• Journal of Environmental Policy
• /
• v.5 no.4
• /
• pp.85-105
• /
• 2006

This article aims to conserve greenbelts by adopting the national trust approach. This article reviews the current issues and problems in managing greenbelts in Korea. And this article redefines the function of greenbelts, and then suggests the new principles of management strategies of greenbelts. Greenbelts is to provide green open space for urban residents and to contain urban sprawl not to reserve lands for the future urban development. This article proposes basic principles for the effective management of green belts. They include (1) preserving environmental value, (2) maximizing public access to open space and environment resources, and (3) enhancing public-participation and collaboration among different groups and organizations for the management of greenbelts. These principles are closely related to those of national trust movement. This article suggests the government to adopt national trust approach (organization, funding, site selection criteria, legislation) to improve the environmental-friendly conservation and management of greenbelts in Korea.

• Journal of Environmental Policy
• /
• v.9 no.2
• /
• pp.41-55
• /
• 2010

This paper analyzes optimal watershed management focusing on reservoir-level sediment removal techniques. Although dams and reservoirs provide several benefits, sedimentation may reduce their storage capacity. As of today, the Aswan High Dam (AHD) in Egypt faces approximately 76% reduced life of the reservoir. Since the AHD is the major fresh water source in Egypt, sustainable use of this resource is extremely important. A model is developed to simultaneously determine optimal sediment removal strategies for upstream soil conservation efforts and reservoir-level sediment control. Two sediment removal techniques are considered: mechanical dredging and hydro-suction sediment removal system (HSRS). Moreover, different levels of upstream soil conservation efforts have introduced to control soil erosion, which is a major contributor of reservoir storage capacity reduction. We compare a baseline case, which implies no management alternative, to non-cooperative and social planners' solution. Our empirical results indicate that the socially optimal sediment removal technique is a mechanical dredging with unconstrained amount with providing a sustainable life of the reservoir. From the empirical results, we find that social welfare can be as high as $151.01 billion, and is sensitive to interest rates and agricultural soil loss.

• Korean Journal of Agricultural Science
• /
• v.37 no.3
• /
• pp.435-449
• /
• 2010

Soils in the sloping uplands in Korea are subject to intensive land use with high input of agrochemicals and are vulnerable to soil erosion. Development of the environmentally sound land management strategy is essential for a sustainable production system in the sloping upland. This report addresses the status of upland agriculture and the best management practices for the uplands toward the sustainable agriculture. More than 60% of Korean lands are forest and only 21% are cultivating paddy and upland. Uplands are about 7% of the total lands and about 62% of the uplands are in the slopes higher than 7%. Due to the site-specificity of the upland, many managerial and environmental problems are occurring, such as severe erosion, shallow surface soils with rocky fragments, and loadings of non-point source (NPS) contaminants into the watershed. Based on the field trials, most of the sloping uplands were classified as Suitability Class III-V and the major limiting factor was slope and rock fragments. Due to this, soils were over-applied with N fertilizer, even though N rate was the recommendation. This resulted in decreases in yield, degradation of soil quality and increases in N loading to the leachate. Various case studies drew management practices toward sustainable production systems. The suggested BMP on the managerial, vegetative, and structural options were to practice buffer strips along the edges of fields and streams, winter cover crop, contour and mulching farming, detention weir, diversion drains, grassed waterway, and slope arrangement. With these options, conservation effects such as reductions in raindrop impact, flow velocity, runoff and sediment loss, and rill and gully erosion were observed. The proper management practice is a key element of the conservation of the soil and water in the sloping upland.

• Journal of the Korean Institute of Rural Architecture
• /
• v.18 no.1
• /
• pp.57-65
• /
• 2016

When the castle of the city was destructed from 1911 through 1915 in Cheongju, the city's spatial structure was reorganized and "Han-ok Housing", a dwelling site filled with Korean traditional houses, was newly formed around the former castle site. These days, the Han-ok housing in Seoun-dong, Cheongju in which elderly couples and senior citizens live is enclosed by modernized roads and three or four-story buildings, leaving the housing as an isolated island in the city block. Nonetheless, the Han-ok housing not only plays an important role in sustaining the historic and local identity of the city, but also offers environmental benefits in terms of daylighting and ventilation. The purpose of this study is to reorganize the housing suitable for those who currently live and recreate it by adding new functionality. Consequently, three strategies are established; the conservation of existing building through the improvement of existing facilities; the conversion of vacant buildings into a new use; and the creation of the urban mid-rise Han-ok housing at street sides. The first strategy has a significance in that the traditional building's single wing plan, small room sizes and lack of storages now cause great inconvenience for current life style. The second strategy also promotes the practical use of abandoned buildings through alterations and additions. Finally, the creation of the urban mid-rise Han-ok housing that is accomplished by the combination of reinforced concrete and wooden structure interacts with or respond to the city's development. As a result, this study for the adaptive reuse of Han-ok housing proves how the traditional properties can be maintained in a careful manner and how its creative reuse can be achieved.

• Journal of the Korean Geographical Society
• /
• v.36 no.4
• /
• pp.444-457
• /
• 2001

Present work aims to analyse the spatio-temporal distribution of Korean bamboos. The northern limit of Korean bamboo species occurs at Baekryung Island(124°10'E, 37°55'N), Hoochang(41°22'N) and Myungchon(129°41\`E, 41°10'N). The presence of bamboo fossils in Korea dates back from Tertiary, but widespread use of bamboos can be noticed since 1454. Reconstructed ranges and temporal changes of bamboo, based upon the eight historical records from 15th to 20th centuries, indicates that both climatic and anthropogenic factors were responsible for the changes of distributional range. The spread of bamboos was balanced by its disappearance due to regional development, and the total bamboo area showing little change. Due to the tendency to spread extensively by means of underground stems, bamboos often invade adjacent forests and disturb natural vegetation. Proper management and conservation strategies, therefore, are required for the maintenance of rural landscape.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.3
• /
• pp.197-208
• /
• 2016

The WCPFC CMMs related to tropical tunas have been strongly restricting fishing capacity and operating activities of main fisheries, especially purse seine fishery. In terms of changes in fishing trend by implementing relevant measures of FAD set, the number of FAD set by Korean purse seine fleet showed a decreasing pattern with the lowest level of FAD set proportion among major distant water fishing nations. With regards to the FAD closure, there was no significant change in fishing effort but a drop in catch, especially bigeye tuna during the period of FAD closure. Moreover, it showed closely similar trends between the number of FAD set and bigeye tuna catch. In terms of measures related to the high sea area including a ban on fishing on the HSP and limitation of fishing days on the high sea by flag state, proportions of catch and effort on the high sea had sharply declined after implementing those measures. As relevant measures are expected to be strengthened, it should pay attention to change of coastal nations policies and focus on improving fishing efficiency of unassociated school set with multi-pronged efforts.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.1
• /
• pp.103-118
• /
• 2018

Ecosystems in subalpine regions are recognized as areas vulnerable to climatic changes because rainfall and the possibility of flora migration are very low due to the characteristics of topography in the regions. In this context, habitat niche was formulated for representative species of arbors in subalpine regions in order to understand the effects of climatic changes on alpine arbor ecosystems. The current potential habitats were modeled as future change areas according to the climatic change scenarios. Based on the growth conditions and environmental characteristics of the habitats, the study was conducted to identify direct and indirect causes affecting the habitat reduction of Abies nephrolepis. Diverse model algorithms for explanation of the relationship between the emergence of biological species and habitat environments were reviewed to construct the environmental data suitable for the six models(GLM, GAM, RF, MaxEnt, ANN, and SVM). Weights determined through TSS were applied to the six models for ensemble in an attempt to minimize the uncertainty of the models. Based on the current climate determined by averaging the climates over the past 30years(1981~2010) and the HadGEM-RA model was applied to fabricate bioclimatic variables for scenarios RCP 4.5 and 8.5 on the near and far future. The results of models of the alpine region tree species studied were put together and evaluated and the results indicated that a total of eight national parks such as Mt. Seorak, Odaesan, and Hallasan would be mainly affected by climatic changes. Changes in the Baekdudaegan reserves were analyzed and in the results, A. nephrolepis was predicted to be affected the most in the RCP8.5. The results of analysis as such are expected to be finally utilizable in the survey of biological species in the Korean peninsula, restoration and conservation strategies considering climatic changes as the analysis identified the degrees of impacts of climatic changes on subalpine region trees in Korean peninsula with very high conservation values.

• Korean Journal of Agricultural Science
• /
• v.35 no.1
• /
• pp.69-83
• /
• 2008

The self-supply rate of Korea in 2006 was approximately 27.3 % by importing 13.99Mt for 19.79Mt of demanded amount. Among the imported crops, wheat, corn, and soybean consumed 95 % for the total imported amount, and wheat, corn, and soybean were 3.5Mt(Table use : 0.22Mt; Feed stuff : 0.13Mt), 8.7Mt(Table use : 0.19Mt; Feed stuff : 0.68Mt), and 1.2Mt (Table use : 0.03Mt; Feed stuff : 0.09Mt), respectively. On the other hand, our government has prepared the strategies for a great fear of food according to sharp price rise of the international crops by maintaining the self-supply rate of 5 % excluding 5.23Mt of rice in Korea. Also concern for recycled energy known as future energy for era of high oil price and global warming due to green house gas is rapidly growing. Therefore, our country which has relied on import of the whole oil needed in Korea and has to keep Kyoto Agent to request reduction of green house gas fully support research and practical use for agricultural products as resource of alternate energy. At first, we have to develop the mass production technology in order to secure a program of self-supply of food for bioenergy production utilizing agricultural product in Korea. But we assume that this matter is difficult to achieve under the current agriculture system that more emphasizes the environment conservation such as environmentally-friendly agriculture than production of food.

• Korean Journal of Environment and Ecology
• /
• v.18 no.2
• /
• pp.221-230
• /
• 2004

Flora of the Dokdo Islet, where located south-east from Ulnung Island, off the east coast of the Korean peninsula, recorded as 59 taxa; 29 families, 50 genus, 48 species, 1 sub-species, 9 varieties and 1 form. Dong-do (East islet) of Dokdo Islet, naturalized plants such as Brassica campestris subsp. napus var. nipp-oleitera and Rumex crispus are widely ranged over the islet. The naturalizedplants affects the native species and their habitats of Artemisia japonica var. macrocephala, Echinochloa crus-galli, Sedum oryzifolium, Arabis stelleri var. japonica and Sedum kamtschaticum var takesimense in the islet. The trail in Seo-do (West islet) is heavily threatened by over-all weathering processes on the rock. The native woody species in the islet are Euonymous japonicus and Lonicera insularis, and the species such as Pinus thunbergii and Hibiscus syriacus are planted in the recent past under the IRP (Islet Restoration Program) by NGO. The Specific Plants, which is designated and categorized by the Ministry of Environment, Korea, such as Lilium lancifolium, Lysimachia mauritiana and Reynoutria sachalinensis are ranged. The ecosystem of Dokdo islet is seriously threatened by invadedplant species and building works for garrison and relevant facilities. The over-all long- and short-term strategies, based on interdisciplinary and integrated approaches for habitat restoration is needed.

• Korean Journal of Plant Resources
• /
• v.27 no.6
• /
• pp.660-670
• /
• 2014

The Korean plum yew (Cephalotaxus koreana Nakai) is a shade-tolerant, coniferous shrub. The seeds have been used as a folk medicine in Korea, and an alkaloid extract (HTT) is known to have anticancer properties. We estimated the genetic diversity of 429 trees in 16 populations in South Korea using 194 polymorphic amplicons from seven combinations of AFLP primer-restriction enzymes. The average number of effective alleles and the percentage of polymorphic loci were 1.37 and 79.4%, respectively. Shannon's diversity index and the expected heterozygosity were 0.344 and 0.244, respectively. We divided 16 populations into four groups on the UPGMA dendrogram and the PCA biplot. The first two principal components explained 84% of the total genetic variation. Genetic differentiation between populations explained 14% of total genetic variation, and the remaining 86% came from difference between individuals within populations, as determined by an analysis of molecular variance (AMOVA). However, the genetic differentiation did not correlate with the geographic distance between populations from the Mantel test. The Bayesian statistics, which are comparable to Wright's $F_{ST}$ and Nei's $G_{ST}$, were ${\theta}^I=0.406$ and ${\theta}^{II}=0.172$, respectively. The population genetic diversity was slightly lower, and the strength of genetic differentiation was much weaker, than the average of those plants having similar life histories, as assessed using arbitrary marker systems. We discuss strategies for the genetic conservation of the plum yew in Korea.