• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.153-153
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• 2016

최근 지구온난화 및 기후변화의 영향으로 수재해가 증가하고 있으며, 강우의 경향성이 변화하고 있다. 태풍 및 집중호우로 인한 피해보다 장기간의 연속적인 강우의 발생으로 인한 피해가 더욱 크며, 기존 수공구조물의 설계기준은 연속적인 호우로 인한 피해를 고려하지 못하고 있는 실정이다. 거대홍수란 집중호우, 태풍, 이상홍수 및 돌발홍수로 인한 홍수피해의 여파가 끝나기도 전에 또 다른 강우사상으로 인하여 거대한 홍수가 발생하는 시나리오적 상황을 의미한다. 본 연구에서는 기상청에서 제공하는 한강권역 30년 동안의 (1986 ${\infty}$ 2015년) 강우자료를 이용하여 거대홍수 발생횟수, 경향성, 설계기준을 초과하여 발생하는 거대홍수 초과빈도를 분석하였다. 최소 무강우 시간 정의(Inter Event Time Definition, IETD)를 이용하여 거대홍수를 산정하고, Mann-Kendall test 및 이중누가우량분석(double mass analysis)을 통하여 거대홍수의 경향성 분석을 실시하였다. 본 연구의 결과는 기존 수공구조물의 설계기준의 취약점을 보완할 수 있을 것이라 판단되며, 태풍, 집중호우, 거대홍수 등으로 발생하는 홍수피해를 줄이기 위한 방재 사업의 우선순위 결정에 대한 근거 자료로 활용할 수 있을 것이라 기대된다.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.169-185
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• 2017

Physicochemical properties of water quality were analyzed to understand the long-term variations in Lake Youngrang from 1998 to 2015. Nonparametric statistical methods were applied to deduct correlation among water quality parameters and water quality trend. In total observations(N=64), the Secchi depth (SD) transparency showed significant positive correlation with salinity (r=0.458) and highly significant negative correlation with chlorophyll-a (r= -0.649) for p<0.0001 in two-tailed test of Spearman's rank correlation. Significant negative correlations of SD were observed with chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). These correlation patterns were very similar in rainy (N=25) and non-rainy (N=39) periods too. Chlorophyll-a (Chl-a) had significant correlation with COD. Sen's slope test was performed along with Mann-Kendall trend test (significance ${\alpha}=0.05$, two-tailed) to find water quality trend. Positive trends were observed for SD and salinity with Sen's slopes 0.012 and 0.385, respectively (p<0.0001). Negative significant trends were observed for total nitrogen (TN) and Chl-a with Sen's slopes -0.02 (p<0.0001) and -0.346 (p=0.0010), respectively. Temperature, COD and phosphorus components had no trends. Carlson's trophic state index (TSI) for SD, TP and Chl-a were obtained in the ranges of 46~80, 37~82 and 39~82, respectively. Trophic index values suggest that Lake Youngrang was mesoeutrophic to eutrophic and there could be possibility of anoxia during the summer and dominance of blue-green algae. Excess nutrient inputs from external and internal sources were the causes of eutrophication in this lake. The findings of this study would be helpful to recognize water quality variables to manage the water body.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3B
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• pp.243-255
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• 2010

The spatial distribution of pan evaporation and pan evaporation trends have been studied. In this study, pan evaporation data from 1973 to 1990 for 56 climatological stations were analyzed. In addition to annual average daily pan evaporation, monthly average daily pan evaporation in April, July, October and January were analyzed, considering seasonal effect. The study results indicate that in case of annual average daily pan evaporation, 38 stations out of 56 stations show decreasing trend. In case of average daily pan evaporation in January, 33 stations show decreasing trend. In April, 38 stations show increasing trend. In July, 47 stations show decreasing trend. In October, 35 stations show increasing trend. Therefore, on the whole, pan evaporation tended to decrease in January, July, and annual basis. On the other hand, pan evaporation tended to increase in April and October. Furthermore, pan evaporation trend in each individual region shows also different trend even though the region is located nearby, indicating that there are geographical and topographical effects on pan evaporation trend. Pan evaporation data and climatic data from 1973 to 2006 for 11 climatological stations were used for trend analysis. Climatic variables such as temperature, relative humidity and wind speed show same or opposite trend direction compared with pan evaporation in annual or monthly basis. Annual and monthly solar radiation trends show the same direction compared with pan evaporation; however, annual and monthly precipitation trends show the opposite direction compared with pan evaporation.

• Health Policy and Management
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• v.32 no.1
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• pp.113-121
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• 2022

This study aims to compare the healthcare status of South Korea and other member of the Organization for Economic Cooperation and Development (OECD) using the OECD health statistics 2021. We used the position value for relative comparison (PARC) index to measure the five elements of the healthcare system, demand, supply, accessibility, quality, and cost. For the statistical analysis, Mann-Kendall test was performed to examine the trend of the PARC values from 2000 to the most recent year. The results showed that supply, demand, accessibility, and quality were above median than the OECD median and the cost was below median. In sectors such as primary care, health employment and mental health care were below median average. With these result, necessary steps for a sustainable healthcare should be taken into effort by policy makers.

• Advances in environmental research
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• v.6 no.4
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• pp.265-279
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• 2017

The climate change has made adverse effects on land surface temperature for many regions of the world. Several climatic studies focused on different downscaling techniques for climatological parameters of different regions. For statistical downscaling of any hydrological parameters, conventional Neural Network Models were used in common. However, it seems that in any modeling study, uncertainty is a vital aspect when making any predictions about the performance. In this paper, Gamma Test is performed to determine the data length selection for training to minimize the uncertainty in model development. Another measure to improve the data quality and model development are wavelet transforms. Hence, Gamma Test with Wavelet decomposed Feedforward Neural Network (GT-WNN) model is developed and tested for downscaled land surface temperature of Patna Urban, Bihar. The results of GT-WNN model are compared with GT-FFNN and conventional Feedforward Neural Network (FFNN) model. The effectiveness of the developed models is illustrated by Root Mean Square Error and Coefficient of Correlation. Results showed that GT-WNN outperformed the GT-FFNN and conventional FFNN in downscaling the land surface temperature. The land surface temperature is forecasted for a period of 2015-2044 with GT-WNN model for Patna Urban in Bihar. In addition, the significance of the probable changes in the land surface temperature is also found through Mann-Kendall (M-K) Test for Summer, Winter, Monsoon and Post Monsoon seasons. Results showed an increasing surface temperature trend for summer and winter seasons and no significant trend for monsoon and post monsoon season over the study area for the period between 2015 and 2044. Overall, the M-K test analysis for the annual data shows an increasing trend in the land surface temperature of Patna Urban.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.121-125
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• 2007

물 수요예측을 실시함에 있어서 사회 경제의 장래동향과 도시의 특성 및 발전 동향을 반영하여 수행하여야 한다. 그러나 지금까지의 관행으로는 수도계획에서 사용할 수 있는 실사용량에 대한 조사와 통계가 이루어지지 않고 있다. 실제 현장에서 얻은 자료를 토대로 하여 수도계획 및 설계에 사용할 수 있는 신뢰성 있는 설계인자의 도출이 필요하다. 본 연구에서는 급수지역의 각 조사 가정의 물 사용량을 실측 조사하여 얻어진 자료를 토대로 하여 물 수요 구조의 변화를 파악할 수 있는 수단의 하나로 가정의 수돗물 사용특성과 경제적 요인에 따른 가정용수의 사용특성 경향을 파악하고자 하였다. 가정에서 사용된 용수량의 조건별 경향성을 분석하기 위하여 한국수자원공사에서 2002년부터 2006년까지 3년여에 걸쳐 표본 집단이 되는 전국 140개 가구에 유량계를 설치하여 유량 자료를 획득하였고, 설문조사를 실시하여 각 가정의 물 사용 특성인자들을 조사하였다. 이 자료를 대상으로 비교적 자료의 신뢰성을 높이기 위한 자료의 선별과정을 거쳤다. 이렇게 선별된 자료들을 경향성 분석에 쓰이는 Mann-Kendall test와 Spearman's Rho test를 이용하여 분석하였다. 그 결과를 바탕으로 가정 용수 소비패턴의 증가 감소에 영향을 끼치는 인자들을 추출하였다. 실측자료를 분석을 통하여 나타난 결과들을 바탕으로 용수 수요처의 조건별 특성을 분석하고, 이를 활용한 생활용수 예측모형을 개발함으로써 합리적인 수요예측에 의한 용수수요의 과다예측 우려를 해소하고, 경제적 수도시설계획을 수립하는 등 과학적 물 수요관리 정책 수립을 위한 의사결정도구가 제공될 수 있다.c}$C의 저온에서 저장한 감자는 $20^{\circ}$C에서 저장한 감자보다 발아의 지연과 함께 낮은 PGA증가율을 보였다.다 높았으며, 전반적인 선호도의 경우 G3(1.5%)를 가장 선호하는 것으로 나타났다. 백년초 분말 첨가 도토리묵의 경우 색상은 0.5% 첨가한 O1이 가장 높은 값을 나타냈으며, 외관은 1.5% 첨가한 O3가 가장 높은 값을 보였다. 향미와 신맛의 경우는 백년초 분말의 첨가량이 증가됨에 따라서 유의적으로 증가했다(p<0.001). 씹힘성, 탄력성, 견고성의 경우는 대조군이 가장 높았으며, 백년초 분말 첨가량이 증가함에 따라 유의적으로 낮아졌다(p<0.001), 떫은맛의 경우는 백년초 분말에 의한 신맛의 영향으로 1% 백년초 분말이 첨가된 O2 가장 높게 나타났다. 전반적인 선호도는 0.5% 백년초 분말이 첨가된 O1이 가장 높게 나타났다. 따라서 녹차와 백년초의 기능성을 살린 도토리묵을 실용화시키는 효과적인 배합비는 녹차 분말 1.5% 첨가와 백년초 분말 첨가 0.5%가 바람직한 것으로 보이며 백년초 분말은 1%까지도 가능한 것으로 나타났다. 그러므로 기능성 식품 소재로써 도토리묵에 녹차와 백년초 분말을 첨가하는 것은 충분히 활용할만한 가치가 있다고 사료된다.론적으로, 비육돈 사료 내 3.32%의 호맥 사일리지의 혼합급여는 혈액 내 코티졸 함량, 도체육의 명도와 황색도, 지방산 조성 및 영양소 소화율에 영향을 미치는 것으로 사료되나 이에 대한 보다 많은 연구가 필요할 것으로 판단된다.니티와 공원과의 관계로 공원 설계와 관리에 있어서 영국에서는 커뮤니티가 직접 고객(client)으로서 역

• Journal of Korea Water Resources Association
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• v.56 no.6
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• pp.381-392
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• 2023

Precipitation, runoff, and evapotranspiration are changing worldwide due to climate change and human activities. Because watershed runoff is an important component of the hydrological cycle, it is important to investigate the changes in watershed runoff for water resources management. This study collected observed data of runoff, precipitation, temperature, and evapotranspiration in the Geum River basin as well as their synthetic data according to Representative Concentration Pathways (RCP) scenarios, investigated the trend of hydro-meteorological variables using the Mann-Kendall test, and quantitatively evaluated the effects of climate change and human activities on the watershed runoff using the climate elasticity approach and the Budyko framework. The results indicated that the relative contribution of climate change and human activity to changes in runoff varies from region to region. For example, the watershed with the greatest contribution from climate change and human activity were the Yongdam Dam (#3001) basin and the Daecheong Dam (#3008) basin, respectively. Future climate change showed an increase in precipitation and temperature in both RCP 4.5 and 8.5 scenarios, resulting in changes in runoff in the Geum River basin from 44.8% to 65.5%, respectively. We concluded that the effect on watershed runoff can be separated into climate change and human activities, which will be important information in establishing sustainable water resource management plans.

• Spatial Information Research
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• v.20 no.3
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• pp.39-50
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• 2012

The objective of this study is the quantitative analysis of climate change effects by performing several statistical analyses with hydrometeorological data sets for past 30 years in Geum river watershed. Temperature, precipitation, relative humidity data sets were collected from eight observation stations for 37 years(1973~2009) in Geum river watershed. River level data was collected from Gongju and Gyuam gauge stations for 36 years(1973~2008) considering rating curve credibility problems and future long-term runoff modeling. Annual and seasonal year-to-year variation of hydrometeorological components were analyzed by calculating the average, standard deviation, skewness, and coefficient of variation. The results show precipitation has the strongest variability. Run test, Turning point test, and Anderson Exact test were performed to check if there is randomness in the data sets. Temperature and precipitation data have randomness and relative humidity and river level data have regularity. Groundwater level data has both aspects(randomness and regularity). Linear regression and Mann-Kendal test were performed for trend test. Temperature is increasing yearly and seasonally and precipitation is increasing in summer. Relative humidity is obviously decreasing. The results of this study can be used for the evaluation of the effects of climate change on water resources and the establishment of future water resources management technique development plan.

• Journal of Soil and Groundwater Environment
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• v.11 no.2
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• pp.56-67
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• 2006

Trends of variation in groundwater levels, electrical conductivities and water temperatures obtained from the national groundwater monitoring stations (95 shallow and 169 deep wells) of Korea were evaluated. For the analysis, both parametric (linear regression) and non-parametric (Mann-Kendall test, Sen's test) methods were adopted. Results of linear regression analysis indicated that about 50% of the monitoring wells showed increasing trends of groundwater levels, electrical conductivities, and water temperatures and the others showed decreasing trends. However, the non-parametric analyses with monthly median values revealed that $14.8{\sim}20.0%$ of water levels were decreased, $24.2{\sim}36.9%$ of electrical conductivities were increased, and $27.4{\sim}32.5%$ of water temperatures were increased at a confidence level of 99%. Highly proportions of increasing or decreasing trends were unexpected and they resulted from the relatively short term of data collection (maximum 6 years). Meanwhile, the investigation of groundwater around the national groundwater monitoring stations showed that the decreasing or increasing trends of water levels, electrical conductivities, themselves, didn't indicate directly groundwater hazards such as groundwater depletion or groundwater contamination. Both the values and variation rates (slopes) of water level, electrical conductivity and temperature in the longer period are considered simultaneously. This study is the first comprehensive work in analyzing trends of groundwater data obtained from the national groundwater monitoring stations. Based on this study, the periodical and regular analysis of groundwater data is essentially required to grasp the overall variational trend of groundwater resources in the country.

• Journal of the Korean Geographical Society
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• v.28 no.3
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• pp.193-199
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• 1993

The interannual fluctuation, trends and perio-dicties in summer rainfall of South Korea were analyzed primarily by using Mann-Kendall rank method and Power Spectrum analysis for the period from 1920 to 1985. Their relations to Indian summer monsoon rainfall have also been examined. Increasing or decreasing rainfall tendencies are not found in South Korea. In Power Spectrum alalysis, 2.5 years periods are predominent at the 95 per cent confidence level in south Korea as a whole and Pusan. Also the period of 11.0 years is found in Seou. There are another prominent spectral peaks at 2.4, 3.1, 6.2 and 7.3 years period, which are significant at 90 per cent confidence level.