• Title/Summary/Keyword: land-use changes

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A Study on Calculation of Urban Compactness Index Considering Space Syntax: Focusing on the Declining Local Cities (공간구문론을 활용한 도시 압축지수 산정에 관한 연구: 소멸위험도시를 중심으로)

  • HA, Ji-Hye;KANG, Jung-Eun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.3
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    • pp.29-58
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    • 2022
  • Recently, Korea has been experiencing a problem of population decline, therefore the transition to a compact spatial structure is being urged. However, what is required is not just physical compression, but a compact city that also considers connectivity, in view of the changes in today's demographic and industrial structure. From this point of view, this study measures the compressibility of domestic cities suffering from extinction risk due to low birth rates, aging population, and population decline, and examined the spatial structure characteristics. In addition to the compressibility evaluation index used in previous studies, the compressibility of six indicators (population, land use, service accessibility, transport accessibility, connectivity, and concentration) was compared and analyzed, and a comprehensive compression index was calculated. The analysis results, based on the comprehensive compression index, classified 2.3% cities in the first grade, 4.6% in the second grade, 16.09% in the third grade, 43.68% in the fourth grade, and 33.33% in the fifth grade areas. Currently, the urban characteristics affecting the compactness index differ from region to region. Therefore, it is necessary to establish measures and policies for extinction risk considering the influence of each region's compactness index. This study is meaningful in that connectivity was considered using spatial syntax, and the compactness of cities at risk of extinction was compared and analyzed quantitatively. It is expected that this study will be used as basic data to establish the direction and action strategy for extinction risk cities.

Classification of Major Reservoirs Based on Water Quality and Changes in Their Trophic Status in South Korea (수질 특성에 따른 우리나라 주요 호소 분류 및 호소 영양 상태 변동 특성 분석)

  • Dae-Seong Lee;Da-Yeong Lee;Young-Seuk Park
    • Korean Journal of Ecology and Environment
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    • v.55 no.2
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    • pp.156-166
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    • 2022
  • Understanding the characteristics of reservoir water quality is fundamental in reservoir ecosystem management. The water quality of reservoirs is affected by various factors including hydro-morphology of reservoirs, land use/cover, and human activities in their catchments. In this study, we classified 83 major reservoirs in South Korea based on nine physicochemical factors (pH, dissolved oxygen, chemical oxygen demand, total suspended solid, total nitrogen, total phosphorus, total organic carbon, electric conductivity, and chlorophyll-a) measured for five years (2015~2019). Study reservoirs were classified into five main clusters through hierarchical cluster analysis. Each cluster reflected differences in the water quality of reservoirs as well as hydromorphological variables such as elevation, catchment area, full water level, and full storage. In particular, water quality condition was low at a low elevation with large reservoirs representing cluster I. In the comparison of eutrophication status in major reservoirs in South Korea using the Korean trophic state index, in some reservoirs including cluster IV composed of lagoons, the eutrophication was improved compared to 2004~2008. However, eutrophication status has been more impaired in most agricultural reservoirs in clusters I, III, and V than past. Therefore, more attention is needed to improve the water quality of these reservoirs.

A Study on the Characteristics of Rural Convention in Geongsang Region - Focused on the Rural Development Projects, Hierarchical Structure and Living Area - (경상지역 농촌협약 특징 - 일반 농산어촌개발사업, 계층구조, 생활권 설정을 중심으로 -)

  • Kim, Sang-Bum;Eom, Seong-Jun;An, Phil-Gyun;Jeong, Myeong-Cheol;Do, Jee-Yoon;Song, Mi-Jeong
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.4
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    • pp.67-75
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    • 2022
  • The purpose of this paper is to provide basic data to Si and Gun preparing for rural agreements in the future through consideration and case analysis for rural conventions, such things as living standards, hierarchical analysis methods, and general rural development projects. In the 1970s, sporadic and one-off projects focused on individual projects were repeatedly carried out in rural areas, which were undergoing dramatic changes in population movement, land use, landscape, economic growth and living. The keyword of the government's policy has changed to a way that existing rural development projects are planned and promoted by local governments themselves in conjunction with the issue of autonomy and decentralization. In addition, with the introduction of Rural Convention, the central and local governments are striving to achieve common policy goals. However, due to the lack of understanding of the Rural Convention introduced as a pilot project in 2020, the lack of living areas setting-standards, unclear classification of hierarchical structure, and excessive goal consciousness for general agricultural and fishing village development projects remain, fading the original purpose of the Rural Convention. Therefore, this study analyzed the seven reports of the Gyeongsang region selected in the 2021 Rural Convention to identify the characteristics of living area, hierarchical structure analysis, and detailed projects (rural center revitalization project, basic living base development project) and provided them as basic data. As a result of the study, first, according to the results of the hierarchical structure analysis, the first class was derived from 6 out of 7 Si and Gun. This is judged to be the result of the current rural population, social, and economic problems. Second, according to the results of the division of living areas, it was confirmed that except for one local government in seven cities and counties, the remaining six local governments were divided into three single living areas and three two living areas. This is the result obtained through a comprehensive review by overlapping the results of various analyses such as hierarchical analysis and resident surveys and OD data, and shows a different form from the existing upper or related plans. It is judged that this is the result of including qualitative contents such as residents' opinions along with various analyses when determining the living area. Third, the proportion of the budget for rural center revitalization and basic living base development projects to the total project cost subject to the Rural Convention was 59.6%, which was relatively higher than that of other general agricultural and fishing village development projects. It is judged that it is preferred because the unit project cost is relatively high in Si and Gun, and that quantitative results can be visually shown after the project is terminated.

Karst Studies in the Korean Geographical Society: Achievements for the Past Fifty Years (한국 지리학계의 카르스트 연구)

  • PARK, Sunyurp
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.127-140
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    • 2011
  • Research achievement of Korean geographers on karst studies was evaluated based on the number of publications for the past fifty years, which were divided into four main periods, including beginning, youth, growth, and maturity stages. The descriptive statistics of research papers published in major geography journals were computed and these articles were classified according to their main subjects and study areas. The role of moisture is particularly important in Karst geomorphology compared to the other geomorphological fields. The morphology, landscape, and formation processes of tropical and temperate karst are different from each other, and the regional and altitudinal characteristics of karst environments are significantly diverse. Thus, it is likely that the detailed records of climatic changes are preserved in the northeast Asian karst landform. Since karst geomorphology can be a major cause of natural hazards, such as collapsed surfaces or subsidence, which are associated with anthropogenic activities, including underground-water pumping and land use, education and training of physical geographers, specializing on monsoon effects, distributions of limestone, and soil characteristics, are critical issues to foster the capacity of disaster management in the nation. Moreover, knowing that the unique and spectacular landscape of karst geomorphology is a valuable, natural resource of tourism and has aesthetic values on its own, contributions of geographers to the introduction, conservation, research, and development of karst environment should be emphasized.

Changes of Street Patterns in Central Part of Taegu City (大邱市 都心部의 街路網 變化)

  • Choi, Seok-Joo
    • Journal of the Korean Geographical Society
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    • v.31 no.3
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    • pp.593-612
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    • 1996
  • This study concern with the changes of street from the Choseon Dynasty to present days around Old-Boundary in Taegu, analyzing the backgrounds of change factors and development trends of the Taegu City. The basis element of a city structure is the street. Therefore, in this study, a chage of street space of a city was investigted. Historically, Taegu was a walled city and had a Mono-nucleus which was restricted by the castle, and served as a starting point of formation of spatial structuure. The form of the artery street took a "T" pattern, othe streets were formed in irregular shapes. As the city grew gradually, the castle was removed on account of diversification in traffic network, change of socio-economic organization in traffic network, change of socio-economic organization, formation of industrial bases and functional distribution. CBD of this city has been located within the area surrounded by these streets. This is a kind of general pattern of traditional walled cities through the world in both Western and Oriental societies. A s the begining of this centry, a 'Dark Ages' descended upon Korea because the country was under the Japanese-Korean Annexation, and, throughout this period, the urban planning was planned exclusively for Japanese. The street pattern within residential areas of Korea took the maze type, in contrast with Japanese residential areas which showed grid pattern of streets. This is another general pattern of almost of all colonial cities especially in Asia. High class residential areas were planned and built by Japanese, and they were located within 5-10 minutes' on-foot distance from the CBD hard core. This high prestige has continued until the 1980s when it occurred land use succession which commerical functions invaded into residential areas. Back in the colonial period, there was a between two hetrogeneous groups due to the fact that the Japanese lived mainly oriented the new railway system but that Koreans still lived along the old highway system which ran through the Korea Peninsula. Street netwook formed in the above process has maintained its shape without great changes after the liberation form the Japanese Colony. Taegu has, accordingly, developed ring-radial network system which has been a combination of radial and ring facilities. The present conditions of street patterns in Taegy mainly depend on 4 rings and 8 radius, with grid pattern street able to be found in Old Boundary.

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Change of Carbon Fixation and Economic Assessment according to the Implementation of the Sunset Provision (도시공원 일몰제에 의한 탄소고정량과 경제성 분석에 대한 연구)

  • Choi, Jiyoung;Lee, Sangdon
    • Ecology and Resilient Infrastructure
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    • v.7 no.2
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    • pp.126-133
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    • 2020
  • In accordance with the implementation of the sunset provision to cancel the designations of urban park sites that remained unexecuted for a prolonged period until 2020, the park sites in the city center, which account for 90% of the long-term unexecuted urban facilities subjected to the provision, are currently on the verge of development. The total area of the 204 park sites that will disappear in Seoul as a result of this provision is 95 ㎢; moreover, 116 of these are privately-owned. It is expected that the possible changes in the use of these park sites could result in reckless development and reduction of green space, which would ultimately affect the ecosystem. This study applied the InVEST model to calculate the changes in the fixed carbon amount before and after the implementation of the sunset provision to estimate the economic value of these changes. The study focused on Jongno-gu in Seoul because it has the most unexecuted park sites subjected to the lifting of the designation. The research findings show that the fixed carbon amount provided by the unexecuted park sites in Jongno-gu was 374,448 mg, prior to the implementation of the sunset provision; however, the amount was estimated to decrease by 18% to 305,564 mg after its execution. When calculated in terms of average value of the real carbon price, this translated into a loss of approximately 700 million won. In addition, considering the social costs including both climate change and the impact on the ecosystem, an economic loss of approximately 98 billion won was projected. This study is meaningful because its predictions are based on the estimation of fixed carbon amount according to the implementation of the sunset provision in Jongno-gu and scientifically calculates the value of ecological services provided by the parks in the city. This study can serve not only as a basis during the decision-making process for policies related to ecosystem conservation and development, but also as an evidentiary material for the compensation of privately-owned land that is designated as urban park sites and was unexecuted for a prolonged period.

The Impact of the Reclamation and Utilization of Idle Hillside Lands on Future Food Production in Korea (식량(食糧)의 안정적(安定的) 공급(供給)을 위한 산지개발이용의 필요성(必要性)과 전망(展望))

  • Park, Johng-Moon
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.4
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    • pp.213-233
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    • 1979
  • It is generally agreed that the country's population will grow up to the level of 52 million by the year of 2000 and that due the active growth of industry, urbanization and road constructions, sizable portion of existing arable lands will be utilized for other purposes than agriculture in near future. From 1966 to 1977, it was estimated that, the average annual conversion of arable lands to other uses, was 12,909 ha. If this trend persists, it is predicted that from 1978 to 1991 when the 6th Five Years Economic Development Plan will terminate, approximately 181,000 ha of arable lands will be converted for other uses again. On the other hand, it is certain that the increased population (39 million in 1981, 45 million in 1991, 52 million in 2001) and the changes in food pattern along with the enhancement of living standards will bring about the phenomenal increase in demands for not only the staple food but also the livestock products such as meat, milk and eggs, vegetables and fruits. These future increased demands for various foods, naturally mean the increased needs for the expansion of arable lands at the same time. It is predicted that, if more activities than present scale are not taken for the expansion of arable lands, the national food self sufficiency level will drop from 79% in 1977 down to 62% in 1991. To meet the increased food demands in future, there are several ways and means. These will include the increased land use intensity, elevation of unit area yield levels, minimization of conversion of arable lands to other uses and expansion of arable lands through the reclamations of idle hillside lands and tidal lands. Among these, the expansion of arable lands through reclamations of idle hillside lands and tidal lands are more positive measures to cope with the increased production of foods in future. The reclamation of hillside lands demands more attention because it needs more advanced technologies in agronomical and engineering aspects, larger scale fundings and integrated socioeconomic considerations. In agromical aspects, the thechniques for early improvement of chemical and physical properties of soils, proper soil conservation measures and rational cropping systems are of particular importance. As to the financial supports to encourage the farmings in hillside land, much bold fund inputs are essential for the construction of roads, installation of irrigation and drainage facilities, soil conservation mechanisms, which will ensure the stabilized farming with reasonable incomes in the newly reclaimed lands.

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Study on Climate Change Impacts on Hydrological Response using a SWAT model in the Xe Bang Fai River Basin, Lao People's Democratic Republic (기후변화에 따른 라오스인민공화국의 시방파이 유역의 수문현상 예측에 대한 연구: SWAT 모델을 이용하여)

  • Phomsouvanh, Virasith;Phetpaseuth, Vannaphone;Park, Soo Jin
    • Journal of the Korean Geographical Society
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    • v.51 no.6
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    • pp.779-797
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    • 2016
  • A calibrated hydrological model is a useful tool for quantifying the impacts of the climate variations and land use/land cover changes on sediment load, water quality and runoff. In the rainy season each year, the Xe Bang Fai river basin is provisionally flooded because of typhoons, the frequency and intensity of which are sensitive to ongoing climate change. Severe heavy rainfall has continuously occurred in this basin area, often causing severe floods at downstream of the Xe Bang Fai river basin. The main purpose of this study is to investigate the climate change impact on river discharge using a Soil and Water Assessment Tool (SWAT) model based on future climate change scenarios. In this study, the simulation of hydrological river discharge is used by SWAT model, covering a total area of $10,064km^2$ in the central part of country. The hydrological model (baseline) is calibrated and validated for two periods: 2001-2005 and 2006-2010, respectively. The monthly simulation outcomes during the calibration and validation model are good results with $R^2$ > 0.9 and ENS > 0.9. Because of ongoing climate change, three climate models (IPSL CM5A-MR 2030, GISS E2-R-CC 2030 and GFDL CM3 2030) indicate that the rainfall in this area is likely to increase up to 10% during the summer monsoon season in the near future, year 2030. As a result of these precipitation increases, the SWAT model predicts rainy season (Jul-Aug-Sep) river discharge at the Xebangfai@bridge station will be about $800m^3/s$ larger than the present. This calibrated model is expected to contribute for preventing flood disaster risk and sustainable development of Laos

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Evaluation of SWAT Applicability to Simulation of Sediment Behaviois at the Imha-Dam Watershed (임하댐 유역의 유사 거동 모의를 위한 SWAT 모델의 적용성 평가)

  • Park, Younshik;Kim, Jonggun;Park, Joonho;Jeon, Ji-Hong;Choi, Dong Hyuk;Kim, Taedong;Choi, Joongdae;Ahn, Jaehun;Kim, Ki-sung;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.23 no.4
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    • pp.467-473
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    • 2007
  • Although the dominant land use at the Imha-dam watershed is forest areas, soil erosion has been increasing because of intensive agricultural activities performed at the fields located along the stream for easy-access to water supply and relatively favorable topography. In addition, steep topography at the Imha-dam watershed is also contributing increased soil erosion and sediment loads. At the Imha-dam watershed, outflow has increased sharply by the typhoons Rusa and Maemi in 2002, 2003 respectively. In this study, the Soil and Water Assessment Tool (SWAT) model was evaluated for simulation of flow and sediment behaviors with long-term temporal and spatial conditions. The precipitation data from eight precipitation observatories, located at Ilwol, Subi and etc., were used. There was no significant difference in monthly rainfall for 8 locations. However, there was slight differences in rainfall amounts and patterns in 2003 and 2004. The topographical map at 1:5000 scale from the National Geographic Information Institute was used to define watershed boundaries, the detailed soil map at 1:25,000 scale from the National Institute of Highland Agriculture and the land cover data from the Korea Institute of Water and Environment were used to simulate the hydrologic response and soil erosion and sediment behaviors. To evaluate hydrologic component of the SWAT model, calibration was performed for the period from Jan. 2002 to Dec. 2003, and validation for Jan. 2004 to Apr. 2005. The $R^2$ value and El value were 0.93 and 0.90 respectively for calibration period, and the $R^2$ value and El value for validation were 0.73 and 0.68 respectively. The $R^2$ value and El value of sediment yield data with the calibrated parameters was 0.89 and 0.84 respectively. The comparisons with the measured data showed that the SWAT model is applicable to simulate hydrology and sediment behaviors at Imha dam watershed. With proper representation of the Best Management Practices (BM Ps) in the SWAT model, the SWAT can be used for pre-evaluation of the cost-effective and sustainable soil erosion BMPs to solve sediment issues at the Imha-dam watershed. In Korea, the Universal Soil Loss Equation (USLE) has been used to estimate the soil loss for over 30 years. However, there are limitations in the field scale mdel, USLE when applied for watershed. Also, the soil loss changes temporarily and spatially, for example, the Imha-dam watershed. Thus, the SW AT model, capable of simulating hydrologic and soil erosion/sediment behaviors temporarily and spatially at watershed scale, should be used to solve the muddy water issues at the Imha-dam watershed to establish more effective muddy water reduction countermeasure.

A Diachronic Study on Historical and Cultural Landscape of Songhyeon-dong, Seoul (서울 송현동(松峴洞) 일원 역사문화경관의 통시적 연구)

  • Kang, Jae-Ung;So, Hyun-Su
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.39 no.4
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    • pp.85-98
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    • 2021
  • In accordance with planning to construct culture park on Songhyeon-dong (district) near Gyeongbokgung Palace, This study analyzed literature and drawings from the early Joseon Dynasty to today for the district, known as 'Songhyeon (pine hill)' to identify historical and cultural landscapes during essential times. The following are the results; First, the owners of significant lots were identified, and land use and landscape components were extracted for a diachronic examination of the landscape of the whole area of Songhyeon-dong. Songhyeon district had been regarded as the 'Inner Blue Dragon (Spot) of Gyeongbokgung Palace' in terms of geomancy since the foundation of Joseon in 1392 in that the government created and managed a 'pine forest' in the district. A state warehouse called 'bungam' was constructed, and small fruit stores, 'ujeon,' opened due to the complete reformation and urban planning led by King Taejong in 1410. From the 19th century, mansions of the upper class, such as 'Gaseonggak', 'Changnyeongwuigung' and 'Byeoksugeosajeong' were in the district. A prominent official residential complex called 'Sigeun Sataek' was constructed in 1919 after Chosen Siksan Bank purchased the site. Later, it was transferred to America in 1948 and used as the 'US Embassy Staff Quarters'. Second, the changes in the site view, associated with the aspects of society by the times, were examined by estimating the location and the time the landscape components lasted in each period extracted and identifying the physical entity. The pine forest, regarded as the 'Inner Blue Dragon' that guards the left side of the palace within the geomantic world view, was located in the highlands in the west of the site. In the same period, the flat area in the east was regarded as the 'commoner's district', the streets adjacent to various government facilities and the market, packed with people from different walks of life. From the 19th century, the gardens of the aristocrats of the capital city were created in the pine forest, turning the place into the forest in the middle of the city. The whole area of Songhyeon-dong, which existed as a large lot in the city center for a long time, was developed by Japanese imperialists in the 20th century based on the concept of 'Ideal Healthy Land,' which interrupted the placeness of Songhyeon-dong that had adhered to the traditional geomatic view of the Joseon Dynasty.