• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.73-86
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• 2001

Taking account of the structural variation on species composition according to the different topographic positions and aspects, the forest community attributes such as species composition, species diversity index, and similarity coefficient were comparatively analyzed for the three topographic positions and the four aspects in the natural deciduous forest of Mt. Gari area. The results are as follows 1. The most dominant species in the overstory were Quercus mongolica in the mid-slope, the ridge, and all aspects areas, however, the stands of the topographic positions were less similar than the stands of the aspects in species composition, because of the appearance of the specific domonant species such as Juglans mandshurica in the valley area and Pinus densiflora in the ridge area. 2. Among the three topographic positions, the mid-slope area had greatest species diversity index in overstory, but the index of the valley had greater value than those of mid-slope and ridge in mid-story and understory. The north-east area among the aspects had greatest the index in all canopy layers. However, The stands of the aspects showed more smaller variation than the stands of the topographic positions. 3. The ridge area showed greatest similarity coefficient value with the mid-slope area, but showed least similarity coefficient value with the valley. However, similarity coefficient among the topographic positions had much smaller value than similarity coefficient among the aspects.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.310-313
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• 2004

The aim of this study is to evaluate the hazard of landslides at Penang, Malaysia, using a Geographic Information System (GIS) and remote sensing. Landslide locations were identified in the study area from interpretation of aerial photographs and from field surveys. Topographical and geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. The factors chosen that influence landslide occurrence were: topographic slope, topographic aspect, topographic curvature and distance from drainage, all from the topographic database; lithology and distance from lineament, taken from the geologic database; land use from TM satellite images; and the vegetation index value from SPOT satellite images. Landslide hazardous area were analysed and mapped using the landslide-occurrence factors by logistic regression model. The results of the analysis were verified using the landslide location data and compared with probabilistic model. The validation results showed that the logistic regression model is better prediction accuracy than probabilistic model.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.295-301
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• 2004

Satellite captures images periodically and economically over the area wider than aerial photographs, and reconnaissance to unapproachable area. For these advantages, mapping using high resolution satellite image has high potentials of marketability and development. Therefore, utilization of satellite image in mapping and GIS is expected to be growing and research on describable feature, positional accuracy and, possible mapping scale is urgently needed. This research presented that Quick Bird orthoimage could be used to update digital map on a scale of 1:5,000. Quick Bird image was corrected geometrically based on ground control points. DEM was generated using height data of digital topographic map. The orthoimge was produced by digital differential rectification based on DEM which was generated using height data of digital topographic map(scale 1;5,000 and 1;1,000). When the digital topographic map was overlaid with the orthoimage, it was very easy to find changed region or new features builded after the map compiled.

• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.130-135
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• 2017

In temperate monsoon regions, extensive shallow landslides triggered by heavy rainfall are recurrent phenomena in mountainous areas. 1,357 landslides over Jinbu area, Korea that totaled 127 km2 were identified from aerial photographs and field survey. We examined characteristics of rainfall-induced shallow landslides and casual factors affecting landslide distribution with respect to topographic and forest settings, and land use. Most landslides occurred in the study area were the results of a complex combination of precondition, preparatory factors and triggering factors. Cumulative rainfall and high intensity rainfall during short period of time made the study area very sensitive to landslides and played as catalysts to enable other factors including topographic and forest settings, and land use to act more effectively. In addition, some landslides at lower elevation involved channel incision or bank erosion influenced by land use changes such as deforestation and intensification of agriculture surrounding riparian forests or hillslopes. The results suggest that most of landslide were triggered by heavy rainstorms while topographic, forest settings, and land use affected landslide distribution occurred in the study area.

• Spatial Information Research
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• v.18 no.4
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• pp.43-53
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• 2010

A dam is effective in stable supply of water required in daily life and reduction of damage from floods. hut a lot of land or houses arc submerged due to the construction of a darn heavily affecting environment in surrounding areas. In order to improve and support daily life environment. surrounding a dam, many projects have been conducted. and the study has focused on analyzing bow to calculate error characteristics of scale effect for submerged area by using GIS spatial overlay. First, as a result of areal error in submerged area by scale based on a 1/3,000 digital topographic map, it was found that the 1/5,000 digital topographic map is 9.5 times, 9.0 times and 10.5 times more accurate than the 1/25,000 digital topographic map, respectively, in the total of areal error, standard error and areal error for submerged area. Second, as a result of analysis on areal error in areas surrounding a dam, it has been found that Jinan-eup in Jinan-gun registered the largest difference in area within 2km and 2~5km catchment area by recording 13.8 times and 20.6 times, respectively, in the 1/5,000 digital topographic map compared to the 1/25,000 digital topographic map. In addition, in areas out of catchment area within 2km, the area of occupation was very small, so there were no characteristics in error. The out of catchment area, Nami-myeon in Geumsan-gun recorded the largest errors of 31.8 times. Finally, it was found that the ratio of the total areal error in area surrounding a dam, standard error and the total areal error in the entire area using 1,5000 digital topographic map is 7.4 times, 11.8 times and 7.4 times more accurate than the 1/25,000 digital topographic map.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.393-398
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• 2004

It is transformed map data of different coordinate system into unique system and We triedto make topographic map on non-accessible area. We transformed Russian map coordinates(Krassovsky, G-K projection) intoWGS-84, TM projection and assessed accuracy. The RMSE(in East and West bearings : ${\pm}$13.67m, in North and South bearings ： ${\pm}$14.67m) using only SCP(Survey Control Point) is more accurate than that(in East and West bearings ： ${\pm}$24.26m, in North and South bearings : ${\pm}$25.32m) using SCP, intersection of road, bridge. Exterior orientation parameters are estimated using rigorous modelling and GCPs are classified with SCP, intersection of road, bridge. Rigorous modelling is performed with each classified GCP. The modelling result usingonly SCP(in East and West bearings : ${\pm}$13.53m, in North and South bearings ： ${\pm}$14.22m) is more accurate than that using intersection of road(in East and West bearings ： ${\pm}$16.l1m, in North and South bearings： ${\pm}$23.85m), bridge(in East and West bearings : ${\pm}$17.21m, in North and South bearings : ${\pm}$21.82m). The results means that SCP is more accurate than intersection of road, bridge because of edit to generate map. therefore, SCP is suitable for object of GCP in paper map(1:50,000). Geographic information on non-accessible area and analysis is performed. The results of stereoscopic plotting is well matched old map data on road, railroad but, many objects are generally editted. It is possible to update on new objects(building, tributary ‥‥etc). Ability of description using SPOT-5(stereo) is more than features and items included in 1:50,000 topographic map. Therefore, it is possible to make large scale map than 1:50,000 topographic map using SPOT-5 imagery. But, there are many problems(accurate GCPs, obtain of high resolution stereoscopic satellite imagery in a period ‥‥ etc) to make topographic map on non-accessible area. It is actually difficult to solve these problems. therefore, it is possible to update 1:50,000 topographic map in part of topographic map generation.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.53-59
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• 2013

The purpose of this study was to analyze the topographic effect of the LAI (Leaf Area Index), which has been widely used as an index that quantifies the structure of forest vegetation in Deogyusan National Park. With this aim, the study was conducted through a regression analysis which took as explanation the following variables: the elevation, slope, aspect, and soil moisture conditions. The LAI was taken as the response variable. Overall, the correlation between the Field-LAI and topographic factors was less than 0.5, which was relatively low. Except for topographic altitude, there was no statistical significance regarding the correlation with other factors. Meanwhile, regarding the orientation of the correlation, the higher the attitude, the steeper slope, the lower the soil moist, the lower the LAI value. The topographic altitude was found as a statistically significant explanation variable. The TWI (Topographic Wetness Index), which was used in this study to explain the soil moisture conditions, was not significantly related to the LAI distribution. The results of this study are expected to be utilized as basic data in more accurate forecasting the LAI distribution using remote sensing data.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.149-156
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• 2006

Existing method of landuse classification using aerial photographs or field survey requires relatively higher amount of time and cost due to necessary manual work. Especially in urban area where the pattern of landuse is densely aggregated, a landuse classification using satellite image is more complex. In this background, this study proposes a landuse classification method to utilize 1:1,000 digital topographic data and IKONOS satellite image. To prove the possibility of this method, the method was applied to Seoul metropolitan area. The results shows the total accuracy of approximately 95% and 14 landuse classes extracted. Based on the results from the pilot study, this method is applicable to landuse classification in urban area.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.73-84
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• 2010

This paper is to analyze effectiveness and efficiency of topographic features in visibility analysis. For this research aim, this paper compares the analysis results of topographic features and relationships between topographic features and their visibility analysis on surfaces. This paper employs peak, pass, pit, ridge and valley features from the topographic features for which five areas including mountain and plain areas in Britain are selected and their DEM data are generated. The summaries of the analysis results are as follows: Firstly, it is clear that relationship between high elevation points and their visibility is not highly correlated. This means that highly elevated points are not necessarily better visible areas and they are not suitable for searching for large visible areas. Secondly, the positions that can see large visible areas are highly correlated with their elevation and are distributed within a certain range which has small deviation of their correlation between visibility and elevation. This means that to search for large visible areas, it is necessary to employ the positions located at relatively high elevation area. Thirdly, for all of the five areas, the visibility results of the topographic features are compared with maximal visibility resulted from a while surface areas, and it is identified that topographic features show similar visibility performances of that maximal visibility. From the results stated above, it can be inferred that topographic features and its topographic characteristics are enable to be a research motivation to the visibility analysis topics. Furthermore, the results of this paper can be contributed to explore suitable variables and factors for solving multiple viewshed problems.