• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.13-18
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• 2019

The DEM(Digital Elevation Model) is a three-dimensional spatial information that stores the height of the terrain as a numerical value. This means the elevation of the terrain not including the vegetation and the artifacts. The DEM is used in various fields, such as 3D visualization of the terrain, slope, and incense analysis, and calculation of the quantity of construction work. Recently, many studies related to the construction of 3D geospatial information have been conducted, but research related to DEM generation is insufficient. Therefore, in this study, a DEM was constructed using a MMS (Mobile Mapping System), UAV image, and UAV LiDAR (Light Detection And Ranging), and the accuracy evaluation of each result was performed. As a result, the accuracy of the DEM generated by MMS and UAV LiDAR was within ± 4.1cm, and the accuracy of the DEM using the UAV image was ± 8.5cm. The characteristics of MMS, UAV image, and UAV LiDAR are presented through a comparison of data processing and results. The DEM construction using MMS and UAV can be applied to various fields, such as an analysis and visualization of the terrain, collection of basic data for construction work, and service using spatial information. Moreover, the efficiency of the related work can be improved greatly.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.123-133
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• 2008

This study evaluated the runoff data collected at 12 stream gauge stations of the Chungjoo dam basin using the IHACRES model. Especially, the geomorphology-related parameters of the IHACRES model could be quantified base on the regionalization technique, which have also been applied many stream gauge stations of the Chungjoo dam basin. Summarizing the results is as follows. (1) The climate-related parameters of the IHACRES model c, $\tau_w{^0}$, and f are found to be estimated and used uniformly over the basin. (2) The geomorphology-related parameters of the IHACRES model $t_q,\;t_s,\;and\;v_s$ are found to be estimated by considering the geomorphological parameters like the basin area, channel length, channel slope, basin slope through the regionalization based on the regression analysis. (3) Using the climate-related parameters applied uniformly over the basin and the geomorphology-related parameters estimated based on the regionalization procedure for each stream gauge station, a total of 12 stream gauge stations have been evaluated with their stream flow measurements. As results, the Sanganmi and Youngwal 1 stream gauge stations have been found to make high quality flow data, but Youngwal, Baekokpo, and Panwoon stations low quality flow data. On the whole, 12 stream gauge stations considered show large differences with their data quality, so a plan for securing more consistent data quality should be prepared imminently.

• Journal of Korea Water Resources Association
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• v.51 no.3
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• pp.235-246
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• 2018

The main purpose of this study is to suggest a methodology for identifying vulnerable region in Choyang creek basin susceptible to soil losses based on runoff aggregation structure and energy expenditure pattern of natural river basin within the framework of power law distribution. To this end geomorphologic factors of every point in the basin of interest are extracted by using GIS, which define tractive force and stream power as well as drainage area, and then their complementary cumulative distributions are graphically analyzed through fitting them to power law distribution to identify the sensitive points within the basin susceptible to soil losses with respect to scaling regimes of tractive force and stream power. It is observed that the range of vulnerable region by scaling regime of tractive force is much narrower than by scaling regime of stream power. This result seems to be due to the tractive force is a kind of scale dependent factor which does not follow power law distribution and does not adequately reflect energy expenditure pattern of river basins. Therefore, stream power is preferred to be a more reasonable factor for the evaluation of soil losses. The methodology proposed in this study can be validated by visualizing the path of soil losses, which is generated from hill-slope process characterized by local slope, to the valley through fluvial process characterized by drainage area as well as local slope.

• Journal of the Korea Computer Graphics Society
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• v.24 no.2
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• pp.21-28
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• 2018

We present interactive methods for visualizing the cloud height data and the backscatter data collected from ceilometers in the three-dimensional virtual space. Because ceilometer data is high-dimensional, large-size data associated with both spatial and temporal information, it is highly improbable to exhibit the whole aspects of ceilometer data simply with static, two-dimensional images. Based on the three-dimensional rendering technology, our visualization methods allow the user to observe both the global variations and the local features of the three-dimensional representations of ceilometer data from various angles by interactively manipulating the timing and the view as desired. The cloud height data, coupled with the terrain data, is visualized as a realistic cloud animation in which many clouds are formed and dissipated over the terrain. The backscatter data is visualized as a three-dimensional terrain which effectively represents how the amount of backscatter changes according to the time and the altitude. Our system facilitates the multivariate analysis of ceilometer data by enabling the user to select the date to be examined, the level-of-detail of the terrain, and the additional data such as the planetary boundary layer height. We demonstrate the usefulness of our methods through various experiments with real ceilometer data collected from 93 sites scattered over the country.

• Journal of the Korean GEO-environmental Society
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• v.17 no.9
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• pp.21-28
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• 2016

The purpose of this study is to compare the three areas that each estimated by using three different river topographic maps. For construction of river topographic maps, the data used in this study are ASTER, SRTM and a 1:5,000 scale digital map data sets in 14 streams of the Cheongdo-gun and Uiseong-gun. HEC-GeoRAS, RAS Mapper, and RiverCAD model are applied for the flooding area analysis using observed data and design rainfalls. The result of analysis is to compare observed flooding area based on the flood plain maps with estimated inundation area by hydraulic models and constructed river topographic maps. The results of this study are as follows; Flooding area by HEC-GeoRAS model is similar to the inundation area of flood plain map and appears in order of RAS Mapper, and RiverCAD model in all watersheds. Flood inundation area by SRTM DEM is similar to the result of 1:5,000 scale digital map in all watersheds and all analysis models. The SRTM DEM shows the most similarity to the digital map than ASTER DEM in all of the watershed scale and analysis models. HEC-GeoRAS and RiverCAD model are efficient models for flood inundation analysis in small watershed and HEC-GeoRAS and Ras Mapper model are efficient in medium to large watershed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.669-676
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• 2018

As the Moon's scientific, technological, and economic value has increased, major space agencies around the world are leading lunar exploration projects by establishing a road map to develop lunar resources and to construct a lunar base. In addition, as the lunar base construction requires huge amounts of resources from the Earth, lunar in-situ construction technology is being developed to produce construction materials from local lunar resources. On the other hand, the characteristics of lunar topography and resources vary spatially due to the crustal and volcanic activities inside the Moon as well as the solar wind and meteorites from outside the Moon. Therefore, in this paper, the geospatial analysis of lunar resource distribution was conducted to suggest regional consideration factors to apply the lunar in situ construction technologies. In addition, the lunar topographic condition to select construction sites was suggested to ensure the safe landing of a lunar lander and the easy maneuvering of a rover. The lunar topographic and resource information mainly from lunar orbiters were limited to the lunar surface with a low spatial resolution. Rover-based lunar exploration in the near future is expected to provide valuable information to develop lunar in situ construction technology and select candidate sites for lunar base construction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.461-470
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• 2020

This study analyzed the determinants of land compensation costs using the CALS (Continuous Acquisition & Life-Cycle Support) system to generate data for the construction (planning, design, building, management) process. For analysis, variables used in the related research on land costs were used, which included eight variables (Land Area, Individual Public Land Price, Appraisal & Assessment, Land Category, Use District 1, Terrain Elevation, Terrain Shape, and Road). Also, the variables were analyzed using the machine learning-based Xgboost algorithm. Individual Public Land Price was identified as the most important variable in determining land cost. We used a linear multiple regression analysis to verify the determinants of land compensation. For this verification, the dependent variable included was the Individual Public Land Price, and the independent variables were the numeric variable (Land Area) and factor variables (Land Category, Use District 1, Terrain Elevation, Terrain Shape, Road). This study found that the significant variables were Land Category, Use District 1, and Road.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.315-330
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• 2000

The GIUH (Geomorphologic Instantaneous Unit Hydrograph) is to be applied to the ungauged or insufficiently gauged basins. For tIris purpose, an accurate estimation of the charactenstlc velocity is one very important part, but any proper method for this has not been developed yet. In case that we have enough rainfall and runoff clata, the estimation of the characteristic velocity may be an easy job, but it is out of the purpose of the GIUH. Remindmg that the purpose of GIUH the characterisbc veloclty should be estimated based on the geomorpholog1c analysis and also be snnple for easy apphcation. In tIris research analysis cmd application of the GruH was given to several sub-basins in Wi-stream river basin, Gono, Donggok and Hyoryung. After deriving the characteristic velocity througn a optimizatlOn process with real data, it is compared w1th several velOCIties der1ved from geOlnoI1Jhoclimatic instantaneous unit hydrograph theory and several other concentration time formulae. The estimated charactenstic velocities using Kerby, Kim, KInematic Wave, and Brasby- Williams formulae found to g1ve the appropriate results. Hmvever, as the Kerby, and the Kinematic Wave require user's decision of the IvIanning's n value, the K1m and the Braby-Williams seem to be more applicable and recommended as characteristic velocity formula.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1635-1639
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• 2007

국가적 차원에서 물을 사용하고 통제하는 일은 국민의 생활에 큰 영향을 미치기 때문에 지구상의 모든 나라들은 주어진 여건에 맞게 효율적으로 물을 사용하고 홍수와 가뭄으로부터 국민의 생명과 재산을 보호하기 위해 많은 일울 수행하고 있다. 이와 같이 수자원 관리를 위해서 가장 근본적으로 이루어져야 하는 것이 물이 언제, 어디에, 얼마나 있는지를 파악하여 물이 있는 곳과 물이 필요한 곳을 연계하여 최적으로 물을 공급하고 관리하는 것이 중요하다. 본 연구에서는 다중목적(이수, 치수, 수질) 적용 기법, 기존 관측소 활용 기법, NARI(Network Analysis for Regional Information) 기법, 지형적 최적 기법 등을 이용하여 하천의 최상류 지점에서 하구까지 모든 지점에 대한 신뢰성 있는 유량정보를 실시간으로 파악할 수 있는 유량측정망을 구축하는데 목적이 있다. 다중목적 적용 기법을 위하여, 수질목적으로는 오염총량제 대상지점을 활용 하였으며, 치수목적으로는 5대강 홍수통제소의 홍수예보 프로그램을 활용 하였고, 이수목적으로는 하천수 사용실태를 조사하여 이를 활용 하였다. 기존 관측소 활용 기법은 5대강 홍수통제소, 지자체, 농촌공사, 수자원공사, 환경부에서 운영하고 있는 수위관측소를 통합하여 중복투자에 따른 손실을 최소화 하고, 최적의 장소에 유량측정망을 구축하는 것이다. NARI 기법은 유량측정망 구축에 있어서 각 지점과의 연계성을 통하여 하천에 흐르는 물의 양을 신뢰성 있게 파악할 수 있도록 분석한 것으로서 하천 상 하류 간의 연계를 통하여 미지의 지점에 대한 유량 값의 유추가 가능하도록 하는 것이다. 지형적 최적 기법은 산간지방, 도시지역, 농촌지역, 산업지역, 상업지역 등과 같이 지형적 특성에 따른 유량측정망을 구축하는 것이다.의 의사결정 지원 도구가 될 것이다. 따라서, 본 연구에서는 도시유역의 물순환 해석을 위한 일련의 과정, 즉 자료의 조사 및 취득에서부터 물순환 해석 모형을 이용한 정량적 현황파악, 물순환 개선 기법 및 평가를 수행함에 있어 주요 착안점 및 실무에서의 기술적 가이드를 제공하고자 하였으며, 보다 세밀한 도시유역의 물순환 해석을 위하여 우리나라와 일본에서 적용이 활발한 물리적 기반의 분포형 모형(WEP, SHER, SWMM)의 적용사례를 통하여 국내 도시하천의 물순환 해석에 활용함에 있어서의 실질적인 적용절차 등을 제시하고자 하였다. 한다.호강유역의 급격한 수질개선을 알 수 있다.世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당위성 상실로 인한 자기수요 감소를 초래하였을 것으로 사료된다. 셋째,

• Journal of Korea Water Resources Association
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• v.40 no.7
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• pp.571-583
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• 2007

The effects of climatic changes owing to urbanization, geographical and topographical conditions on Penman-Monteith reference evapotranspiration, and energy and aerodynamic terms of Penman-Monteith reference evapotranspiration have been studied. In this study, 56 climatological stations including the Seoul metropolis in South Korea have been selected, and the area of study site was set at $314\;km^2$. The climatological station is centrally located In the study area with a 10 km radius. The geographical and topographical characteristics of these sites were examined using GIS analysis. Land use status of the study area was also examined to estimate the extent of urbanization. The study results indicated that the variation of reference evapotranspiration rate is closely related to urbanization in most climatological stations. The level of change in reference evapotranspiration was higher in areas with higher urbanization rates. The change in reference evapotranspiration appears to be caused by temperature rises following heat island phenomena due to urbanization, and by the decrease in humidity, wind speed and sunshine duration due to the Increase in residential areas in urban districts. Especially, the humidity decrease causes a significant decrease in evapotranspiration rate. The study results showed that climatic change due to urbanization and proximity to the coast had the greatest effect on reference evapotranspiration.