• 한국농공학회논문집
• /
• 제66권1호
• /
• pp.49-66
• /
• 2024

Extreme rainfall will become intense due to climate change, increasing inundation risk to agricultural land. Hydrological and hydraulic simulations for the entire watershed were conducted to analyze the impact of climate change. Rainfall data was collected based on past weather observation and SSP (Shared Socio-economic Pathway)5-8.5 climate change scenarios. Simulation for flood volume, reservoir operation, river level, and inundation of agricultural land was conducted through K-HAS (KRC Hydraulics & Hydrology Analysis System) and HEC-RAS (Hydrologic Engineering Center - River Analysis System). Various scenarios were selected, encompassing different periods of rainfall data, including the observed period (1973-2022), near-term future (2021-2050), mid-term future (2051-2080), and long-term future (2081-2100), in addition to probabilistic precipitation events with return periods of 20 years and 100 years. The inundation area of the Aho-Buin district was visualized through GIS (Geographic Information System) based on the results of the flooding analysis. The probabilistic precipitation of climate change scenarios was calculated higher than that of past observations, which affected the increase in reservoir inflow, river level, inundation time, and inundation area. The inundation area and inundation time were higher in the 100-year frequency. Inundation risk was high in the order of long-term future, near-term future, mid-term future, and observed period. It was also shown that the Aho and Buin districts were vulnerable to inundation. These results are expected to be used as fundamental data for assessing the risk of flooding for agricultural land and downstream watersheds under climate change, guiding drainage improvement projects, and making flood risk maps.

• 한국농공학회논문집
• /
• 제59권1호
• /
• pp.81-96
• /
• 2017

Along with climate change, it is reported that the scale and the frequency of extreme climate events (e.g. heavy rain, typhoon, etc.) show unstable tendency of increase. In case of Korea, also, the frequency of heavy rainfall shows increasing tendency, thus causing natural disaster damage in downtown and agricultural areas by rainfall that exceeds the design criteria of hydraulic structures. In order to minimize natural disaster damage, it is necessary to analyze how extreme precipitation event changes under climate change. Therefore a new design criteria based on non-stationarity frequency analysis is needed to consider a tendency of future extreme precipitation event and to prepare countermeasures to climate change. And a quantitative and objective characteristic analysis could be a key to preparing countermeasures to climate change impact. In this study, non-stationarity frequency analysis was performed and inundation risk indices developed by 4 inundation characteristics (e.g. inundation area, inundation depth, inundation duration, and inundation radius) were assessed. The study results showed that future probable rainfall could exceed the existing design criteria of hydraulic structures (rivers of state: 100yr-200yr, river banks: 50yr-100yr) reaching over 500yr frequency probable rainfall of the past. Inundation characteristics showed higher value in the future compared to the past, especially in sections with tributary stream inflow. Also, the inundation risk indices were estimated as 0.14 for the past period of 1973-2015, and 0.25, 0.29, 1.27 for the future period of 2016-2040, 2041-2070, 2071-2100, respectively. The study findings are expected to be used as a basis to analyze future inundation damage and to establish management solutions for rivers with inundation risks.

• 대한토목학회논문집
• /
• 제39권1호
• /
• pp.33-44
• /
• 2019

최근 기후변화 현실화로 강우 발생 시기와 패턴이 변화하면서 유역에 따라 유황이 변화하고 있는 실정이다. 이로 인한 하천 유황의 장기적 변화는 수중생태계의 구조와 기능에 커다란 변화를 야기한다. 하지만 국내에서는 기후변화와의 연계성은 물론, 유량변화와 생태학적 특성을 포함한 수생태계 관점에서의 분석은 대부분 이루어지지 않고 있다. 따라서 본 연구에서는 기후변화로 인한 현재-미래의 유황 변화가 만경강 하도와 홍수터 영역에서 감돌고기의 서식환경에 미치는 영향을 정량적으로 평가하였다. 그 결과, 현재보다 미래에 홍수와 가뭄 등 극한 수문 조건이 심화됨을 확인하였고, 특히 크기, 빈도, 지속시간, 시기와 변화율 등을 비교 분석함으로써 유황 특성의 변화를 명확히 파악하였다. 그리고 유황 특성과 물리서식처 해석을 연계함으로써 기후변화로 인해 미래 생태환경 변동에 대한 위험성이 크게 증대될 것이라는 결과 제시가 가능하였다.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2011년도 학술발표회
• /
• pp.18-18
• /
• 2011

Climate change is impacting and will increasingly impact both the quantity and quality of the world's water resources in a variety of ways. In some areas warming climate results in increased rainfall, surface runoff, and groundwater recharge while in others there may be declines in all of these. Water quality is described by a number of variables. Some are directly impacted by climate change. Temperature is an obvious example. Notably, increased atmospheric concentrations of $CO_2$ triggering climate change increase the $CO_2$ dissolving into water. This has manifold consequences including decreased pH and increased alkalinity, with resultant increases in dissolved concentrations of the minerals in geologic materials contacted by such water. Climate change is also expected to increase the number and intensity of extreme climate events, with related hydrologic changes. A simple framework has been developed in New Zealand for assessing and predicting climate change impacts on water resources. Assessment is largely based on trend analysis of historic data using the non-parametric Mann-Kendall method. Trend analysis requires long-term, regular monitoring data for both climate and hydrologic variables. Data quality is of primary importance and data gaps must be avoided. Quantitative prediction of climate change impacts on the quantity of water resources can be accomplished by computer modelling. This requires the serial coupling of various models. For example, regional downscaling of results from a world-wide general circulation model (GCM) can be used to forecast temperatures and precipitation for various emissions scenarios in specific catchments. Mechanistic or artificial intelligence modelling can then be used with these inputs to simulate climate change impacts over time, such as changes in streamflow, groundwater-surface water interactions, and changes in groundwater levels. The Waimea Plains catchment in New Zealand was selected for a test application of these assessment and prediction methods. This catchment is predicted to undergo relatively minor impacts due to climate change. All available climate and hydrologic databases were obtained and analyzed. These included climate (temperature, precipitation, solar radiation and sunshine hours, evapotranspiration, humidity, and cloud cover) and hydrologic (streamflow and quality and groundwater levels and quality) records. Results varied but there were indications of atmospheric temperature increasing, rainfall decreasing, streamflow decreasing, and groundwater level decreasing trends. Artificial intelligence modelling was applied to predict water usage, rainfall recharge of groundwater, and upstream flow for two regionally downscaled climate change scenarios (A1B and A2). The AI methods used were multi-layer perceptron (MLP) with extended Kalman filtering (EKF), genetic programming (GP), and a dynamic neuro-fuzzy local modelling system (DNFLMS), respectively. These were then used as inputs to a mechanistic groundwater flow-surface water interaction model (MODFLOW). A DNFLMS was also used to simulate downstream flow and groundwater levels for comparison with MODFLOW outputs. MODFLOW and DNFLMS outputs were consistent. They indicated declines in streamflow on the order of 21 to 23% for MODFLOW and DNFLMS (A1B scenario), respectively, and 27% in both cases for the A2 scenario under severe drought conditions by 2058-2059, with little if any change in groundwater levels.

• 대한토목학회논문집
• /
• 제44권2호
• /
• pp.161-172
• /
• 2024

일반적으로 수문기상변량의 상관관계를 파악하기 위해서는 Copula 기법을 활용하여 의존관계를 규명하고 있으나, 단순히 Copula 기법을 다변량으로 확장하는 것은 분석결과가 유연하지 않으며 Copula 기법에 대한 수학적인 가정을 확인하여 만족 여부를 판단해야 하는 등 복잡해지는 단점이 있다. 또한, 기존의 이변량 Copula 기법을 활용하여 기후변화모델의 지속시간에 따른 설계강우량을 추정하는 과정은 주로 일별 자료만을 활용하여 분석하므로 24시간 최대강우량에 대한 정보와의 의존관계를 규명하여 추정하는 방법을 채택하고 있다. 그러나, 24시간 최대강우량만을 활용하여 다른 지속시간에 대한 설계강우량을 산정하는 것은 다른 지속시간에 대한 의존관계 정보는 제공되지 않아 지속시간에 따른 강우 강도가 역전되는 현상이 야기되는 원인이다. 따라서, 본 연구에서는 변수간의 쌍구조 관계를 연결하는 Vine Copula 기법을 활용하여 다른 지속 시간에 대한 정보를 반영하여 미래 강우강도의 변화를 전망하고자 한다.

• 대한지리학회지
• /
• 제49권4호
• /
• pp.489-508
• /
• 2014

본 연구에서는 최근 40년 동안(1973~2012) 우리나라 기상청 61개 기상관측소에서 관측한 일최고기온 및 일최저기온 자료를 분석하여 계절별 극한기온현상 변화의 시 공간적 특징을 밝히고자 하였다. 우리나라 평균적으로 봄철에는 온난일의 증가, 여름철에는 한랭야의 감소와 온난야의 증가 현상이 가장 뚜렷하게 나타난다. 가을철에는 여름철과 유사하게 한랭야의 감소와 온난야의 증가, 겨울철에는 한랭야의 감소와 한랭일의 감소 경향이 가장 뚜렷하게 나타난다. 도시화 정도에 상관없이 온난야와 같은 야간 극한기온 현상의 변화는 대부분의 계절 전이 기간에 뚜렷하게 나타나지만, 주간 극한기온현상의 변화는 특정 월에만 나타난다. 대조적으로, 한랭일은 봄철과 여름철에, 온난일은 여름철에, 온난야는 겨울철에 대부분의 관측지점에서 통계적 유의성을 지닌 변화를 살펴볼 수 없다. 온난화에 대한 극한기온현상 변화 민감도는 봄철에 온난일(+6.3일/$^{\circ}C$)과 한랭야(-6.2일/$^{\circ}C$), 여름철에 온난야(+10.4일/$^{\circ}C$)와 온난일(+9.5일/$^{\circ}C$), 가을철에 온난일(+7.7일/$^{\circ}C$), 겨울철에 한랭야(-4.7일/$^{\circ}C$)가 상대적으로 높게 나타났다. 이러한 결과들은 온난화 과정에서 복잡한 기후변화 피드백에 의해 우리나라의 극한기온현상들이 계절마다 주 야간별로 비대칭적인 변화 추세와 민감도를 보이면서 변화하고 있음을 가리킨다.

• 한국대기환경학회지
• /
• 제30권2호
• /
• pp.188-200
• /
• 2014

The IPCC 5th Assessment Report (Climate Change 2013: The Physical Science Basis) was accepted at the 36th Session of the IPCC on 26 September 2013 in Stockholm, Sweden. It consists of the full scientific and technical assessment undertaken by Working Group I. This comprehensive assessment of the physical aspects of climate change puts a focus on those elements that are relevant to understand past, document current, and project future of climate change. The assessment builds on the IPCC Fourth Assessment Report and the recent Special Report on Managing the Risk of Extreme Events and Disasters to Advance Climate Change Adaptation. The assessment covers the current knowledge of various processes within, and interactions among, climate system components, which determine the sensitivity and response of the system to changes in forcing, and they quantify the link between the changes in atmospheric constituents, and hence radiative forcing, and the consequent detection and attribution of climate change. Projections of changes in all climate system components are based on model simulations forced by a new set of scenarios. The report also provides a comprehensive assessment of past and future sea level change in a dedicated chapter. The primary purpose of this Technical Summary is to provide the link between the complete assessment of the multiple lines of independent evidence presented in the main report and the highly condensed summary prepared as Policy makers Summary. The Technical Summary thus serves as a starting point for those readers who seek the full information on more specific topics covered by this assessment. Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of $CO_2$ since 1750. Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system. Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions. The in-depth review for past, present and future of climate change is carried out on the basis of the IPCC 5th Assessment Report.

• 한국건설관리학회논문집
• /
• 제20권2호
• /
• pp.44-52
• /
• 2019

기후변화로 인해 극한 기후 사상이 야기하는 피해의 빈도와 세기가 증가하고 있다. 사회기반시설물이 기후변화로 인한 위험에 대비되어 있지 않으면 시설물 자체와 그 주변 지역의 자산 손실이 발생할 수 있다. 따라서 기존의 기후에 근거하여 설계된 사회기반시설물들에 기후변화 적응기술을 도입하여 미래에 발생할 손실을 낮추어야 한다. 정책 결정자는 적응기술을 도입하기 위해 각 기술의 경제적 파급효과를 이해해야 한다. 기후변화 적응의 경제적 파급효과를 올바르게 이해하려면, 시설물에 직접적인 피해인 1차 피해와 기후 사상으로 인해 주변지역에 미치는 피해인 2차 피해를 모두 파악하여야 한다. 본 논문은 기후변화 적응기술들이 저감하는 1차 및 2차 피해액을 도출하기 위한 방법론을 제시하여, 각 사회기반시설물에 특화된 기후변화 적응기술 가치평가 방법을 제안하였다.

• Asian Journal of Atmospheric Environment
• /
• 제8권3호
• /
• pp.140-153
• /
• 2014

The extreme heat watch and warnings (EHWW) which is constructed as a part of the climate change adaptation took effect in the summer of 2008, but active response actions failed to be taken because of low perception among citizens. Therefore, a survey investigation targeting citizens residing in Busan and the Gyeongnam province was conducted in order to know the perception regarding EHWW issued by the Korea Meteorological Administration, to identify the main media through which information is acquired, and to propose an improvement measures which may enhance the usefulness and the degree of satisfaction of weather information. The results are as follows; The perception regarding EHWW was not very high as it remained at 59.8% in terms of percentile. Although the statistical significance was not fulfilled in the categories of gender or occupation, significant differences did exist among age groups. The main medium through which citizens acquired information regarding EHWW was the television, which was followed in order by the internet, acquaintances, short message service (SMS), radio, newspapers, the 131 weather hotline, and other media. The usefulness of EHWW was somewhat high (67.2%), and female students were found to utilize the information to a higher degree than male students. The statistics on the level of satisfaction regarding the weather information (65.4%) revealed that most respondents were satisfied. Housewives, professional, and the elder age groups exhibited great satisfaction, leading to the conclusions that the level of perception and interest regarding to the special weather reports (SWR) have an impact on satisfaction of SWR.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권2호
• /
• pp.62-70
• /
• 2012

Rainfall, on Jeju Island varies regionally in relation to Mt. Halla with higher rainfall within southern area and lower in western area, and its variability is expected to expand according to the climate change scenario. Non-parametric trend analysis for rainfall, using both historic (1971-2010) and simulated (2011-2100) data assuming the A1B emissions scenario, shows regionally increasing trends with time. In perspective of agricultural land use, area for market garden including various crop types with high water demand is increasing over the Island, especially in the western area with lower rainfall compared to southern area. On the other hand, area for fruit including mandarin and kiwi with low water demand is widely distributed over southern and northern part having higher rainfall. These regional disparity of water demand/supply may be more affected by extreme events such as drought and heavy rainfall that has not yet been considered. Therefore, it is necessary to make policies for water resource management considering both demand and supply in different regions with climate change impacts over Jeju Island.