김선주 Kim Sun Joo , 박기춘 Park Ki Chun

DOI: JKWST Vol.49(No.5) 3-9, 2007

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In this study, the effect of the purification materials is analyzed and tested by Flow 3D and Hydraulic model test. Three dimension numerical analysis led from the research that sees abnormal form and the size back of the water purification material conferred the flowing water conduct inside the test channel against the test condition. Comparison it analyzed the flux distribution, a water depth of the channel which establishes the water purification materials the cross section, an interval of the water purification material, a conference with general channel, it change executed. As a result, the cross section ratio of the purification materials against and a flux change from the test which it sees. The interval of the purification materials in order to prevent three dimension that follows in decrease of increase and flux must decide an interval.

맹승진 Maeng Seung-jin , 이배성 Lee Bae-seong

DOI: JKWST Vol.49(No.5) 11-20, 2007

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In this study, we reviewed the optimal space for the fish road and fish storage establishment in the section between the downstream of the Hwacheon dam and the joint point of the Pungsan river. The hydraulic stability of these facilities was also examined. In the section between the downstream of Hwacheon dam and the joint point of Pungsan river, the release flow of Hwacheon dam was set at 5,495㎥/s, 6,110㎥/s and 7,537㎥/s, and numerical simulations were executed for each instance using the HEC-RAS model and RMA-2. In the analysis of the flow velocity distributions in the subject section by release flows of Hwacheon dam, it was shown that there was over 5.0m/s of high flow velocity at Sta. #1～Sta. #3, Sta. #4～Sta. #6, and Sta. #12～Sta. #13. of the sections analyzed in this study. The Sta. #0～Sta. #1 was considered appropriate for the fish road and fish storage establishment. As seen in the results of the numerical stability review by release flow conditions of Hwacheon dam subject to the selected available areas for fish road and fish storage, the topographically available section for the establishment of fish road and fish storage exists at Sta. #1～Sta. #3 when the release flow of Hwacheon dam is 5,495㎥/s, whereas Sta. #0～Sta. #1 should be reviewed for the subject section for the establishment of fish road at release flows of 6,110㎥/s and 7,537㎥/s, in addition to the figures gathered at the 5,495㎥/s release flow. Finally, the available section for the establishment of fish road and fish storage was determined to be Sta. #0～Sta. #3. Further, if fish road and fish storage are established in the outer bank within this section, the high flow velocity section should be avoided. An alternative would be to establish for the fish road in the inner band on the section of Sta. #1 or Sta. #3.

원종필 Won Jong Pil , 이재영 Lee Jae Young , 박찬기 Park Chan Gi , 박성기 Park Seong Gi , 김완영 Kim Wan Young

DOI: JKWST Vol.49(No.5) 23-30, 2007

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This research was to evaluate the shrinkage and durability performance of latex modified repair mortar and to improve the service lift of the agricultural concrete structures. The shrinkage characteristics of the repair material creates the delamination of repair materials and existing concrete. It may reduce the service life of structures. Also the reduction of durability performance of the repair materials induces the destruction of the repaired concrete structures at early stage. In this research, plastic and drying shrinkage, thermal expansion coefficient for shrinkage properties, durability performance, permeability, repeated freezing and thawing, and resistance of chemical solution test were performed. Test results showed that the latex modified repair mortar indicated the shrinkage amount which the delamination does not happen, and the latex modified repair mortar appeared excellent long-term durability performance which can increase the service life.

배승종 Bae Seung-jong , 정하우 Chung Ha-woo

DOI: JKWST Vol.49(No.5) 33-44, 2007

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This study proposed a Rural Amenity Values Assessment Model (RAVAM) to evaluate the rural amenity resources based on the Myun as a spatial unit. In RAVAM, 61 rural amenity resources were classified into almost intact nature resources, interaction between nature and man resources, man-made resources, respectively. Especially, Rural Scenic Value Index (RSVI) was developed to quantify rural scenic views as a rural amenity resource. RSVI was utilized in evaluation process of rural amenity resources. The weighing factors for the amenity resources were evaluated from the step wise pair-comparison results of 11 specialists by Analytic Hierarchy Process(AHP). In the results, the weighting values of almost intact nature resources, interaction between nature and man resources, man-made resources were 496, 323 and 181, respectively, among total value being 1,000.

배승종 Bae Seung-jong , 정하우 Chung Ha-woo

DOI: JKWST Vol.49(No.5) 45-54, 2007

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The purpose of this paper is to test the applicability of the rural amenity values assessment model(RAVAM) to a case study area. To verify the practical applicabilities of the RAVAM, south-east area of Kyounggi province was selected as a study area. Full data of 101 Myuns of Kyounggi province were gathered with Geographic In-formation System(GIS) and Remote Sensing(RS) techniques. All the 101 Myuns' rural amenity resources were assessed. Cluster analysis was performed on almost intact nature, interaction between nature and man, man-made amenity values to classify rural amenity characteristics. It was expected that the proposed RAVAM could be used in developing rural development plans considering local rural amenity resources' distribution.

김재옥 Kim Jae-ok , 김원장 Kim Won-jang , 조국현 Jo Kuk-hyun

DOI: JKWST Vol.49(No.5) 57-65, 2007

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The objective of this study was to evaluate chemical water quality by hourly monitoring(25hr) of Saemangeum esturary. For this study, we selected 2 sites like a Mangyong Bridge(St. 6) and Dongjin Bridge(St. 7). Inflow of salt water was not detected during low tide(maximum 553, 508cm) of all stations, while the salinity rises were detected in spring tide(750cm). When 602m of maximum tide was reached, salinity concentration was increased at St. 7, while there was no change in St. 6. Therefore, We know that salinity variation is greatly influenced by tide height at survey site. Also, significant variance of salinity(p<0.05) was found between St. 6 and St. 7 because dike construction made the flood tide move into the Dongjin river. Total suspened solids(TSS) concentration was increased because of the river runoff at St. 6, and also the turbulance and resuspension according to salt intrusion at St. 7. During the high tide, the water discharge from the sea seemed to dilute the nutrient but to elevate TSS concentration in St. 7. Silicate and nitrate concentrations in the studied site were decreased by the mixing of sea water, whereas the evident trend of phosphate concentration was not found. This result can be explained by the phosphorus condition. Phosphorus exists inactive when it is affected by hydrated iron and adsorbed onto suspended matters. Compared to the environmental conditions of the St. 6 and St. 7, physical factors such as temperature, dissolved oxygen and TSS have statistically no significant difference(p<0.001), but nutrient concentrations were higher at St. 6 than St. 7. It could be suggested from these results that it is important to control the discharge of fresh water by sewage treatment plants located in St. 6 for water quality management.

윤성한 Yoon Sung-han , 최진용 Choi Jin-yong , 유승환 Yoo Seung-hwan , 장민원 Jang Min-won

DOI: JKWST Vol.49(No.5) 67-77, 2007

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The images of MODerate resolution Imaging Spectroradiometer (MODIS) that provide wider swath and shorter revisit frequency than Land Satellite (Landsat) and Satellite Pour I' Observation de la Terre (SPOT) has been used fer land cover classification with better spatial resolution than National Oceanic and Atmosphere Administration/Advanced Very High Resolution Radiometer (NOAA/AVHRR)'s images. Due to the advantages of MODIS, several researches have conducted, however the results for the land cover classification using MODIS images have less accuracy of classification in small areas because of low spatial resolution. In this study, uncertainty of paddy fields classification using MODIS images was conducted in the region of Gyeonggi-do and the relation between this uncertainty of estimating paddy fields and topographical factors was also explained. The accuracy of classified paddy fields was compared with the land cover map of Environmental Geographic Information System (EGIS) in 2001 classified using Landsat images. Uncertainty of paddy fields classification was analyzed about the elevation and slope from the 30m resolution Digital Elevation Model (DEM) provided in EGIS. As a result of paddy classification, user's accuracy was about 41.5% and producer's accuracy was 57.6%. About 59% extracted paddy fields represented over 50 uncertainty in one hundred scale and about 18% extracted paddy fields showed 100 uncertainty. It is considered that several land covers mixed in a MODIS pixel influenced on extracted results and most classified paddy fields were distributed through elevation I, II and slope A region.

남원호 Nam Won-ho , 최진용 Choi Jin-yong , 장민원 Jang Min-won , B. A. Engel

DOI: JKWST Vol.49(No.5) 81-90, 2007

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Watershed topographical information is required in hydrologic analysis, supporting efficient hydrologic model operation and managing water resources. Watershed topographical data extraction systems based on desktop GIS are abundant these days placing burdens for spatial data processing on users. This paper describes development of a Web-based Geographic Information Systems that can delineate the Geum River sub-basins and extract watershed topographical data in real time. Through this system, users can obtain a watershed boundary by selecting outlet location and then extracting topographical data including watershed area, boundary length, average altitude, slope distribution about the elevation range with Web browsers. Moreover, the system provides watershed hydrological data including land use, soil types, soil drainage conditions, and NRCS(Natural Resources Conservation Service) curve number for hydrologic model operation through grid overlay technique. The system operability was evaluated with the hydrological data of WAMIS(Water Management Information System) with the government operation Web site as reference data.