• Title/Summary/Keyword: River Surveying

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Analysis of Water Storage Variation in Yangtze River Basin and Three Gorges Dam Area using GRACE Monthly Gravity Field Model (GRACE 월별 중력장모델을 이용한 양자강유역 및 삼협댐 지역 저수량 변화 분석)

  • Huang, He;Yun, Hong-Sic;Lee, Dong-Ha;Jeong, Tae-Jun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.3
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    • pp.375-384
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    • 2009
  • The GRACE satellite, Launched in March 2002, is applied to research on glacial melt of polar regions, glacial isostatic adjustment(GIA), sea level change, terrestrial water storage(TWS) variation of river basin and large-scale earthquake etc. In this research, the TWS variation of Yangtze river basin from August, 2002 to January, 2009 is analyzed using Level-2 GRACE monthly gravity field model. Particularly, gravity changes of the Three Gorges Dam during the impoundment process in 2003, 2006 and 2008 is observed by estimating equivalent water thickness(EWT). The research results show the distinct annual and seasonal changes of Yangtze river basin, and its amplitude of annual variation is 2.3cm. In addition, we compare the results with water resource statistics and hydrologic observation data to confirm the possibility of research of TWS variation of river basin using GRACE observation data, and also the satellite gravity data is of great help for the research on the movement and periodic changes of river basin.

Determination of the Improvement Priority in a Small River Using GRID Analysis Technology of GSIS (GSIS의 그리드 분석 기법에 의한 소하천 정비 우선순위 결정)

  • 양인태;최영재;오명진
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.3
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    • pp.233-240
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    • 2000
  • A small rivers take advantage of not only a site of superb scenic beauty, a play space, a rest place but also a momentous waters reservoir, a drainage on territory residents. Likewise, part of the most massed a life space to a region dwellers shall be extremely in harmony with coexistence space in that every kind plant, animal over again a human being and so on. For improvement planning of small river, various way and model are presented. But, it's want of ability for small rivers of a adaption many-side and throwing in a lot of financial resources. Because the improvement planning of small river was designed all small river in a county, the priority must be preprocessed. Now, the counties prioritized for improvement planning of small river are a few, and acquisition and manipulation of the data are time-consuming. Geo-Spatial Information System (GSIS) is specifically designed to manage and analyze spatial data. It will be to offer the benefit to the determination of the improvement priority in a small river. The purpose of this study is to offer priority for improvement planning of small river using GSIS. For this purpose, it was developed using Arc/Info software and AML was used as a developing tool.

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Accuracy Evaluation of DEM Construction for River Region using ALS & MBES (ALS와 MBES를 이용한 하천지역 DEM 구축의 정확도 평가)

  • Kwon, O-Chul;Kwon, Jay-Hyoun;Lee, Ji-Sun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.4
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    • pp.421-428
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    • 2009
  • In Korea, the change of river flux due to seasons change is so considerable because of the mountainous terrain with the sharp slope and leaned rainfall. This unfavorable natural condition and the difficulties in precise grasping of the river status made the water resource management difficult so that the necessity of the precise river management has been continuously increased. In this study, a precise river-region DEM using the latest equipments of ALS and MBES is constructed. After acquiring DEM from each senor on the river region, a single DEM was generated by combining them. Also, the field inspection was carried out in the overlapped region of ALS and MBES in order to verify the quality of DEM. The verification of DEM was carried out by comparison between TINs obtained from the combined result of ALS and MBES and the surveying result from total station at more than 10 points in the selected two test areas. As a result, NO.1-area's RMSE of 0.322m and 0.113m are obtained for NO. 1 and NO. 2 areas, respectively. The result of this study shows the feasibility of DEM construction for river region using ALS and MBES as seen in the case of NO. 2 area. At the same time, it was appeared that a better method on the data fusion should be developed as seen in the result of NO. 1 area.

Numerical Analysis of Riverbed Changes at the Downstream of the Ji-Cheon (수치모형을 이용한 지천하류부의 하상변동 분석)

  • Choi, Ho;Rim, Chang-Soo;Jung, Jae-Wook
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.117-125
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    • 2011
  • River bed variation drops storage capacity of dams and reservoirs, and furthermore deteriorates safety of banks and peers. Therefore, understanding of bed variation is important to use and manage river water. Study section is downstream part of Ji- Cheon nearby Ji-Cheon Bridge which is located in Gum river basin. The river surveying at fourteen places with the length of 1,320m were undertaken on November 7, 2003 and September 24, 2004, and the results of river surveying were analyzed for the study. Real bed variation was compared with the simulation results of HEC-6 and GSTARS 3.0. Cross section data for the simulation of HEC-6 and GSTARS3.0 were composed of the basis of river surveying data on November 7, 2003. Hydrological data were acquired from Gu-Ryong watermark located at Ji-Chun Bridge. The research results revealed that when using Toffaleti equation, simulation results of two models were similar to the real bed variation. The bed variation simulated by using GSRARS 3.0 with only one stream tube was similar to the real bed variation. The bed variation simulated by using two models(HEC-6 and GSTRARS 3.0) with Toffaleti equation was also similar to the real bed variation. Therefore, it is expected that HEC-6 and GSTARS 3.0 models have applicability to predict the bed variation at the downstream of Ji-Cheon.

A Study on the Detection of Land Cover Changes in Southern Han River Using Landsat Images (인공위성 영상을 이용한 남한강 유역의 토지피복 변화량 검출)

  • 윤홍식;조재명;안영준
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.2
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    • pp.145-153
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    • 2002
  • Reforming land is an important foundation for benefit of society as well as national development. A correct investigation and information acquirement as to land must go first to establish land management and plan. Land investigation by remote sensing is one of the most reasonable methods that doesn't need lots of time and manpower. In this study, Image classification on land use from Landsat data was carried out, which were respectively in 1980, 1985, 1990, 1995 and 2000, covering southern Han river and then land use changes were detected. In addition, an available information was reported, which could be used in the control of southern Han river. As a result, there is an obvious change in land use, especially the increase of water and decrease of forest and agriculture. Those are caused by the industrialization and the construction of dam.

Accuracy of Image Transformation Methods and Supervised Classifications on Multi-Spectral TM: A Comparative Study on Lower Tumen River Area (다분광 TM 영상 변환기법과 감독분류 정확도 비교연구 -두만강 하류 지역을 중심으로-)

  • Lee, Ki-Suk;Nan, Ying
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.17 no.3
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    • pp.311-320
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    • 1999
  • This study conducts to analyze comparative accuracy when both Image Transformation Methods and Supervised Classifications on multi-spectral TM using a case of Lower Tumen River Area. In terms of overall classification accuracy, maximum likelihood method turns out higher than other one, but in a case of vegetation only, MNF and TC image transformation methods produce a better quality of the result. Especially, seven dimensional images including MNF, TC, and NDVI create better image than three dimensional one. Among these transformation methods, maximum likelihood method results out the best one. Multi-spectral image could be useful as an important basic material for site selection of industrial allocation as well as Tumen River Area Economic Development Plan.

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A STUDY ON THE ANALYSIS OF THE RIPARIAN VEGETATION NATURALITY AND VIEWSCAPE IN URSTREAM (하천상류지역의 하반식생 자연도 및 경관 분석에 관한 연구 - 경기도 남양주군 수입천을 중심으로 -)

  • ;Amada Takaaki;Ichihara Kouichi
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.3
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    • pp.222-233
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    • 1997
  • Riparian zone occupies not more than 5% of the total watershed area and can be considered in between the terrestrial and aquatic ecology as that does not fall under both of them. Unlike to common terrestrial plant that can e seen on other land, the riparian vegetation that exist in riparian zone can be classified into various groups because of their peculiar living form. The recognition of importance of terrestrial environment has considered the importance of natural river due to which even today, the movement throughout the world to retrograde the river development is taking place customarily. In this research, noticing the actual condition of the river management reality, the original capacity of river landscaping of Han river has been quantified grasping the actual condition of riparian vegetation from distribution area surveying and analysis. The objective of the research is to find out the river retrogression and maintenance methods based on the ecological environmental quality around the river by maintaining the river plants having high natural capacity and river planning method based on the harmony between conservation of river environment and use of riparian zone.

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Saltwater Intrusion Characteristics in Seomjin River Estuary using EFDC (3차원 수치모델을 이용한 섬진강 하구역의 염수침입 특성)

  • KANG, Bo-Sik;PARK, Hyo-Bong;KIM, Jong-Kyu
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.6
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    • pp.1842-1853
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    • 2015
  • The behavior characteristics of the saltwater intrusion in the Seomjin River Estuary by the inflow of fresh water were analysed by the field observation using CTD in the neap tide in January, June, and August 2013 as well as a numerical model, EFDC (Environmental Fluid Dynamics Code). As a result, Seomjin River Estuary is found that the saltwater intrusion is sensitive to the tide and tidal and freshwater flow. The results of field observation and numerical model were similar in the range of salt, but the results of salt wedge distribution were quite different. The observation of tide and tidal current as well as hydrographic surveying the Seomjin River Estuary will be jointly conducted for the accurate analysis.

The Analysis of GIS DB for the Evaluation of Turbid Water Considering Spatial Characteristics of River Channel (하천의 공간적 특성을 고려한 탁수평가 GIS DB 분석)

  • Park Jin-Hyeog;Lee Geun-Sang
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.1
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    • pp.19-26
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    • 2006
  • Andong and Imha reservoir adjoins each other, but turbid water shows too much different when it rains. The characteristics of geological rock in basin and agricultural area around river boundary are pointed out as the major reason of turbid water of Imha reservoir. This study analyzed rock type of topsoil layer using soil map by National Institute of Agricultural Science and Technology (NIAST). Among rock types, sedimentary rock affects on the occurrence of turbid water. In the analysis of sedimentary rock type, the distribution of sedimentary rock of Imha basin shows 1.87 times higher than that of Andong basin. Also, the distribution of sedimentary rock of Imha basin shows higher than that of Andong basin within 1,600m from river channel in according to the buffer zone of river boundary. And Agricultural area of Imha basin shows higher than that of Andong basin in analysis of land cover within 1,600 m from river channel. As this agricultural characteristics of Imha basin, cover management factor of Imha basin represents more higher that that of Andong basin.

Application of Remote Sensing and GIS technology for monitoring coastal changes in estuary area of the Red river system, Vietnam

  • Lan, Pham Thi;Son, Tong Si;Gunasekara, Kavinda;Nhan, Nguyen Thi;Hien, La Phu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.6_2
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    • pp.529-538
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    • 2013
  • Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.