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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korea Water Resources Association
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Journal DOI :
Korea Water Resources Association
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Volume & Issues
Volume 46, Issue 12 - Dec 2013
Volume 46, Issue 11 - Nov 2013
Volume 46, Issue 10 - Oct 2013
Volume 46, Issue 9 - Sep 2013
Volume 46, Issue 8 - Aug 2013
Volume 46, Issue 7 - Jul 2013
Volume 46, Issue 6 - Jun 2013
Volume 46, Issue 5 - May 2013
Volume 46, Issue 4 - Apr 2013
Volume 46, Issue 3 - Mar 2013
Volume 46, Issue 2 - Feb 2013
Volume 46, Issue 1 - Jan 2013
Selecting the target year
Assessment of Climate Change Impact on Evapotranspiration and Soil Moisture in a Mixed Forest Catchment Using Spatially Calibrated SWAT Model
Ahn, So Ra ; Park, Geun Ae ; Jang, Cheol Hee ; Kim, Seong Joon ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 569~583
DOI : 10.3741/JKWRA.2013.46.6.569
This study is to evaluate the future climate change impact on hydrological components in the Seolmacheon (
) mixed forest catchment located in the northwest of South Korea using SWAT (Soil and Water Assessment Tool) model. To reduce the uncertainty, the model was spatially calibrated (2007~2008) and validated (2009~2010) using daily observed streamflow, evapotranspiration, and soil moisture data. Hydrological predicted values matched well with the observed values by showing coefficient of determination (
) from 0.74 to 0.91 for streamflow, from 0.56 to 0.71 for evapotranspiration, and from 0.45 to 0.71 for soil moisture. The HadGEM3-RA future weather data of Representative Concentration pathway (RCP) 4.5 and 8.5 scenarios of the IPCC (Intergovernmental Panel on Climate Change) AR5 (Assessment Report 5) were adopted for future assessment after bias correction of ground measured data. The future changes in annual temperature and precipitation showed an upward tendency from
and from 7.9% to 20.4% respectively. The future streamflow showed an increase from 0.6% to 15.7%, but runoff ratio showed a decrease from 3.8% to 5.4%. The future predicted evapotranspiration about precipitation increased from 4.1% to 6.8%, and the future soil moisture decreased from 4.3% to 5.5%.
Evaluation of Hybrid Downscaling Method Combined Regional Climate Model with Step-Wise Scaling Method
Lee, Moon Hwan ; Bae, Deg Hyo ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 585~596
DOI : 10.3741/JKWRA.2013.46.6.585
The objective of this study is to evaluate the hybrid downscaling method combined Step-Wise Scaling (SWS) method with Regional Climate Model (RCM) simulation data for climate change impact study on hydrology area. The SWS method is divided by 3 categories (extreme event, dry event and the others). The extreme events, wet-dry days and the others are corrected by using regression method, quantile mapping method, mean & variance scaling method. The application and evaluation of SWS method with 3 existing and popular statistical techniques (linear scaling method, quantile mapping method and weather generator method) were performed at the 61 weather stations. At the results, the accuracy of corrected simulation data by using SWS are higher than existing 3 statistical techniques. It is expected that the usability of SWS method will grow up on climate change study when the use of RCM simulation data are increasing.
Parameters Estimation of Clark Model based on Width Function
Park, Sang Hyun ; Kim, Joo-Cheol ; Jung, Kwansue ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 597~611
DOI : 10.3741/JKWRA.2013.46.6.597
This paper presents the methodology for construction of time-area curve via the width function and thereby rational estimation of time of concentration and storage coefficient of Clark model within the framework of method of moments. To this end time-area curve is built by rescaling the grid-based width function under the assumption of pure translation and then the analytical expressions for two parameters of Clark model are proposed in terms of method of moments. The methodology in this study based on the analytical expressions mentioned before is compared with both (1) the traditional optimization method of Clark model provided by HEC-1 in which the symmetric time-area curve is used and the difference between observed and simulated hydrographs is minimized (2) and the same optimization method but replacing time-area curve with rescaled width function in respect of peak discharge and time to peak of simulated direct runoff hydrographs and their efficiency coefficient relative to the observed ones. The following points are worth of emphasizing: (1) The optimization method by HEC-1 with rescaled width function among others results in the parameters well reflecting the observed runoff hydrograph with respect to peak discharge coordinates and coefficient of efficiency; (2) For the better application of Clark model it is recommended to use the time-area curve capable of accounting for irregular drainage structure of a river basin such as rescaled width function instead of symmetric time-area curve by HEC-1; (3) Moment-based methodology with rescaled width function developed in this study also gives rise to satisfactory simulation results in terms of peak discharge coordinates and coefficient of efficiency. Especially the mean velocities estimated from this method, characterizing the translation effect of time-area curve, are well consistent with the field surveying results for the points of interest in this study; (4) It is confirmed that the moment-based methodology could be an effective tool for quantitative assessment of translation and storage effects of natural river basin; (5) The runoff hydrographs simulated by the moment-based methodology tend to be more right skewed relative to the observed ones and have lower peaks. It is inferred that this is due to consideration of only one mean velocity in the parameter estimation. Further research is required to combine the hydrodynamic heterogeneity between hillslope and channel network into the construction of time-area curve.
Analysis for the Regional Characteristic of Climatic Aridity Condition in May
Rim, Chang-Soo ; Kim, Seong-Yeop ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 613~627
DOI : 10.3741/JKWRA.2013.46.6.613
In this study, to understand the May aridity condition of each region for the year of the worst drought on record in each duration (1-, 3-, 6-, 12-, 24 months), monthly climate data recorded from 1973 to 2006 at 53 climatological stations in South Korea were used to estimate the FAO Penman-Monteith reference potential evapotranspiration (RET). Monthly precipitation and RET were used to estimate P/RET as aridity index and variation index (VI) of P/RET, and these indexes are compared with SPI (Standard Precipitation Index). Fifty three climatological stations were grouped into 20 regions, so that May aridity conditions of 20 regions were studied. Furthermore, regional trend of May aridity index was studied by applying Mann-Kendall trend analysis, Spearman rank test, and Sen's slope estimator. The study results show that variation index (VI) of P/RET and SPI have close correlation. Throughout the country, as the duration is shorter, May aridity was more severe. In case of 3-month and 6-month duration, most of region show significant or non-significant decreasing trend of aridity index. However, no region show significant decreasing trend of aridity index in case of 12-month and 24-month duration.
Assessment of Influx Efficiency at By-Pass Fishway Using Two-Dimensional Physical Habitat Simulation Model -Focused on Zacco Platypus-
Baek, Kyong Oh ; Park, Ji Hyun ; Kim, Young Do ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 629~642
DOI : 10.3741/JKWRA.2013.46.6.629
In this study, the efficiency of the by-pass fishway installed at Kangjung-Goryong Weir in Nakdong River was assessed by using River2D which is a two-dimensional physical habitat simulation model. The model was calibrated and validated through the measured water elevation. The assessment was performed according to flow condition such as flood, normal, and low flow. Especially the low flow condition was focused on because the target fish, Zacco Platypus, have moved frequently up and downstream at the spawning season from April to June. From simulation results, it can be deduced that the influx efficiency and the passage efficiency of the fishway in the low flow is higher than that in the flood and normal flow due to occurrence of proper velocity at fishway entrance.
A Study on Empirical Distribution Function with Unknown Shape Parameter and Extreme Value Weight for Three Parameter Weibull Distribution
Kim, Taereem ; Shin, Hongjoon ; Heo, Jun-Haeng ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 643~653
DOI : 10.3741/JKWRA.2013.46.6.643
The most important procedure in frequency analysis is to determine the appropriate probability distribution and to estimate quantiles for a given return period. To perform the frequency analysis, the goodness-of-fit tests should be carried out for judging fitness between obtained data from empirical probability distribution and assumed probability distribution. The previous goodness-of-fit could not consider enough extreme events from the recent climate change. In this study, the critical values of the modified Anderson-Darling test statistics were derived for 3-parameter Weibull distribution and power test was performed to evaluate the performance of the suggested test. Finally, this method was applied to 50 sites in South Korea. The result shows that the power of modified Anderson-Darling test has better than other existing goodness-of-fit tests. Thus, modified Anderson-Darling test will be able to act as a reference of goodness-of-fit test for 3-parameter Weibull model.
Applicability Evaluation of Flood Inundation Analysis using Quadtree Grid-based Model
Lee, Dae Eop ; An, Hyun Uk ; Lee, Gi Ha ; Jung, Kwan Sue ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 655~666
DOI : 10.3741/JKWRA.2013.46.6.655
Lately, intensity and frequency of natural disasters such as flood are increasing because of abnormal climate. Casualties and property damages due to large-scale floods such as Typhoon Rusa in 2002 and Typhoon Maemi in 2003 rapidly increased, and these show the limits of the existing disaster prevention measures and flood forecasting systems regarding irregular climate changes. In order to efficiently respond to extraordinary flood, it is important to provide effective countermeasures through an inundation model that can accurately simulate flood inundation patterns. However, the existing flood inundation analysis model has problems such as excessive take of analysis time and accuracy of the analyzed results. Therefore, this study conducted a flood inundation analysis by using the Gerris flow solver that uses quadtree grid, targeting the Baeksan Levee in the Nakdong River Basin that collapsed because of a concentrated torrential rainfall in August, 2002. Through comparisons with the FLUMEN model that uses unstructured grid among the existing flood inundation models and the actual flooded areas, it determined the applicability and efficiency of the quadtree grid-based flood inundation model of the Gerris flow solver.
Dissolved Oxygen Trend in Sapgyo Stream Watershed
Rim, Chang-Soo ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 667~681
DOI : 10.3741/JKWRA.2013.46.6.667
In this study, monthly and seasonal dissolved oxygen trends of 19 water quality measurement stations in Sapgyo stream watershed were analyzed using monthly dissolved oxygen (DO) data measured for 16 years (1995~2010). Mann-Kendall trend test and Sen's slope estimator were carried out for trend analysis. Furthermore, Sapgyo stream watershed was divided into four different sections (Sapgyo stream, Muhan stream, Gykgyo stream, and Sapgyo lake) and chi-square test of homogeneity for DO trend was carried out for four different sections. The study results indicated that most of water quality measurement stations showed increasing or non-significant trend of DO on a monthly and seasonal basis. The chi-square test of homogeneity for each water quality measurement station showed the statistical homogeneity in seasonal DO trend; however, the test results showed the statistical non-homogeneity in monthly DO trend for the stations located in the reservoir. Overall, the dissolved oxygen trend in each water quality measurement station showed different patterns depending on the location of each station and season.
Prospect of Design Rainfall in Urban Area Considering Climate Change
Son, Ah Long ; Bae, Sung Hwan ; Han, Kun Yeun ; Cho, Wan Hee ;
Journal of Korea Water Resources Association, volume 46, issue 6, 2013, Pages 683~696
DOI : 10.3741/JKWRA.2013.46.6.683
Recent inundation damage has frequently occurred due to heavy rainfall in urban area, because rainfall has locally occurred exceeding the capability of a flood control plan by the exiting design rainfall from the data of Seoul weather station. Accordingly the objective of this study is to predict new design rainfall in order to make a future flood control plan considering climate change. In this study, for considering spatial characteristics of rainfall in urban area, data of AWS was used and for retaining insufficient rainfall data, WGR model was estimated the application of target area. The results were compared with the observation data and consequently show reasonable results. In addition, to prepare for climate change, design rainfall was calculated by applying for various climate scenarios and the result would be used in order to establish future flood control plan.