• Title/Summary/Keyword: Basin scale

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Optimum Scale Evaluation of Sedment Basin Design by Soil Erosion Estimation at Small Basin (소유역의 토사유실량에 따른 유사저류지 설계적정성 검토)

  • Lee, Sang-Jin;Choi, Hyun;Kwak, Young-Joo;Lee, Bae-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.2 s.40
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    • pp.25-31
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    • 2007
  • The recent frequent heavy rainfall has caused an increased in soil erosion and the soil drain which drained soil has caused decreased in channel radius and environmental problems by turbidity. In this study, the optimum size of the sediment basin was tested with soil erosion estimated from the Universal Soil Loss Equation (USLE) in the basin using by GIS data. The results show that the estimated soil erosion and the designed soil deposit are $72.1\;m^3$ and $85.0\;m^3$ respectively and the size of sediment basin is proper. In this study the water depth was calculated from the Hec-Ras model to test the stability of the bank and to prove submersion of the inside fields from stream overflow.

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Utilizing SPOT-5 Satellite Data for Present State Analysis of Irrigation Reservoirs of the Yeseong River Basin (예성강 유역의 저수지 현황 분석을 위한 SPOT-5 위성자료의 이용)

  • Lee, Jin-Duk;Lee, Byung-Hwan;Song, Young-Suk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.2
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    • pp.255-263
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    • 2010
  • In order to prepare the interchange between and the unification of North and South Korea, it is needed to establish the development direction of irrigation reservoirs and formulate technological and political directions for preparing effectively against the demand of agricultural countermeasure information like the analysis of rural comprehensive development projects and the present state of agricultural land of North Korea. The purpose of this research is to construct the database of agricultural productive infrastructures and analyze the present state of irrigation reservoirs of the Yeseong River Basin in North Korea using SPOT-5 satellite imagery. As a result of the research, we were able to not only design classification items but establish method and precedure for producing thematic maps related agricultural productive infrastructure without on-site survey by analyzing present condition related to agricultural water of the basin. And we intend to provide basic data for analyzing suitabile locations of irrigation reservoirs in the basin by performing basin extraction, volume evaluation of the existing reservoirs, scale cultivative lands, benefit area fo the reservoirs, and the existing agricultural water system. In addition, we were able to understand the problem and limit in constructing the database related agricultural productive facilities.

Habitat Potential Evaluation Using Maxent Model - Focused on Riparian Distance, Stream Order and Land Use - (Maxent 모형을 이용한 서식지 잠재력 평가 - 하천으로부터의 거리, 하천의 차수, 토지이용을 중심으로-)

  • Lee, Dong-Kun;Kim, Ho-Gul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.6
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    • pp.161-172
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    • 2010
  • As the interest on biodiversity has increased around the world, researches about evaluating potential for habitat are also increasing to find and comprehend the valuable habitats. This study focus on comprehending the significance of stream in evaluating habitat's potential. The purpose of this study is to evaluate habitat potential with applying stream as a main variable, and to comprehend the relationship between the variables and habitat potential. Basin is a unit that has hydrological properties and dynamic interaction with ecosystem. Especially, biodiversity and suitability of habitat in basin area has direct correlation with stream. Existing studies also are proposing for habitat potential evaluation in basin unit, they applied forest, slope and road as main variables. Despite stream is considered the most important factor in basin area, researchers haven't applied stream as a main variable. Therefore, in this study, three variables that can demonstrate hydrological properties are selected, which are, riparian distance, stream order and land use disturbance, and evaluate habitat potential. Habitat potential is analyzed by using Maxent (Maximum entropy model), and vertebrate's presence data is used as dependent variables and stream order map and land cover map is used as base data of independent variables. As a result of analysis, habitat potential is higher at riparian and upstream area, and lower at frequently disturbed area. Result indicates that adjacent to stream, upstream, and less disturbed area is the habitat that vertebrate prefer. In particular, mammals prefer adjacent area of stream and forest and reptiles prefer upriver area. Birds prefer adjacent area of stream and midstream and amphibians prefer adjacent area of stream and upriver. The result of this research could help to establish habitat conservation strategy around basin unit in the future.

A Study on the Runoff Reduction According to the Calculation Method of the LID Scale Considering the Land Use Area and the Application of Stormwater Storage Basin (토지이용면적을 고려한 LID 규모 산정 및 우수저류지 적용에 따른 유출저감 연구)

  • Kim, Byung Sung;Kim, Jea Moon;Kim, Seong Su;Shin, Gang Wook;Lee, Sang Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.3
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    • pp.229-235
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    • 2021
  • Globally, due to climate change and urbanization, problems with water cycle destruction in urban areas frequently occur. In order to solve this problem, LID technique is being actively conducted the application in urban and research. In this study, some areas of the new city located in Busan was constructed using a widely used SWMM model to verify the effectiveness of the LID technique. This is to present a plan to maximize the efficiency of urban water cycle of the stormwater management target figure and the LID scale calculation method. In addition, the efficiency of runoff reduction using stormwater storage basin was analyzed in urban development projects. By calculating the scale of customized LID for each sub basin, the amount of runoff and peak runoff after LID application was reduced by 86.8 % and 69.5 %, respectively. Depending on the application of the stormwater storage basin, the reduction effect of peak runoff from 0.5 m3/s to 4.9 m3/s and delay effect of 8 minutes to 10 minutes was shown.

The Analysis of Basin Parameters Using Digital Map (수치지도를 이용한 유역특성분석)

  • Kang, In-Joon;Choi, Hyun;Lee, Byung-Gul
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.3
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    • pp.229-236
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    • 2001
  • One of the basic tasks in hydrological analysis is to delineate drainage basins and channel networks. Characteristics of channel networks and drainage basin parameters have been used widely in hydrologic calculation and modeling. DEMs(Digital Elevation Models) are generally used to automatically map the channel networks and to delineate drainage basins. This paper presents an effort to analyze basin characteristics using various DEMs. The quantitative analysis of channel networks begins with Horton's method of classifying stream according to Horton orders in hydro-geomorphy. HGSIS(Hydro-Geo-Spatial Information System) is possible to extract parameters. Usually, hydrologists. surveyors and GSIS researchers have some difficulties in accessing satellite images and in extracting DEMs from them. Therefore, the extracted DEMs from contours of digital map is widely used to have the basic works of hydrological analysis. This study presents proper DEMs to calculate Horton's orders, width function, drainage area, main channel length, total channel length, basin elevation and basin slope at digital map of 1:25,000 scale.

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The assessment of the contribution of overland flow to basin response by means of hydrological approach (수문학적 접근법에 의한 유역응답내 지표면유동의 기여도 평가)

  • Kim Joo-Cheol;Yoon Yeo-Jin;Kim Jae-Han
    • Journal of Korea Water Resources Association
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    • v.39 no.7 s.168
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    • pp.553-562
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    • 2006
  • The relative contributions of overland-flow and stream-flow to the response process at the basin scale are evaluated in the present study. The moments of GIUH models were applied to the data of the Bocheong watershed in the Geum river basin in Korea in order to discuss the feasibility. The GIUH model derived in this study consists of the stream path and overland region. The characteristic velocities for the flows between two cases mentioned above make a clear distinction as expected and would have more physical meaning than the ones of the model by Rodriguez-Iturbe and Valdes(1979). The path lengths of overland for each stream order are nearly constant, whereas the case of stream is shown to grow larger according to the basin sizes. As a result, the overall basin response process was founded out to be greatly under the influence of the hydrodynamic behavior of overland, and its behavior is suggested to be further researched for catching the broader meanings.

A Study on the Geomorphologic Synthesis of Hydrologic Response (수문응답의 지형학적 합성방법에 관한 연구)

  • Cho, Hong Je;Lee, Sang Bae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.1
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    • pp.99-108
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    • 1990
  • A Synthetic Unit Hydrograph Method was investigated for representation of the effective rainfall-direct runoff hydrograph by using a Geomorphologic Instantaneous Unit Hydrograpb(GIUH) proposed by Gupta et al(1980). The response function of the basin was assumed to be the two-parameter gamma probability density function. The physical parameters of the response function(Nash Model) was determined by using the regression eqs. were parameterized in terms of Horton order ratios and the relations between the basin lag time and time-scale parameter. The capability of the Synthetic Unit Hydrograph to the real basin was tested for the Pyungchang river basin and Wi Stream basin, and its capability to reproduce the hydrologic response was investigate and compared with the Moment Method and the Least Square Method used incomplete gamma function. The representation of the peak flow, the time to peak and the hydrographs the derived Synthetic Unit Hydrograph were tested on some obseved flood data and showed promising, and it was approved to be used for prediction of the ungaged basins.

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Gravity Characteristics on the Eastern Asia by using GRACE Data (GRACE자료를 이용한 동아시아의 중력특성)

  • Yu Sang Hoon;Min Kyung Duck
    • Economic and Environmental Geology
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    • v.38 no.3 s.172
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    • pp.299-304
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    • 2005
  • Geoid undulation and gravity anomaly were calculated from GRACE satellite data on the eastern Asia including Korean peninsula. Geoid undulation varies from -60m in the China to 60m toward the Pacific Ocean across the Korean Peninsula. Calculated gravity anomalies are in the range of -60 and 60 mgal except the subduction zone showing -100 mgal. High positive values are observed at Mt. Baekdu, Kaema highland and Taebaek mountains, and low values at Ulleung, Japan and Yamato basins in the East sea. We removed regional components below the spherical harmonic degree of 10 from gravity anomaly to get the residual anomaly for crust components. Residual gravity anomaly shows high anomalies at the northern mountainous area and Kyungsang basin in the Korean Peninsula. And low anomalies appears at the western Korea bay basin, Kunsan basin, Cheju basin, and Ulleung basin in the marine. Anomalies separated by the spherical harmonic degree as well as the residual anomalies are useful for the study of large crustal structure about geologic scale and depth distribution and for the survey of natural resources.

Estimation of Nonpoint Source Pollutant Loads of Juam-Dam Basin Based on the Classification of Satellite Imagery (위성영상 분류 기반 주암댐 유역 비점오염부하량 평가)

  • Lee, Geun-Sang;Kim, Tae-Keun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.3
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    • pp.1-12
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    • 2012
  • The agricultural area was classified into dry and paddy fields in this study using the near-infrared band of Landsat TM to extract land cover classes that need to the application of Expected Mean Concentration (EMC) in nonpoint source works. The accuracy of image classification of the land cover map from Landsat TM image showed 83.61% and 78.41% respectively by comparing with the large and middle scale land cover map of Ministry of Environment. As the result of Soil Conservation Service (SCS) Curve Number (CN) using the land cover map from image classification, Dongbok dam and Dongbok stream basin were analyzed high. Also Geymbaek water-gage and Bosunggang upstream basin showed high in the analysis of EMC of BOD, TN, TP by basin. And also Geymbaek water-gage and Bosunggang upstream basin showed high in the analysis of non-point source through coupling with direct runoff. Therefore these basins were selected with the main area for the management of nonpoint source.