• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.61-64
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• 1997

본 연구는 매립 작업중인 준호기성매립지에서 유출가스를 측정하여, 다음과 같은 결론을 얻었다. (1) CH$_4$가스는 대부분 입형가스포집관에서 유출되며, $CO_2$가스는 총유출량의 약 50% 정도가 입형가스포집관을 통하여 유출된다. (2) 매립지 표면에서는 CH$_4$가스 보다 $CO_2$가스가 많이 유출된다. (3) 법면 복토층은 면적비율이 작으나 가스 발생량이 많으며, 특히 $CO_2$가스의 발생율이 높다. (4) 쓰레기층 표면에서의 CH$_4$가스 발생량은 미소이므로 무시하여도 된다. (5) 쓰레기층 노출, 복토층 다짐정도등에 따라 발생량의 변화를 보인다. (6) 매립부에서 새로 반입된 쓰레기층에서 $CO_2$가스 유출량이 많다. (7) 가스포집관과 복도 표면을 포함한 가스 유출량은 CH$_4$가스 유출이 많으나, 전체로는 $CO_2$가스 유출량이 많다.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.63-72
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• 1997

This study presents a surveying of methane and carbon dioxide at sanitary landfills. The following results are obtained. (1) The majority of methane and the half of carbon dioxide pour out from vertical gas vents. (2) The quantity of carbon dioxide in cove. soil was greater than methane. (3) Even though gas extrusion in side slop area was small, the quantity of gas extrusion in side slop area was much greater than in coversoil area as especially carbon dioxide rate. (4) As were carried raw refuse layer, methane extrusion was trace, but carbon dioxide was large. (5) Gas extrusion quantity were changed by the compaction of soil, and the operating area of refuse. (6) Carbon dioxide portioned much larger in the whole landfill, but methane portioned much larger in gas vent and coversoil.

• Ecology and Resilient Infrastructure
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• v.8 no.1
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• pp.32-43
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• 2021

Multichannel automated chamber systems (MCACs) were developed for the continuous monitoring of soil CO2 efflux in forest ecosystems. The MCACs mainly consisted of four modules: eight soil chambers with lids that automatically open and close, an infrared CO2 analyzer equipped with eight multichannel gas samplers, an electronic controller with time-relay circuits, and a programmable logic datalogger. To examine the stability and reliability of the developed MCACs in the field during all seasons with a high temporal resolution, as well as the effects of temperature and soil water content on soil CO2 efflux rates, we continuously measured the soil CO2 efflux rates and micrometeorological factors at the Nam-san experimental site in a Quercus mongolica forest floor using the MCACs from January to December 2010. The diurnal and seasonal variations in soil CO2 efflux rates markedly followed the patterns of changes in temperature factors. During the entire experimental period, the soil CO2 efflux rates were strongly correlated with the temperature at a soil depth of 5 cm (r2 = 0.92) but were weakly correlated with the soil water content (r2 = 0.27). The annual sensitivity of soil CO2 efflux to temperature (Q10) in this forest ranged from 2.23 to 3.0, which was in agreement with other studies on temperate deciduous forests. The annual mean soil CO2 efflux measured by the MCACs was approximately 11.1 g CO2 m-2 day-1. These results indicate that the MCACs can be used for the continuous long-term measurements of soil CO2 efflux in the field and for simultaneously determining the impacts of micrometeorological factors.

• Journal of Korea Water Resources Association
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• v.37 no.4
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• pp.305-314
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• 2004

Climate change mainly due to the increase of green house gases cause different patterns of water cycle within the basin. However, it is common that current planning and management practices do not consider the effect of the climate change. So, this study evaluated the effect of climate change on the water circulation within the watershed. This study used several GCM simulations for the double $CO_2$condition for the generation of temperature and rainfall series using the Markov chain. Daily runoff series for 100 years were generated using a rainfall-runoff model. As results. annual temperature increase by ＋3.2 ∼＋4.6$^{\circ}C$, annual precipitation change －7 ∼ ＋8 %, annual runoff change －14 ∼ ＋7 %, and potential evapotranspiration amount change ＋3 ∼＋4 % for the change of 1 $^{\circ}C$ are found to be expected depending on GCM simulations. Even though the simulation results are very dependent on the GCM predictions considered, overall variability of runoff is expected to become higher than the current state.

• Journal of Korea Water Resources Association
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• v.37 no.3
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• pp.185-193
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• 2004

The main purpose of this study is to investigate and evaluate the impact of climate change on the runoff and water resources of Yongdam basin. First, we construct global climate change scenarios using the YONU GCM control run and transient experiments, then transform the YONV GCM grid-box predictions with coarse resolution of climate change into the site-specific values by statistical downscaling techniques. The values are used to modify the parameters of the stochastic weather generator model for the simulation of the site-specific daily weather time series. The weather series fed into a semi-distributed hydrological model called SLURP to simulate the streamflows associated with other water resources for the condition of $2CO_2$. This approach is applied to the Yongdam dam basin in southern part of Korea. The results show that under the condition of $2CO_2$, about 7.6％ of annual mean streamflow is reduced when it is compared with the observed one. And while Seasonal streamflows in the winter and autumn are increased, a streamflow in the summer is decreased. However, the seasonality of the simulated series is similar to the observed pattern.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.335-345
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• 2001

The objective of this research is to analyze the hydrological environment changes in Daechung Dam Basin due to the global warming. GCM simulation results are used to predict the possible changes in precipitation and temperature. The changes of potential evapotranspiration, soil moisture and runoff due to the changes of precipitation and temperature are analyzed using a conceptual water balance model. From the simulation results using the water balance model for lx$CO_2$ and 2x$CO_2$ situations, it has been found that the runoff would decrease in Winter, but increase in Summer and Fall due to the global warming. Therefore, it is predicted that the frequency of drought and flood occurrences in Daechung Dam Basin would be increased in 2x$CO_2$ condition.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1417-1421
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• 2009

최근 들어 유역의 정확한 수문현상을 파악하기 위하여 유역의 유출량 자료를 직접 유출과 기저유출로 분리한 후 수문 모형의 직접유출 및 기저유출의 수문컴포넌트 검증에 활용하는 연구가 많이 이루어지고 있다. 미국 국립지리국 (USGS) 에서 개발한 HYSEP 모형이 지난 수 년 동안 유출 컴포넌트 분리에 널리 이용되어 오고 있다. 그러나 USGS 기반의 HYSEP의 경우 능숙한 컴퓨터 사용자가 아닌 비전문가들이 HYSEP을 운영하기에는 여러 가지 많은 제한점이 있어 왔다. 그리하여 본 연구에서는 고해상도 위성영상 Google Map 기반의 기저유출분리 프로그램인 Web-based HYSEP 인터페이스를 개발하였다. 이 시스템에는 HYSEP에서 제공하는 3가지 방법인 Fixed Interval / Sliding Interval / Local Minimum 방법이 제공되고 있다. 본 연구에서 개발된 Google Map 기반의 HYSEP 시스템은 USGS 유량 관측지점들에 대해 XML 데이터 포맷으로 DB를 구축하여 Google Map 과 연계하였으며 이를 통해 사용자가 원하는 관측소의 실시간 유량자료를 다운로드 할 수 있도록 개발되어졌다. Google Map 기반의 HYSEP 기저유출 분리 시스템(http://www.EnvSys.co.kr/${\sim}$hysep)은 Perl/CGI 및 자바스크립트, Google Map script 등을 이용하여 개발되었다. 현재 개발된 Google Map 기반의 USGS HYSEP 시스템은 한 곳의 유량관측지점에 대해서 총 3가지 기저유출 모듈을 적용하여 결과를 제공하고 있으며, 그 결과를 테이블이나 그래프 형태로 제공하도록 되어 있다. 본 연구에서는 Google Map 기반의 USGS HYSEP 시스템을 이용하여 미국 인디애나 주의 Little Eagle Creek 유역의 유량자료와 Fixed Interval / Sliding Interval / Local Minimum 방법을 이용하여 기저유출을 분리하였으며, 기존에 널리 활용되는 기저유출 분리 프로그램인 Web 기반의 WHAT 시스템 (http://www.EnvSys.co.k.r/~what) 산정 기저유출량과 비교분석하였다. 분석결과 HYSEP 예측 기저유출치가 전반적으로 WHAT 예측치보다 크게 산정되었다. WHAT 시스템과 본 연구에서 개발한 Web 기반의 HYSEP 일단위 기저유출량을 비교해 본 결과 $R^{2}$가 0.56, EI는 0.52로 어느 정도 비슷한 경향을 나타냈으나, 유역의 특성을 반영하는 WHAT 시스템과는 달리 주어진 유량자료만을 이용하여 기저유출을 분리하는 Web 기반의 HYSEP 기저유출 분리모듈을 개선할 필요가 있는 것으로 판단된다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.307-319
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• 2009

Carbon dioxide capture and storage (CCS) technology has been regarded as one of the most possible and practical option to reduce the emission of carbon dioxide ($CO_2$) and consequently to mitigate the climate change. Korean government also have started a 10-year R&D project on $CO_2$ storage in sea-bed geological structure including gas field and deep saline aquifer since 2005. Various relevant researches are carried out to cover the initial survey of suitable geological structure storage site, monitoring of the stored $CO_2$ behavior, basic design of $CO_2$ transport and storage process and the risk assessment and management related to $CO_2$ leakage from engineered and geological processes. Leakage of $CO_2$ to the marine environment can change the chemistry of seawater including the pH and carbonate composition and also influence adversely on the diverse living organisms in ecosystems. Recently, IMO (International Maritime Organization) have developed the risk assessment and management framework for the $CO_2$ sequestration in sub-seabed geological structures (CS-SSGS) and considered the sequestration as a waste management option to mitigate greenhouse gas emissions. This framework for CS-SSGS aims to provide generic guidance to the Contracting Parties to the London Convention and Protocol, in order to characterize the risks to the marine environment from CS-SSGS on a site-specific basis and also to collect the necessary information to develop a management strategy to address uncertainties and any residual risks. The environmental risk assessment (ERA) plan for $CO_2$ storage work should include site selection and characterization, exposure assessment with probable leak scenario, risk assessment from direct and in-direct impact to the living organisms and risk management strategy. Domestic trial of the $CO_2$ capture and sequestration in to the marine geologic formation also should be accomplished through risk management with specified ERA approaches based on the IMO framework. The risk assessment procedure for $CO_2$ marine storage should contain the following components; 1) prediction of leakage probabilities with the reliable leakage scenarios from both engineered and geological part, 2) understanding on physio-chemical fate of $CO_2$ in marine environment especially for the candidate sites, 3) exposure assessment methods for various receptors in marine environments, 4) database production on the toxic effect of $CO_2$ to the ecologically and economically important species, and finally 5) development of surveillance procedures on the environmental changes with adequate monitoring techniques.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• autumn
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• pp.31-34
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• 2004

• Journal of Korea Water Resources Association
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• v.37 no.2
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• pp.163-172
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• 2004

In this paper, the sub-soil storage system for utilizing urban instream flow of rainfall runoff was developed and examined through experiments. The artificial rainfall facility and sub-soil storage were installed in the experimental area. The effect of the water qualify improvement and the storage effect were analyzed through the several experiments. Through the experiments of rainfall intensity variation, which are the rainfall intensity of 20mm/hr, 30mm/hr, 40mm/hr, 50mm/hr was indicated SS concentration can be reduction until 68％. Also, the ration of the storage volume is varied from 42.8％∼79.9％ based on the rainfall intensity. The reduction rate of the BOD, CO $D_{Mn}$, SS, T-N, T-P was 30％, 42％, 68％, 39％, 26％. As the result, water quality of runoff and efficient of runoff reduction by the system are much improved. The rainfall runoff with the installation of sub-soil storage could be used for instream flow.