• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.242-242
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• 2015

Monitoring the land cover changes in Nakdong River Basins using the multi-temporal remote sensing datasets is necessary for preserving properties in the river basins and monitoring the environmental changes in the river basins after the 4 major river restoration project. This research aims to monitor the land cover changes using the multi-temporal Landsat imageries and the airborne topographic LiDAR data. Firstly, the river basin boundaries are determined by using the LiDAR data, and the multiple river basin imageries are generated from the multi-temporal Landsat imageries by using the river basin boundaries. Next the classification method is employed to identify the multiple land covers in the generated river basin imageries. Finally, monitoring the land cover changes is implemented by comparing the differences of the same clusters in the multi-temporal river basin imageries.

• Journal of the Korean Data and Information Science Society
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• v.14 no.1
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• pp.23-35
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• 2003

This paper provides the checklist of statistical methods in the water environmental research of Han and Nakdong river basins in South Korea. There are many errors pointed out in adopting statistical methods for the researches, as an example, basic statistical assumptions are missed for t-tests or regression analyses. Some new ideas are proposed for better researches of the river basins in Korea.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.965-975
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• 2012

Loading of NPS pollutant was valued through simulation by using BASINS/HSPF model which can simulate runoff volume in rainfall by time. For the verification of the model, it was analyzed the scatter diagram of the simulation value and measure value of water quality and runoff volume in Dongcheon estuary. Using the built model, a study on the time-variant characteristics of runoff and water quality was simulated by being classified into four cases. The result showed the simulation value was nearly same as that of the measured runoff. In the result of fit level test for measured value and simulated value, correlation of runoff volume was computed high by average 0.86 and in the water quality items, fit level of simulation and measurements was high by BOD 0.82, T-N 0.85 and T-P 0.79.

• Journal of Environmental Science International
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• v.23 no.1
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• pp.7-23
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• 2014

This study estimates unit for the nonpoint source(NPS), classified according to the existing Level-1(large scale) land cover map, by monitoring the measurement results from each Level-2(medium scale) land cover map, and verifies the applicability by comparison with previously calculated units using the Level-1 land cover map. The NPS pollutant loading for a basin is evaluated by applying the NPS pollutant unit to Dongcheon basin using the Level-2 land cover map. In addition, the BASINS/HSPF(Better Assessment Science Integrating point & Non-point Sources/Hydrological Simulation Program-Fortran) model is used to evaluate the reliability of the NPS pollutant loading computation by comparing the loading during precipitation in the Dongcheon basin. The NPS pollutant unit for the Level-2 land cover map is computed based on precipitation measured by the Sangju observatory in the Nakdong River basin. Finally, the feasibility of the NPS pollutant loading computation using a BASINS/HSPF model is evaluated by comparing and analyzing the NPS pollutant loading when estimated unit using the Level-2 land cover map and simulated using the BASINS/HSPF models.

• Journal of Korea Water Resources Association
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• v.38 no.6 s.155
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• pp.471-483
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• 2005

A monthly Ensemble Streamflow Prediction (ESP) system was developed by applying a daily rainfall-runoff model known as the Streamflow Synthesis and Reservoir Regulation (SSARR) model to the Han, Nakdong, and Seomjin River basins in Korea. This study first assesses the accuracy of the averaged monthly runoffs simulated by SSARR for the 3 basins and proposes some improvements. The study found that the SSARR modeling of the Han and Nakdong River basins tended to significantly underestimate the actual runoff levels and the modeling of the Seomjin River basinshowed a large error variance. However, by implementing optimal linear correction (OLC), the accuracy of the SSARR model was considerably improved in predicting averaged monthly runoffs of the Han and Nakdong River basins. This improvement was not seen in the modeling of the Seomjin River basin. In addition, the ESP system was applied to forecast probabilistic runoff forecasts one month in advance for the 3 river basins from 1998 to 2003. Considerably improvement was also achieved with OLC in probabilistic forecasting accuracy for the Han and Nakdong River basins, but not in that of the Seomjin River basin.

• Journal of the Korean Professional Engineers Association
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• v.35 no.4
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• pp.48-51
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• 2002

Due to locally torrential downpours which shows Increasing trend, high tide of the southern sea of Korea and etc. submerged and Inundated districts at the lowlands of Nakdong River Basins has been Increasing year by year In order to protect flood hit, it is necessary to make an early implementation of flood control dam and other flood protection works according to Nakdong River Comprehensive Development Project. In addition to the large scale comprehensive projects, local key measures, such as lowland development control, embankment reinforcement, leakage protection, maintenance and management of facilities, increase in pumping station, will be highly effective.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.2
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• pp.120-128
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• 2021

The objective of this study was to analyze the genotype of black-spotted pond frog (Pelophylax nigromaculatus) using seven microsatellite loci to quantify its genetic diversity and population structure throughout the spatial scale of basins of Han, Geum, Yeongsan, and Nakdong Rivers in South Korea. Genetic diversities in these four areas were compared using diversity index and inbreeding coefficient obtained from the number and frequency of alleles as well as heterozygosity. Additionally, the population structure was confirmed with population differentiation, Nei's genetic distance, multivariate analysis, and Bayesian clustering analysis. Interestingly, a negative genetic diversity pattern was observed in the Han River basin, indicating possible recent habitat disturbances or population declines. In contrast, a positive genetic diversity pattern was found for the population in the Nakdong River basin that had remained the most stable. Results of population structure suggested that populations of black-spotted pond frogs distributed in these four river basins were genetically independent. In particular, the population of the Nakdong River basin had the greatest genetic distance, indicating that it might have originated from an independent population. These results support the use of genetics in addition to designations strictly based on geographic stream areas to define the spatial scale of populations for management and conservation practices.

• Journal of Environmental Science International
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• v.31 no.2
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• pp.103-116
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• 2022

Heavy metal contaminations were investigated in fishes inhabiting the basins of Andong, Imha and Yeongju dam basins along the upper stream of the Nakdong river. The characteristics of heavy metals contamination in fish were investigated based on sampling sites located in the Andong dam basin. The muscle tissue was analyzed for 267 objects of 26 species from the Andong dam, 50 objects of 17 species from Imha dam, 38 objects of 9 species fromYoungju dam basin.The type and amount of heavy metals concentrated in the body of the fishes was found to be species-dependent. The heavy metal species which contamination increase through the Seokpo smelter are chromium, zinc, cadmium, and lead, and these are very likely the influence of the smelter. The concentration of eight heavy metals in fish from the Andong dam basin was higher than that in fish from the Imha and Youngju dam basins; the values for zinc, arsenic, and cadmium were significantly higher. However, mercury and lead exhibited high values in the Imha and Yeongju dam basins, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.2
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• pp.55-63
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• 1980

To study run-off characteristics in the small watersheds in Korea, investigations had been carried out for a period of 4 years from 1972 to 1975 in the sample watersheds. The samples were selected in four major river basins such as the Han River, the Keum River, the Nakdong River and the Yongsan River. Water levels and rainfall data had been. collected from each sample area where the measuring instruments were installed. The findings of this investigation can be summarized as follows; 1. With an average runoff rate of 60% in the sample watersheds, the average runoff rate. in each sample proved to be as below; the Han River Basin : 41.4% the Keum River Basin : 61.7% the Nakdong River Basin : 69.4% the Yong San River Basin : 69.2% 2. The base flow rate in the sample watersheds proved to be 8.1 mm/month. 3. A comparison of the runoff obtained from actual measurements made and that calculated by the Kaijyama formula showed that the latter is 9.1% lower than the former.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.2
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• pp.174-189
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• 2015

The objective of this study was to reconstruct spatial information using the results of the investigation and evaluation of the health of the living organisms, habitat, and water quality at the investigation points for the aquatic ecosystem health of the Nakdong River basin, to support the rational decision making of the aquatic ecosystem preservation and restoration policies of the Nakdong River basin using spatial analysis techniques, and to present efficient management methods. To analyze the aquatic ecosystem health of the Nakdong River basin, punctiform data were constructed based on the position information of each point with the aquatic ecosystem health investigation and evaluation results of 250 investigation sections. To apply the spatial analysis technique, the data need to be reconstructed into areal data. For this purpose, spatial influence and trends were analyzed using the Kriging interpolation(ArcGIS 10.1, Geostatistical Analysis), and were reconstructed into areal data. To analyze the spatial distribution characteristics of the Nakdong River basin health based on these analytical results, hotspot(Getis-Ord Gi, $G^*_i$), LISA(Local Indicator of Spatial Association), and standard deviational ellipse analyses were used. The hotspot analysis results showed that the hotspot basins of the biotic indices(TDI, BMI, FAI) were the Andong Dam upstream, Wangpicheon, and the Imha Dam basin, and that the health grades of their biotic indices were good. The coldspot basins were Nakdong River Namhae, the Nakdong River mouth, and the Suyeong River basin. The LISA analysis results showed that the exceptional areas were Gahwacheon, the Hapcheon Dam, and the Yeong River upstream basin. These areas had high bio-health indices, but their surrounding basins were low and required management for aquatic ecosystem health. The hotspot basins of the physicochemical factor(BOD) were the Nakdong River downstream basin, Suyeong River, Hoeya River, and the Nakdong River Namhae basin, whereas the coldspot basins were the upstream basins of the Nakdong River tributaries, including Andong Dam, Imha Dam, and Yeong River. The hotspots of the habitat and riverside environment factor(HRI) were different from the hotspots and coldspots of each factor in the LISA analysis results. In general, the habitat and riverside environment of the Nakdong River mainstream and tributaries, including the Nakdong river upstream, Andong Dam, Imha Dam, and the Hapcheon Dam basin, had good health. The coldspot basins of the habitat and riverside environment also showed low health indices of the biotic indices and physicochemical factors, thus requiring management of the habitat and riverside environment. As a result of the time-series analysis with a standard deviation ellipsoid, the areas with good aquatic ecosystem health of the organisms, habitat, and riverside environment showed a tendency to move northward, and the BOD results showed different directions and concentrations by the year of investigation. These aquatic ecosystem health analysis results can provide not only the health management information for each investigation spot but also information for managing the aquatic ecosystem in the catchment unit for the working research staff as well as for the water environment researchers in the future, based on spatial information.