• Journal of Environmental Impact Assessment
• /
• v.32 no.6
• /
• pp.389-406
• /
• 2023

The research area, located in the northern coastal region of South Korea's West Sea, involves three bird habitats. Among these are two newly established habitats in Songdo International Business District, created by filling and developing tidal flats that were previously utilized as stopover sites for migratory birds. One of these areas showed decrease (Residual tidal flats, site.1) while the other showed increase (Artificial lake, site.2) in bird influx. The third habitat (Namdong reservoir, site.3) is a pre-existing stable habitat which has been maintained as a stable habitat. This study conducts an assessment of habitats based on avian population clusters and environmental surveys and proposes habitat management measures. A survey of bird populations and habitat environments was conducted for a total of 39 occasions from January to December 2022. The observed bird species totaled 14 families and 48 species with 20,760 individuals. Compared to the existing habitats, the newly established habitats showed relatively lower influx of bird species and individuals. During the habitat assessment, the newly established habitats were rated as I to II grade, while the existing habitat was rated as relatively high III grade on the grading assessment of the tidal flat. An analysis of habitat types revealed that the existing habitat, in which diverse strategies for habitat type diversity and mitigating anthropogenic interference were demonstrated, attracted a diverse range of bird species. Through this research, it was deduced that the diversity of habitat types plays a significant role in attracting various bird species. Upon evaluation of habitat types concerning the habitat characteristics of the bird species selected for habitat management, as habitat management measures, it is deemed that the creation of shielded green areas (referred to as 'buffer green') to minimize interference from the surroundings, the establishment of reed fields (site.1, 2) positively correlated with reservoirs, and the improvement of sandbanks (site.1) positively associated with tidal flats, the two relations which we drew from correlation analysis between occurrence species and habitat types, would contribute to the future restoration and maintenance of stable habitats. The results of this study can be applied not only to the study area but also to other development zones, such as coastal reclamation sites, which share similar geographical and environmental characteristics, including arrival sites for migratory birds.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.10 no.1
• /
• pp.1-7
• /
• 2005

Tidal flats have been regarded to carry out transformation and removal of land-derived organic matter, and this purifying capability of organic matter by tidal flats is one of very important reasons for their conservation. However, integral biogeochemical studies on production and decomposition of organic matter by benthic microbes in tidal flats have been absent in Korea, although the information is indispensable to quantification of the purifying capability. Our major goals in this multidisciplinary research were to understand major biogeochemical processes and rates mediated by diverse groups of microbes dominating material cycles in the tidal flats, and to assess the contribution of benthic microbes to removal of organic matter and nutrients in the tidal flats. Our study sites were Ganghwa and Incheon north-port tidal flats that had been regarded as naturally well reserved and organically polluted, respectively. Our research group measured over 3 years primary production, biomass and community structure of primary producers, abundance and production of bacteria, enzyme activities, distribution of protozoa and protozoan grazing rates, rates of denitrification and sulfate reduction, early sediment diagenesis, primary production and respiration based on oxygen microelectrode. We analyzed major features of each biogeochemical process and their interactions. The results are compiled in the following articles in this special issue: An (2005), Hwang and Cho (2005), Mok et at. (2005), Na and Lee (2005), Yang et at. (2005), and Yoo and Choi (2005).

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.6
• /
• pp.447-453
• /
• 2009

Vegetation distribution and soil salinity were surveyed on the conservation plot in the Daeho reclaimed tidal land, in where the plants species distribution was more various than a periodically inundated tidal flat and the early stage of reclamation. According to the soil salinity where the vegetation patches were occurred, the mono patches of Salicornia europaea, Suaeda maritima, and Suaeda glauca were distributed in the average range of 31.05 dS/m in soil salinity, the mixed patches of them were distributed in the average range of 42.75 dS/m. Therefore, Salicornia europaea, Suaeda maritima, and Suaeda glauca showed strong salt tolerance. The mono patches of Aster tripolium, Sonchus brachyotus, and Scirpus planiculm were distributed in the range of 11.73 dS/m in soil salinity, and the mixed patches were distributed in the average range of 9.43 dS/m. Therefore Aster tripolium, Sonchus brachyotus, and Scirpus planiculmis showed moderate salt tolerance. The mono patches of Imperata cylindrica, Trifolium pratense, Miscanthus sinensis, Setaria viridis, and Trisetum bifidum were distributed in the range of 2.42 dS/m in soil salinity. These species showed characteristics of glycophytes with weak salt tolerance. The distribution of vegetation patches was influenced by the soil salinity as pioneer halophytes patches occurred at higher soil salinity zone than facultative halophytes patches, glycophytes patches occurred at lower soil salinity zone than facultative halophytes. These results suggested that occurrence of plant species and plant distribution type might be useful index to evaluate the soil salinity and desalinization in the reclaimed land of the midwest coastal area of Korea.

• Journal of the Korean earth science society
• /
• v.27 no.2
• /
• pp.221-235
• /
• 2006

In order to understand the transport mechanism of tidal beach sediments in Deukryang Bay, south coast of Korea, beach profiles, surface sediments, sedimentation rates and hydrodynamic conditions have been investigated. The beach is composed of a steep beach face and gentle low-tide terrace, showing general morphologic characteristics of tide dominated beach. Central beach face of an indented coast becomes flattened in summer, but ridge and runnel system developed in other seasons makes the beach profile rather irregular. These seasonal variations of beach profiles and sedimentation rate indicate that beach sedimentation is mainly controlled by both tide and wave processes. Erosion is prevalent in winter when strong wind wave is dominant, while deposition is dominant in other seasons. However, central beach showed an apparent erosional phase in summer. This is caused by strong waves induced by southerly strong winds occurring ephemerally during the summer. On the other hand, sedimentation rates are -89.2 mm/yr on the central beach and 60.5 mm/yr and 38.2 mm/yr on the sides. This result suggests that sediments are eroded on the central beach and subsequently transported to the both sides. Therefore, the central part of Sumun beach, used as a beach bathing site, will be continuously eroded, if nearby dyke continues to prevent the sediment supply from sources.

• The Korean Journal of Petroleum Geology
• /
• v.11 no.1 s.12
• /
• pp.18-26
• /
• 2005

An occurrence of inclined heterolithic stratification (IHS) is described from a tidal point bar in a 40-m-deep distributary of the macrotidai, Han River delta, Korea. The channel bank demonstrates a convex-upward profile with intermittent presence or wave-formed scarps and terraces near the low-water level. The vertical succession of IHS is approximately 25 m thick and dips into the channel with angles reaching up to $14^{\circ}C$. The IHS overlies 15 m of trough cross-bedded sand deposited in the channel bottom. Even though the channel as a whole is ebb dominated, the preserved cross bedding is predominantly flood directed because the mutually evasive nature of the ebb and flood currents causes the point bar surface to be flood dominated. The IHS itself consists of inter-stratified fine sand, sandy silt, and silt with an fining-upward textural trend. Seasonal discharge variations of the Han River are not obvious in the deposits, because tile large size, distal location, and energetic tidal environment of the studied channel reduces the impart of river-stage fluctuations.

• Journal of Korean Society for Atmospheric Environment
• /
• v.23 no.2
• /
• pp.225-241
• /
• 2007

A closed flux chamber system was used for measuring major greenhouse gas (GHG) emission from tideland and/or wetland soils in estuarine area at Saemankum, Kunsan in southwestern Korea during from months of February to June 2006. Hourly averaged GHG soil emissions were measured two to three times a day during the ebb tide hours only. Site soils were analyzed for soil parameters (temperature, pH, total organic contents, N and C contents in soil) in the laboratory. Soil GHG fluxes were calculated based on the GHG concentration rate of change measured inside a closed chamber The analysis of GHG was conducted by using a Gas Chromatography (equipped with ECD/FID) at laboratory. Changes of daily, monthly GHGs' fluxes were examined. The relationships between the GHG emissions and soil chemical contents were also scrutinized with respect to gas production and consumption mechanism in the soil. Soil pH was pH $7.47{\pm}0.49$ in average over the experimental period. Organic matter contents in sample soil was $6.64{\pm}4.98\;g/kg$, and it shows relatively lower contents than those in agricultural soils in Kunsan area. Resulting from the soil chemistry data, soil nitrogen contents seem to affect GHG emission from the tidal land surface. The tidal soil was found to be either source or sink for the major GHG during the experimental periods. The annual average of $CH_{4}\;and\;CO_{2}$ fluxes were $0.13{\pm}0.86\;mg\;m^{-2}h^{-1}\;and\;5.83{\pm}138.73\;mg\;m^{-2}h^{-1}$, respectively, which will be as a source of these gases. However, $N_{2}O$ emission showed in negative flux, and the value was $-0.02{\pm}0.66\;mg\;m^{-2}h^{-1}$, and it implies tidal land surface act as a sink of $N_{2}O$. Over the experimental period, the absolute values of gas fluxes increased with soil temperature in general. Averages of the ambient gas concentration were $86.8{\pm}6.\;ppm$ in $CO_{2},\;1.63{\pm}0.34\;ppm\;in\;CH_{4},\;and\;0.59{\pm}0.15\;ppm\;in\;N_{2}O$, respectively. Generally, under the presence of gas emission from agricultural soils, decrease of gas emission will be observed as increase in ambient gas concentration. We, however, could not found significant correlation between the ambient concentrations and their emissions over the experimental period. There was no GHG compensation points existed in tide flat soil.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.11 no.1
• /
• pp.1-12
• /
• 2008

The prohibition of usage of tributyltin (TBT) compounds and the legal usage of new antifouling agents have changed the Korean costal environments in recent. 39 sampling sites of southwestern tidal flats were chosen in order to investigate the concentration of antifouling agents, and results in 2006 were compared with previous results in 1998. The concentrations of TBT compounds in most of sites except Incheon (It1) have been drastically decreased. Interestingly, In Jebudo (Jt2), Mokpo(MOt4) and Suncheon(SUt3) sites were detected as below the limit of detection and it is because of the legal restriction of TBT compounds. However, in most of the sampling sites in Korea, new antifouling agents, viz. Irgarol 1051, Dichlofluanid and Chlorothalonil, were detected. In particular, Irgarol 1051 was detected with high concentrations. In Jebudo (Jt4), a high concentration of Irgarol 1051 of 159.45 ng $g^{-1}$(dry wt) was detected. We were able to observe that the concentration of TBT compounds are has gradually been reduced whereas the new major antifouling agents are easily detected in most Korean tidal flats.

• Economic and Environmental Geology
• /
• v.37 no.3
• /
• pp.335-345
• /
• 2004

Total and extractable contents of heavy metals were measured in sediment and seafood from Bukhang and Boggil-ri tidal flats along the Mokpo coastal area, south-western part of Korean peninsular in order to assess the degree of metal pollution, metal bioavailability and metal hioaccumulation. The metal concentrations, except Pb were found to be greater than the background concentrations of sediments indicating the progress of cumulative contamination by anthropogenic origin of metals. The order of extractable metal concentrations in sediments were Mn(32-53 mg/kg)＞Zn(14-42 mg/tg)＞Cu(2.5-17.0 mg/kg)＞Pb(2.4-6.8 mg/kg)＞Cd(0.5-0.7 mg/kg). However, the amount of metals associated with extractable fraction of sediments were significantly high in Bukhang relative to Boggil-ri. Significant bioaccumulation of all metals, except Pb were observed in seaweed and benthos. The order of bioaccumulation of metals were: in concentration; all biota commonly, Mn(129-374 mg/kg)＞Zn(19-106 mg/kg)＞Cu(6-87 mg/kg)＞Cd(4.6-7.6 mg/kg)＞Pb(0.2-3.7 mg/kg), in BCF; Enteromorpha, Cd＞Mn＞Cu＞Zn＞Pb, Ilyoplax deschampsi, Cu＞Cd＞Mn＞Zn＞Pb, Urechis unicinctus, Cd＞Zn＞Mn＞Cu＞Pb. Some metal concentrations of Enteromorpha, especially Cu, Zn, weakly Pb in bukhang, Mn, Cd in boggili-ri, were correlate well with concentrations in sediment, indicating relatively more contaminated by the anthropogenic origin of metals in each tidal flat. The results clearly indicate that the seafood of bukhang, even of Boggili-ri known as clean area, are contaminated with metals.

• Journal of The Geomorphological Association of Korea
• /
• v.17 no.1
• /
• pp.15-27
• /
• 2010

This study investigated the sedimentary environment changes in the Baramarae beach of Anmyeondo through spatio-temporal surface sediment analysis. In the winter season 2009, surface sediments were classified into 7 sedimentary facies such as gravel, sand, gravelly sand, gravelly muddy sand, muddy sand, silty sand, and sandy silt. Time-series analysis of average grain size from 2002 to 2009 revealed that the average grain size of sediments became finer and sorting was much worse. On the contrary, during the same period, the grain size became coarsening-trend and sorting was much better in beach area. These different grain size patterns resulted from the different change characteristics of beach and tidal flats. The southwestern beach area was connected to the open sea and thus fine sediments were removed by the environments with relatively high-energy. The sedimentation of fine sediments in the bay resulted from the tidal current action and the reduction of energy by the topographic effects. Fine sediments in the outer part of southwestern tidal flats could be explained such that the Seomot isle blocked ocean waves and as a result, low-energy environments accelerated sedimentations of fine sediments.

• Journal of Environmental Impact Assessment
• /
• v.17 no.2
• /
• pp.105-112
• /
• 2008

Human activity has been the major threat to wetlands. Agriculture, industrial development, and urban and suburban sprawl have caused the greatest losses of coastal wetlands. In fact, riceland agriculture, because of the flooding that goes with it, provides some additional wetland habitat not otherwise available. The biggest current source of loss for freshwater coastal wetlands is from urban sprawl. In this study, spatial analysis method such as landscape index were applied to Sihwa area in Ansan city. The SMA (Spectral Mixture Analysis) method using Landsat image showed the change distribution of wetland vegetation from 1996 to 2004. The southern part of Sihwa wetland have been changed with Suda japonica of 24% and reed vegetation of 34% on coastal wetland which were covered with tidal flat.