• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.6
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• pp.453-461
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• 2009

Camera monitoring of topographical changes of intertidal flat was performed at Daehang-ri mud flat outside Semangeum sea dike No. 1, where creation of mud flat was reported after sea dike construction. Ground survey on the mud flat is often limited only to points or few line surveys because of difficulty of walking and limitation of working hours by flood/ebb. This study uses natures of tide that the water lines moving on the intertidal flat during a flood indicate depth contours between low and high tide. Ground coordinates for the water lines extracted from the consecutive images of intertidal flat are calculated and information of topography is acquired by integrating all the water line data. Analysis of 6 camera monitoring data between September 2005 and September 2009 shows 0.127 m deposition per year on the average and variation of deposition/erosion in space and time.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.82-84
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• 2003

Watershed boundaries and flow paths within the watershed are the most important factors required in watershed analysis. Most often the derivation of watershed boundaries and stream network and flow paths is based on topographical maps but spatial variation of flow direction is not clearly understandable using this method. Water resources projects currently use 1: 50, 000-scale ground survey or aerial photography-based topographical maps to derive watershed boundary and stream network. In basins, where these maps are not available or not accessible it creates a real barrier to watershed geo-spatial analysis. Such situations require the use of global datasets, like GTOPO30. Global data sets like ETOPO5, GTOPO30 are the only data sets, which can be used to derive basin boundaries and stream network and other terrain variations like slope aspects and flow direction and flow accumulation of the watershed in the absence of topographic maps. Approximately 1-km grid-based GTOPO 30 data sets can derive better outputs for larger basins, but they fail in flat areas like the Karkheh basin in Iran and the Amudarya in Uzbekistan. A new window in geo-spatial hydrology has opened after the launching of the space-borne satellite stereo pair of the Terra ASTER sensor. ASTER data sets are available at very low cost for most areas of the world and global coverage is expected within the next four years. The DEM generated from ASTER data has a reasonably good accuracy, which can be used effectively for hydrology application, even in small basins. This paper demonstrates the use of stereo pairs in the generation of ASTER DEMs, the application of ASTER DEM for watershed boundary delineation, sub-watershed delineation and explores the possibility of understanding the drainage flow paths in irrigation command areas. All the ASTER derived products were compared with GTOPO and 1:50,000-based topographic map products and this comparison showed that ASTER stereo pairs can derive very good data sets for all the basins with good spatial variation, which are equal in quality to 1:50,000 scale maps-based products.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.2
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• pp.25-32
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• 2014

Many Korean university campuses are located on hilly terrain where the hierarchy of the path system is unclear. Therefore, it is difficult to analyze the pedestrian network through space syntax, in which only horizontal direction changes are considered as depths of space. The purpose of this study is to compare pedestrian movement patterns and space syntax analysis in order to find their relevance to each other and the relationship between them. We conducted a survey regarding the most-visited buildings and pathways at S-University, which is located on a hilly area in Seoul. The survey results were compared with the Space Syntax integration map by regression analysis. For the segments where the relationship between pedestrian volume and integration was weak, field observations were conducted. As a result, topographical aspects, functional aspects, and location aspects were observed as the main influential factors. In addition, the research proposes that adding an extra axial line per vertical directional change can potentially compensate for the low relevance of stairs. This study suggests the possibility and the necessity of three-dimensional space syntax programs and emphasizes the importance of campus planning for the pedestrian environment.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.3
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• pp.1-8
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• 2022

In this study, a farm map utilization strategy for sustainable agricultural environmental resource management was derived. In addition, it is intended to present an efficient method of providing farm map-related services. As a result of the demand survey, the additional information required for the farm map includes 29% of information on crops grown on farmland, 21% of management-related information such as the owner or business entity, 17% of topographical information including slope, 15% of agricultural water information, 17% of land status information, and the addition of functions. 2% was investigated. As a result of intensive interview survey, it was found that it can be used for information on crops cultivated by agricultural businesses, actual cultivated area by township, arable land consolidation division boundary, and management of agricultural promotion zones. The farm map can be used as basic data to efficiently manage agricultural environmental resources. Since the status of support for individual farms or lots, such as soil improvement agent support and organic fertilizer support, may belong to personal information, it can be processed and provided in units required by administration or policies, such as administrative boundaries, subwatersheds, and watersheds. It can serve as a basis for executing the direct payment currently supported only by individual farms, even in a community unit that manages environmental direct payments.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.2
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• pp.46-54
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• 2023

Helicopter pilots are required to perform many visual workloads in topographical avoidance, flight path modification and navigation, because helicopters operate at very low altitudes. The helicopter-specific instability also require the pilot to have precise perception and control. This has caused frequent human error in helicopter accidents. In Korea, two to three cases have occurred annually on average over the past 10 years, and this trend has not decreased. The purpose of this study was to identify human error risks in advance to prevent helicopter accidents and to help develop measures for missions and mission phases with high risk of human error. Through the study, the tasks and mission phases where accidents occur frequently were classified and the risk of human error was calculated for each mission phases. To this end, the task of frequent accidents during helicopter missions was first identified, detailed steps were classified, and the number of accidents was analyzed. Next, the AHP survey program was developed to measure the pilot's risk of human error and the survey was conducted on the pilots. Finally, the risk of human error by helicopter mission and by mission phases calculated and compared with the actual number of accidents.

• Fire Science and Engineering
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• v.19 no.4 s.60
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• pp.75-79
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• 2005

This study has developed Forest Fire Occurrence Danger Index (FFODI) using fuel and topographical characteristics for the practical purposes of forecasting forest fire occurrence danger rating. This was made on the basis of the 126 forest fire site according to field survey. The result of fire frequency analysis showed 87 sites on conifer $(69\%)$, 21 on mixed $(16.7\%)$ and 18 $(14.3\%)$ on non-conifer. The scale for Fuel Model Index(FMI) ranges from 1 to 10 and Topography Model Index(TMI) from 1 to 5. FMI is 10 on the conifer, 3 on the mixed and 2 on the non-conifer. In case of topographical analysis, it was estimated that 90 site $(71.4\%)$ of ignition point was bottom foot hill and 22 site $(17.5\%)$ was on the southwest. TMI in southwest direction is 5.0, 4.5 in the northwest and the northeast, 4.0 in the southeast and the south, 2.5 in the north and the west and 1.5 in the east. TMI in the bottom foot hill is 5 in the bottom foot hill, 1.5 in the upper foot hill, 1.0 in the bottom middle slope and 0.5 in the upper middle slope and bottom ridge.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.330-330
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• 2002

The combination of Multi-Beam Echo Sounder swath bathymetry and high-resolution towed Sidescan sonar provides a powerful method of examination about hydrographic survey results. In this paper, we investigate the fast method of 3D bathymetric reconstruction with the Digital Sidescan sonar(Benthos SIS 1500) and Shallow Multi-Beam Echo Sounder(Reson Seabat 8125). The Seabat 8125 is a 455KHz high resolution focused Multibeam echo sounder(MBES) system which measures the relative water depth across a wide swath perpendicular to a vessel's track. The Benthos SIS1500 is a chirp(nominal fq. 200KHz) sonar which map the topographical features & sediment texture of ocean bottom using backscattered amplitude. We generates the very large 3D bathymetric texture mapping model with the Helical System's HHViewer and describes additional benefits of combining MBES and Sidescan Sonar imagery, the removal of geometric distortions in the model and a deterministic sounding noise.

• The Journal of Information Technology
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• v.10 no.3
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• pp.121-129
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• 2007

This study aimed at analyze the Regional Information of Geumsan-gun, Chung-Nam, Korea. The study area, the Geumsan-gun, is located in $35^{\circ}57'{\sim}36^{\circ}17'N$, $127^{\circ}19'{\sim}127^{\circ}39'E$. The Landforms, and Drainage network were analyzed from topographical maps on 1:25,000 & 1:50,000 and field survey. The Climate, Population, Economy, Transportation and etc. were analyzed from regional statistics. The results are as follows: The Centripetal forces of unit areas are not powerful because Geumsan-gun located contiguity with Daejeon metropolitan city. The accessibility of Geumsangun is good and is available for a site of specialized agriculture area.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.85-88
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• 2001

Since mountainous area has access restrictions for field work, assessors need to establish a conceptual model of the contamination prior to the field investigation. In this study we established a conceptual model of the contamination based on site inspection and geological survey, followed by the field investigation for the petroleum spill site. In the conceptual model, we estimated that tile contamination should have spread by groundwater and topographical characteristics within the top soil layer. The spread of contamination through rock was not considered in the conceptual model due to impermeable characteristics of metasyenite. The contaminated environmental media of the petroleum spill site include soil and groundwater. According to the analysis result of the contamination, the volume of contaminated soil is estimated approximately 4, 150 cubic meters (7, 055 ton) with most contaminants existing along the groundwater flow within top soil layer.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1031-1037
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• 2002

CCA (Canonical Correspondence Analysis) was used so as to analyze the relation between vegetation and soil environment of Mankyeong river located in Jeollabuk-do. Vegetation survey consulted 1:5,000 topographical map, set up 30 plot and analyzed from June, 2001, to september, 2001. Plant communities of Mankyeong river was investigated by phytosocialogical method. The species composition of plant communities showed high correlation to soil pH, soil organic matter, $P_2$$O_5$, total nitrogen, EC, when they were analyed by CCA. According to the results of CCA hydrophyte communities were distributed in the region that high pH. But the vegetation of disturbed site and wetland plants were distributed in a good nutrients.