• Title/Summary/Keyword: Urban rivers

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An Analysis of the Visual Characteristics and Preference Factors of Traditional Landscape of Rivers in Kangnam Region of China - With a Case of River in Zhouzhuang, Jiangsu Province of China - (중국 강남 전통 수향(水鄕) 하천 경관의 시각적 특성 및 선호요인 분석 - 중국 강수성 주장(周莊) 하천경관을 중심으로 -)

  • Kim, Dong-Chan;Song, Mei-Jie
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.3
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    • pp.122-130
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    • 2010
  • The Study takes the rivers in Zhouzhuang - traditional Chinese Kangnam watery landscape as the object. The purpose of this study is to grasp the relationships between visual characteristics and the preference. The following is the research process: Firstly, the theoretical study of Zhouzhuang, the traditional Kangnam region in China, is conducted, the watery landscape is taken pictures, and 22 photos are selected. Secondly, in order to grasp the visual preference and landscape characteristics of the watery landscape in Zhouzhuang, 22 pictures and 25 pairs of adjectives are adopted for the questionnaire survey. Thirdly, in order to have a better understanding on the physical properties and effects of physical quantity on the preference, the occupation ratios of buildings and sculptures, natural elements, footpaths, bank revetments and other landscape elements are calculated, and the mean analysis, dispersion analysis and regression analysis are conducted. In order to grasp the landscape characteristics and preference factors, 25 pairs of adjectives are used to conduct the factor analysis. In order to grasp the effects of characteristics of visual factors on the preference, the dispersion analysis and regression analysis are carried out. The results are as follows: From the results of the landscape preference analysis, in the No.22 photo with the top preference, 11 pairs of adjectives, namely, "harmonious-disharmonious", "beautiful-ugly", "rural-urban", "soft-rough", "stable-instable", "romantic-realistic", "cheerful-gloomy", "brilliant-simple", "natural-artificial", "familiar-strange", and "clean-dirty" have positive effects on watery landscape. It can be viewed as the relatively important factor in the visual preference. In terms of the results of visual physical quantity analysis of traditional Chinese Kangnam watery landscape, the landscape with high occupation ratio of buildings and sculptures has positive effects on visual preference. The results of analysis of visual physical quantity and preference show that the preference degree increases as the occupation ratio of footpath area increases. The analysis results of visual characteristics of traditional Chinese Kangnam watery landscape identify four factors, namely psychological factor, cultural factor, condition factor and physical factor. It can be concluded from the results of analysis of the relationships between visual preference and visual characteristics that the return coefficient B of the psychological factor is +0.936. It can significantly affect the watery landscape, so it can be identified as the most important factor among the visual preference factors of Chinese Kangnam watery landscape.

A Study of Community Awareness in Local Residents after the Restoration of Seongnaecheon (성내천 복원 후 지역주민의 커뮤니티 의식에 대한 연구)

  • Kim, Nam-Su;Lee, In-Hwan;Kim, Yong-Geun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.4
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    • pp.74-82
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    • 2011
  • During the industrialization and urbanization of the country, urban rivers have been covered over and developed without forethought and thus became estranged from spaces utilized by area residents in everyday life. Recently, an influx of people and uses have increased largely because accessibility improved through restoration projects which have transformed these river areas into pleasant environments. It thus appears that these projects have an impact on community consciousness for area residents who live near the restored rivers to some extent. The purpose of this study was to determine via questionnaire the effects and influences of urban river restoration on area residents targeting visitors to Seongnaecheon(stream), Songpa-gu, Seoul, which has been restored recently. Factors in the questionnaire analysis included such items as the use status of Seongnaecheon, community consciousness(feeling of belonging, solidarity, feeling settled), and a before and after comparison of the restoration(change of consciousness, regional effects), etc. According to the results of analysis, visitors who have utilized the stream more than 1~2 times per week after the restoration project accounted for the greatest portion. The main purposes of these visits were to 'rest' and 'exercise' while the ratio of using it as a 'meeting space with neighbors and strangers' was low. Community consciousness of area residents using Seongnaecheon was generally high. As a result of an analysis of consciousness differences between groups after dividing visitors into 3 groups according to the frequency of visits, there were significant differences in the consciousness level between groups with high community consciousness levels in visitors who visited frequently. In consideration of these results, the provision of programs along with proper facilities that can be used is deemed important for area residents so as to inspire community consciousness of the area by means of activating both community activities and the progressive use of the restored river.

A Study on the Improvement of Measuring Methods in Land Suitability Assessment: Focused on the Distance Measurement and Threshold Definition (토지적성평가 평가방법 개선방안 연구 : 거리측정 및 임계치 설정방안을 중심으로)

  • Jeong, Yeun-Woo;Lee, Sang-Jun
    • Land and Housing Review
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    • v.3 no.1
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    • pp.69-78
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    • 2012
  • This study proposes an approach to improve the accuracy of land assessment result focused on the Land Suitability Assessment. The detailed analysis processes are; (a) that they are analyzed considering resistance in distance measurement on the space characteristics of location, and; (b) that an assessment result is measured according to the threshold definition of membership function, which is applied in estimating conservation suitability. The assessment results are; firstly, the method considering resistance better reflects the local characteristics of area with worse accessibility including rivers and mountains than one by linear distance; secondly, the existing method that the maximum value of a target area is defined as the maximum threshold may draw a value evaluated lower than a threshold definition considering the distribution of measured indices. Finally, satellite images are overlapped with the assessed results, the applicability level from the approach proposed by this study is more coincident with the present status. The assessment method proposed by this study can be meaningful in view of that it improves the accuracy of Land Suitability Assessment. Furthermore, it can be applied as SDSS, which can support effective establishment of urban policies, in case of complementing the problems in executing the assessment system.

Problems of lake water management in Korea (한국의 호수 수질관리의 문제점)

  • 김범철;전만식;김윤희
    • Proceedings of the Korean Society of Environment and Ecology Conference
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    • 2003.10a
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    • pp.105-126
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    • 2003
  • In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.

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A Study on the Risk Assessment of River Crossing Pipeline in Urban Area (도심지 하천매설배관의 위험성 평가에 관한 연구)

  • Park, Woo-Il;Yoo, Chul-Hee;Shin, Dong-Il;Kim, Tae-Ok;Lee, Hyo-Ryeol
    • Journal of the Korean Institute of Gas
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    • v.24 no.2
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    • pp.22-28
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    • 2020
  • In this study, quantitative risk assessment was carried out for city gas high-pressure pipelines crossing through urban rivers. The risk assessment was performed based on actual city gas properties, traffic volume and population and weather data in the worst case scenario conditions. The results confirmed that the social and individual risks were located in conditionally acceptable areas. This can be judged to be safer considering that the risk mitigation effect of protecting the pipes or installing them in the protective structure at the time of the construction of the river buried pipe is not reflected in the result of the risk assessment. Also, SAFETI v8.22 was used to analyze the effects of wind speed and pasquil stability on the accident damage and dispersion distances caused by radiation. As a result of the risk assessment, the safety of the pipelines has been secured to date, but suggests ways to improve safety by preventing unexpected accidents including river bed changes through periodic inspections and monitoring.

A Study on the Surface Wind Characteristics in Suwon City Using a GIS Data and a CFD Model (GIS 자료와 CFD 모델을 이용한 수원시 지표 바람 특성 연구)

  • Kang, Geon;Kim, Min-Ji;Kang, Jung-Eun;Yang, Minjune;Choi, Seok-Hwan;Kang, Eunha;Kim, Jae-Jin
    • Korean Journal of Remote Sensing
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    • v.37 no.6_2
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    • pp.1837-1847
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    • 2021
  • This study investigated wind corridors for the entire Suwon-city area using a geographic information system and a computational fluid dynamics model. We conducted numerical simulations for 16 inflow wind directions using the average wind speeds measured at the Suwon automated synoptic observation system (ASOS) for recent ten years. We analyzed the westerly (dominant wind direction) and easterly cases (not dominant but strong wind speed) in detail and investigated the characteristics of a wind speed distribution averaged using the frequencies of 16 wind directions as weighting factors. The characteristics of the wind corridors in Suwon city can be summarized as; (1) In the northern part of Suwon, complicated flows were formed by the high mountainous terrain, and strong (weak) winds and updrafts (downdrafts) were simulated on the windward (leeward) mountain slope. (2) On the leeward mountain slope, a wind corridor was formed along a valley, and relatively strong airflow flowed into the residential area. (3) The strong winds were simulated in a wide and flat area in the west and south part of Suwon city. (4) Due to the friction and flow blocking by buildings, wind speeds decreased, and airflows became complicated in the downtown area. (5) Wind corridors in residential areas were formed along wide roads and areas with few obstacles, such as rivers, lakes, and reservoirs.

Assessment of the Freshwater Comprehensive Soundness in the Geum River Basin - Focusing on Ecological Soundness and Water Welfare - (금강유역의 하천 종합건전성 평가 - 생태적 건전성 및 물 복지를 중심으로 -)

  • Kim, Hong-Myung;Ha, Sung-Ryong
    • Journal of Environmental Impact Assessment
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    • v.31 no.3
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    • pp.184-199
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    • 2022
  • Freshwater soundness can be broadly divided into the health of river ecosystems and social services for human water use, that is, water welfare. In this study the ecological soundness and water welfare index of rivers were calculated, and the freshwater comprehensive soundness was analyzed using the quadrant model for 14 basins in the Geum River basin. As for the ecological soundness of the river, the area upstream of the dam (based on Daecheong Dam) was evaluated as 'good', and the area downstream of the dam was evaluated as 'bad'. On the other hand as for water welfare, the area downstream of the dam with a large population was in a relatively 'good' condition, and the area upstream of the dam had a relatively 'poor' level of water welfare. In terms of freshwater comprehensive soundness, it was found that the basins of Mujunamdaecheon, Bocheongcheon and Daecheongdam showed good ecological soundness and water welfare, and the Geumganggongju, Nonsancheon and Geumganhagueon basins were all poor. The Gapcheon basin showed good results in 2014 due to continuous investment and systematic management. Therefore, it is necessary to find ways to utilize it for other watersheds through benchmarking.

Establishing Habitat Quality Criteria for the Ecosystem Services InVEST Model Using AHP Techniques (AHP기법을 적용한 생태계서비스 InVEST 모형 서식지질 기준 설정)

  • Hae-Seon Shin;Jeong-Eun Jang;Sang-Cheol, Lee;Hye-Yeon Kwon;Gyeong-Rok Kim;Jin Jang;Song-Hyun Choi
    • Korean Journal of Environment and Ecology
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    • v.38 no.1
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    • pp.67-78
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    • 2024
  • The term ecosystem services refers to natural ecosystems' benefits to humans. Various models have been developed and applied to quantify ecosystem services. Habitat quality assessment is a widely used leading InVEST ecosystem service model. In Korea, habitat quality assessment is conducted for national parks. For habitat quality assessment, the initial value of habitat quality must be used to assess the sensitivity to threats, which varies depending on the country and application field. Therefore, an expert survey (AHP) was conducted based on previous habitat quality assessments in national parks to adjust the sensitivity, the initial value for the habit quality assessment. As a result of the AHP, 18 items were adjusted, including 10 items, such as natural grassland and unarranged fields, upward and 8 items, such as rivers and ponds, downward. Based on the adjusted sensitivity results, the habitat quality of Bukhansan National Park and Gyeryongsan National Park (urban type), Gyeongju National Park (historic type), Hallyeohaesang National Park (ocean type), and Jirisan National Park and Seoraksan National Park (mountain type) were adjusted. The results of the analysis showed that the habitat quality of urban dry areas and water bodies distributed in the national parks was reflected in the habitat quality assessment. In the future, it will be possible to evaluate the habitat quality of natural parks using this standard.

Analysis Schemes of Wind Ventilation Forest Types - A Case Study of Daegu Metropolitan City - (바람길숲의 유형별 분석 방안 - 대구광역시를 사례로 -)

  • EUM, Jeong-Hee;OH, Jeong-Hak;SON, Jeong-Min;KIM, Kwon;BAEK, Jun-Beom;YI, Chaeyeon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.4
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    • pp.12-23
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    • 2019
  • This study aims to suggest analysis schemes of urban forests acting as wind ventilation corridor(wind ventilation forest). For this purpose, wind corridor forests were classified into three types: wind-generating forests(WGF), wind-spreading forests (WSF), and wind-connecting forests(WCF), and they were classified into three grades. WGF, WSF and WCF were classified based on the density of forest type map, vegetation index, and ventilation networks, respectively. As a result of analyzing wind corridor forests for Daegu Metropolitan City(883.56㎢), the area of WGF was classified as 443.1㎢ and distributed in the northern and southern regions of Daegu Metropolitan City. Among them, the first grade of WGF occupied the largest area(345.59㎢) and the highest rate(54.44%) in Dalseong-gun. On the other hand, WGF was not found in Jung-gu, because this administrative district is isolated from the forest area. WSF was 32.4㎢, which included representative urban parks of Daegu Metropolitan City, and WSF were found relatively much in Suseong-gu and Dalseong-gun. However, WSF were distributed throughout Metropolitan City, and the vegetation index was not high. The ventilation network that can form WCF included major rivers and roads in Daegu Metropolitan City, but this network was not connected to the urban park from the outer forest. Therefore, it was judged that the formation of WCF connecting WGF outside the city and WSF inside the city would be important. The results of this study can be used as a basic data for systematic wind corridor forest projects, and can be used as basic data for establishing guidelines for wind corridor forest analysis at national and local levels.

Ecological health assessment of Yangjaecheon and Yeouicheon using biotic index and water quality (생물지수와 수질을 이용한 양재천과 여의천의 생태건강성평가)

  • Jin Hyo Lee;Hyeon Han;Jun Yeon Lee;Young Seop Cha;Seog Ju Cho
    • Korean Journal of Environmental Biology
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    • v.40 no.2
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    • pp.172-186
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    • 2022
  • Benthic macroinvertebrates are important ecological and environmental indicators as primary or secondary consumers, and therefore are widely used in the evaluation of aquatic environments. However, there are no comprehensive river ecosystem monitoring surveys that link the major physicochemical water quality items with benthic macroinvertebrates in urban streams. Therefore, this study investigated the distribution characteristics of benthic macroinvertebrates and physicochemical water quality items (17 items) in Yangjaecheon and Yeouicheon from 2019 to 2020. At the same time, by applying Spearman's rank correlation analysis and nonmetric multidimensional scaling (nMDS) analysis in the water quality data and biotic index, we tried to provide basic data for diagnosing the current status of river ecosystems in major urban rivers in Seoul. Based on the study results, a total of 39 species and 3,787 individuals were identified in Yangjaecheon, the water quality(based on BOD, TOC, and TP) of Yangjaecheon was higher than Grade Ib(good), and the BMI using benthic macroinvertebrates appeared as Grade C(normal) at all the sites. In Yeouicheon, a total of 51 species and 4,199 individuals were identified, the water quality(based on BOD, TOC, TP) was higher than Grade Ib(good) similar to Yangjaecheon, and the BMI of both Upstream and Saewon bridge was Grade B(good), while Yeoui bridge was Grade C(normal). Overall, analysis results for the distribution of benthic macroinvertebrates by a nonmetric multidimensional scaling method showed no significant difference between the two streams (p=0.1491). Also, significant environmental variables related to benthic macroinvertebrates distribution were determined as water temperature and DO. On the other hand, the results of the correlation analysis between biotic index and major water quality items confirmed that R1 and BMI could be used for on-site urban river water quality evaluation.