• Economic and Environmental Geology
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• v.28 no.4
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• pp.405-414
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• 1995

An algorithm for monitoring geomorphological change using remote sensing data is investigated and tested using two LANDSAT TM data sets acquired over the Kyunggi Bay on April 15 1986 and September 22 1992, respectively. The algorithm exploits change vector analysis and tasseled cap transform. Although change vector analysis is effective for change detection, efficiency is decreased as the number of variables are increased. In this algorithm, we overcome the problem by utilizing the tasseled cap transform which can reduce six bands of LANDSAT TM data into only two components called Brightness and Greenness. The test results demonstrate that the algorithm is very effective in monitoring small-scaled changes over coastal area as well as significant changes in geomorphology. The resulting change vector image, however, is more sensitive to the changes occurred by human activities than by pure geological processes mainly because of relatively short time interval between two LANDSAT TM data sets.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.34-34
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• 2011

최근 우리나라에서는 기상이변과 기후변화에 의한 국지성 집중호우의 발생으로 인해 인명 및 재산 피해가 증가하는 추세이다. 따라서 이러한 기상현상을 좀 더 정확하게 예측하고 이를 대응하고자 악기상 모형의 개발과 구축 및 활용에 대한 연구들이 활발하게 진행 중에 있다. GCM이 제공하고 있는 많은 유용한 정보에도 불구하고 대부분의 모델이 시 공간 분해능과 물리 과정의 한계점으로 인해 지역적인 기후 특성이나 변화를 예측하기에는 많은 문제점들이 나타나고 있다. GCM의 한계점을 극복하기 위한 방법으로 세밀한 규모의 기후 정보를 얻기 위해 복잡한 지형과 해안선, 호수, 식생, 지표특성과 같은 아격자 규모의 강제 효과를 반영할 수 있는 고해상도 지역 기후 모델(Regional Climate Model, RCM)의 필요성이 제기되었다. 본 연구에서는 전지구 20km 격자자료를 입력장으로 하여 8km 격자로 한반도를 포함하는 도메인에 대해 비정역학 완전 압축성 중규모 모델인 WRF를 이용하여 상세예측자료를 생산하고자 하였다. 강수 예측의 경우 돌발적으로 발생하는 경우가 많아, 이를 예측하기 위해서는 상세한 강수량 정보를 빠른 시간 내에 정확히 제공할 수 있는 모델을 사용하여야 한다. 강수의 경우 온도와는 달리 공간적 편차가 매우 커 지역적으로 정확한 강수량을 예측 하는데 어려움이 있다. 상세강수 예측을 위해 미세 격자 규모의 비 정역학 모형을 사용할 경우 계산양이 매우 늘어나기 때문에 장시간의 모형 적분 시간뿐 아니라, 상당한 컴퓨터 자원을 필요로 하므로 이에 대한 대안으로 지형효과를 포함한 강수량 진단 모형인 QPM(Quantitative Precipitation Model)을 사용하였다. 최종적으로 한반도의 복잡한 지형적 영향을 반영하기 위해 1 km의 수평해상도를 가지는 고해상도 강수량 진단 모형(QPM)과 상세한 지리적, 공간적 분석을 할 수 있는 ARCGIS를 이용하여 한반도 도별 상세 강수자료를 생산하고자 한다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.4
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• pp.184-191
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• 2010

Epiphytic diatoms are very important organisms in the seagrass ecosystem because their colonization on leaves increases microtopography and provides attachment sites that make the leaves more hospitable for other epiphytes. Epiphytic diatoms were attached to the leaves in the following 3 manners: (1) parallel to the cells of the seagrass leaf or by molding the shape of the diatom along the cell shape of the leaf; (2) with increasing diatom density toward the leaf tip; (3) Cocconeis species as attaching species than the Naviculoid species as the second attaching species on the leaf tip. In addition, the epiphytic diatom communities on Zostera marina leaves differed from those on the Zostera japonica leaves, but were very similar to the epiphytic communities on Zostera caespitosa leaves. Our results suggest that the epiphytic community on seagrass leaves varied according to the leaf shape such as leaf length and width, but the leaf cell shape or size did not influence the dynamics of the diatom communities.

• Journal of the Korean Geographical Society
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• v.44 no.2
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• pp.122-145
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• 2009

Terrain parameters calculated from digital elevation models (DEM) have become increasingly important in current spatially distributed models of earth surface processes. This paper investigated how the ability of upslope area for predicting the spatial distribution of soil properties varies depending on the selection of spatial resolutions of DEM and algorithms. Four soil attributes from eight soil-terrain data sets collected from different environments were used. Five different methods of calculating upslope area were first compared for their dependency on different grid sizes of DEM. Multiple flow algorithms produced the highest correlation coefficients for most soil attributes and the lowest variations amongst different DEM resolutions and soil attributes. The high correlation coefficient remained unchanged at resolutions from 15 m to 50 m. Considering decreasing topographical details with increasing grid size, we suggest that the size of 15-30 m may be most suitable for soil-landscape analysis purposes in our study areas.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.101-112
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• 2006

Currently, highway design speed is determined by considering highway function, area type, and terrain type. Sometime it is pointed out that determining a reasonable design speed which is both efficient and safe is not an easy task and that Practicing engineers often select an unsuitable design speed on purpose, capitalizing on some ambiguous and discretionary expressions in describing the highway design speed. This undesirable Problem is arising mostly due to the fact, that the current geometric design standard fails to include rolling terrain type and can not reflect the whole characteristics of land use patterns adjacent to the design highway route. A recent research was Published considering this problem and it attempted to improve the highway design speed determining process. In this research Project, tn see the effects of this recently developed procedure, a new and reduced design speed was calculated based on the new Procedure and subsequently another highway design route was selected. The travel time. construction cost. and the expected degree of safety associated with the new route were assessed to be compared with the ones with the existing procedure. As a result. it was found that the new procedure was successful in reflecting the localities such as terrain type and area type into better determining highway design speed, eliminating much of highway engineers' discretion when applying engineering judgments. Also the new Procedure is keen to produce a more economical highway project. In other words, despite of producing reduced amount of user benefits accrued, in the new highway route, the construction cost has been cut significantly leading to higher values in B/C. NPV, and IRR. Also EMME-II output, which Provided the link assigned volumes, rendered only a slightly reduced Levels of Service along surrounding links in the study network. This reduction was believed to occur because of lower design speed and it had been expected from the beginning.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.234-253
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• 2018

Within the Gyeongju Basin lies the central an ancient tombs (Wolseongbuk tombs), which are seen to be the core tombs of the Silla ruling class. An accurate understanding of the location of the ancient tombs, commonly known as a flatland area, provides a clue to understanding the contrast process and direction of the ancient tombs. This in turn requires an accurate understanding of the surrounding landscape, including where the ancient tombs are located. In other words, it must be possible to restore as much of the highland area as possible within the basin in which the ancient tombs are located. All data were analyzed as deeply as possible in order to identify the topographical features of the ancient tombs. As a result, it appears that the ancient tombs are located at the end of a fan or at the end of the line, and a large number of springs and wetlands are distributed around the area. This area is relatively low and unsuitable for generating high levels of moisture on the ground. These topographical features are directly related with the distribution of polymers, and solids were completely formed to avoid wetlands. Meanwhile, the ancient tombs are divided into several zones by springs and wetlands, and each area also has the characteristics of large groups where the boundaries are protruding and isolated. Also, this aspect was found to be true for the Oreung around Namcheon. After all, the location and distribution of Silla in the Daerungwon area are the result of the reflection of the fine geographical features of the Gyeongju basin, which are the key factors of springwater and wetlands.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.223-224
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• 2003

포장도로에서 발생되는 미세먼지는 주로 자동차의 운행에 의한 직접 배출되는 입자와 도로 표면에서 비산되는 토양입자 그리고 타이어나 브레이크 패드의 마모에 의한 고무 및 석면 둥 다양한 배출원에 의해 발생되는데, 도로 주변의 배출원에 의해 많은 영향을 받을 것으로 판단된다. (최금찬등, 1996) 특히 인천에는 많은 비산먼지 배출원이 산재하여 있어, 이 들 배출원들의 영향이 여타 대도시보다 클 것으로 판단된다. 따라서, 본 연구에서는 인구와 교통량이 많고 공업활동이 활발한 인천지역의 주요 포장도로(H-ADT: High Average Daily Traffic, 5,000대/일 이상인 도로)에서 채취한 silt를 주거지역, 공업지역, 상업지역, 기타지역별로 채취하여 화학적 성분분석을 통해 지역별 특성을 조사하여, 각 지역 별 포장도로에서의 silt의 기원이 무엇인지를 추정하는 기초자료를 구축하고자하였다. (중략)

• Journal of Korea Water Resources Association
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• v.39 no.2 s.163
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• pp.151-160
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• 2006

In this study, threshold runoff which is a hydrologic component of flash flood guidance(FFG) is estimated by using Manning's bankfull flow and Geomorphoclimatic Instantaneous Unit Hydrograph(GcIUH) methods on Han River watershed. Geographic Information System(GIS) and 3' Digital Elevation Model database have been used to prepare the basin parameters of a very fine drainage area($1.02\~56.41km^2$), stream length and stream slope for threshold runoff computation. Also, cross-sectional data of basin and stream channel are collected for a statistical analysis of regional regression relationships and then those are used to estimate the stream parameters. The estimated threshold runoff values are ranged from 2 mm/h to 14 mm/6hr on Han River headwater basin with the 1-hour duration values are$97\%$ up to 8mm and the 6-hour values are $98\%$ up to 14mm. The sensitivity analysis shows that threshold runoff is more variative to the stream channel cross-sectional factors such as a stream slope, top width and friction slope than the drainage area. In comparisons between the computed threshold runoffs on this study area and the three other regions in the United States, the computed results on Han River watershed are reasonable.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.4
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• pp.307-316
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• 2010

Complex terrain refers to irregular surface properties of the earth that influence gradients in climate, lateral transfer of materials, landscape distribution in soils properties, habitat selection of organisms, and via human preferences, the patterning in development of land use. Complex terrain of mountainous areas represents ca. 20% of the Earth's terrestrial surface; and such regions provide fresh water to at least half of humankind. Most major river systems originate in such terrain, and their resources are often associated with socio-economic competition and political disputes. The goals of the TERRECO-IRTG focus on building a bridge between ecosystem understanding in complex terrain and spatial assessments of ecosystem performance with respect to derived ecosystem services. More specifically, a coordinated assessment framework will be developed from landscape to regional scale applications to quantify trade-offs and will be applied to determine how shifts in climate and land use in complex terrain influence naturally derived ecosystem services. Within the scope of TERRECO, the abiotic and biotic studies of water yield and quality, production and biodiversity, soil processing of materials and trace gas emissions in complex terrain are merged. There is a need to quantitatively understand 1) the ecosystem services derived in regions of complex terrain, 2) the process regulation occurred to maintain those services, and 3) the sensitivities defining thresholds critical in stability of these systems. The TERRECO-IRTG is dedicated to joint study of ecosystems in complex terrain from landscape to regional scales. Our objectives are to reveal the spatial patterns in driving variables of essential ecosystem processes involved in ecosystem services of complex terrain region and hence, to evaluate the resulting ecosystem services, and further to provide new tools for understanding and managing such areas.

• Economic and Environmental Geology
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• v.45 no.2
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• pp.137-144
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• 2012

Soil pan typically presents the problems in soil water movement or in aeration which is not appropriate for a plant root growth, In this study physico-chemical characteristics of soils and micromorphological characteristic of clay accumulated zone were investigated to identify redox characteristic and evolution of a fragipan of Gangreung series commonly developed in coastal terraces. Gangreung series is classified as Aquic Fragiudalfs according to the USDA soil taxonomy. It is known that sedimentary ocean floor results in soil pan having parallel liner soil structure due to landscape evolution around 200 to 250 million years ago. it is considered that illite, kaolinite, and vermiculite are major clay minerals contained in a fragipan of Gangreung series. Mixed gray and reddish brown colored band around soil pores was found and would be the redoxmorphic features of fragipan. It is possibly due to accumulated illuvial clay and ferriargillans in soil pores and aggregates in reducing conditions eluding ferrous material. Therefore, mixed colored band around pores in soils of Gangreung series would be developed from the eluted ferrous materials which were accumulated in fragipan during the emerged land formation.