• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.132-142
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• 2003

A significant deficiency of most computer models used for stream floodplain analysis, is that the locations of structures impacted by flood waters, such as roads, buildings, and bridges, cannot be effectively compared to the floodplain location. The purpose of this study is the integration of the HEC River Analysis System(HEC-RAS) with ArcView geographic information system to develop a regional model for floodplain determination and representation. Also this study presents to enable two- and three-dimensional floodplain mapping and analysis in the ArcView. The methodology is applied to a Yeoju of Kyunggi-do, located in South Han River Basin. A digital terrain model is synthesized from HEC-RAS cross-sectional data and a digital elevation model of the study area. The flood plain data developed in ArcView was imported into HEC-RAS where it was combined with the field surveyed channel data in order to construct full floodplain cross sections that reflected accurate channel and overbank data for the HEC-RAS model. The flood plain limits could be expressed more accurately on ArcView by using water level data to be computed in HEC-RAS program. The computed water surface elevations and information of cross-section must be manually plotted in order to delineate floodplains. The resulting of this study provided a good representation of the general landscape and contained additional detail within the stream channel. Overall, the results of the study indicate that GIS combined with HEC-RAS is proven to be very useful and efficient for the automatic generation of flood maps, and an effective environment for floodplain mapping and analysis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.2
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• pp.141-151
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• 2020

Since it was first studied in 1980, solar energy analysis model for geographic information systems has been used to determine the approximate spatial distribution of terrain. However, the spatial pattern was not able to be grasped in 3D (three-dimensional) space with low accuracy due to the limitation of input data. Because of computational efficiency, using a constant value for the brightness of the sky caused the simulation results to be less reliable especially when the slope is high or buildings are crowded around. For the above reasons, this study proposed a model that predicts solar energy of vertical surfaces of buildings with four stages below. Firstly, CIE (Commission Internationale de l'Eclairage) luminance distribution model was used to calculate the brightness distribution of the sky using NREL (National Renewable Energy Laboratory) solar tracking algorithm. Secondly, we suggested a method of calculating the shadow effect using ray tracing. Thirdly, LOD (Level of Detail) 3 of 3D spatial data was used as input data for analysis. Lastly, the accuracy was evaluated based on the atmospheric radiation data collected through the ground observation equipment in Daejeon, South Korea. As a result of evaluating the accuracy, NMBE was 5.14%, RMSE 11.12, and CVRMSE 7.09%.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.49-56
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• 2017

In this study, flood analysis was conducted to prepare for damage caused by typhoons and heavy rain due to abnormal climate and climate change. Two - dimensional flooding analysis using the FLUMEN model, which is widely used for national and international flood risk mapping, was conducted for the Nam River Basin, which is the tributary of the Nakdong River. This study divides the topography into $5m{\times}5m$ DEM by ArcView, so that the accuracy of river repair and hydrological characterization and flood area identification can be maximized. As a result of simulation of water flooding, 163.3ha in section 1, 227.7ha in section 2 and 59.9ha in section 3 were simulated.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.124-135
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• 2007

The purpose of this study is to analyze the hydraulic behavior in a stream reach using SMS RMA-2 model with a series of dynamic boundary conditions of main stream and lateral flows simulated by WMS HEC-1 program. For the stream reach (10.5 km) between Gongdo and Pyeongtaek water level gauge stations of Anseongcheon, the model simulated two dimensional flow characteristics by applying dynamic flow conditions of rainfall frequencies of 50, 100, 500, and 1,000 years for the main stream and three tributaries. The temporal flow behavior successfully simulated and the results showed that the distribution of mean velocity and water level within the stream reach increased according to the increase of flow frequency. Especially, the flow velocity sensibly increased at the near downstream of lateral inflow as the width of main stream is narrower.

• Spatial Information Research
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• v.16 no.4
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• pp.479-488
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• 2008

This paper performs investigation of the state-of-the-art approaches to building extraction in terms of their sensory input data and methodologies. For the last decades, there have been many types of sensory input data introduced into the mapping science and engineering field, which are considerably diverse in aspects of spatial resolution and data processing. With the cutting-edge technology in this field, accordingly, one of the key issues in GIS is to reconstruct three -dimensional virtual models of the real world to meet the requirements occurring in spatial applications such as urban design, disaster management, and civil works. Thus, this study investigates the strengths and weaknesses of previous approaches to automating building extraction with two categories - building detection and modeling and with sensor types categorized. The findings in this study can be utilized in enhancing automation algorithms and choosing suitable sensors, so that they can be optimized for a specific purpose.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.48-53
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• 2006

Noise mapping is performed in the city of Cheongju which has 626,614 inhabitants on a $153.41km^2$ area. This city has 71,387 buildings and 969,274m roads. Many database sets like information of roads, topography and buildings are required for making the noise map of large area. These database sets are provided by the various departments of the regional administration in Cheongju city. Using the given database sets, 3-dimensional model of topography and buildings are made to consider the multi-reflections and diffractions. A predicted noise level is compared with measured noise level of the road traffic noise. As the tool of management and decision of urban noise policy, noise map is combined into the map of land use to make the conflict noise map. This conflict noise map is useful to assess the present urban noise and to make the better life in complicated urban life.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.136-145
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• 2018

The disaster monitoring technique by combination of the measurement method and the fine precision of the sensor collecting the satellite-based information that can determine the displacement space is available in a variety of diagnostic information and the GIS/GNSS by first sensor it is being requested from them. Be large and that the facility is operated nationally distributed torsional displacement of the terrain and facilities caused by such natural disasters progress of various environmental factors and the surroundings. To diagnose this spatial information, which contains the various sensors and instruments tracks the precise fine displacement of the main construction structures and the first reference in the Geospatial or more three-dimensional detailed available map and location information using the installed or the like bridges and tunnels produced to a USN/IoT change at any time, by combining the various positioning analysis of mm-class for the facility main area observed is required to constantly in the real time information of the USN/IoT environment sensor, and to utilize this as a precise fine positioning information by UAV/Drone to the precise fine displacement of the semi-permanent infrastructures. It managed to be efficient management by use of new technologies, analyzing the results presented to a method capable of real-time monitoring for a large structure or facility to construction disaster prevention.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.707-720
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• 2011

For the lake case, the detention phenomenon of water body occurs and stays for a long time. Especially, following the layer of water depth direction, the lake body and water quality problems are different from the water quality of river. So according to time, the stream and water quality can be simulated by the 3-Dimensional Model, which can divide water layer for reservoir or lake. The water quality simulation result will become more reliability. For this study, the 3-Dimension Model - EFDC was used to simulate water quality of Unam reservoir in the Sumjin Dam. The HEC-GeoHMS and HEC-HMS Rainfall - Runoff Model based on GIS were used to estimate long-term runoff, and input data was constructed to the observed water level, meteorological data, water temperature, T-N and T-P. In order to apply the EFDC model, water depth was divided into 3 layers and 5,634 grids were extracted. After constructing the grid net, the water quality change of Unam reservoir in time and space was simulated. Overall, long term runoff simulation reflected the actual observed runoff well, through the water quality simulation, according to the pollution factors, the behavior characteristics can be checked, and the simulated water quality can be properly reflected. The function of EFDC has been confirmed, which water quality can be properly simulated. In the near future, to establish countermeasures for Intake Facilities of Watershed and Management, this support which some basic tools can be applied is in expectation.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.27-33
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• 2004

Recently, as a part of NGIS project, cultural-assets digital map is produced by cultural properties administration and local autonomous entities. Cultural-assets unified GIS(Geographic Information System) is essential to cultural properties managers md other organizations which are executing land related business for appling it at planning stage. With explosive national land developments, it has been obligated to implement surface survey by the cultural properties protection Art. In this paper, the authors used the district of Sachon city and made 3D terrain model using digital map which is made of 1/5000 stale. Moreover, the authors improved to RDBMS(Relational Database Management System) structure and remodeled the existing DB design in detail, and also tried recovery of past sea level, based on researches about the water level of southern area. By recover past sea level. the shell mound, apart from lever is actually near lever at past, and it make sure its nature. The authors suggested to realize shape and kind of remains which have 3D information of accuracy and actualization from surface-surveying to excavation.

• Journal of the Korean association of regional geographers
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• v.9 no.2
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• pp.203-216
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• 2003

The process of constructing coastal digital elevation model(DEM), for the 3 dimensional analysis, is composed by abstracting land layers for land elevation and water depth, reprojecting UTM, relocating geographical grid, and interpolating works. The geomorphic set of shallow sea, including tidal current, tidal zone deposition, and water depth distribution, was analyzed by eye search of Landsat TM image, masking of land zone, band combination and regression analysis. Some horizontal differences, between combined DEM and surveyed data of shallow sea, was corrected for analysis. Analyzed geomorphic elements are stream channel, alluvial fan, coastal terrace, tidal current. and shallow sea bank. Results of analysis present that transported fluvial materials influence tidal sedimentation, especially from Gahwacheon river, for the role of artificial draining flooding waters from Jinyang Reservoir, almost in the summer season. In the coastal area with less tidal current, more fine materials are deposited. The influence of currental deposition are higher on small pockets with west coast of well developed terraces. The lower skirt of alluvial fans developed into the tidal zone of shallow sea. Small pocket type bays are closed by coastal current, and less influenced from tidal deposition. The bank of Jinju Bay are developed originally from submerging of remnant erosional mountain ranges, and play on the role of trapping fine materials.