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31.
Jungho Nam Jongseong Ryu David Fluharty Chul-hwan Koh Karen Dyson Won Keun Chang Hee-Jung Choi Daeseok Kang Jong Seong Khim Chang-Hee Lee 《Ocean & Coastal Management》2010,53(11):703-710
The history of Korean tidal flat management and the process for designating Coastal Wetland Protected Areas (CWPAs) are described. Korean coastal wetlands have a long history of intensive use through reclamation for agricultural and industrial uses in the 20th century. Recently, the management policy is shifting away from intensive use towards the conservation of wetlands. This shift is caused by increasing public awareness of the value of wetlands and strong institutional support from the government. Since the Wetlands Conservation Act was passed in 1999, a total of twelve CWPAs have been designated through both top-down and bottom-up processes. Three designation paths are classified based on the relevant drivers, namely government-driven designations (seven CWPAs), local community driven designations (three CWPAs), and conflict resolution (trade-offs) driven designation (two CWPAs). The lessons learned from the designation of Korean CWPAs is that diversification of designation process could facilitate voluntary participation of local stakeholders and thereby enhance the chance of successful implementation of wise use strategy of tidal flats. 相似文献
32.
Keun-Hyung Choi Sung-Mi Lee Sang-Min Lim Mark Walton Gyung-Soo Park 《Journal of Oceanography》2010,66(3):307-317
Yellow Sea tidal flats are internationally recognised for their contribution to biological diversity and yet are under enormous
pressure from reclamation, pollution and overexploitation. The benthic macroinfauna community is the dominant community on
these tidal flats and a reliable indicator of benthic environmental changes. We surveyed the current benthic macroinfauna
community of the Ganghwa Southern Tidal Flat, the largest remaining Korean mud flat in the Yellow Sea, in order to examine
changes in the environmental situation of this benthic ecosystem. The results show a significant decline in species diversity
from the last survey made in 2003, and a shift in species composition with appearances of polychaetes indicative of pollution
and physical disturbances and other opportunistic species becoming dominant in both density and biomass. The benthic community
shift observed during the two study periods may be associated with increased nutrient pollution as well as increased physical
disturbances in this area. However, we recognise the limitations of the data both in frequency and scope but believe the significant
changes to the composition of the benthic fauna are sufficient to warrant concern. Observations are required to examine the
extent to which these human activities induce benthic community shift in this tidal flat. 相似文献
33.
ABSTRACT In this paper, we propose a method to regenerate Rational Polynomial Coefficients (RPCs) using KOMPSAT-3A imagery and to reduce the geolocation error using minimum ground control points (GCPs). To estimate the new RPCs, the physical sensor model fitted to KOMPSAT-3A imagery was utilized and virtual GCPs over the study area were created. The size of the virtual grid used was 20x20x20. To remove the sensor-related errors in physical sensor model, three different image correction models (image coordinate translation model, shift and drift model, and affine transformation model) were additionally applied. We evaluated our proposed method in two areas within Korea, one in urban (Seoul) and one in rural (Goheung) areas. The results showed that there was a significant improvement after applying the suggested approach in the two areas. The image coordinate translation model is suggested in terms of GCP requirement and expected errors estimated from the error propagation analysis using Gauss–Markov Model (GMM). 相似文献
34.
Sea surface height and transport stream function of the South China Sea from a variable-grid global ocean circulation model 总被引:8,自引:0,他引:8
The study on the South China Sea (SCS) circulation has a history of more than 40 years. Nevertheless, the SCS circulation is not fully understood compared with the Bohai Sea, Yellow Sea and East China Sea (ECS). Many numerical studies on the SCS circulati… 相似文献
35.
Biomonitoring of coastal pollution status using protozoan communities with a modified PFU method 总被引:10,自引:0,他引:10
Structural and functional parameters of protozoan communities were assessed as indicators of water quality in Korean coastal waters in the summer of 2000. A modified polyurethane foam unit (PFU) method, named the bottled PFU (BPFU) system, was used in order to carry out the bioassessment. Both parameters suggested that biomonitoring using the BPFU system was more effective than the conventional PFU method in offshore areas. The species number collected by the BPFU system generally decreased as pollution intensity increased at three main stations and was greater than that collected using the PFU method (paired t-test, t = 4.83, p < 0.0001). The Margalef diversity index coincided well with the water conditions. The diversity index values calculated from the BPFU system were also significantly higher than those from the PFU method (paired t-test, t = 5.37, p < 0.0001). Furthermore, the functional parameters, i.e. S(eq),G and T90%, correlated with the pollution status and could thus clearly discriminate the different classes of water quality. 相似文献
36.
37.
The crustal-scale Kyonggi shear zone of central Korea has been identified as a major boundary between the Precambrian Kyonggi massif in the south and the Imjingang belt in the north. The latter is an eastward extension of the Qinling-Dabie-Sulu collisional belt of China. Field observations and microstructural analysis indicate that the extensional shear zone evolved from a deep crustal ductile regime to a shallow crustal brittle regime, associated with a rapid uplift of the Kyonggi massif following the Late Permian-Early Triassic collision between the Sino-Korean and Yangtze cratons. A Rb-Sr muscovite age (226+/-1.2 Ma) of the mylonite suggests that the extensional ductile shearing occurred during the Late Triassic. 相似文献
38.
Summary A three-dimensional non-hydrostatic numerical model and lagrangian particle model (random walk model) were used to investigate
the effects of the atmospheric circulation and boundary layer structure on the dispersion of suspended particulates in the
Seoul metropolitan area. Initially, emitted particulate matter rises from the surface of the city towards the top of the convective
boundary layer (CBL), owing to daytime thermal heating of the surface and the combined effect of an onshore wind with a westerly
synoptic-scale wind. A reinforcing sea-valley breeze directed from the coast toward the city of Seoul, which is enclosed in
a basin and bordered by mountains to its east, disperses the suspended particulate matter toward the eastern mountains. Total
suspended particulate concentration (TSP) at ground level in the city is very low and relatively high in the mountains. Radiative
cooling of the surface produces a shallow nocturnal surface inversion layer (NSIL) and the suspended particulate matter still
present near the top of the CBL from the previous day, sinks to the surface. An easterly downslope mountain wind is directed
into the metropolitan area, transporting particulate matter towards the city, thereby recycling the pollutants. The particulates
descending from the top of the NSIL and mountains, combine with particulates emitted near the surface over the city at night,
and under the shallow NSIL spread out, resulting in a maximum ground level concentration of TSP in the metropolitan area at
2300 LST. As those particles move toward the Yellow Sea through the topographically shaped outlet west of Seoul city under
the influence of the easterly land breeze, the maximum TSP concentration occurs at the coastal site. During the following
morning, onshore winds resulting from a combined synoptic-scale westerly wind and westerly sea breeze, force particulates
dispersed the previous night to move over the adjacent sea and back over the inland metropolitan area. The recycled particulates
combine with the particulates emitted from the surface in the central part of the metropolitan area, producing a high TSP
and again rise towards the top of the CBL ready to repeat the cycle. 相似文献
39.
Modern and known-age Pleistocene fluvial sediments were investigated by optical dating of quartz to test the suitability of the approach for dating deposits from the deeply incised Middle Rhine Valley. Samples from modern flood sediments revealed skewed distributions indicating different residual levels of equivalent dose (De) within the different aliquots. Nevertheless, a substantial number of aliquots from the modern deposits reflect De values close to zero. For the Pleistocene samples, optical ages are in general consistent with age control given by the presence of the Laacher See Tephra and radiocarbon dating. However, some samples overestimate the known age by a few thousand years when using the arithmetic mean. This is apparently explained by including aliquots in the determination of mean De where the optical signal was incompletely bleached at deposition. The most difficult issue in this context is identifying a suitable approach that can distinguish between the variability of De due to partial bleaching and microdosimetry. However, even when considering these limitations it appears that optical dating will by a quite suitable method to date Pleistocene sediments from such a complex fluvial environment, especially when focusing on a precision scale beyond a few thousand years. 相似文献
40.
Optically stimulated luminescence (OSL) dating was applied to quartz samples recovered from the gravel sediments of deformed marine terrace at the Suryum site, southeastern Korea, but has yielded stratigraphically inconsistent ages. Micromorphological, chemical, and mineralogical analyses of the gravels indicate the possible influence of chemical weathering on the apparent OSL ages. In the course of weathering after emerging from beach environments, originally permeable gravels underwent infilling by halloysite-rich clays in their voids, export and import of radioactive elements, and loss of mechanical strength with the creation of a porosity within pebbles. Calculation based on the evolution of the weathering profile showed a severe fluctuation of dose rate caused by the change of water content and radioactive element concentrations. Samples recovered from the weathering profile inevitably include quartz grains derived from mechanically weakened pebbles or illuviated from the upper layer, making it difficult to determine the equivalent dose (De) values of exclusively depositional quartz sands. Quantitative evaluation of the change of fabric and chemistry of the sediments on the basis of pedologic insight significantly aids in the derivation of OSL ages consistent with geomorphology and other independent age controls. 相似文献