• Journal of Wetlands Research
• /
• v.9 no.1
• /
• pp.1-11
• /
• 2007

The objectives of this study are: (1) to compare the rates and pathways of organic matter minerlaization at stagnant freshwater wetland in Shiwha to highly irrigated coastal wetland in Ganghwa; and (2) to discuss the significance of irrigation into the sediment in controlling the organic carbon oxidation in Shiwha wetland. Concentrations of $CO_2$, $NH_4{^+}$ and $H_2S$ in the pore water of the Shiwha wetland were 3 times, 30 times, and 3 times higher than that in the pore water of the Ganghwa wetland, respectively. The ratio of Fe(III) to total reduced sulfur at the Ganghwa wetland was 12 times higher than at the Shiwha wetland. The results indicated that the Ganghwa wetland with frequent tidal inundation were relatively oxidized than highly stagnant Shiwha wetland. Rates of organic matter oxidation at the Ganghwa wetland ($0.039mM\;C\;h{-1}$) was 390 times higher than that at the Shiwha wetland ($0.0001mM\;C\;h{-1}$). Rates of sulfate reduction at the Shiwha wetland ($314{\sim}580nmol\;cm^{-3}\;d{-1}$) were comparable to the sulfate reduction at Ganghwa wetland ($2{\sim}769nmol\;cm^{-3}\; d{-1}$), whereas Fe(III) reduction rates were 1.7 times higher at the Ganghwa wetland ($0.1368{\mu}mol\;cm^{-3}\;d{-1}$) than at the Shiwha wetland ($0.087{\mu}mol\;cm^{-3}\;d{-1}$). The results implied that the water flow system of the Shiwha wetland was too stagnant to flush out the reduced pore water from the sediment, and thus anaerobic microbial respiration was limited by the availability of electron acceptors.

• Journal of Environmental Science International
• /
• v.16 no.2
• /
• pp.233-239
• /
• 2007

In the coastal wetland the mud is consist of fine particles, which means that it is characterized by small gap, and heat transfer is obstructed since moisture is found between the gaps. The relationship between net radiation ($R_N$) and soil heat flux($H_G$) shows a counterclockwise hysteresis cycle, which refer to a time lag behind in the maximal soil heat fluxes. The albedo is independent of seasonal variation of the vegetation canopy which plays very important roles to store and control the heat in the atmospheric surface layer.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.85-85
• /
• 2022

The world's most extensive and active deltas, Louisiana's wetlands, are deteriorating rapidly due to multiple stressors such as the discharge of the Mississippi River, sea-level rise, and coastal retreat, the substantial but spatially and temporally variable impacts. However, the ecological and anthropogenic histories, the mode of environmental changes on a multi-millennial timescale have not been thoroughly documented. This study, a palynology-based multiproxy analysis, investigates hydrological, geological, geochemical, and anthropogenic impacts on southern Louisiana wetlands and a variety of external forcing agents influencing ecological succession. Sediment cores extracted from a small pond on a mangrove-dominate island near Port Fourchon, Louisiana, USA yielded a 4,000-year record. The site has been transformed from freshwater to saline water environments, to a mangrove dominant island over the late Holocene. The multivariate principal component analysis identified the relative strength of external drivers responsible for each ecological shift. The Mississippi River delta cycle (lobe switching) was the dominant driver of ecosystem changes during the late Holocene, while relative sea-level rise, tropical cyclones, climate, and anthropogenic effects have been the main drivers late in the site's history.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.10 no.6
• /
• pp.70-80
• /
• 2007

This study was surveyed from January to september, 2007 in order to evaluate the function of coastal wetland as a ecological axis in korea peninsula. Assessment was done by RAM (Rapid Assessment Method). RAM is consisted of total 8 contents and divided into high, moderate, low. The preservation grade of RAM is divided into 4 grades; absolute preservation, preservation, improvement and improvement or restoration. Throughout survey on total 14 wetlands of marine, estuary wetland and back marsh which are distributed in west coast in chung-nam province, their function was assessed. As result, total all the 14 wetlands were judged as preservation grade by assessment of 8 functional contents. The function of wetlands assessed as preservation grade showed high in water quality protection and improvement. Also, showed high in vegetation diversity, wildlife habitat and aesthetic recreation. Meanwhile, showed low in ground water recharge, Shoreline/Stream Bank Protection, Flood/Stormwater storage and Flood flow alteration. Of wetlands evaluated as preservation grade, Dae-ho, Sinduri, Bu-Nam lake, Sowhang dune and keum river estuary were assessed as absolute preservative area owing to habitation of international protection species and endangered species. These wetlands are essential to be managed continuously as a area having high ecological value. Farther, this wetlands will be done as a axis of ecological network related to land ecosystem.

• Journal of Wetlands Research
• /
• v.11 no.1
• /
• pp.105-113
• /
• 2009

Heat energy exchange is very important processes in the coastal wetland ecosystems. We observed and analyzed the net radiation flux, the sensible heat flux, the latent heat flux and the soil heat flux, which are balanced in the heat energy balance, over a reclaimed land covered with reeds at Goheung, Jeonllanamdo where is horizontally plane. The atmospheric turbulence had been measured in order to estimate the heat transfer during 5 intensive observation periods (IOPs). It was considered that the soil consists of water, fine particles, and vegetation canopy that changes color and density according to the season. We examined the characteristics of the heat flux and the vegetation effect on the air temperature control. It was noted that the heat was transported mainly by latent heat flux in the summer season and the vegetation canopy decreased the daily temperature range due to the heat storage. The air temperature was lower at the IOPs site than near urban area. This showed that the coastal wetland covered with the vegetation control the thermal environment.

• Journal of Wetlands Research
• /
• v.11 no.2
• /
• pp.29-38
• /
• 2009

A coastal wetland is the important area of diverse biodiversity as a transitional zone between coast and land. The results of surveying the flora were recorded as 310 taxa; 85 families, 212 genera, 278 species, 27 varieties and 5 forma. The halophytes were 14 taxa; Atriplex gmelini, Salsola komarovii, Suaeda asparagoides and so forth. The hydrophytes and hygrophytes were 23 taxa; Boehmeria spicata, Persicaria hydropiper, Persicaria japonica and so forth. The naturalized plants were 40 taxa; Fagopyrum esculentum, Rumex crispus, Chenopodium ambrosioides and so forth. The specific plants for the floral region were 28 taxa; Pteris multifida, Cyrtomium fortunei, Dryopteris erythrosora and so forth. In future, the flora of coastal wetland will be analyzed in series, and community dynamics and species composition for the halophytes will be studied.

• The Korean Journal of Ecology
• /
• v.24 no.1
• /
• pp.27-34
• /
• 2001

We described the vegetation of a disturbed lagoon wetland in relation to water and soil environments in Kungae lagoon reclaimed 30 years ago. Water depth and soil organic matter showed a great spatial heterogeneity in Kungae wetland which was changed into a freshwater marsh by the dike construction. Detrended canonical correspondence analysis suggested that differences in vegetation structure were primarily the result of variation in water depth or microtopography and soil organic matter Various emergent vegetations were developed in the wetland: species such as Phragmites australis, Calamagrostis epigeios, Carex dispalata and Lythrum anceps in a wide area, hydrophyes such as Typha angustifolia and Scirpus tabernaemontani at the low elevation with deep water, ruderals such as Bidens frondosa and Persicaria perfoliata near upland with much soil organic matter and sand-dune vegetation such as Carex kobomugi, Diodia tens, Pinus thunbergii and Potentilla egedei var. groenlandica at the high elevation. These results suggest that development of a prototype for wetland restoration from vegetation analysis of other natural lagoons and restoration of natural water tables and hydrologic connections between the diked wetland and the sea are important in the disturbed Kungae wetland.

• Journal of Cadastre & Land InformatiX
• /
• v.47 no.1
• /
• pp.27-35
• /
• 2017

Human activity such as agriculture, industrial development and urban sprawl has been the major threat to wetlands ecosystem, which have caused the greatest losses of coastal wetlands. The Garorim bay provides one of the most important wetland habitate and Ministry of Oceans and Fisheries designated Garorim bay to marine ecosystem protected area in July 2016. The purpose of this research is to analysis the spatial pattern of Garorim bay using Landsat 5 (TM), Landsat 7 (ETM+), Landsat 8 (OLI & TIRS). The surface temperature and NDVI of Garorim bay were processed with spatial analysis method and time series analysis were applied to 25 years Landsat satellite 19 images. The results of time series distribution map compared with the several wetland habitate on remotely sensed images. Landsat images showed the change area of wetland vegetation distribution from 1988 to 2014. The southern part habitate of Garorim bay have been changed with vegetation patterns on coastal wetland which were covered with tidal flat.

• Journal of Korea Water Resources Association
• /
• v.50 no.6
• /
• pp.429-440
• /
• 2017

A series of multispectral high-resolution Korean Multi-Purpose Satellite (KOMPSAT) images were analyzed to detect the geographical changes in four different tidal flats in the west coast of South Korea. The method of unsupervised classification was used to generate a series of land use/land cover (LULC) maps from the satellite images, which were used as the input of the temporal trajectory analysis to detect the temporal change of coastal wetlands and its association with natural and anthropogenic activities. The accurately classified LULC maps extracted from the KOMPSAT images indicate that these multispectral high-resolution satellite data is highly applicable to generate good quality thematic maps for extracting wetlands. The result of the trajectory analysis showed that, while the tidal flat area of Gyeonggi and Jeollabuk provinces was estimated to have changed due to tidal effects, the reductive trajectory of the wetland areas belonging to the Saemangeum province was caused by a high degree of human-induced activities including large reclamation and urbanization. The conservation of the Jeungdo Wetland Protected Area in Jeollanam province revealed that the social and environmental policies can effectively protect coastal wetlands from degradation. Therefore, monitoring for wetland change using high resolution KOMPSAT is expected to be useful to coastal environment management and policy making.

• Journal of the Korean Geographical Society
• /
• v.38 no.5
• /
• pp.822-834
• /
• 2003

It is difficult to analyse geomorphic landscape changes effectively by a field survey. A satellite image interpretation may play an important role to overcome such a problem. The purpose of this study is to assess the accuracy of different method to identify geomorphic landscape change by using satellite imagery. The study area is the Yongjong coastal wetland in which a huge man-made environmental change occured to build a new international airport in the past decade. These changes may be summarized that a coastal landscape has been changed to a terrestrial landscape, and also a natural landscape to a man-made landscape. In order to detect these changes, we applied three different satellite interpreting methods, including a binary change mask using band difference. a binary change mask using normalized band difference. and a binary change mask using NDVI. We concluded that a binary change mask using NDVI is the best method among three different methods analysing the coastal geomorphic-landscape changes.