• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.190-196
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• 2003

The top-of-atmosphere(TOA) radiance and its seasonal variation for various surface types have been analyzed using the MODIS direct broadcasting data acquired from the KARI ground station for the period between July 2002 and November 2003. The selected study areas considering the MODIS spatial resolution and the characteristics of the Korean peninsular are as follows: agricultural land, forest land, inland water, sea water, urban land, wetland, and atmosphere(cloud). The results showed that TOA radiances depend on the surface characteristics for the selected sample areas. Furthermore, the MODIS observations appear to well depict the general features of earth radiation properties. The authors hope that this study may provide the basic information on the analysis of hyperspectral data.

• Korean Journal of Environment and Ecology
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• v.18 no.4
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• pp.465-474
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• 2004

Due to the rapid increase of human population and economic development, the natural ecosystem has been severely degraded. To restore the degraded ecosystem is extremely urgent and an important task in China. High biodiversity status in the natural ecosystem in tropical and subtropical regions in China has given high attention to the conservationists. The recent trends to the ecological restoration on degraded ecosystem in the tropical and subtropical regions of China were discussed for four different ecological recovery types: watershed ecosystems, wetlands, mining wastelands and mountain forests. The successful restoration case studies in tropical and subtropical regions of China were also discussed.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.110-126
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• 2024

This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.686-697
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• 2018

Due to the advance in remote sensing technology, it has become easier to more frequently obtain high resolution imagery to detect delicate changes in an extensive area, particularly including forest which is not readily sub-classified. Time-series analysis on high resolution images requires to collect extensive amount of ground truth data. In this study, the potential of land coverage mapas ground truth data was tested in classifying high-resolution imagery. The study site was Wonju-si at Gangwon-do, South Korea, having a mix of urban and natural areas. KOMPSAT-3A imagery taken on March 2015 and land coverage map published in 2017 were used as source data. Two pixel-based classification algorithms, Support Vector Machine (SVM) and Random Forest (RF), were selected for the analysis. Forest only classification was compared with that of the whole study area except wetland. Confusion matrixes from the classification presented that overall accuracies for both the targets were higher in RF algorithm than in SVM. While the overall accuracy in the forest only analysis by RF algorithm was higher by 18.3% than SVM, in the case of the whole region analysis, the difference was relatively smaller by 5.5%. For the SVM algorithm, adding the Majority analysis process indicated a marginal improvement of about 1% than the normal SVM analysis. It was found that the RF algorithm was more effective to identify the broad-leaved forest within the forest, but for the other classes the SVM algorithm was more effective. As the two pixel-based classification algorithms were tested here, it is expected that future classification will improve the overall accuracy and the reliability by introducing a time-series analysis and an object-based algorithm. It is considered that this approach will contribute to improving a large-scale land planning by providing an effective land classification method on higher spatial and temporal scales.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.23-43
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• 2020

The purpose of this paper is to create ecological values for urban rivers. For this, the paper looks into river bed structures and how nearby lands are used. This study was performed to set the specific sections for analysis through a field investigation of the infrastructure conditions, surrounding land use, and the inter habitat structure of Seongnaecheon(Stream). A total of 780 individuals from 31 species of wild birds appeared in Seongnaecheon(Stream). According to foraging guild's habitat, there were 9 species of water, 8 types of water edges, 5 types of crowns, 5 types of shrubs, 2 types of tree trunks, 2 types of birds of raptors, and 355 individuals of water, 243 shrubs, 90 crowns, 84 water edges and 5 raptors. Many water birds were observed at the site where the Seongnaecheon(Stream) sandy plains and wetland herbaceous area were developed and the open water was secured. Most of the forest birds appeared on levee slope connected with forest around and riverside with fewer facilities for use. The species diversity index of Shannon, the entire section of Seongnaecheon(Stream), was 2.2697 and the downstream ecological landscape conservation area of Seongnaecheon(Stream) was found to be useful as a habitat for wild birds in the city compared to other sections. Some sections of Seongnaecheon (Stream) had low species diversity index due to lack of green space and surrounding urbanization areas. In choosing target species, I researched the special features of the habitats and the habitation structure of wild birds in each zone. Regarding detailed plans, by classifying the breeding place & roosting site and the roosting site & shelter that took account of the inhabitation characteristics of the target species in different sections, this paper suggested the major plant species and multilayer planting structures. Moreover, this study proposed the development of habitats for water birds and forest birds along with the connection of the green network for improving the Eco-corridor linkage and inhabitation features in Seongnaecheon(Stream).

• Journal of Wetlands Research
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• v.25 no.3
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• pp.167-175
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• 2023

Precipitation data is one of the essential input datasets used in various fields such as wetland management, hydrological simulation, and water resource management. In order to efficiently manage water resources using precipitation data, it is essential to secure as much data as possible by minimizing the missing rate of data. In addition, more efficient hydrological simulation is possible if precipitation data for ungauged areas are secured. However, missing precipitation data have been estimated mainly by statistical equations. The purpose of this study is to propose a new method to restore missing precipitation data using machine learning algorithms that can predict new data based on correlations between data. Moreover, compared to existing statistical methods, the applicability of machine learning techniques for restoring missing precipitation data is evaluated. Representative machine learning algorithms, Artificial Neural Network (ANN) and Random Forest (RF), were applied. For the performance of classifying the occurrence of precipitation, the RF algorithm has higher accuracy in classifying the occurrence of precipitation than the ANN algorithm. The F1-score and Accuracy values, which are evaluation indicators of the classification model, were calculated as 0.80 and 0.77, while the ANN was calculated as 0.76 and 0.71. In addition, the performance of estimating precipitation also showed higher accuracy in RF than in ANN algorithm. The RMSE of the RF and ANN algorithms was 2.8 mm/day and 2.9 mm/day, and the values were calculated as 0.68 and 0.73.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.417-425
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• 2023

As climate change gets severe, the ecosystem acts as an important carbon sink, therefore efforts are being made to utilize these functions to mitigate climate change. In this study, we inventoried and analyzed the previous studies related to carbon storage and flux by ecosystem type (forest, cropland, wetland, grassland, and settlement) and carbon pool (aboveground and belowground biomass, dead wood, Litter, soil organic carbon, and ecosystem) in Korean ecosystems. We also collected the results of previous studies and calculated the average value of carbon storage and flux for each ecosystem type and carbon pool. As a result, we found that most (66%) of Korea's carbon storage and fluxes studies were conducted in forests. Based on the results of forest studies, we estimated the storage by carbon stock. We found that much carbon is stored in vegetation (aboveground: 4,018.32 gC m^-2 and belowground biomass: 4,095.63 gC m^-2) and soil (4,159.43 gC m^-2). In particular, a large amount of carbon is stored in the forest understory. For other ecosystem types, it was impossible to determine each carbon pool's storage and flux due to data limitations. However, in the case of soil organic carbon storage, the data for forests and grasslands were comparable, showing that both ecosystems store relatively similar amounts of carbon (4,159.43 gC m^-2, 4,023.23 gC m^-2, respectively). This study confirms the need to study carbon in rather diverse ecosystem types.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.101-115
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• 2013

11 alpine wetlands at the upper reaches of Bangtae River on a high flat summit around Mt. Jeombong were found. Two core samples(JB-1 and JB-2) among them were collected in order to reconstruct paleovegetation history and climate change using pollen analysis. Pinus and Quercus dominated at the wetland of JB-2 with a deep water depth were developed from 1,700 yr BP to 1,000 yr BP of the pollen zone I. Subsequently Quercus dominated in the pollen zone II from 1,000 to 400 yr BP, and it is supposed that warm weather prevailed with oak climax forest corresponding to the Medieval Warm Period. Moreover, sphagnum grew densely in the alpine wetlands and the wetlands were extended widely on the summit around Mt. Jeombong with the beginning of subzoneIIc at JB-2. The pollen zone III from 400 yr BP to the present with an increase in Pinus and a decrease in Quercus suggests cold climates under the Little Ice Age. Moreover, human disturbances at JB-2 were more significant than those at JB-1, based on the increase in Pinus.

• Journal of Wetlands Research
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• v.6 no.3
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• pp.107-118
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• 2004

The flora of the vascular hydrophytes and hygrophytes and the change of flora according to the fluctuation of the water level before and after flooding were investigated from September 2002 to October 2003 in Woopo Wetland and Topyeong Stream, Changnyeong-gun, Gyeongsangnam-do, Korea. The flora of the Woopo, Mokpo, Sajipo, Jokjibyeol, Topyeongcheon Upstream, and Topyeongcheon Downstream were composed of 256, 242, 265, 177, 201, and 180 taxa, respectively. The flora of total study area was 86 families, 232 genera, 302 species, 42 varieties, 6 form, or total 350 taxa. Among them, hydrophytes, hygrophytes, and others were 36, 96, and 218 taxa, respectively. The life form of the vascular hydrophytes was classified as 19 taxa of emergent plants, 6 taxa of floating-leaved plants, 4 taxa of free-floating plants, and 7 taxa of submersed plants. The specified wild plants designated by the Korean Association for Conservation of Nature, Ministry of Forest, and Ministry of Environment were Euryale ferox, Hydrocharis dubia, Persicaria amphibia, Acorus calamus var. angustatus. And Aristolochia contorta was distributed in the study area. The floras of the naturalized plants of the Woopo, Mokpo, Sajipo, Jokjibyeol, Topyeongcheon Upstream, and Topyeongcheon Downstream were composed of 27, 25, 35, 21, 26 and 24 taxa, respectively. The flora of the naturalized plants of total study area was 43 taxa, this equalled 12.3% of total vascular plants in the study area. And 165~244 taxa were surveyed in the each study area before flooding, total 299 taxa, and 86~212 taxa after flooding, total 299 taxa. Among them, hydrophytes, hygrophytes, and others were 33 and 29, 93 and 83, 183 and 187 taxa before and after flooding, respectively. Before and after flooding, the species number of emergent plants, floating-leaved plants, free-floating plants, and submersed plants was nearly the same. It was guessed that vascular hydrophytes and hygrophytes adapted to fluctuation of the water level in the study area.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.525-547
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• 2021

The main purpose of this study is to examine the use of plant species in ecological restoration projects. To this end, planting drawings from 58 sites that had completed the return of the ecosystem conservation cooperation fund for the past six years were collected and analyzed. The analysis used the construction completion and design drawings to determine the overall selection status and analyze frequency by classifying planted plants into wild and cultivated plants by nature, size, vegetation climate, and upland and wetland habitat. The investigation and analysis process found many cases of wrong plant names, so an analysis was also performed on the matter. In the 58 investigation sites, 282 plants were used for planting: 91 tree species, 69 shrub species, 11 vine species, and 111 herbal species. The most commonly used plant species was Spiraea prunifolia f. simpliciflora, followed by Sorbus alnifolia, Quercus acutissima, Zoysia japonica, Callicarpa dichotoma, and Weigela subsessilisin that order. The most commonly used tree species was Sorbus alnifolia,followed by Quercus acutissima, Zelkova serrata, Chionanthus retusus, and Cornus officinalis, in that order. The most commonly used shrub species was Spiraea prunifolia f. simpliciflora, followed by Weigela subsessilis, Callicarpa dichotoma, Rhododendron yedoense f. poukhanense. and Euonymus alatusin that order. The most commonly used herbal plant species was Zoysia japonica, followed by Dendranthema zawadskii var. latilobum, Aster koraiensis, Miscanthus sacchariflorus, and Pennisetum alopecuroidesin that order. In the analysis by vegetation climate, Spiraea prunifolia f. simpliciflora, Callicarpa dichotoma, and Sorbus alnifoliawere most used in that order in both the temperate central and the warm temperate forest zones, but the pattern does not properly reflect the climate characteristics. In the analysis by habitat, Miscanthus sacchariflorus and Lythrum salicariawere most used in the wetland. In particular, the ratio of wild plants to cultivated plants was 76% to 24%, indicating the ratio of selecting cultivated plants was high. The names of plants on the drawings were mostly common names that did not appear in the Korea National Arboretum or the National Species List of Korea. It is necessary to use proper plant names in the future. Regarding the use of planting plants for ecological restoration, it is necessary to adopt the approach of diversifying selected plants, selecting plants according to characteristics of climate zones, and lowering the specifications of plants used for ecological restoration. Moreover, it is important to fully understand the ecological characteristics of wetland plants and minimize the ratio of using cultivated plants to ensure the plant selection centered on wild plants.