• Korean Journal of Remote Sensing
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• v.29 no.5
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• pp.569-579
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• 2013

In this study, land-cover classification was implemented using features extracted from multi-temporal SAR data through 3D wavelet transform and the applicability of the 3D wavelet transform as a feature extraction approach was evaluated. The feature extraction stage based on 3D wavelet transform was first carried out before the classification and the extracted features were used as input for land-cover classification. For a comparison purpose, original image data without the feature extraction stage and Principal Component Analysis (PCA) based features were also classified. Multi-temporal Radarsat-1 data acquired at Dangjin, Korea was used for this experiment and five land-cover classes including paddy fields, dry fields, forest, water, and built up areas were considered for classification. According to the discrimination capability analysis, the characteristics of dry field and forest were similar, so it was very difficult to distinguish these two classes. When using wavelet-based features, classification accuracy was generally improved except built-up class. Especially the improvement of accuracy for dry field and forest classes was achieved. This improvement may be attributed to the wavelet transform procedure decomposing multi-temporal data not only temporally but also spatially. This experiment result shows that 3D wavelet transform would be an effective tool for feature extraction from multi-temporal data although this procedure should be tested to other sensors or other areas through extensive experiments.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.6
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• pp.101-110
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• 2016

Development activities in forest areas are analysed based on degree of slope, altitude, land cover, and prefectures in order to improve the capacity of existing regulations of 'feasibility of forest land conversion' and 'assessment of forest land characteristics' in this research. 959 land based developments between year 2007 and 2013 have been analysed. A development site includes over 50% of forest is categorized as a forest type, degree of slope is steeper than $8.5^{\circ}$ as mountain type, and a development included in the both categories as combined type. Distribution characteristics of the above three types are analysed by development categories and regions adopting Relative Mountain Development Index(RMDI). In results, 44.94% of total development activities have been carried out in Gyeongsang Do in order of urban development, industrial complex, sports facilities, and soil and stone collection quarrying. Developments less than $0.3km^2$ which are exempt from the feasibility of forest land conversion regulation consist 86 cases of forest type, 78 cases in mountain type, and 78 cases in combined type. SAI by slope range showed the highest value of 1.55 in less than $5^{\circ}$ and the lowest value of 0.69 between $20^{\circ}-25^{\circ}$. RMDI value in Gyeongsang Do where mountain ratio is 67.05% appeared 1.17, which is 5 times more than Gangwon Do where mountain area ratio is 81.30%, and 2 times more than Chungchung Do where mountain area ratio is 51.24%. Development activities in forestland in Korea showed unequal distributions and 26% of those developments were not subjected to the feasibility of forest land conversion regulation.

• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.445-451
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• 2008

This study was carried out to develop Tablet PC based customizing system for fine mapping of forest cover type. The major contents and characteristics of FIS developed in this study were as follows. Field Investigation System (FIS) has a merit of accessibility to display exact location in various spatial data with position information received from the GPS. FIS can be used to record and manage many field information on which field investigation is done, with the help of the memo tool, field-sheet tool, calculating distance and area with measuring tool as well as editing forest type. It is possible to do field investigation effectively using FIS developed in this study. Accordingly, investigation and time costs can be reduced and field-work productivity will be improved.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.2
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• pp.114-123
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• 2010

The Environmental Conservation Value Assessment Map (ECVAM) is a five grade assessment map created with nationally integrated environmental information and environmental values. The map is made through the evaluation of 67 items, including greenbelt area and bio-diversity. The ECVAM assesses the stability of the community using forest maps. However, the existing assessment method is problematic because the assessment grades are evaluated using higher than practical values; in part because it uses even-valued overlay and minimal indicator methods. This study was performed in order to suggest an integrated assessment method that could complement the stability evaluation based on existing methods. Accordingly, this study added forest type information, including whether the forest was natural or artificial, to the overlay method using forest diameter maps and forest density maps. As a result, the proposed ECVAM indicated a drastic grade change. After applying the method in South Korea, Grade I areas decreased 12.1%, from 52.6% to 40.6%, Grade II areas increased 11.9%, from 17.4% to 29.2%, and Grade III areas increased 0.2%, from 17.1% to 17.4%, respectively. From the results of the field survey, we found differences between natural forest and planted forest with regard to the number of mortality, species of shrubs, and vine cover. This means that natural forests are more stable than planted forests. This study suggests an improved assessment methodology to complement the existing EVCAM method. The results are expected to be used in environmental evaluations and forest conservation value assessments in ecology and environmental fields.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1083-1096
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• 2020

Global attention to the greenhouse gas emissions from deforestation and forest degradation is increasing. There is a growing recognition of reducing emission from deforestation and forest degradation plus (REDD+) as an effective way to reduce greenhouse gas emissions in the forestry sector. The Republic of Korea is implementing REDD+ pilot projects in four Southeast Asian countries as part of its efforts to reduce greenhouse gas emissions. This study evaluates countries with the potential to become priority partner countries for Korea's REDD+ programs, using the following five criteria: The first criterion is that a country should include the forest sector and REDD+ in its national plan for reducing greenhouse gas (GHG) emissions. The second and third criteria refer to an average forest coverage rate of over 44% and a forest change rate of over - 0.1%, among the countries with forest cover of more than 10 million ha. The fourth criterion is that the country should meet the Forest Reference Emission Level requirements, one of the four elements of the Warsaw REDD+ Framework. The fifth criterion is that the country should have bilateral relations with the Republic of Korea in forestry while at the same time be a partner country for cooperation on climate change as well as a REDD+ pilot country. Based on our evaluation, we conclude that the first priority countries are Indonesia, Cambodia, and Myanmar. The second priority countries include Brazil, Ecuador, and Peru. Finally, the third priority countries are Columbia, Congo, and Mozambique. This study suggests that for the selection of priority partner countries, Korean REDD+ programs should center on existing REDD+ pilot countries.

• Korean Journal of Remote Sensing
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• v.24 no.1
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• pp.35-43
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• 2008

The purpose of this study is to evaluate the hydrological impact due to temporal land cover change by gradual urbanization of upstream watershed of Pyeongtaek gauging station of Anseong-cheon. WMS HEC-1 was adopted, and OEM with 200 m resolution and hydrologic soil group from 1:50,000 scale soil map were prepared. Land covers of 1986, 1990, 1994 and 1999 Landsat TM images were classified by maximum likelihood method. The watershed showed a trend that forest & paddy areas decreased and urban/residential area gradually increased during the four selected years. The model was calibrated at 2 locations (Pyeonglaek and Gongdo) by comparing observed with simulated discharge results for 5 summer storm events from 1998 to 2001. The watershed average CN values varied from 61.7 to 62.3 for the 4 selected years. To identify the impact of streamflow by temporal area change of a target land use, a simple evaluation method that the CN values of areas except the target land use are unified as one representative CN value was suggested. By applying the method, watershed average CN value was affected in the order of paddy, forest and urban/residential, respectively.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.317-323
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• 2007

Almost all the people, particularly the rural people are directly dependent on the continued productivity of natural resources, like water, soils, forests and fisheries. But the overuse by the extremely high population pressures has degraded the natural resources into severe widespread deforestation. The degradation of natural resources, particularly the plant resources has been a great concern for socio-economic and sustainable development of the country. The Forests in Bangladesh have been depleted and degraded in volume, area, and quantity, thus requiring urgent forest protection by identifying the causes of forest loss. There are so many causes of deforestation and loss of genetic resources such as; the timber industry, which, legal or not, are cutting too many trees; indigenous forest dwellers, having their own types of problems; migrants, who, because of problems in their places of origin, have decided to move to the forests and the government through its Forest Department which is not able or willing to implement suitable policies to regulate the cutting trees and to prevent illegal cutting. Because it is a time consuming task to mitigate the first and second sets of factors, we recommend involving forest dwellers in forestry practices as much as possible and taking necessary steps to alleviate the third and fourth sets and thereby reduce the rate of forest depletion. Accordingly, a number of strategies that should be adopted to halt the loss of remaining forest cover are discussed.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.365-369
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• 2006

This study was conducted to clarity the differences in density and body weight of rodents among unburned and two burned areas (silvicultured and natural restored areas) after forest fire from July to September 2004 in coniferous forest of Samcheok, Korea. The density of rodents was the least in the silvicultured area. There was no differences in density between the unburned and natural restored areas. Also, mean body weight of rodents in the natural restored area was higher than in the silvicultured area. Shrubs, seedlings, snags and CWD (coarse woody debris) would be good for inhabitation of the rodents in forest fired area. Therefore, coverage of understory layer should be maintained in forest fired area.

• Journal of Forest and Environmental Science
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• v.37 no.2
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• pp.91-103
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• 2021

We conducted an analysis of agroforestry system efficiency to conserve biodiversity in the Mbalmayo Forest Reserve (MFR) between March 2018 and June 2018. A synthesis of forest fragmentation data observed on multiple strata and scale satellite imageries over 31 years, between 1987 and 2018 as well as, the use of both a floristic and a faunal surveys, revealed that although 29.28% of natural forests was fragmented and converted to agroforests landscapes, banana and cocoa based agroforest appeared to perform the most relevant records in carbon storage and to attract wild terrestrial and avifauna. Analysis of NDVI, NDWI and Iron Oxyde helped monitor the vegetation cover of the reserve, and differentiate natural and fragmented classes, majority of conserved forest wetlands and agroforestry systems, and a minority of natural dryland forest. Further analysis also revealed significant correlations between NDVI and Shannon Index, and between NDVI and carbon stock. Based on the NDVI value and the equation Y=3.827×X-1.587 (where Y for the carbon stocks and X for NDVI value), we estimated the total carbon stock of the forest reserve at about 99557.6 tonnes, and its mean value at about 8.491 tons/ha. Nevertheless, environmental efforts to sustainably manage agroforestry landscape appear to be a relevant key to conserve wild biodiversity and mitigate climate change at the level of the Mbalmayo Forest Reserve. If anthropogenic activities have deeply changed the reserve's natural landscape, reduced its carbon sequestration performance, and wildlife conservation status, forest wetlands appear to remain its most conserved places and the best refuge for wild fauna still occurring in diverse strata of the MFR.

• Journal of Forest and Environmental Science
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• v.31 no.2
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• pp.73-77
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• 2015

Acquiring accurate quantitative and qualitative information is necessary for the technical and scientific management of forest stands. In this study, stratification and systematic random sampling methods were used to estimation of quantitative characteristics in study area. The estimator ($((E%)^2xT)$) was used to compare the systematic random and stratified sampling methods. 100 percent inventory was carried out in an area of 400 hectares; characteristics as: tree density, crown cover (canopy), and basal area were measured. Tree density of stands was compared through systemic random and stratified sampling methods. Findings of the study reveal that stratified sampling method gives a better representation of estimates than systematic random sampling.