• Title/Summary/Keyword: 하천 지형

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The Impact of Monsoon on Seasonal Variability of Basin Morphology and Hydrology (호수 지형 및 수리수문학적 변화에 대한 몬순 영향)

  • An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.33 no.4 s.92
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    • pp.342-349
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    • 2000
  • This paper demonstrates the influence of intensity of the monsoon on morpho-hydrological fluctuations in Taechung Reservoir during 1993${\sim}$1994. During the study, hydrological variables including rainfall, inflow, and discharge volume showed distinct contrast between 1993 and 1994. Interannaul differences in rainfall occurred during the monsoon in July${\sim}$August monsoon and influenced inflow, discharge, and water residence time (WRT). Total inflow in 1993 was four times greater than that of 1994, and summer inflow in 1993 was 8 times greater than summer 1994. Annual Mean WRT was 93.2 d in 1993 vs. 158.6 d in 1994 and the largest differences occurred between monsoons of 1993 and 1994. Morphometric variables reflected the interannual contrasts of hydrology, so that in 1993 surface area, total volume, shoreline development, and mean depth increased consistently from premonsoon to postmonsoon and over this same period in 1994 they decreased. This outcome indicates that the area of shallow littoral zones in 1993 was greater than in 1994. Also, the drainage area to surface area (D/L) at 80 m MSL was 60.7 which was much greater than values in Soyang and Andong reservoirs and natural lakes world-wide. The morpho-hydrodynamic conditions seemed to influence in-reservoir nutrient concentration which is one of the most important factors regulating the eutrophication processes. I believe, under the maximum hydrodynamic fluctuations in Korean waterbodies during the monsoon, applications of mass balance models to man-made lakes for assessments of external loading should be considered because the models can be used under the seasonally stable inflow and water residence time.

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Classification and Characterization for Water Level Time Series of Shallow Wells at the National Groundwater Monitoring Stations (국가지하수관측소 충적관측정의 수위 변동 유형 분류 및 특성 비교)

  • Kim, Gyoo-Bum;Yum, Byoung-Woo
    • Journal of Soil and Groundwater Environment
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    • v.12 no.5
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    • pp.86-97
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    • 2007
  • The principal component analysis was performed to identify the general characteristics of groundwater level changes from 202 deep and 112 shallow wells monitoring data, respectively, which came from the National Groundwater Monitoring Stations operated by KWATER with time spans of 156 continuous weeks from 2003 to 2005. Eight principal components, which accounted for 80% of the variability of the original time series, were extracted for water levels of shallow and deep monitoring wells. As a result of cluster analysis using the loading value of three principal components for shallow wells, shallow monitoring wells were divided into 3 groups which were characterized with a response time to rainfall (Group 1: 4.6 days, Group 2: 24.1 days, Group 3: 1.4 days), average long-term trend of water level (Group 1: $2.05{\times}10^{-4}$ m/day, Group 2: $-7.85{\times}10^{-4}$ m/day, Group 3: $-3.51{\times}10^{-5}$ m/day) and water level difference (Group 1 < Group 2 < Group 3). Additionally, they showed significant differences according to a distance to the nearest stream from well (Group 3 < Group 2 < Group 1), topographic slope of well site (Group 3: plain region, Group 1: mountainous region) and groundwater recharge rate (Group 3 < Group 2 < Group 1) with a p-value of 0.05.

An Experimental Study to Evaluate Hydraulic Characteristics and Stability of Scour Protection for Historic Site Restoration of Woljeong-gyo (월정교 사적지 복원을 위한 수리특성 및 세굴보호공 안정성 검토에 관한 수리모형실험 연구)

  • Kang, Joon-Gu;Yeo, Hong-Koo;Son, Byung-Ju;Ji, Un
    • Journal of Korea Water Resources Association
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    • v.41 no.8
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    • pp.845-854
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    • 2008
  • The old bridge of Woljeong-gyo, which has the fluvial history and culture, represents the ancient construction and civil engineering techniques. It is the oldest stone bridge in Korea and currently restored with its vicinities. In this study, the experimental model was used to analyze the hydraulic characteristics, the local pier-scour depth without scour protection, and the stability of riprap protection using the old grid type panels and stones for Woljeong-gyo of the study area. The water levels were increased around 30cm due to the restored bridge piers and foundations and the effects went up to 200m upstream. The maximum scour depth of 5.4m was measured and the scour protection tests were performed with the riprap size calculated using empirical equations and the existing scour protection range. The riprap of the existing scour protection in the upstream side was broken away, while the riprap of extended scour protection was very stable for the design flood condition of Woljeong-gyo area.

Analysis of Water Quality on Distributed Watershed using Topographic Data (공간정보를 이용한 분포형 유역 수질 모의)

  • Ryu, Byong-Ro;Jung, Seung-Kwon;Jun, Kye-Won
    • Journal of Korea Water Resources Association
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    • v.37 no.11
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    • pp.897-913
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    • 2004
  • There has been continuous efforts to manage the water resources for the required water quality criterion at river channel in Korea. However, we could not obtain the partial improvement only for the point source pollutant such as, wastewater from urban and industrial site through the water quality management. Therefore, it is strongly needed that the Best Management Practice(BMP) throughout the river basin for water quality management including non-point source pollutant loads. This problem should be resolved by recognizing the non-point source pollutant loads from upstream river basin to the outlet depends on the land use and soil type characteristic of the river basin using the computer simulation by distributed parameter model based on the detailed investigation and the application of Geographic Information System(GIS). Used in this study, Annualized Agricultural Non-Point Source Pollution (AnnAGNPS) model is a tool suitable for long term evaluation of the effects of BMPs and can be used for un gauged watershed simulation of runoff and sediment yield. Now applications of model are in progress. So we just describe the limited result. However If well have done modeling and have investigated of propriety of model, well achieve our final goal of this study.

The riparian vegetation community models according to hydrologic and soil environments - Case of Daecheongho lake reservoirs - (수문 및 토양환경을 고려한 수변식생군락 조성 모델 - 대청호 저수지를 사례로 -)

  • Park, Miok
    • Journal of Wetlands Research
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    • v.19 no.1
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    • pp.144-154
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    • 2017
  • The riparian vegetation is one of corridor type ecosystems, an ecotone and able to improve the ecological soundness by structural and functional link. And they act as habitats, sources and sinks of species, conduits, filters and barriers. This study was carried out to develop the vegetation model for the fluctuation areas of lake reservoirs consider of hydrologic and soil environments according to the vegetation structure of the reference ecosystem. To develop the case study, 2 sites within 10degree slope of the Daecheong Lake were selected. The riparian vegetation models were built by the results of GIS analysis, remote satellite analysis, field survey results, consider of water level, flooded frequency, soil and topographic index, land cover or land use etc. 1) study area varied from FWL to -5m of NFWL, 2) slope 10% below, 3) vegetations flooded below 100days yearly are Salix koreensis, Salix chaenomeloides, Salix gracilistyla, 4)land cover type classified wildlife grassland, abandoned paddy field, cropland according to landuse (or landcover), 5)finally model was constructed as ecological landscape forest. The model designs were suggested by 2 types in Daecheong lake reservoir. The model for the riparian vegetation corridors could be the basic and useful data to improve the ecological and landscape properties.

Framework for Optimum Scale Determination for Small Hydropower Development Using Economic Analysis (경제성분석에 의한 소수력 개발의 최적규모 결정 방안)

  • Kim, Kil-Ho;Yi, Choong-Sung;Lee, Jin-Hee;Shim, Myung-Pil
    • Journal of Korea Water Resources Association
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    • v.40 no.12
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    • pp.995-1005
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    • 2007
  • This study presents a framework for optimum scale determination for small hydropower development in a river basin. The framework includes the construction of hydrology and topography data, the simulation of hydropower operation, the economic analysis, and the determination of optimum scale of the small hydropower. The optimum scale of design flow and facility are determined by Net Present Value among economic analysis indices. The investment cost is estimated by the cost function derived from the construction cost of existing small hydropower plants. The benefit from power generation is estimated by the price announced by government. The presented framework is applied to the two potential sites in Cho River basin for the dam and run-of-river type of plants. Finally, the sensitivity analysis for a design flow and scale of the plant is performed for the each site. The usage of the framework presented in the study is highly expected for the estimation of potential hydropower resources or the decision support tool for a proprietor by estimating the optimum scale and economical feasibility in advance.

The Landscape Characteristics of Utopia Shown in the Travel Records of Jirisan Mountain (지리산 유람록에 나타난 이상향의 경관 특성)

  • So, Hyun-Su;Lim, Eui-Je
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.3
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    • pp.139-153
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    • 2014
  • This study contemplates the utopian landscape recognized by the scholars with twenty three pieces of 'travel record'. Consequently, five key words - Mureungdowon(武陵桃源), Byeolcheonji(別天地), Dongcheon(洞天), Chonghakdong, Eungeoji(hermitage) - are chosen for comprehending the utopia and their landscape characteristics are organised as follows. Mureungdowon in Jirisan Mountain which the scholars dreamed of is a flatland with the full energy for local vegetation and domestic animals in the mysterious and deep gorge. This utopia eventually reflects the rural landscape. Byeolcheonji is a utopia combining the concept of a fairyland and beautiful scenery. The scholars also used the term 'Dongcheon' for naming the enclosed landform which is suitable for seclusion and defining the some areas of beautiful scenery. Cheonghakdong, which is set only in Jirisan Mountain, has been formed by the stone scenery of gorges and Buril waterfalls around the whole area of Burilam Hermitage, the vegetation scenery of pine trees and bamboos with the legend of Choi Chiwon and his engraved inscription on a rock. Adding to the utopia passed down, the scholars perceived the village with geographical features with back to the mountain and facing the water, the river practising the trade, the flatland enclosed by bamboo forests, the vegetation mainly consisting of fruit trees and beautiful scenery as the utopia realized on earth. It is equivalent to the world of human beings laboring appropriately and living in Mother Nature. As mentioned above, this study has significance for apprehending the relevance between the culture of strolling in the mountains by the scholars of Joseon Dynasty and the fairyland and explaining the various traditional utopias from the inherited concepts from China to the naturalized realistic utopia.

The Distribution and Changes of the Place Names in Bukhansanseong : Focusing on the Place Names in Bukhanji (북한산성 지명의 분포와 변천: 『북한지(北漢誌)』 수록 지명을 중심으로)

  • Kim, Sun Bae
    • Journal of the Korean association of regional geographers
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    • v.23 no.2
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    • pp.325-353
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    • 2017
  • This article aims to investigate the geographical distribution and the cultural, historical, and symbolic meanings of the place names in the area of Bukhansanseong (Fortress), and to basically suggest the several features which have happened throughout the process of toponymic changes. In order to realize the purpose of the article, I collected the chronological toponymic data, particularly focusing on the Bukhanji (Record of Bukhansanseong, 1745) in which the most existing place names related to Bukhansanseong are recorded. In the meantime, I proposed the character of distributions and types of the physical, human place names according to the rear-part of toponymic morpheme, i.e. the generic name. Moreover, selecting the main place names such as 'Bukhansan', etc., I analyzed some features on the toponymic meanings and changes in accordance with the fore-part of toponymic morpheme, the specific name. Consequently, I identified the facts that the name of 'Bukhansan' in the era of the Three Kingdoms, 'Samgaksan' in the Goryeo Dynasty, and again 'Bukhansan' or 'Buksan' in the Joseon Dynasty era had been primarily called. And then the place name, 'Bukhansan' has been officially named until now since constructing the Bukhansanseong Fortress in 1711. Meanwhile, the physical place names related to mountainous and fluvial topography, the place names of artificial facilities such as a mountain fortress on this geographical environment, and especially Buddhistic place names which was named and identified by Buddhist monk, Seongneung who wrote the Bukhanji, representing the Buddhistic identity and ideology, form a large majority of the place names within Bukhansanseong.

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The Analysis of the Plant Distributional Pattern in Yugu Stream (Gongju, Chungnam) (유구천(충남, 공주)의 식물 분포 현황분석)

  • Moon, Ae-Ra;Lee, Youl-Kyong;Park, Jeong-Mi;Jang, Chang-Gee
    • Korean Journal of Environmental Biology
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    • v.30 no.2
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    • pp.107-120
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    • 2012
  • This study was carried out to illiminate the diversity of vascular plants by making list of rheophyte and hydorphyte plants at Yugu stream. This study was conducted from Aug., 2009 to Sept. 2010 at 7 points. Based on the voucher specimens, vascular plants from investigated areas were 88 families 229 genera 290 species 3 subspecies 30 varieties 5 forms, totally 328 taxa. Korean endemic plants were 3 species such as Forsythia koreana (Rehder) Nakai (planted) and Paulownia coreana Uyeki (planted), and Weigela subsessilis (Nakai) L.H. Bailey. The rare and endangered plants were designated by Korea Forest Service were 4 taxa, such as Penthorum chinense Pursh, Acorus calamus L., Lilium callosum Siebold & Zucc. and Iris ensata var. spontanea (Makino) Nakai. Floristic special plants were totally 26 taxa, which were grade V of 2 taxa, grade IV of 2 taxa and grade III of 9 taxa. Naturalized plants were 27 taxa, that was 8.3% of whole discovered vascular plants in this area. Even naturalized plants has not influence on the vegetation of Yugu stream. Since village was composed along the stream and the roads and banks were linked, naturalized plants were flowed continuously into this region. So, strategy of the conservation for this region should be designed. Based on flora, 3 types of group were discriminated such as main stream type (4 points), branch stream type (2 points) and reservior type (1 point). Each group has difference in composition of plants.

Response of Vegetation to Shoreline Alternation in a Large Reservoir (대형 저수지에서 호안 정비에 대한 식생의 반응)

  • Chu, Yun Soo;Cho, Hyunsuk;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.3 no.2
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    • pp.143-151
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    • 2016
  • Shoreline armoring is a globally used engineering strategy to prevent shoreline erosion along stream, lake and reservoir coastlines. Armoring alters the land-water interface and has the potential to affect shoreline vegetation by changing nearshore geomorphology, hydrology, sediment composition and water quality. We quantified the effects of the artificial disturbances and alternation of the land-water interface on the community structure and distribution of shoreline vegetation in a large reservoir, Uiam Reservoir, Korea. More than 60% of shorelines were disturbed by armoring with retaining wall of concrete block, riprap and gabion in the Uiam Reservoir. The results of detrended correspondence analysis showed that the vegetation structures of the shoreline modified by armoring changed from hydrophyte-dominated to hygrophyte-dominated ecosystems. The shoreline armoring caused the disruption of gradual continuity in the water-land interface and the biological invasion by alien plants. The changes in distribution area of shoreline vegetation showed that the area of hydrophytic vegetation decreased and that of hygrophytic vegetation increased from 2010 to 2013. In conclusion, the human disturbance such as armoring, road construction, recreation etc. could lead to terrestrialization, the loss of transverse continuity and biological invasion in the shoreline vegetation of the Reservoir Uiam. Our findings suggest that redesigning or removing shoreline armoring structures may benefit nearshore hydrophytic vegetation for the conservation of novel shoreline ecosystems.