• Title/Summary/Keyword: Microtopography

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Effects of Microtopography on the Development of Riparian Vegetation in Stream Corridors (하천통로에서 미세 지형 발달이 하천 식생에 미치는 영향)

  • 정경진;김동엽
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.4
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    • pp.39-49
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    • 1999
  • Urban streams have, recently, been straightened and widened to alleviate flooding problem. As a result, the stream have been modified inadvertently for ecological functions and microtopography. In this study, we investigated riparian vegetation and microtopography of the tributaries of Han River before and after the monsoon rain in summer. The purpose of this study was to relate the stream microtopography to the distribution of riparian vegetation. The stream microtopography was investigated for its scale and pattern. Vegetation was investigated from 131 plots by Braun-Blanquet method. The distribution of riparian vegetation was significantly correlated with the stream microtopography. Various herbaceous species occurred at stream bank slop, high terrace and channel side. However, at channel side and concave part of terrace where soils were in high moisture level, only a few wetland species were dominated. The complexity of the microtopography in the stream corridors led to heterogeneous riparian vegetation. The vegetation showed more stability against flooding at the stream corridors with natural and complex microtopography than at the urban-type stream corridors with simple topographical features. The results showed that the development of riparian vegetation was influenced by the changes in microtopography, which was primarily determined by the shape and characteristics of channel. It seemed that a close-to-nature river system would be restored more readily with an understanding of microtopographical features affecting the distribution of riparian vegetation.

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A Study on Spatial Characteristics of Microtopography of Stream by Topographic Names (지형호칭에 의한 하천 미지형경관의 공간특성에 관한 연구)

  • 강영주;김현정
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.3
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    • pp.111-123
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    • 1997
  • In order to understand the spatial forms of stream, this study aimed to typify stream microtopography through the collection of common names of topography determined by fishermen and to describe stream landscapes by using these typology. The seventeen stream microtopography names were sorted out and divided into three types : the streamside space which includes Kaeul-jari, Hapsu-mori, Cholpyok-jidae, Kyekok-jidae and Korpuri, stream plate which includes Youl, Mulgol, So and Ungdongi, and streambed materials which includes Ampan-jidae, Pawi-jidae, Dolpat-jidae, Chagal-jidae, Chanchgal-jidae, Moraetop, Kamtang-padak and Suchodae. The spatial characteristics of stream microtopography landscape were described according to the comparison of landform, the support of fishing, accessibility, viewpoint and eye-catching degree. The tipification of stream microtopography and their symbolization will offer a rich vocabulary to describe diverse spatial forms of stream.

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Plant community development in the first growing season of a created mitigation wetland bank as influenced by design elements

  • Ahn, Chang-Woo
    • Journal of Ecology and Environment
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    • v.33 no.4
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    • pp.363-376
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    • 2010
  • Vegetative communities of created wetlands often display lower species richness, less cover, higher occurrence of non-native or invasive species, and fewer obligate wetlands species than those in natural wetlands, thus failing to meet basic success criteria for wetland mitigation. This study examined the effects of two design elements, disking-induced microtopography and hydrologic regime, on the first year vegetation development pattern of a mitigation wetland newly created in the Virginia piedmont. Elevation and species cover were measured along replicate multiscale circular transects in two adjacent wetland sites that are different in their hydrologic regime. Two microtopographic indices, tortuosity (T) and limiting elevation difference (LD), were calculated from the elevation measurements. Both indices were higher in disked plots than non-disked plots, showing the effect of disking on microtopography. Out of forty-one vegetation taxa observed in the wetland, 29 taxa were naturally colonized and 12 taxa were seeded. All plots except one non-disked plot were dominated by wetland vegetation. Species richness and diversity were higher in disked than in non-disked plots. Vegetation community development seemed also influenced significantly by hydrologic regime of the site. The effect of microtopography on species richness and diversity was more pronounced in a relatively dry site compared to a wet site. In addition, percent cover, species richness and diversity of vegetation were positively correlated with microtopographic indices such as T and LD. Two design elements, microtopography and hydrologic regime, should be considered and incorporated in wetland creation to enhance plant community development.

Surface Microtopography of Pyrophyllite Crystals from Gussi Deposit, Korea (전남 구시광산에서 산출하는 엽납석 결정의 표면 미세형태)

  • Mayumi Jige;Ryuji Kitagawa;Hwang, Jin-Yeon
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.2
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    • pp.115-121
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    • 2004
  • The surface microtopography of pyrophyllite collected from the Gussi deposit, Korea was observed by mean of transmission electron microscopy (TEM) with the gold decoration technique. As results, closed step patterns with malformed circular islands were characteristically observed on the (001) surface of pyrophyllite, contrasting with spiral step patterns common in illite and kaolinite. Gussi pyrophyllite was likely crystallized from hydrothermal solution of higher temperature and/or higher supersaturation than those of other clay minerals. Comparing with micro-topographies of pyrophyllite from the Shokozan and the Uku deposits, southwest Japan, growth mechanism of Gussi pyrophyllite is almost equivalent to those from the Shokozan and the Uku deposits.

Analysis of GIS for Characteristics on the Slow-Moving Landslide: With a Special Reference on Slope and Grade of Landslide (GIS를 이용한 땅밀림지 특성 분석: 산지경사 및 산사태위험등급을 중심으로)

  • Park, Jae-Hyeon;Seo, Jung Il;Lee, Changwoo
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.311-321
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    • 2019
  • This study was carried out to establish basic data for the development of slow-moving landslide hazard classes. Mountain slopes in slow-moving landslide areas ranged from $11.8^{\circ}$ to $37.0^{\circ}$ with a mean slope of $23.8^{\circ}$. However, the slope inclination of microtopography in slow-moving landslide areas was slightly different, with a mean slope of $23.5^{\circ}$ ($10.7^{\circ}{\sim}41.5^{\circ}$) compared with the mountain slope. There was a significant difference (p < 0.05) between the contour intervals of microtopography and the contour intervals of the slow-moving landslide areas. Among all the slow-moving landslide areas examined, 14 plots (approximately 38.0%) were classified into landslide hazard class I, 6 plots (approximately 16.0%) into landslide hazard class II, 5 plots (approximately 14.0%) into landslide hazard class III and IV, and 16 plots (approximately 43.0%) into landslide hazard class V, whereas 9 plots (approximately 24.0%) fit the no landslide hazard class.

Initial Survey on Pit and Mound in Fir Forests in Soraksan Mountain (설악산 전나무림에 나타난 흙 패임과 둔덕에 관한 기초조사)

  • 전상규;윤영일
    • Korean Journal of Environmental Biology
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    • v.22 no.2
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    • pp.287-294
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    • 2004
  • Pits and mounds created by windthrow have significant impacts on forest ecosystem. In order to establish initial data base, 80 pits and mounds were sampled and surveyed in 5 fir forests in Nae-Sorak Mountain. Characteristics and forms were surveyed and frequency of tree species appearance were surveyed as well. 4.9% of surveyed area (0.4 ha) was pits and mounds in El and E2 areas except old areas where survey was done by estimation. E3 area showed the highest proportion, 11.7% of 0.1 ha of sampling area.

Effect of implant surface microtopography by hydroxyapatite grit-blasting on adhesion, proliferation, and differentiation of osteoblast-like cell line, MG-63

  • Park, Sung-Jae;Bae, Sang-Bum;Kim, Su-Kyoung;Eom, Tae-Gwan;Song, Seung-Il
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.37 no.3
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    • pp.214-224
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    • 2011
  • Objective: This study examined the potential of the in vitro osteogenesis of microtopographically modified surfaces, RBM (resorbable blasting media) surfaces, which generate hydroxyapatite grit-blasting. Methods: RBM surfaces were modified hydroxyapatite grit-blasting to produce microtopographically modified surfaces and the surface morphology, roughness or elements were examined. To investigate the potential of the in vitro osteogenesis, the osteoblastic cell adhesion, proliferation, and differentiation were examined using the human osteoblast-like cell line, MG-63 cells. Osteoblastic cell proliferation was examined as a function of time. In addition, osteoblastic cell differentiation was verified using four different methods of an ALP activity assay, a mineralization assay using alizarin red-s staining, and gene expression of osteoblastic differentiation marker using RT-PCR or ELISA. Results: Osteoblastic cell adhesion, proliferation and ALP activity was elevated on the RBM surfaces compared to the machined group. The cells exhibited a high level of gene expression of the osteoblastic differentiation makers (osteonectin, type I collagen, Runx-2, osterix). imilar data was represented in the ELISA produced similar results in that the RBM surface increased the level of osteocalcin, osteopontin, TGF-beta1 and PGE2 secretion, which was known to stimulate the osteogenesis. Moreover, alizarin red-s staining revealed significantly more mineralized nodules on the RBM surfaces than the machined discs. Conclusion: RBM surfaces modified with hydroxyapatite grit-blasting stimulate the in vitro osteogenesis of MG-63 cells and may accelerate bone formation and increase bone-implant contact.