• Title/Summary/Keyword: Vegetation Structures

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UAV-based Land Cover Mapping Technique for Monitoring Coastal Sand Dunes

  • Choi, Seok Keun;Kim, Gu Hyeok;Choi, Jae Wan;Lee, Soung Ki;Choi, Do Yoen;Jung, Sung Heuk;Chun, Sook Jin
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.1
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    • pp.11-22
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    • 2017
  • In recent years, coastal dune erosion has accelerated as various structures have been developed around the coastal dunes. A land cover map should be developed to identify the characteristics of sand dunes and to monitor the condition of sand dunes. The Korean Ministry of Environment's land cover maps suffer from problems, such as limited classes, target areas, and durations. Thus, this study conducted experiments using RGB and multispectral images based on UAV (Unmanned Aerial Vehicle) over an approximately one-year cycle to create a land cover map of coastal dunes. RF (Random Forest) classifier was used for the analysis in accordance with the experimental region's characteristics. The pixel- and object-based classification results obtained by using RGB and multispectral cameras were evaluated, respectively. The study results showed that object-based classification using multispectral images had the highest accuracy. Our results suggest that constant monitoring of coastal dunes can be performed effectively.

Construction of 3D Earth Optical Model for Earth Remote Sensing (Amon-Ra) Instrument at L1 Halo Orbit

  • Ryu, Dong-Ok;Seong, Se-Hyun;Hong, Jin-Suk;Kim, Sug-Whan
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.30.1-30.1
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    • 2011
  • We present construction of 3D Earth optical Model for in-orbit performance prediction of L1 halo orbiting earth remote sensing instrument; the Albedo Monitor and Radiometer (Amon-Ra) using Integrated Ray Tracing (IRT) computational technique. The 3 components are defined in IRT; 1) Sun model, 2) Earth system model (Atmosphere, Land and Ocean), 3)Amon-Ra Instrument model. In this report, constructed sun model has Lambertian scattering hemisphere structure. The atmosphere is composed of 16 distributed structures and each optical model includes scatter model with both reflecting and transmitting direction respond to 5 deg. intervals of azimuth and zenith angles. Land structure model uses coastline and 5 kinds of vegetation distribution data structure, and its non-Lambertian scattering is defined with the semi-empirical "parametric kernel method" used for MODIS (NASA) missions. The ocean model includes sea ice cap with the sea ice area data from NOAA, and sea water optical model which is considering non-Lambertian sun-glint scattering. The IRT computation demonstrate that the designed Amon-Ra optical system satisfies the imaging and radiometric performance requirement. The technical details of the 3D Earth Model, IRT model construction and its computation results are presented together with future-works.

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Evaluating Erosion Risk of Revegetated Cutslope with Seed Spraying (식생기반재 뿜어붙이기의 비탈면 녹화이후 침식 안정성 평가 방법)

  • Kil, Sung-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.6
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    • pp.63-76
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    • 2016
  • Slope revegetation refers to the use of vegetation and construction to protect a barren slope devastated by road and building construction. Among many revegetation strategies, hydroseeding has been widely utilized to stabilize barren slopes and has become the representative approach. Previous studies on slope stability have been conducted from a civil engineering perspective, mainly evaluating the stability of cut-slopes on solid bedrock and the use of concrete structures to stabilize devastated slopes. This study was conducted to develop a method to evaluate erosion risk of revegetated cut-slopes, based on criteria derived from previous studies. Twenty-five factors were surveyed on both on-the-spot erosion slopes and non-erosion slopes after slope revegetation to compare slope types. The scores of all non-erosion slopes exceed 80 score while erosion slopes are 80 below. Erosion slopes got the range of 68-74 score while non-erosion slopes got the range of 81-100 score in the first result which was not applied for weighted-values. The scores of all non-erosion slopes exceeded 3.10, while erosion slopes were below 3.10. Erosion slopes were in the range of 2.73-3.09, while non-erosion slopes were in the range of 3.15-3.90 in the second result, which was applied with weighted-values according to the AHP result from a previous study.

Distribution and Ecological Range of the Alien Plant Species Mikania micrantha Kunth (Asteraceae) in Taiwan

  • Willis, Maja;Zerbe, Stefan;Kuo, Yau-Lun
    • Journal of Ecology and Environment
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    • v.31 no.4
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    • pp.277-290
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    • 2008
  • In the past two decades Mikania micrantha Kunth, a climbing plant species originating from tropical America, has spread across Taiwan. It can now be found frequently in the lowlands and lower mountain areas up to 1,000 m a.s.l. in the centre and south of the island. Mikania micrantha is considered a problematic invasive alien plant species which is said to cause economical as well as environmental damage. This study investigated the ecological site characteristics of M. micrantha in Taiwan. 112 vegetation surveys were carried out in habitats where the alien plant was present. A comparison between sites with a high and a low abundance was carried out in order to assess which factors especially influence the extensive spread of the plant. Furthermore, the influence of disturbances was examined. Results showed that Mikania micrantha grows very dense in habitats which are characterized by good light conditions combined with vertical structures, such as trees. Results revealed that this invader occurs most frequently in agricultural fallows and wastelands, but it could hardly be found in the intensively managed plantations in the investigation area. Results provide great evidence that the plant is strongly influenced by disturbances, but only if impacts occur rarely.

Development for Eco-Design of Hydraulic Structures based on Web-based Information System (친환경 정비공법 선정 지원을 위한 웹기반 정보시스템 구축)

  • Cho, Young-Kweon;Kim, Kwan-Ho;Kim, Han-Joong;Choi, Soo-Myung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.1
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    • pp.95-106
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    • 2008
  • Eco-friendly material and implementation methods have become important along with the existing standardized maintenance concept for the irrigation and flood control. However, the intrinsic function of the hydraulic structure is water supply and disaster prevention. Therefore, the material and work methods should be considered both eco-friendliness, durability and safety which are prerequisite elements to maintain the engineering function. In this study eco-friendly material and work methods would be classified into the vegetation based system, eco-friendly concrete system and stone-material system according to the characteristics of material. The quality standard for durability followed KS specification and related regulations. The quality standard for safety and eco-friendliness was set after literature review, and the database was developed using the standard. The structure applicable to onsite - the eco-friendly material and work method were classified based on the function and material of the hydraulic structure. Finally, database has been established for convenient management and selection of the proper material and work method. The eco-friendly material and work method could be searched easily for the convenience of the users, and the web-based data system has been developed for continuous registration of the material and work methods to be developed in the future.

Evaluation of Thermal Environment of External Space following the Fence Demolition Campaign in Detached Housing Area (담장허물기로 인한 주택지 외부공간의 열환경 평가)

  • Ryu, Ji-Won;Jung, Eung-Ho;Shimizu, Aki;Oh, Sang-Hak;Hoyano, Akira
    • Journal of the Korean housing association
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    • v.23 no.1
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    • pp.19-26
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    • 2012
  • This study examines how fence demolition may change the thermal environments of external spaces of houses and suggests what factors need to be considered when a fence is demolished. The results of the research are summarized as follows. In terms of the surface temperature, there was no significant difference in all time plots after the removal of all materials. However, applying greening methods (changing the surface materials, planting trees, and building a green roof following fence demolition) could lower the surface temperatures, calling for proper plans for various greening methods. The MRT results indicates that walls block solar radiation and provide shade, reducing radiant heat from roads and surrounding structures during the daytime when solar radiation directly effects surface temperatures. Also, the application of greening methods such as planting vegetation and trees could have shading and evapotranspiration effects, leading to a lower temperature distribution. The HIP results were similar to the MRT results. They indicated that walls block solar radiation within the residential sections and provide shade, resulting in a lower temperature distribution during the daytime. However, areas where greening methods such as a green roof or tree planting were applied showed $1{\sim}2^{\circ}C$ difference in temperature distribution.

New records of three lecanid rotifers(Rotifera: Monogononta: Lecanidae) from Korea

  • Yang, Hee-Min;Min, Gi-Sik
    • Journal of Species Research
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    • v.10 no.3
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    • pp.262-266
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    • 2021
  • In this study, three lecanid rotifer species were newly recorded in Korea: Lecane inermis (Bryce, 1892), L. furcata (Murray, 1913), and L. nana (Murray, 1913). Most of the lecanid rotifers recorded in Korea have been collected from stagnant water, and Lecane furcata and L. nana were collected from a reservoir. In contrast, L. inermis was found in a soil sample. Lecane inermis is the first illoricated lecanid species reported in Korea. This species is distinguished from other illoricated species by its toes with relatively long claws. Lecane furcata is the most common lecanid rotifer in submerged vegetation. The morphological characteristics of its lorica are similar to many other lecanid rotifers, but it can be distinguished by its completely fused toes with a terminal fissure, an absence of antero-lateral spines, and the ratio of lorica/toe length. Lecane nana is most similar to L. tryphema Harring & Myers, 1926, but can be distinguished by the toe tips curved outwards. The three species in this study are considered to have a cosmopolitan distribution and have been recorded in many Asian countries. In this paper, we describe the morphological characteristics of the three lecanid species with trophi structures observed by scanning electron microscope.

Construction of Spatial Information Big Data for Urban Thermal Environment Analysis (도시 열환경 분석을 위한 공간정보 빅데이터 구축)

  • Lee, Jun-Hoo;Yoon, Seong-Hwan
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.5
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    • pp.53-58
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    • 2020
  • The purpose of this study is to build a database of Spatial information Bigdata of cities using satellite images and spatial information, and to examine the correlations with the surface temperature. Using architectural structure and usage in building information, DEM and Slope topographical information for constructed with 300 × 300 mesh grids for Busan. The satellite image is used to prepare the Normalized Difference Built-up Index (NDBI), Normalized Difference Vegetation Index (NDVI), Bare Soil Index (BI), and Land Surface Temperature (LST). In addition, the building area in the grid was calculated and the building ratio was constructed to build the urban environment DB. In architectural structure, positive correlation was found in masonry and concrete structures. On the terrain, negative correlations were observed between DEM and slope. NDBI and BI were positively correlated, and NDVI was negatively correlated. The higher the Building ratio, the higher the surface temperature. It was found that the urban environment DB could be used as a basic data for urban environment analysis, and it was possible to quantitatively grasp the impact on the architecture and urban environment by adding local meteorological factors. This result is expected to be used as basic data for future urban environment planning and disaster prevention data construction.

Biotope Types and Mapping for Ecological Management of Tricholoma matsutake Production Area: The Case of Expressway in Yangyang-gun, Gangwon-do (송이생산지의 생태적 관리를 위한 소나무비오톱 유형화 및 지도 작성: 강원도 양양군 동서고속도로 건설구간을 중심으로)

  • Kim, Jeong-Ho;Choi, Song-Hyeon;Yoon, Yong-Han
    • Journal of Environmental Policy
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    • v.11 no.3
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    • pp.25-47
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    • 2012
  • This research is to suggest an ecological management methods by classification of biotope type and its mapping for Tricholoma matsutake. The target area was construction site of the East Hongchun - Yangyang Highway (Yangyang section) where massive production of Tricholoma matsutakes is in place. Specifically, the 700 m long range of area around the road route, Yangyang section, which is over a total area of $19,79km^2$. The flow of this research was as follows: first studied were the characteristics of the Yangyang Tricholoma matsutakes; second, reviews on previous studies on Tricholoma matsutakes; third, the formulation of standards and processes of biotope type considering Tricholoma matsutake production; and fourth, mapping of biotope considering the production area of Tricholoma matsutake. In 24.77% of the region, slope angle measured $30{\sim}40^{\circ}C$, which is suitable for Tricholoma matsutake production. Also, 17.44% of the region had southward vegetation structures, and as for the Pinus densiflora; 26.00% had average receipts; the tree ages was $38{\pm}8.34$ years; and the average density of canopy layer was $9.55{\pm}4.89/100m^2$. The soil acidity (pH) values of 5.0 to 5.6(47.96%) > 5.6 to 7.0(42.90%) > 4.0 to 5.0(9.14%) were slightly high for Tricholoma matsutake growth; but 57.10% of the area had a soil pH of 4.0-5.6. The organic horizon (A0 layer) was $3.39{\pm}2.14cm$, and the mean depths were 4-6cm(78.03%) > 0-2cm(18.10%) > 2-4cm(3.87%). Based on the results of previous studies and field researches on the presence of vegetation (the pine dominance ratio), the topographic structure (the terrain characteristics and slopes), the receipt, the soil structure (the soil acidity and the organic layers interposed between the depths), and the vegetation density, six clusters based on the identified types of biotopes are produced in this paper. Area of distribution according to the type of biotope was Tricholoma matsutake of the potential-production (II) biotope (32.86%) > Tricholoma matsutake of the inadequate-production biotope (22.17%) > Tricholoma matsutake of the adequate (II)-production biotope (17.79%) > Tricholoma matsutake of the adequate (I)-production biotope (14.86%) > Tricholoma matsutake of the potential-production (I) biotope (9.77%) > Tricholoma matsutake of the produced biotope (2.55%).

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Erosion Control Effect by Soil ansi Vegetation Transition in Mountainous Area after Soil Erosion Measures were Initiated (토양 및 식생변화에 따른 토지 사방 공사의 효과에 관한 연구)

  • 이천용
    • Journal of the Korean Institute of Landscape Architecture
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    • v.14 no.2
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    • pp.7-16
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    • 1986
  • This study was carried out to investigate the effects of such erosion control measures as sowing, planting and small earth structures on the soil and vegetation. In order to study the changes in soil and vegetation, 36 plots were surveyed from 1981 to 1982 in the large erosion control area which is restored last 20 years. The factors which were measured included vegetation coverage, tree growth, number of species, soil depth, soil consistancy, and Chemical properties of soil. The results were as follows; 1) Maximum coverage of the overstory and understory was attained 7 years after the initiation of erosion control. So the overstory need to be tended and pruned. 2) Diversity of species increased until age 6 after which it began to decrease. 3) In order of tree growth, black locust was the fastest, followed by siberian alder and pitch pine. The initial growth of black locust, though the best among the 3 tree stop., decreased rapidly year by year. At the same time, siberian alder and pitch pine grew well until 12 and 6 years after the initiation of erosion control respectively. 4) Fifty percent of the initially planted trees died within 8 yeard. The mortality of siberian alder occurred until the 20th year while the mortality of pitch pine stopped after 10 years. Thereafter 500 trees per hectare were maintained. 5) The soil depth in A and B horision increased by 2cm annually during 20 years. The soil consistency also decreased rapidly until 7th year. The physical soil properties of the rehabilitated areas were improved after the 14th year. 6) The soil pH tend to decrease from 5.3 during the first year to 5.1 during the twentieth year. 7) The organic matter and nitrogen content in the soil were increased by fertilization but after 20 years these nutrients are still deficient for normal tree growth. 8) The phosphorous content in the soil was high in the first year but the longer the period after the initiation of erosion control the lese the content of phosphorous. 9) The biomass of black locust was the highest and increased continuously. The biomass of siberian alder on the contrary decreased from the 15th year because the number of trees in this place was very low. The total biomass in the twentieth year after erosion control initiation was 105.7 ton per hectare.

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