• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.519-534
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• 2019

When the fresh water from the artificial lakes (Ganwolho and Bunamho) were discharged to Cheonsu Bay in summer to prevent the flood over the reclaimed farmland near the lakes, the impact on water qualities (nutrients, organic matters, trace metals) within the bay was investigated through four surveys (June, July, August and October, 2011). Dissolved inorganic nitrogen (DIN) increased about as much as 3-4 times over the whole water column when the freshwater was discharged. And the main species composition of DIN changed from ammonia to nitrate. Dissolved inorganic phosphorus (DIP) decreased as much as 2 times in surface waters, but increased as much as 1.5 times in deep waters, and also silicate concentrations increased as much as 3-4 times in deep waters of the inner bay. The N/P ratios in Chunsu bay seawaters were much higher (2 to 7 times) than the Redfield ratio when the freshwaters were discharged, which indicated the phosphorus limiting in the phytoplankton growth. Dissolved organic carbon (DOC) and nitrogen (DON) increased as much as about 2 times. In addition, particulate organic matters (POC, PON, POP, Bio-Si) increased as much as above 2 times in the surface waters of the inner bay. Trace metals (Fe, Mn, Co, Ni, Cu) increased in the surface waters of the inner bay, but dissolved Cd concentrations decreased as much as 2 times. Therefore, when the contaminated fresh waters from the artificial lakes were discharged into the bay, nutrients, organic matters and trace metals generally increased compared to normal period. Since the phytoplankton bloom occurred in the surface waters of the inner bay, dissolved oxygens at the surface waters were oversaturated and hence hypoxic in the deep waters. Highly enriched nutrients concentrations were found in deep waters of the inner bay, which was accompanied with the hypoxic condition. Finally, the water quality in the inner bay of the Chunsu bay was deteriorated from less than grade 3 in normal periods to grade 5 when the freshwaters from the artificial lakes were discharged in summer.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.237-251
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• 2011

This study presents a review on the recent climate change over the Korean peninsula, which has experienced a significant change due to the human-induced global warming more strongly than other regions. The recent measurement of carbon dioxide concentrations over the Korean peninsula shows a faster rise than the global average, and the increasing trend in surface temperature over this region is much larger than the global mean trend. Recent observational studies reporting the weakened cold extremes and intensified warm extremes over the region support consistently the increase of mean temperature. Surface vegetation greenness in spring has also progressed relatively more quickly. Summer precipitation over the Korean peninsula has increased by about 15% since 1990 compared to the previous period. This was mainly due to an increase in August. On the other hand, a slight decrease in the precipitation (about 5%) during Changma period (rainy season of the East Asian summer monsoon), was observed. The heavy rainfall amounts exhibit an increasing trend particularly since the late 1970s, and a consecutive dry-day has also increased primarily over the southern area. This indicates that the duration of precipitation events has shortened, while their intensity became stronger. During the past decades, there have been more stronger typhoons affecting the Korean peninsula with landing more preferentially over the southeastern area. Meanwhile, the urbanization effect is likely to contribute to the rapid warming, explaining about 28% of total temperature increase during the past 55 years. The impact of El Nino on seasonal climate over the Korean peninsula has been well established - winter [summer] temperatures was generally higher [lower] than normal, and summer rainfall tends to increase during El-Nino years. It is suggested that more frequent occurrence of the 'central-Pacific El-Nino' during recent decades may have induced warmer summer and fall over the Korean peninsula. In short, detection and attribution studies provided fundamental information that needed to construct more reliable projections of future climate changes, and therefore more comprehensive researches are required for better understanding of past climate variations.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.111-125
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• 2001

An estuary is semi-inclosed inlets, located between terrestrial and marine environment. Since many estuaries along south-western coasts of Korean peninsula were affected by human settlements and activities, significant changes in sedimentation environments have been observed. The research area is divided into three distinct morpho-stratigraphic units: fluvial dominated area(Area1), mixed area(Area 2), tide-dominated area(Area3). The landform of this area has been changed by reclamation and river channel change. Temporal variations affected by dam construction, periodic freshet was iterrupted. Sediments began to continuously accmulate on estuary banks by tide. Meanwhile, because of the continuous but reduced discharge of fresh water, the salinity of estuarine sediments was declined. That processes made vegetated area( Phregmites lonivalvis and Suaeda japonica) to be expanded. It indicates that the magnitude and frequency of geomorphic processes has been significantly changed.

• Korean Journal of Environment and Ecology
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• v.36 no.1
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• pp.102-111
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• 2022

Among protected areas, National Parks are rich in biodiversity, and the benefits of ecosystem services provided to human are higher than the others. Ecosystem service evaluation is being used to manage the value of national parks based on objective and scientific data. Ecosystem services are classified into four services: supporting, provisioning, regulating and cultural. The purpose of this study is to evaluate habitat quality among supporting services. Habitat Quality Model of InVEST was used to analyze. The coefficients of sensitivity and habitat initial value were reset by reflecting prior studies and the actual conditions of protected areas. Habitat quality of 21 national parks except Hallasan National Park was analyzed and mapped. The value of habitat quality was evaluated to be between 0 and 1, and the closer it is to 1, the more natural it is. As a result of habitat quality analysis, Seoraksan and Taebaeksan National Parks (0.90), Jirisan and Odaesan National Parks (0.89), and Sobaeksan National Park (0.88) were found to be the highest in the order. As a result of comparing the area and habitat quality of 18 national parks except for coastal-marine national parks, the larger the area, the higher the overall habitat quality. Comparing the value of habitat quality of each zone, the value of habitat quality was high in the order of the park nature preservation zone, the park nature environmental zone, the park cultural heritage zone, and the park village zone. Considering both the analysis of habitat quality and the legal regulations for each zone of use, it is judged that the more artificial acts are restricted, the higher the habitat quality. This study is meaningful in analyzing habitat quality of 21 National Parks by readjusting the parameters according to the situation of protected areas in Korea. It is expected to be easy to intuitively understand through accurate data and mapping, and will be useful in making policy decisions regarding the development and preservation of protected areas in the future.