate logistics transportation and management, and many warehouses named after the jurisdiction of Pyongyangbu were distributed near the roads and Provincial Offices of the main gates. In addition, it was characterized by the urban area systematically divided with hierarchical roads, 'Bukjangnim' of willow trees planted on the main entrance roads of Pyongyang Castle, a linear landscape created by 'Simnijangnim' consisting of mixed forests with elm trees. Third, Pungnyu City is realized by the distribution of amusement facilities. The riverside of Daedonggang adjacent to Naeseong exhibits characteristics of artificial landscape such as a canal leading to the inside of the castle, a docking facility with embankments, and a port with cargo ships anchored. However, Bukseong of the natural surroundings had numerous pavilions and platforms such as 'Bubyeongnu', 'Eulmildae', 'Choeseungdae', 'Jebyeokjeong' and engraved letters such as 'Cheongnyubyeok', 'Jangbangho'. 'Osunjeong', 'Byeogwolji', 'Banwolji' near 'Sachang', and 'Aeryeondang', built on the island of a square pond, created waterscape in Naeseong invisible from the Daedonggang, and for practical purposes, ponds and repeated willow vegetation landscape related to Gija were placed in the western rampart of Jungseong. In addition, 'Seonyeondong', a cemetery of Gisaeng, located near by Chilseongmun, was used as poem titles and themes by literary people, contributing to the creation of the Pungnyu image of Pyongyang.