• Journal of Korean Society on Water Environment
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• v.36 no.3
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• pp.229-244
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• 2020

Hydrologic models, as a useful tool for understanding the hydrologic phenomena in the watershed, have become more complex with the increase of computer performance. The hydrologic model, with complex configurations and powerful performance, facilitates a broader understanding of the effects of climate and soil in hydrologic partitioning. However, the more complex the model is, the more effort and time is required to drive the model, and the more parameters it uses, the less accessible to the user and less applicable to the ungauged watershed. Rather, a parsimonious hydrologic model may be effective in hydrologic modeling of the ungauged watershed. Thus, a semi-distributed hydrologic partitioning model was developed with minimal composition and number of parameters to improve applicability. In this study, the validity and performance of the proposed model were confirmed by applying it to the Namgang Dam, Andong Dam, Hapcheon Dam, and Milyang Dam watersheds among the Nakdong River watersheds. From the results of the application, it was confirmed that despite the simple model structure, the hydrologic partitioning process of the watershed can be modeled relatively well through three vertical layers comprising the surface layer, the soil layer, and the aquifer. Additionally, discussions were conducted on antecedent soil moisture conditions widely applied to stormwater estimation using the soil moisture data simulated by the proposed model.

• Journal of the Korean Society of Costume
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• v.60 no.2
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• pp.51-67
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• 2010

The purpose of this study was to develop the high value-added cultural product design with local cultural resources, and to contribute to promoting cultural tourism festivals. To accomplish this study, first, a preliminary survey is carried out the investigation of cultural product stores and visitors' questionnaire survey. Next, based on these survey and prior study, this study established the development direction and concept of fashion cultural products and to developed fashion cultural products using local cultural resources. Adobe Photoshop 6.0, and Adobe Illustrator CS Program were used for the standardization of patterns, textile design and illustration. The results of this study were as follows; First, based on preliminary research results, the problems of the design of cultural tourism festival products were derived. As one solution to solve this problem, this study established the development direction and concept of fashion cultural products to develop fashion cultural products. The concept of the Andong Maskdance Festival was 'Tribal-Holic'; the Boryeong Mud Festival, 'Get away form it all'; the Gangjin Celadon Festival, 'Timeless Memories'; the Jinju Namgang Yudeung Festival, 'Lighting up the River'; the Chungju World Martial Arts Festival, 'Next Ergonomics Gym'; and the Muju Firefly Festival, 'Eco-Purity'. Second, based on the desired items of festival organizers and the survey of visitor's preference for cultural products, 4 items were selected by festival type. Then a total of 96 designs of 4 kinds each were developed using logos or characters, traditional patterns, special products, symbolizing region, or festival as a motif. Third, the strategy for development of cultural products design for promotion of cultural tourism festivals were 'Place identity design strategy', 'Market oriented design strategy', 'Buyer-Based pricing strategy', 'Regional brand strategy', and 'Distribution networks expansion strategy'.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.71-79
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• 2009

In this study, a distributed rainfall-runoff model, K-DRUM, based on physical kinematic wave was developed to simulate temporal and spatial distribution of flood discharge considering grid rainfall and grid based GIS hydrological parameters. The developed model can simulate temporal and spatial distribution of surface flow and sub-surface flow during flood period, and input parameters of ASCII format as pre-process can be extracted using ArcView. Output results of ASCII format as post-process can be created to express distribution of discharge in the watershed using GIS and express discharge as animation using TecPlot. an auto calibration method for initial soil moisture conditions that have an effect on discharge in the physics based K-DRUM was additionally developed. The baseflow for Namgang Dam Watershed was analysed to review the applicability of the developed auto calibration method. The accuracy of discharge analysis for application of the method was evaluated using RMSE and NRMSE. Problems in running time and inaccuracy setting using the existing trial and error method were solved by applying an auto calibration method in setting initial soil moisture conditions of K-DRUM.

• Research in Plant Disease
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• v.11 no.2
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• pp.201-203
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• 2005

The stem rot disease was found on Hosta longipes that planted in the flower beds along the Namgang riverside in Jinju city, Korea. The disease occurred first time in July, 2004 and sporadically occurred in 2005. The typical symptom of the disease is water-soaking, dark brown spot on the stem, and getting wilt. The infected plants were mostly died. White mycelial mats were spread over lesions and sclerotia were formed on stems and near soil line. The sclerotia were globoid in shape, $1\~3$ mm in diameter and white to brown in color, The optimum temperature for mycelial growth of the fungus on PDA was $30^{\circ}C$ and the hyphal width was $4\~8{\mu}m$. Clamp connections were observed in the hyphae of the fungus grown on PDA. Pathogenicity of the causal organism was proved on Hosta longipes according to Koch,s postulate. On the basis of mycological characteristics and pathogenicity to host plants, the fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of H. longipes caused by S. rolfsii in Korea.

• Journal of Korean Society on Water Environment
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• v.33 no.1
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• pp.40-50
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• 2017

We were interested in the long-term temporal and spatial variability trends of water quality. Trend tests such as the Seasonal and Regional Kendall tests and LOWESS (LOcally WEighted Scatter plot Smoother) have been recommended as outstanding tools for trend detection. In this study, we conducted four types of nonparametric trend tests (Seasonal and Regional Kendall tests, LOWESS, and flow-adjusted Seasonal Kendall). We aimed to identify water quality trends using the monthly data for five variables (BOD, COD, TN, TP, and flow) collected from 24 sites in the Nakdong River from August 2004 to December 2013. According to the Regional Kendall test, BOD, COD, and TN increased but TP decreased trend. The Seasonal Kendall test showed that BOD, TN, and TP remained constant at 62.5-83.3% of the sites. COD remained constant at 58.3% of the sites. LOWESS showed that TP gradually increased between 2007 and 2008, then decreased slowly at the Gumi, Geumhogang6, Daeam-1 and Milyanggang3 sites. BOD increased slightly between 2008 and 2009, and then decreased slowly at the Namgang4-1 site. Lastly, a flow-adjusted Seasonal Kendall test was conducted. There were different results between Seasonal Kendall and flow-adjusted Seasonal Kendall tests at 11 of the 24 sites. According to the results from six of the eleven sites, BOD increased at one site, showed no trends at three sited, and decreased at two sites. Each of COD, TN increased at two, one site. but TP decreased at two sites.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.3-12
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• 2004

The need to predict the rate of soil erosion, both under existing conditions and those expected to occur following soil conservation practice, has been led to the development of various models. In this study Morgan model especially developed for field-sized areas on hill slopes was applied to assess the rate of soil erosion using RS/GIS environment in the Dukchun river basin, one of two tributaries flowing into Jinyang lake. In order to run the model, land cover mapping was made by the supervised classification method with Landsat TM satellite image data, the digital soil map was generated from scanning and screen digitizing from the hard copy of soil maps, digital elevation map (DEM) in order to generate the slope map was made by the digital map (DM) produced by National Geographic Information Institute (NGII). Almost all model parameters were generated to the multiple raster data layers, and the map calculation was made by the raster based GIS software, IL WIS which was developed by ITC, the Netherlands. Model results show that the annual soil loss rates are 5.2, 18.4, 30.3, 58.2 and 60.2 ton/ha/year in forest, paddy fields, built-up area, bare soil, and upland fields respectively. The estimated rates seemed to be high under the normal climatic conditions because of exaggerated land slopes due to DEM generation using 100 m contour interval. However, the results were worthwhile to estimate soil loss in hilly areas and the more precise result could be expected when the more accurate slope data is available.

• Journal of Korea Water Resources Association
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• v.46 no.2
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• pp.183-193
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• 2013

Selecting the evaluation index to determine water resources system design yield is an important problem for water resources engineers. Reliability, resilience and vulnerability are three widely used indices for yield analysis. However, there is an overlap region between indices as well as resilience and vulnerability can show improvement in non-monotonic phenomena although yield condition becomes worse. These problems are usually not recognized and the decisions are made according to calculated estimates in real situation. The reason for this is caused by a diverse characteristics of water resources system such as seasonal variability of hydrologic characteristics and water demands. In this study, the applicability of resilience and vulnerability for multi indices application in addition to reliability which is applied generally is examined. Based on highly seasonal irrigation water demand ratio, the correlation and non-monotonic phenomena of each index are analyzed for seven selected reservoirs. Yongdam reservoir which supplies constant water supply showed the general tendency, but Chungju, Andong, Namgang and other reservoirs which supplies irrigation water showed clear non-monotonic phenomena in resilience and vulnerability.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.19-30
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• 2013

This study is to evaluate the use of dual-polarization radar data for storm runoff modeling in Namgang dam (2,293 $km^2$) watershed using KIMSTORM (Grid-based KIneMatic wave STOrm Runoff Model). The Bisl dual-polarization radar data for 3 typhoons (Khanun, Bolaven, Sanba) and 1 heavy rain event in 2012 were obtained from Han River Flood Control Office. Even the radar data were overall less than the ground data in areal average, the spatio-temporal pattern between the two data was good showing the coefficient of determination ($R^2$) and bias with 0.97 and 0.84 respectively. For the case of heavy rain, the radar data caught the rain passing through the ground stations. The KIMSTORM was set to $500{\times}500$ m resolution and a total of 21,372 cells (156 rows${\times}$137 columns) for the watershed. Using 28 ground rainfall data, the model was calibrated using discharge data at 5 stations with $R^2$, Nash and Sutcliffe Model Efficiency (ME) and Volume Conservation Index (VCI) with 0.85, 0.78 and 1.09 respectively. The calibration results by radar rainfall showed $R^2$, ME and VCI were 0.85, 0.79, and 1.04 respectively. The VCI by radar data was enhanced by 5 %.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.63-74
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• 2018

As part of the Four Major Rivers Restoration Project, multifunctional weirs have been constructed in the rivers and operated for river-level management. As the weirs play a role in draining water from tributaries, the aim of this study was to determine the influence of the weirs on the water level of the Nam River, which is one of the Nakdong River's tributaries. Self-organizing maps (SOMs) and a locally weighted scatterplot smoothing (LOWESS) technique were applied to analyze the patterns and trends of water level and quality of the Nakdong River, considering the operation of the Changnyeong-Haman weir, which is located where the Nam River flows into the Nakdong River. The software program HEC-RAS was used to find the boundary points where the water is well drained. Per the study results at the monitoring points ranging between the junction of the two rivers and 17.5 km upstream toward the Nam River, the multifunctional weir influenced the water level at the Geoyrong and Daesan observation stations on the Nam River and the water quality based on automatic monitoring at the Chilseo station on the Nakdong River was affected strongly by the Nakdong River and partly by the Nam River.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.471-483
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• 2020

Flood prediction is an important issue to prevent damages by flood inundation caused by increasing high-intensity rainfall with climate change. In recent years, machine learning algorithms have been receiving attention in many scientific fields including hydrology, water resources, natural hazards, etc. The performance of a machine learning algorithm was investigated to predict the water elevation of a river in this study. The aim of this study was to develop a new method for securing a large enough lead time for flood defenses by predicting river water elevation using the a long- short-term memory (LSTM) technique. The water elevation data at the Oisong gauging station were selected to evaluate its applicability. The test data were the water elevation data measured by K-water from 15 February 2013 to 26 August 2018, approximately 5 years 6 months, at 1 hour intervals. To investigate the predictability of the data in terms of the data characteristics and the lead time of the prediction data, the data were divided into the same interval data (group-A) and time average data (group-B) set. Next, the predictability was evaluated by constructing a total of 36 cases. Based on the results, group-A had a more stable water elevation prediction skill compared to group-B with a lead time from 1 to 6 h. Thus, the LSTM technique using only measured water elevation data can be used for securing the appropriate lead time for flood defense in a river.