• Title/Summary/Keyword: Vegetation model

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Development of Vegetation Structure after Forest Fire in the East Coastal Region, Korea (동해안 산불 피해지에서 산불 후 경과 년 수에 따른 식생 구조의 발달)

  • 이규송;정연숙;김석철;신승숙;노찬호;박상덕
    • The Korean Journal of Ecology
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    • v.27 no.2
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    • pp.99-106
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    • 2004
  • We developed the estimation model for the vegetation developmental processes on the severely burned slope areas after forest fire in the east coastal region, Korea. And we calculated the vegetation indices as a useful parameter for the development of land management technique in the burned area and suggested the changes of the vegetation indices after forest fire. In order to estimate the woody standing biomass in the burned area, allometric equations of the 17 woody species regenerated by sprouter were investigated. According to the our results, twenty year after forest fire need for the development to the normal forest formed by 4 stratum structure, tree, sub-tree, shrub and herb layer. The height of top vegetation layer, basal area and standing biomass of woody species show a tendency to increase linearly, and the ground vegetation coverage and litter layer show a tendency to increase logarithmically after forest fire. Among vegetation indices, Ive and Ivcd show a tendency to increase logarithmically, and Hcl and Hcdl show a tendency to increase linearly after forest fire. The spatial variation of the most vegetation factors was observed in the developmental stages less than the first 5 years which were estimated secondary disaster by soil erosion after forest fire. Among vegetation indices, Ivc and Ivcd were the good indices for the representation of the spatial heterogeneity in the earlier developmental stages, and Hcl and Hcdl were the useful indices for the long-term estimation of the vegetation development after forest fire.

Anisotropy of Turbulence in Vegetated Open-Channel Flows (식생된 개수로 흐름에서의 난류의 비등방성)

  • Kang, Hyeong-Sik;Choi, Sung-Uk
    • Journal of Korea Water Resources Association
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    • v.38 no.10 s.159
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    • pp.871-883
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    • 2005
  • This paper investigates the impacts of turbulent anisotropy on the mean flow and turbulence structures in vegetated open-channel flows. The Reynolds stress model, which is an anisotropic turbulence model, is used for the turbulence closure. Plain open-channel flows and vegetated flows with emergent and submerged plants are simulated. Computed profiles of the mean velocity and turbulence structures are compared with measured data available in the literature. Comparisons are also made with the predictions by the k-$\epsilon$ model and by the algebraic stress model. For plain open-channel flows and open-channel flows with emergent vegetation, the mean velocity and Reynolds stress profiles by isotropic and anisotropic turbulence models were hardly distinguished and they agreed well with measured data. This means that the mean flow and Reynolds stress is hardly affected by anisotropy of turbulence. However, anisotropy of turbulence due to the damping effect near the bottom and free surface is successfully simulated only by the Reynolds stress model. In open-channel flows with submerged vegetation, anisotropy of turbulence is strengthenednear the vegetation height. The Reynolds stress model predicts the mean velocity and turbulence intensity better than the algebraic stress model or the k-$\epsilon$ model. However, above the vegetation height, the k-$\epsilon$ model overestimates the mean velocity and underestimates turbulence intensity Sediment transport capacity of vegetated open-channel flows is also investigated by using the computed profiles. It is shown that the isotropic turbulence model underestimates seriously suspended load.

Restoration of the Stream Runoff by the Physical Deterministic Modeling and Formulation of Water Balance for the Catchment of Byungchun River in Chungcheong Province in Korea (물리 결정 모델링에 의한 충청도 병천천 유역의 하천 유출량 복원과 물 수지 수립)

  • KIM, Man-Kyu
    • Journal of The Geomorphological Association of Korea
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    • v.15 no.2
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    • pp.37-53
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    • 2008
  • This study has developed a water balance model for the catchment of Byungchun river using a BROOK90 4.4e physical deterministic water balance model with the long-term meterological data and stream run off data obtained from the basin of Byungchun river in Korea. It is intended that the validation model with calibrated model fitting parameter can build a long-term water balance plan for a period when meterological data are available but stream runoff data are not. Results of this study have satisfied the first expectation as an experiment for water balance modeling since measured stream runoff data have turned out to be very similar to simulated stream runoff data. Through the confirmation of model fitting parameters and validated simulation, water balance for the period of 1998 to 2006 has been restored. Unless the conditions of geomophology, vegetation, soil and land use change, meterological data alone can produce various hydrometeorological data related to stream runoff amount, soil water amount, and evapotranspiration. This study opens up a new horizon in restoring water balance in the past as well planning water balance in the present. The obtained results from this study are expected to be used in predicting future water balance in the wake of the changes in climate and vegetation in Korea.

Development of Evaluation Model on Greenspace for Sustainability of Site-scale Development Projects (단지규모 개발사업의 지속가능성 확보를 위한 녹지 평가 모형 개발)

  • 양병이;이관규
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.2
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    • pp.97-107
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    • 2000
  • This study aims to develop the model of evaluation on greenspace to increase the sustain ability of the planning and management for site-scale development projects. The results of this study can be summarized as follows: (1) The comprehensive principles of sustainable development projects were established, which include coexistence of man and nature, reflection of ecological principles, minimization of environmental pollution and damage, recycling and reuse of materials. (2) According to established principles, the evaluation criteria were classified into seven categories as follows: retention of ample greenspace, formation of greenspace as a habitat, species diversity of vegetation, consideration of indigenous plants, construction of green network, conservation of greenspace, and reuse of plant materials. (3) As a result of the analysis of questionnaire of experts, evaluation model was worked out with which we can evaluate environmental friendliness greenspace. And, the final evaluation indicators for greenspace are the rate of greeneries volume, securing habitat, indigenous plants, reuse of plant materials, and species diversity of vegetation, and the indicator of greenspace conservation.

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How to utilize vegetation survey using drone image and image analysis software

  • Han, Yong-Gu;Jung, Se-Hoon;Kwon, Ohseok
    • Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.114-119
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    • 2017
  • This study tried to analyze error range and resolution of drone images using a rotary wing by comparing them with field measurement results and to analyze stands patterns in actual vegetation map preparation by comparing drone images with aerial images provided by National Geographic Information Institute of Korea. A total of 11 ground control points (GCPs) were selected in the area, and coordinates of the points were identified. In the analysis of aerial images taken by a drone, error per pixel was analyzed to be 0.284 cm. Also, digital elevation model (DEM), digital surface model (DSM), and orthomosaic image were abstracted. When drone images were comparatively analyzed with coordinates of ground control points (GCPs), root mean square error (RMSE) was analyzed as 2.36, 1.37, and 5.15 m in the direction of X, Y, and Z. Because of this error, there were some differences in locations between images edited after field measurement and images edited without field measurement. Also, drone images taken in the stream and the forest and 51 and 25 cm resolution aerial images provided by the National Geographic Information Institute of Korea were compared to identify stands patterns. To have a standard to classify polygons according to each aerial image, image analysis software (eCognition) was used. As a result, it was analyzed that drone images made more precise polygons than 51 and 25 cm resolution images provided by the National Geographic Information Institute of Korea. Therefore, if we utilize drones appropriately according to characteristics of subject, we can have advantages in vegetation change survey and general monitoring survey as it can acquire detailed information and can take images continuously.

The Vegetation Health Assessment in Riparian Vegetation of Lake Reservoirs (저수지 수변 식생 건강성 평가)

  • Kim, Hyoungdae;Koo, Bonhak
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.6
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    • pp.111-121
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    • 2016
  • This study was carried out to assess the riparian vegetation health in the fluctuation area and vicinity of reservoirs. The results of this study could be a basic data to improve the ecological function and establish green-network of waterside ecosystem. The study site is Daecheong lake reservoirs which the representative landscape of Geum river and with great number of visitors near metropolitan city. The 6 survey plots of 2 survey area were selected, survey area 1 had 4 survey plots and survey area 2 had 2 survey plots, and to compare the study results 4 control plots were selected in Gyeongcheon reservoir. The main dominant specie of survey sites was Salix koreensis in tree and subtree layer, were Salix koreensis and Salix glandulosa. in shrub layer. 2 survey plots of Samjeongdong and Kyeongcheon reservoir were assessed as 'Good', 2 survey plots of chudong were assessed as 'Fair' in vegetation health assessment. In the fluctuation area from flood water level to low water level, 58 populations of Salix koreensis were found in survey sites and Salix koreensis, Salix glandulosa and Acer tataricum subsp. ginale were found in control sites. The most adequate species at the condition affected by inundation impacts would be Salix koreensis and Salix glandulosa was more healthy at the area less affected by inundation. This study was carried out the vegetation health assessment on Daecheong reservoir which has been advanced natural succession for more than 30 years after the construction. Further, it should carry continuously out the research on the planting model of the waterside ecosystem for ecological restoration.

Flood Stage Analysis and Prediction of River Bed Change for Stream Corridor Restoration Model with River Vegetation (하천식생 복원모형의 홍수위 분석과 하상변동 예측)

  • Song, Joong-Geun;Kim, Byeong-Chan;Lee, Jong-Seok
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.437-441
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    • 2009
  • The modern times is as special as from the river, the river is very important of our life. The importance to preserve the river environment has been issued and the river developing method is being changed to use potential function of nature as well as flood control. Essential element of the river restoration is a vegetation. The flow resistance by vegetation along the river banks is greatly increase the flood stage. Therefore, the flow resistance due to vegetation in the river and roughness coefficient changes to understand the hydraulic characteristics is an important elements in the river restoration. The purpose of this study is to analyze the flood stage and the aspects of riverbed changes due to the corridor restoration with river vegetation. In order to simulate the flood stage and riverbed changes, HEC-RAS, RMA-2, and SED-2D model were applied for the upstream and downstream in study reaches, respectively.

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The Trend Analysis of Vegetation Change Applied to Unsupervised Classification Over East Asia: Using the NDVI 10-day data in 1999~2010 (무감독분류 기법을 이용한 동아시아지역의 식생변화 경향분석: 1999~2010 NDVI 10-day 자료를 바탕으로)

  • Kim, Sang-Il;Han, Kyung-Soo;Pi, Kyoung-Jin
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.4
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    • pp.153-159
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    • 2011
  • Vegetative land cover is an important variable many Earth system process, general circulation and carbon exchange model requires vegetative cover as boundary layer necessary to run model. The purpose of this study is to detect and to understand land surface change. To monitor changes of East Asia vegetation, we used NDVI 10-day MVC data derived from SPOT VEGETATION during 12 years from 1999 to 2010. Finally, according to the land cover of classified class, we performed analysis for dynamic zone(positive change zone and negative change zone), static zone in 1999, 2010. Therefore, land covers corresponding to each class have appeared change by 2010. Land cover change was confirmed by analyzing data during 12 years which appeared vegetation change of surrounding the actual desert area to east.

Modeling the long-term vegetation dynamics of a backbarrier salt marsh in the Danish Wadden Sea

  • Daehyun Kim
    • Journal of Ecology and Environment
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    • v.47 no.2
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    • pp.49-62
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    • 2023
  • Background: Over the past three decades, gradual eustatic sea-level rise has been considered a primary exogenous factor in the increased frequency of flooding and biological changes in several salt marshes. Under this paradigm, the potential importance of short-term events, such as ocean storminess, in coastal hydrology and ecology is underrepresented in the literature. In this study, a simulation was developed to evaluate the influence of wind waves driven by atmospheric oscillations on sedimentary and vegetation dynamics at the Skallingen salt marsh in southwestern Denmark. The model was built based on long-term data of mean sea level, sediment accretion, and plant species composition collected at the Skallingen salt marsh from 1933-2006. In the model, the submergence frequency (number yr-1) was estimated as a combined function of wind-driven high water level (HWL) events (> 80 cm Danish Ordnance Datum) affected by the North Atlantic Oscillation (NAO) and changes in surface elevation (cm yr-1). Vegetation dynamics were represented as transitions between successional stages controlled by flooding effects. Two types of simulations were performed: (1) baseline modeling, which assumed no effect of wind-driven sea-level change, and (2) experimental modeling, which considered both normal tidal activity and wind-driven sea-level change. Results: Experimental modeling successfully represented the patterns of vegetation change observed in the field. It realistically simulated a retarded or retrogressive successional state dominated by early- to mid-successional species, despite a continuous increase in surface elevation at Skallingen. This situation is believed to be caused by an increase in extreme HWL events that cannot occur without meteorological ocean storms. In contrast, baseline modeling showed progressive succession towards the predominance of late-successional species, which was not the then-current state in the marsh. Conclusions: These findings support the hypothesis that variations in the NAO index toward its positive phase have increased storminess and wind tides on the North Sea surface (especially since the 1980s). This led to an increased frequency and duration of submergence and delayed ecological succession. Researchers should therefore employ a multitemporal perspective, recognizing the importance of short-term sea-level changes nested within long-term gradual trends.

Application of Simple Biosphere Model (SiB2) to Ecological Research (Simple Biosphere Model 2 (SiB2)의 생태학적 응용)

  • 김원식;조재일
    • The Korean Journal of Ecology
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    • v.27 no.4
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    • pp.245-256
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    • 2004
  • The simple biosphere model 2 (SiB2), which is one of the land surface models, simulates the exchange of momentum, energy and mass such as water vapor and carbon dioxide between atmosphere and biosphere, and includes the biochemical sub-model for representation of stomatal conductance and photosynthetical activities. Throughout the SiB2 simulation, the significant information not only to understand of water and carbon budget but also to make an analysis of interaction such as feed-back and-forward between environment and vegetation is given. Using revised SiB2-Paddy, one sample study which is the evaluation of the runoff in Chaophraya river basin according to land use/cover change is presented in this review. Hence, SiB2 is available in order to ecological studied, if revised SiB2 for realistic simulation about soil respiration, computing leaf area index, vegetation competition and soil moisture is improved.