• Journal of the Korean Geographical Society
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• v.45 no.2
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• pp.275-292
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• 2010

This study investigated the land-cover changes in the tidal flat of the Taean peninsula due to man-made environmental changes between 1972 and 2008, through time-series analysis based on a modified post-classification comparison method and multi-temporal satellite images. The analysis revealed that the land-cover of the tidal flat has changed from tidal flat to wetland and from wetland to paddy field between 1972 and 2008. Also, the pattern of detailed land-cover changes is as follows: tidal flat to wetland; lake and saltpan to bare land and paddy field. The accurate classification of each image is needed for the application of the post-classification comparison method. The overall accuracy of the classified images was found to be 95.33% on average, and the Kappa value was 0.941 on average.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.95-101
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• 2019

In tidal flats that lack plants, methane ($CH_4$) fluxes are both positive (gas emission) and negative (gas "sinking") in nature. The levels of methanotroph populations significantly affect the extent of $CH_4$ sinking. This preliminary study examined $CH_4$ flux in tidal flats using a circular closed-chamber method to understand the effects of macroinvertebrate burrowing activity. The chamber was deployed over decapods (mud shrimp, Laomedia astacina and crab, Macrophthalmus japonicus) burrows for ~ 2 h, and the $CH_4$ and $CO_2$ concentrations were continuously monitored using a closed, diffuse $CH_4/CO_2$ flux meter. We found that Laomedia astacina burrow (which is relatively long) site afforded higher-level $CH_4$ production, likely due to diffusive emission of $CH_4$ in deep-layer sediments. In addition, the large methanotrophic bacteria population found in the burrow wall sediments has $CH_4$ oxidation (consumption) potential. Especially, nitrite-driven anaerobic oxidation of methane (AOM) may occur within burrows. The proposed $CH_4$-oxidation process was supported by the decrease in the ${\delta}^{13}C$ of headspace $CO_2$ during the chamber experiment. Therefore, macroinvertebrate burrows appear to be an important ecosystem environment for controlling atmospheric $CH_4$ over tidal flats.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.683-696
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• 2023

The conservation of wetland ecosystems has a significant role in climate change. Notably, the Han River Protected Area, including the Siam-ri wetland and Janghang wetland, provides high biodiversity value. Thus, it is necessary to comprehensively evaluate the function and value of wetland ecosystems. This study evaluated the ecosystem services of Siam-ri and Janghang Wetlands located in the Han River Protected Area using the Rapid Assessment Wetland Ecosystem Services approach, a function-oriented ecosystem analysis. The results were calculated using the Ecosystem Services Index formula to analyze wetland ecosystem services. We also assessed the key ecosystem services based on a focus group interview. We identified that the supporting and cultural services index scores were relatively high in the study area. The results can provide helpful information for sustainable wetland conservation, conservation planning as primary data, and raising awareness for the Han River Protected Area.

• Journal of Wetlands Research
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• v.8 no.4
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• pp.41-47
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• 2006

Global climatic changes are expected to influence various biogeochemical processes in wetland ecosystems. In particular, coastal mud flat is anticipated to be affected directly by temperature increase as well as indirectly by a sea level rise and changes in precipitation. This study aimed to determine changes in methane production under different temperature and salinity by employing a laboratory-scale manipulation experiment. Soil samples were collected from a mud flat in Dong-Gum Kang-Hwa island in winter and two types of experiments were conducted. In the first experiment soil samples at 0-5 cm, 5-10 cm depth were incubated under same salinity with pore water and diluted salinity to 50 % of natural condition for 20 days and methane production was measured every other days. In the second experiment, soil samples at 5-10 cm depth were incubated in different temperature, $5^{\circ}C$ and $15^{\circ}C$, under same salinity conditions with first experiment for 31 days and methane production was measured. Results of the first experiment revealed that higher amount of methane was produced at 5-10 cm depth, and salinity effect was predominant at the end of the experiment. The second experiment showed that methane production was higher in $15^{\circ}C$ than $5^{\circ}C$. In addition, methane production was higher when sea water diluted to 50 % compared to control. Global climatic changes are expected to influence various biogeochemical processes in wetland ecosystems. In particular, coastal mud flat is anticipated to be affected directly by temperature increase as well as indirectly by a sea level rise and changes in precipitation. This study aimed to determine changes in methane production under different temperature and salinity by employing a laboratory-scale manipulation experiment. Soil samples were collected from a mud flat in Dong-Gum Kang-Hwa island in winter and two types of experiments were conducted. In the first experiment soil samples at 0-5 cm, 5-10 cm depth were incubated under same salinity with pore water and diluted salinity to 50 % of natural condition for 20 days and methane production was measured every other days. In the second experiment, soil samples at 5-10 cm depth were incubated in different temperature, $5^{\circ}C$ and $15^{\circ}C$, under same salinity conditions with first experiment for 31 days and methane production was measured. Results of the first experiment revealed that higher amount of methane was produced at 5-10 cm depth, and salinity effect was predominant at the end of the experiment. The second experiment showed that methane production was higher in $15^{\circ}C$ than $5^{\circ}C$. In addition, methane production was higher when sea water diluted to 50 % compared to control. These results suggest that methane production is highly influenced by changes in temperature and salinity in coastal mud flat. And that global climatic change may induce biological feedback by affecting production of another greenhouse gas, namely methane from coastal mud flat.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.386-393
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• 2023

The domestic marine healing industry is undergoing significant revitalization efforts, with a focus on understanding the efficacy and effectiveness of marine healing resources. This study establishes utilization and management standards through a detailed analysis of the active components within well-recognized marine healing mud materials. Samples of mud materials were collected from domestic tidal flats. These samples exhibited an average composition of 7.87% sand, 74.95% silt, and 17.17% clay, with a combined mud content (silt+clay)(silt+clay) consistently exceeding 90%. Notably, SiO₂ emerged as the most prevalent effective ingredient at 68.4%, followed by Al₂O₃ (13.3%)>Fe₂O₃ (4.0%)>K₂O (2.9%)>Na₂O (2.3%)>MgO (1.6%)>CaO (1.0%)>TiO₂ (0.7%), in terms of average content. Subsequently, through an analysis of effective ingredients, Si, Al, Fe, K, Na, Mg, and Ca were identified as elements demonstrating significant functionality. Among these, key indicator ingredients were selected for quality control, all of which were found to possess efficacious properties. Notably, K, Mg, and Ca exhibited particularly high concentrations. Based on these findings and referencing existing literature, it is recommended that domestic tidal flat mud resources earmarked for utilization as marine healing resources should possess a raw material mud content of no less than 70.0%. Moreover, the cumulative index components K₂O+MgO+CaO should meet or exceed a threshold of 5.0% for optimal effectiveness.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.213-215
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• 2002

함평만은 길이가 171km, 최대 폭이 12km에 달하는 반폐쇄적인 만으로서, 평균조차는 315.4cm인 중조차 해 역이다. 함평만 주변은 1910년대부터 간척사업이 진행되어 해안선이 크게 달라졌으나 해제반도로 둘러싸인 해안선은 비교적 자연성을 잘 유지하고 있다. 따라서 2001년 12월에는 무안군에 인접한 35.6$\textrm{km}^2$의 갯벌이 연안습지보전지역으로 선정되었으며 현재 보전계획이 수립되고 있다. (중략)

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.10-27
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• 2017

Recently, the importance of recognizing the natural environment and the need for its conservation are increasing due to rapid urbanization. Suncheon Bay, designated as Scenic Site No. 41 and one of the World's Five Greatest Coastal Wetlands, is the only tideland among the tidal flats in Korea, which has salt marsh reserves. It has high conservation value from the ecological aspect. In addition to the Suncheon Bay National Garden, it provides various benefits not only to visitors but to local residents as well in terms of economics, environmental issues, and history and cultural aspects. Two million tourists visit the site annually, which has constantly highlighted the limits of ecological capacity. The valuation of the Suncheon Bay wetland is more important for the sustainability of the Suncheon Bay wetland than for its value as a tourism resource for the activation of the local economy. This study used the Logit model, which is commonly used among probabilistic choice models, to evaluate the economic value of Suncheon Bay wetland with the contingent valuation method(CVM). Applying the conservation value of the Suncheon Bay wetland to the benefit of KRW 8,200 for 1 person and 1 day, the benefit from exploration is KRW 2,050, the management and conservation value is KRW 3,034, and the heritage value is KRW 3,116. The results of this study are that benefit from the annual exploration of Suncheon Bay wetland was KRW 44.3 in billion, the management and conservation value was KRW 6.55 in billion, and the heritage value was KRW 6.73 in billion. When converted to the number of paying visitors per year, the conservation value is about KRW 177.1 billion. This study was conducted to evaluate the use and conservation aspects of the economic value of Suncheon Bay wetland. Based on the latent value of the Suncheon Bay wetland, it provides basic data about the efficient management and policy establishment of Suncheon Bay wetland. The study is significant in that the ecological sustainability of the Suncheon bay wetland and the value of non-marketable were evaluated based on the recognition of 'benefit through exploration', 'management and conservation value' and 'value of heritage'. It can be used as policy decision data on the integrated collection of the admission fee of the Suncheon Bay wetland and Suncheon Bay National Garden.

• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.344-354
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• 2007

Estuarine wetlands for 33 watersheds in the Han River estuary were delineated on topographic maps from the 1910s, 1970s, and 2000s. Then, these data were used to address the issue of spatial distribution and temporal variation. Watershed characteristics such as drainage density, location, watershed size, slope, and elevation were identified for each watershed to determine the relationship between watershed characteristics and spatial distribution of estuarine wetlands. The analysis of estuarine wetlands indicated that wetlands in the estuary had declined gradually between the 1910s and the 1970s, although most wetlands were lost since the 1970s mainly caused by the large development projects related to urban expansion in metropolitan Seoul. The sediment composition and formation processes of the wetlands differed with watershed location; mud flats dominate in the lower part of the estuary, and relatively more sandy and emergent-plant wetlands occur near the main channel and tributaries of the Han River. Relatively more estuary wetlands occur in large watersheds, which have high slopes and low elevations. Estuarine wetlands have been lost dramatically in the densely populated watershed regions (i.e., Han River Seoul, Han River Goyang, West Han River), while relatively more wetlands have remained in undeveloped regions, including the Lower Imjin River and Lower Han River. In particular, anthropogenic disturbance has played an important role in the loss of wetland through the conversion of wetland into agricultural and developed land.

• Journal of the Korean Geographical Society
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• v.49 no.3
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• pp.321-338
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• 2014

This study aims to identify spatial distribution of estuarine wetlands in Korea, and to assess temporal variation of the wetlands in the last few decades. Widely known in environmental and coastal management, watershed-based regions which composed with Han-river(western and eastern parts), Keum-river, Yeoungsan-river, Seomjin-river, Nakdong-river, and Jeju, are analyzed to evaluate temporal change of estuarine wetlands in the 1980s, 1990s, and 2000s, through the land-cover map. Results show that estuarine wetlands dramatically decreased in Han-river(western part), Keum-river, Yeoungsan-river that estuarine circulation have been interrupted with man-made structures such as dyke and drainage. But, estuarine wetlands surrounded by forests and grasslands has been relatively less damaged. Habitat diversity providing healthy estuary ecosystem is lower in interrupted estuaries than circulated estuaries, which are composed of tidal-flat, open water, salt marsh, rocky coasts and sandy shoreline. This study indicates that spatial distribution and temporal variation of estuarine wetlands are different with estuary type and region, so estuary type with seven regions can be applied to provides a framework for estuary management strategies and to establish estuary restoration plans.

• Korean Journal of Environment and Ecology
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• v.22 no.5
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• pp.521-529
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• 2008

This research conducted a survey on waterbirds visiting this area four times by season from February to October in 2007 to look into the habitat use of waterbirds, to do a value and grade testing of the tidal flat by dividing the foreshore on Muan Bay located in Jeollanam-do into four areas (Dongam, Guro, Bokryong and Wangsan tidal flats). The survey results revealed that there existed a total of 15,755 individuals of 54 species including 2 species of grebes, 7 species of herons, 7 species of dabbling ducks, 6 species of diving ducks, 20 species of waders, 3 species of gulls and 9 other species and this survey also observed 9,291 individuals of the wading birds as a dominant group on Muan Bay. In these classified groups, the gulls and waders were observed to mostly use Dongam tidal flat as their habitat, while the group using Guro tidal flat as their habitat was mostly grebes, dabbling and diving ducks. As a result of UPGMA clustering analysis in consideration of the species and number of individuals, there appear the close similarities between Dongam and Bokryong tidal flats and so do Guro and Wangsan tidal flats. Taking a look at the grading of tidal flats by setting up ecological indexes, such as diversity index, abundance index, and dominance index, etc. legally reserved species and maximum number of individuals as a standard, the rank for the value and importance degree of Bokryong tidal flat appeared higher than that of the other three tidal flats. Like this, the gradation of tidal flats according to waterbirds are judged to able to suggest objective data on the issue of proper judgment and designation of valuable tidal flat areas and its subsequent effective preservation and management.