• Title/Summary/Keyword: mountain city

Search Result 275, Processing Time 0.029 seconds

Recycling of Suspended Particulates by Atmospheric Boundary Depth and Coastal Circulation (대기경계층과 연안순환에 의한 부유입자의 재순환)

  • Choe, Hyo
    • Journal of Environmental Science International
    • /
    • v.13 no.8
    • /
    • pp.721-731
    • /
    • 2004
  • The dispersion of suspended particulates in the coastal complex terrain of mountain-inland basin (city)-sea, considering their recycling was investigated using three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). Convective boundary layer under synoptic scale westerly wind is developed with a thickness of about I km over the ground in the west of the mountain, while a thickness of thermal internal boundary layer (TIBL) is only confined to less than 200m along the eastern slope of the mountain, below an easterly sea breeze circulation. At the mid of the eastern slop of the mountain, westerly wind confronts easterly sea breeze, which goes to the height of 1700 m above sea level and is finally eastward return flow toward the sea. At this time, particulates floated from the ground surface of the city to the top of TIBL go along the eastern slope of the mountain in the passage of sea breeze, being away the TIBL and reach near the top of the mountain. Then those particulates disperse eastward below the height of sea-breeze circulation and widely spread out over the coastal sea. Total suspended particulate concentration near the ground surface of the city is very low. On the other hand, nighttime radiative cooling produces a shallow nocturnal surface inversion layer (NSIL) of 200 m thickness over the inland surface, but relatively thin thickness less than 100m is found near the mountain surface. As synoptic scale westerly wind should be intensified under the association of mountain wind along the eastern slope of mountain to inland plain and further combine with land-breeze from inland plain toward sea, resulting in strong wind as internal gravity waves with a hydraulic jump motion bounding up to about 1km upper level in the atmosphere in the west of the city and becoming a eastward return flow. Simultaneously, wind near the eastern coastal side of the city was moderate. Since the downward strong wind penetrated into the city, the particulate matters floated near the top of the mountain in the day also moved down along the eastern slope of the mountain, reaching the. downtown and merging in the ground surface inside the NSIL with a maximum ground level concentration of total suspended particulates (TSP) at 0300 LST. Some of them were bounded up from the ground surface to the 1km upper level and the others were forward to the coastal sea surface, showing their dispersions from the coastal NSIL toward the propagation area of internal gravity waves. On the next day at 0600 LST and 0900 LST, the dispersed particulates into the coastal sea could return to the coastal inland area under the influence of sea breeze and the recycled particulates combine with emitted ones from the ground surface, resulting in relatively high TSP concentration. Later, they float again up to the thermal internal boundary layer, following sea breeze circulation.

Running safety of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city

  • Zhang, Yunfei;Li, Jun;Chen, Zhaowei;Xu, Xiangyang
    • Structural Engineering and Mechanics
    • /
    • v.76 no.2
    • /
    • pp.207-222
    • /
    • 2020
  • Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train subjected to fluctuating crosswind. To ensure the safe operation in metro lines in mountain cities, running safety of the metro train over the high-pier bridge under crosswind is analyzed in this paper. Firstly, the dynamic model of the wind-train-bridge (WTB) system is built, in which the speed-up effect of crosswind is fully considered. On the basis of time domain analysis, the basic characteristics of the WTB system with high-pier are analyzed. Afterwards, the dynamic responses varies with train speed and wind speed are calculated, and the safety zone of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city is determined. The results indicate that, fluctuating crosswind triggers drastic vibration to the metro train and high-pier bridges, which in turn causes running instability of the train. For this reason, the corresponding safety zone for metro train running on the high-pier is proposed, and the metro traffic on the high-pier bridge should be closed as the mean wind speed of standard height reaches 9 m/s (15.6 m/s for the train).

Water Quality Characteristics of Nonpoint Pollutants based on the Road Type (도로 유형별 비점오염원의 수질특성)

  • Jang, Dae-Chang;Kang, Seon-Hong
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.23 no.5
    • /
    • pp.631-636
    • /
    • 2009
  • This study has its intention to investigate the water quality of non-point source which is runoff from roads. We have classified and selected twelve sites as city road, industrial road, national road and mountain road by considering their traffic volume and surroundings. Water quality was analyzed based on BOD, COD, SS, T-N and T-P and the concentrations were measured by sampling after rainfall with the interval of 10 minutes, 20 minutes, and 30 minutes. BOD was the highest in city road with 57.6 mg/L and the lowest in mountain road with 45.0 mg/L. For COD, the highest concentration in industrial road was 146.5 mg/L and the lowest was in mountain road with 98.0 mg/L. The run off concentration of SS was up to maximum 630.0 mg/L (average 280.4 mg/L) which was remarkable compared to other types of road. It showed its lowest concentration in national road with 76.0 mg/L. T-N and T-P were the highest in industrial road and the lowest in mountain road. We found out that the runoff concentration was high with large amount of traffic volume and it seemed to be high in city road and industrial road where they were largely affected by their surroundings. Relatively, national road and mountain road seemed to show low concentration as they have less traffic volume and less affected by their surroundings.

Landscape Ecology and Management Measure of Urban Mountain Forest in Seoul (서울시 도시 숲의 경관생태와 관리방안)

  • Kong, Woo-Seok;Kim, Kunok;Lee, Sle-Gee;Park, Hee-Na
    • Journal of Environmental Impact Assessment
    • /
    • v.23 no.3
    • /
    • pp.208-219
    • /
    • 2014
  • This work aims to establish the landscape ecological countermeasures to improve the sustainability of urban mountain forest and to enrich the biodiversity in twenty mountains of the Seoul Metropolitan City. Landscape ecological analysis was conducted based upon various criteria, such as area and elevation of mountains, flora, naturalized plants, vegetation, forest types, mountain trails, and public facilities. Various measures were suggested for the better maintenances of floristic diversity, introduced plants, vegetation and forest types of urban mountain forests. Sustainable recommendations for land use adminstration were developed for the preparations of a climate change-adapted urban mountain forests, as well as rational managements of ecosystem, walking trails, and public facilities within mountain forest. Rich and diverse natural vegetation as well as high floristic diversity were reported at mountains with higher elevations, larger area size, and rich landscape diversity. Mountains with low elevation, small size with easy public access, however, might require an urgent action to decrease the burdens by anthropogenic disturbances and urban development.

Restoration of Iksan Imperial Capital City Structure and Construction Model in Late Baekje from the Point of Ancient Capital City Planning (백제 후기 익산도성 조영계획모델에 대한 도성계획사적 해석)

  • Lee, Kyung-Chan
    • Journal of architectural history
    • /
    • v.24 no.3
    • /
    • pp.31-41
    • /
    • 2015
  • This study aims to draw out planning principles and structure of Iksan imperial capital city in late Baekje, especially in view of the relationship among imperial capital city planning area, skeletal axis and the location of royal castle. With site survey and analysis of historical records, old maps, topographical maps, archeological excavation data, land registration map of 1915, some significant inferences were drawn out. Firstly from the point of topological conditions, the contiguous line of a stratum from Mireuk mountain(彌勒山) to Wangkung-ri castle(王宮里遺蹟) and two waterways made a topological axis of Iksan Imperial capital city. Secondly district of Iksan imperial capital city can be deduced to the inner area north to Kummado soil wall(金馬都土城), south to the confluence of Iksan river(益山川) and Busang river(扶桑川), west to Okum mountain fortress(五金山城) and Galjeon river(葛田川), east to line near to eastern wall of Jesuksa temple(帝釋寺). Iksan ssang-reung(益山雙陵) was located outside western boundary line of capital city. Thirdly axis from Wangkung-ri castle to northern Kummado soil wall made a skeletal axis of city structure. It got through northern lowland along Buk river(北川) between Yonghwa(龍華山) and Mireuk mountain. Fourthly the location of royal palace can be deduced to the north part of the city around Kumma town area along the planning principle of northern royal palace.

The Educational Needs Analysis on Migration to Mountains Area by City Dwellers (도시민 대상 귀산촌 교육 요구도 분석)

  • Chang, Chu-youn;Kim, Jae-hyun
    • Journal of Korean Society of Forest Science
    • /
    • v.104 no.3
    • /
    • pp.466-475
    • /
    • 2015
  • The purpose of this study was to investigate the educational needs targeted at city dwellers with hope of migration to mountain areas. 80 city dwellers participating in the education program operated by Korea Forestry Promotion Institute were selected. Results showed that city dwellers had higher preference for the education including medium scale(20-40 persons)and the type of camp with field experience. Real experiences and knowledge and understanding of migration to rural area are the most important element of the qualifications of the program teachers. In the contents of education, city dwellers wanted the teaching programs about 'how to have forest land', 'how to produce the forest products', 'field experience' and 'forest tourism' and so on. In other words, city dwellers who wanted to move to mountain areas were interested in basic things for living. In addition, it will need to investigate people who have real experiences migrating to mountain areas and then it is necessary to discuss educational needs and supporting system helping people can settle in mountain areas.

The Setting of Restoration Priority and Assessment for Mountain Range Fragmented Points in Daegu : Focused on the Ecological Aspect (생태적 측면에서의 대구광역시 산줄기 단절지점 평가 및 복원우선순위 설정)

  • Kim, Jin-Hyo;Ra, Jung-Hwa;Kwon, Oh-Sung;Cho, Hyun-Ju
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.21 no.5
    • /
    • pp.1-16
    • /
    • 2018
  • The purpose of this study is to identify the fragmented points of mountain ranges in Daegu metropolitan city using New Sangyeongpyo (Chart of Mountain Ranges), road system map and GIS spatial analysis, and to prioritize the identified fragmented points for restoration based on quantitative assessment. Moreover, this study proposes restoration plans reflecting the assessment results and characteristics of each fragmented point. The results of this study are summarized as follows: First of all, analysis of the distribution of mountain ranges in Daegu metropolitan city showed that jimaek and semaek in Daegu account for 2% of all mountain ranges in the country, implying that the mountain ranges of Daegu do not hold significant ranking on a national level. However, it was found that numerous fragmented points are appearing due to roads. According to the analysis, 35 fragmented points were identified, of which 15 were found to be restorable. In terms of restoration potential and involved risks, assessment results of the 15 fragmented points indicated that 6 points are at Grade I, 3 points are at Grade II and 6 points are at Grade III. Therefore, a methodology of restoring fragmented mountain ranges was proposed through three suggestions of restoration plans that consider the characteristics of each fragmented points. The results of this study are expected to be highly useful as basic data for effective restoration of mountain ranges in connection with mountain range restorations and relevant projects implemented on a national level in the future.

Why is Seogwipo Warm in Winter? The wind from Jeju City to Seogwipo-The Wind from Seogwipo to Jeju City (서귀포는 겨울철에 왜 따뜻할까? 제귀지풍과 귀제지풍)

  • Sung kook Lee;Moon Ho Lee;Jeong Su Kim
    • The Journal of the Convergence on Culture Technology
    • /
    • v.9 no.4
    • /
    • pp.121-125
    • /
    • 2023
  • In winter, Jeju's Seogwipo and Jungmun areas are 2~3℃ warmer than Jeju City. The reason is that when the north wind over Halla Mountain crosses Baengnokdam of Halla Mountain and passes the 300m long and 260m vertical rock face of Donnaeko at an altitude of 1600m above sea level, the cold air turns into warm air through adiabatic compression, and the warmth rides on Donnaeko and flies to Seogwipo and Jungmun. Conversely, the south wind that rises over the sea in Seogwipo in the summer passes over Hallasan Mountain and passes 99 valleys before turning into a muggy, humid climate, making Jeju hot. In other words, it is because of The wind from Jeju City to Seogwipo-The Wind from Seogwipo to Jeju City.

A Study on the Theory of Mountain Village Region in Korea of Globalization Age (세계화 시대의 한국 산지촌에 관한 이론연구)

  • Oh, Nam-Hyun
    • Journal of Korean Society of Rural Planning
    • /
    • v.13 no.4
    • /
    • pp.43-51
    • /
    • 2007
  • The propose of this paper is to study a theory on the research of mountain village region in korea of globalization age. The theory of this study is over-depopulation region study, endogenous regional development theory and resident organization, localities and new regional studies The case of over-depopulation region study, which population and land use of mountain village region due to urbanization and industrialization are changed by external factors. However, the case of some region is changed by internal factors of community residents. The endogenous regional development theory and have approached by investment policy of authorities of the mountain village region development and resident organization. The development of mountain village region have to described simultaneously both behavior strategy of community residents and investment policy of the authorities. According to localities and new regional studies, which agricultural products of mountain village region is extended to big-scale city by the progress transportation-communication and globalzation So, the research of mountain village region have to explained together intra with inter region. In the future, the research of mountain village region has to described all of case of over-depopulation region study, endogenous regional development theory, localities and new regional studies.

Analysis of Ancient Document and Establishment of Petrological Database for Presumption of Stone Source Area of the Seoul City Wall, Korea (한양도성 석재공급지 추정을 위한 고문헌 분석 및 암석학적 데이터베이스 구축)

  • Jo, Young Hoon;Lee, Chan Hee
    • The Journal of the Petrological Society of Korea
    • /
    • v.24 no.3
    • /
    • pp.193-207
    • /
    • 2015
  • This study analyzed ancient documents and established petrological database through extensive field investigation of provenance sites to presume stone source areas of the Seoul City Wall. By summarizing the ancient documents, the rampart stone was mostly supplied from a stony mountain adjacent to the City Wall in the early Joseon period, whereas the stone was provided from fixed quarry outside the City Wall in the late Joseon period. As a result of the petrological investigation based on quarries recorded in the ancient documents, pinkish granite and leucogranite were distributed as a whole, and the granitoid rocks are similar in mineralogical compositions and geochemical behavior characteristics. However, the pinkish granite with magnetic-series show that the magnetic susceptibility increased from the north slope of Namsan Mountain to Bulamsan Mountain. The leucogranite with ilmenite-series mainly occurred along the boundary between granite and gneiss from Yongmasan Mountain to Inwangsan Mountain. Consequently, the important petrological indicators for presumption of stone source areas are the rock color and the magnetic susceptibility. In addition to the petrological features, the reliability for provenance interpretation should improve considering stone quantities in the quarries, transportation distance and technical skills.