• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.49-56
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• 2001

The water quality simulation was carried out to predict water quality in Tan stream of the Han river using water quality model, QUAL2E. In the end, the future variations in water quality of Tan stream were simulated and the prediction of the impacts of Tan stream on water quality in the Han river was carried out by applying the Tan stream simulation results into the model. The results are as follows. The predicted results of future water quality of Tan stream suggested that the concentrations of BOD, T-N and T-P at Chungdam bridge would increase to 0.68~0.77 mg/$\ell$, 1.33~1.62 mg/$\ell$ and 0.05~0.06 mg/$\ell$, respectively in 2006 and 2011 and that with the implementation of advanced treatment in Sungnam and Tanchun sewage treatment plants, the concentration of T-N would be reduced more as the amount of treated sewage increase, while the concentration of T-P would stay 0.49 mg/$\ell$. The results obtained from simulation of the impacts of future Tan stream water quality improvement on the main stream of the Han river showed that with implementation of advanced treatment in both Sungnam and Tanchun sewage treatment plants, the concentration of T-N, T-P and chlorophyll-a at Hangang bridge and Heangju bridge would be reduced by 11.6%, 7.7% and 20.9%, respectively in 2..6 and by 13.6%, 9.4% and 22.2%, respectively in 2011, which indicates that the effect on the reduction of T-N and T-P would be relatively significant while the effect on the decrease of algae would be slight.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.301-313
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• 2003

Effects of the West sea tide to the flow of the Han and Imjin river during floods and normal seasons was analyzed by the hydraulic model. Tidal effect diagrams which represent the inter-relationships between flow of two livers and tide of Wolgot were developed using the results of analysis. At Jamsu and Hangang bridge, the stage rise due to the tide can be reached about 2m at maximum when the discharge of Paldang dam is less than 5,000cms, and the stage rise is very small when the discharge of Paldang dam is more than 15,000cms. In the Imjin river, the stage rise can be reached about 3.5m at maximum when the discharge is below 5,000cms, and can be neglected when the discharge is over 5,000cms.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.4
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• pp.50-65
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• 2021

In this study, the water flow system by measuring the flow-way type and distance of flow path that composes the Gugok through literature survey, field survey, and map work on Gugok gardens in Korea whose existence has been confirmed, while investigating and analyzing watersheds, river orders, and river grades. It was intended to reveal the watershed distribution and stream morphological characteristics of the Gugok gardens and to use them as basic data for future enjoyment and conservation of the Gugok gardens. The conclusion of the study is as follows. First, Of the 93 Gugok gardens that have been confirmed to exist, it was found that 11 places(11.8%) were found to have a descending(top-down) type of Gugok that develops while descending along a stream. Second, As a result of analysis of the length of the flow path for each valley, Okryudonggugok(玉流洞九曲, Namsan-gugok) in Gimcheon, Gyeongsangbuk-do was found to have the shortest length of 0.44km among the surveyed valleys, while the flow distance of Muheulgugok(武屹九曲) located in Seongju-gun and Gimcheon-si, Gyeongsangbuk-do was 31.1km, showing the longest flowing distance. The average flow path length of the Gugok Garden in Korea was 6.24km, and the standard deviation was 4.63km, indicating that the deviation between the 'curved type'e and the 'valley type' was severe. In addition, 14(15.1%) Gugok gardens were found to be partially submerged due to dam construction. Third, As a result of analyzing the waters area where Gugok garden is located, the number of Nakdong river basins was much higher at 52 sites(55.9%), followed by the Hangang river basin at 27 sites(28.7%), the Geum river basin at 9 sites(9.7%), and the Yeongsan river and Seomjin river basins at 5(5.4%). Fourth, All Gugok gardens located in the Han river region were classified as the Han river system, and the Gugok garden located on the Nakdong river was classified as the main Nakdong river system, except for 7 places including 5 places in the Nakdong Gangnam Sea water system and 2 places in the Nakdong Gangdong sea water system. As a result of synthesizing the river order of the flow path where Gugok garden is located, Gugok, which uses the main stream as the base of Gugok, is 3 places in the Hangang water system, 5 places in the Nakdong river system, 2 places in the Geumgang water system, and 1 place in the Yeongsangam/Seomjin river system. A total of 11 locations(11.5%) were found, including 36 locations(38.2%) in the first branch, 29 locations(31.2%) in the second branch, and 16 locations(17.0%) in the third branch. And Gugok garden, located on the 4th tributary, was found to be Taehwa Five-gok(太華五曲) set in Yonghwacheon Stream in Cheorwon in the Han river system, and Hoenggyegok(橫溪九曲) in Yeongcheon Hoenggye Stream in the Nakdong river system. Fifth, As a result of the river grade analysis of the rivers located in the Gugok garden Forest, the grades of the rivers located in the Gugok garden were 13 national rivers(14.0%), 7 local first-class rivers(7.5%), and 74 local second-class rivers(78.5%) was shown.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.21-30
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• 2023

The aim of this study is to investigate how travelers' destination visit intentions are influenced by avatar self-congruence in the metaverse platform. We extended the impression management theory by considering both perceived enjoyment and social engagement, and illustrated the interaction effect based on users' digital age. To achieve this, we conducted an online survey with 302 users. The survey results revealed that avatar self-congruence significantly influenced users in terms of perceived enjoyment and social engagement, thereby affecting their destination visit intentions. This study also revealed a significant interaction effect between digital age type and avatar self-congruence on users' perceived enjoyment. The results of this study are expected to provide not only a theoretical reference for metaverse research and travel research but also managerial implications for destination management and metaverse applications.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.1-15
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• 2006

This study is to review the site of Seoul and its urbanized area expansion in relation with a geomorphic environments. Surveying on the urbanized area of Seoul by period and related geomorphic conditions found the following conclusions. Seoul urbanized area had been expanded from the cheonggyecheon drainage basin to its surrounding hills and marshland. The marshland development began during the Japanese period from around the tributaries of the Hangang river and expanded to the areas by the main stream of the river. The extensive marshland at the point where the main stream and its tributaries of the river join has been developed relatively new. The marshland development, which took advanced engineering skills and a huge investment, is comparatively later and also involves large additional expenses to keep the areas from food damages. Judging from the above findings, this study concluded that the urbanized area expansions in a big metropolitan city such as Seoul, are greatly influenced by geomorphic environments and the importance of geomorphic conditions still hold true even today when scientific and technological developments have reached unprecedented heights.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.109-119
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• 2011

In this study, the flow characteristics of Han River Estuary were investigated by using a two-dimensional numerical model according to the assumption of shift and modification of the Shingok submerged weir. The two-dimensional analysis has contributed to our understanding of the hydraulic effects induced by shift of the weir on the topography, especially wetlands. The tide and flow discharge of 2007 were adopted as an input data for the simulation. The tidal data contained both spring and neap tide, and the flow discharge condition was divided into monsoon and normal seasons. The boundaries of this study were Hangang Bridge, Tongil Bridge, and Yu island. The simulation results showed that influence area of seawater changed depending on the weir shift, and the water level at particular station fluctuated according to the condition of tide and flow discharge.

• Journal of Korean Society of Disaster and Security
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• v.12 no.2
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• pp.73-82
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, the flood damage on riverside social infrastructures was extended so that there has been a threat of overflow. Therefore, a rapid prediction of potential flooding in riverside social infrastructure is necessary for administrators. However, most current flood forecasting models including hydraulic model have limitations which are the high accuracy of numerical results but longer simulation time. To alleviate such limitation, data driven models using artificial neural network have been widely used. However, there is a limitation that the existing models can not consider the time-series parameters. In this study the water surface elevation of the Hangang River bridge was predicted using the NARX model considering the time-series parameter. And the results of the ANN and RNN models are compared with the NARX model to determine the suitability of NARX model. Using the 10-year hydrological data from 2009 to 2018, 70% of the hydrological data were used for learning and 15% was used for testing and evaluation respectively. As a result of predicting the water surface elevation after 3 hours from the Hangang River bridge in 2018, the ANN, RNN and NARX models for RMSE were 0.20 m, 0.11 m, and 0.09 m, respectively, and 0.12 m, 0.06 m, and 0.05 m for MAE, and 1.56 m, 0.55 m and 0.10 m for peak errors respectively. By analyzing the error of the prediction results considering the time-series parameters, the NARX model is most suitable for predicting water surface elevation. This is because the NARX model can learn the trend of the time series data and also can derive the accurate prediction value even in the high water surface elevation prediction by using the hyperbolic tangent and Rectified Linear Unit function as an activation function. However, the NARX model has a limit to generate a vanishing gradient as the sequence length becomes longer. In the future, the accuracy of the water surface elevation prediction will be examined by using the LSTM model.

• Development and Reproduction
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• v.21 no.1
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• pp.55-62
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• 2017

We used flowcytometry to ploidy verification after that investigate difference between diploid and spontaneous triploid through the truss dimension and classical dimension at crucian carp, Carassius auratus, crucian carp C. cuvieri and common carp, Cyprinus carpio collected from Hangang river, Hantangang river, Imjingang river, Geumgang river, Yeongsangang river and Nakdonggang river, Korea. There were significant differences among the three species for the truss dimensions anterior origin of dorsal fin $(2){\times}$ anterior origin of anal fin (5), $2{\times}$ anterior origin of pelvic fin (6), $2{\times}$ origin of pectoral fin (7), posterior origin of dorsal fin $(3){\times}5$, $3{\times}6$, and $3{\times}7$ (P<0.05). There were no significant differences among the three species in the truss dimensions dorsal fin length ($2{\times}9$) and eye diameter (ED)(P>0.05). On the other hand, there were no significant differences in the several classical dimensions of each species (P>0.05). Three classical dimensions, most anterior extension of the head $(1){\times}2$, $1{\times}6$ and $2{\times}$ most posterior scale in lateral line (4) did not differ between the C. auratus diploid and spontaneous triploid (P>0.05). Two classical dimensions, $1{\times}6$ and longest length between most anterior extension of the head and gill cover ($1{\times}8$) did not differ between the C. cuvieri diploid and spontaneous triploid (P>0.05). One classical dimensions, $1{\times}2$ did not differ between the common carp diploid and spontaneous triploid (P>0.05). There were significant differences in the each diploid and triploid species (P<0.05). These results suggest that the classification of each species and classification between diploid and spontaneous triploid morphometrical parameters used in this study are useful indices of morphometrical status in the each species from major river of Korea.

• Journal of Korea Water Resources Association
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• v.47 no.11
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• pp.1017-1026
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• 2014

To investigate the effect of upstream dam operation and river water use on the downstream flows, SWAT-K watershed model was applied to the Paldang Dam watershed of the Han River basin. Analysis results from 2001 to 2009 showed that outflows from the multi-purpose dams such as the Soyanggang Dam and Chungju Dam much have a strong influence on the downstream flows during both the low- and high-flow seasons. This resulted an increase of low-flow at the Paldang Dam, the end of Pukhangang, and the Yangpyeong stage station by $100.57m^3/s$, $33.01m^3/s$, and $49.66m^3/s$, respectively. Whereas, the impact of river water use was hardly found in the Pukhangang, and also was not significant in the (Nam)hangang. Therefore, the effect of small dam such as the Hoengseong Dam or river water use would be able be excluded for long-term runoff analysis. But, in the case of the areas with a large amount of water use, a sufficient information such water-intake and water movement also must be taken into account like this study.

• Journal of Korea Water Resources Association
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• v.38 no.5 s.154
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• pp.401-413
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• 2005

This study analyzed the hydraulic effects of Singok submerged weir in the lower Han River. 1-D hydraulic flood routing model was used and calibration and verification were performed using 8 flood or nonflood events. Flow characteristics were analyzed using various outflows of Paldang Dam and tidal data of the Yellow Sea. Water level increase effects by establishment of Singok submerged weir were as following, when maximum flood tidal was 2.4m, highest water level increased about 0.65m, and lowest water level increased about 1.25m in the downstream of Jamsil submerged weir. In Hangang Bridge, due to the Singok submerged weir, when maximum flood tidal was 2.4m, tidal range was 0.07m and decrement of tidal range was about $90\%$. And when maximum flood tidal was 5.5m, tidal range was 1.6m and decrement of tidal range was about $35\%$. When the outflow of Paldang Dam was over 20,000cms, tidal range was below about 0.06m, and tidal effect did not appear hardly.