• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.3-17
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• 1998

The purposes of this study is to investigate the possibility of planting trees at space land in the riverside. The space land is for the green space. Calculating the plantable space in the representation section and the flood flowing stability of the existing banks based on the hydrological and meteorological data of the Kap-Chon riverbasin located in Tae-jon, the following results are drawn. (1) The flood discharges in each flow section are $698.7m^3/s$ in section 1, $654.6m^3/s$ in section 2, and $1353.3m^3/s$ in section 3 during 100 years recurrence interval. Because the designed-flood discharges in those sections are $1719.9m^3/s$, $2119.7m^3/s$, and $1512.8m^3/s$ respectively, safety for flood flowing is sufficient in existing banks. (2) The possible clearance for planting trees is 1.80m in section 1, 3.90m in section 2, and 0.01m in section 3. Planting clearance is enough in section 1 and 2. However, planting should be planned after estimating a rise-height due to the bridge piers, because many piers under riverine-highway are now on the construction in section 2. The section 3 does not have sufficient clearance for planting trees, but the planting is possible after getting enough flow area with slope by cutting the terrace land on the river artificially heightened. (3) In case of planting a tree 70cm diameter in $1m^2$ in section 1, the water level increases by 0.60m. Planting a tree in a $48m^2$ area increases the water level by 0.90m. Considering that plantable clearance is 1.8m in section 1, it is sufficient to flow safely. But if the trees are planted so compactly from the upper stream, expected heavy resistance is expected due to caught materials on the trees. So, trees have to be planted widely in upper streams but compactedly in lower streams. (4) The river width without changing, Kap-Chon's flow channel can be snaked in accordance with the nature law the wide terrace land in the riverside. Decreased flow area due to planting trees will be compensated by the inclination of terrace land. And, it is theoretically proved that the flood discharge is safe even though the terrace land on the river is parked similar to the nature. Planting trees in the terrace land of the Kap-chon river to the extent that flood flowing is not adversely affected, we can get the enjoyable park to citizens not spending expensive cost. It also contributes to the recovery of ecosystem, which gives the natural beauty of river and shade to citizens and becomes good natural-educational places for children.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.121-128
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• 2008

Instream flows are defined as the stream flows needed to protect and preserve instream resources and values. They are supplied by the essential discharge for maintaining the channel. However, due to the lack of precipitation during the dry season, which is usually between the months of January and April, natural flows are not enough for the instream flows, thus leaving the dams at a shortage. In this paper, the method which will be discussed will show a physical way to improve water quality by the dilution of water that is supplied from a reservoir or dam, and how it is analyzed at the Han River basin. For the sake of this analysis, the basin has been divided into 33 catchments. Each catchment's natural flow has been simulated by SWAT-K, and the future water demand has been estimated using statistical data. It has also been assumed that the Han River basin has two large reservoirs(Chung-ju dam, and So-yang dam). The supply of potential discharge has been calculated using a case of water separately from each dam, as well as supply water from both dams.

• Journal of the Korean association of regional geographers
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• v.17 no.6
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• pp.649-665
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• 2011

Estuary of River Nakdong(in south-eastern coast of Korean Peninsula) is the most representative site of delta in Korea. This study is to elucidate morpho-structural background associated with the embayment area and sedimentation processes, having allowed development of the delta. In this area, Great morphological trait of the embayment area had been formulated by differential erosion exploiting regional fracture system(NNE-SSW, NNW-SSE, E-W,...) of tectonic origin. For this reason, outline of the embayment basin shows quadrangular plan, and ridges and dissected valleys of neighbouring mountains draw frequently morphological lineament pattern. At the last glacial age when delta deposit had not yet filled the actual embayment basin of the Nakdong, mechanical weathering(frost shattering) and mass-movement processes had provided detritus materials composed of blocks, boulders on bottom the basin. With the postglacial transgression in the Holocene, the basin had been submerged, then began to be filled with fluvio-marine deposits from Kimhae-Yangsan area toward actual estuarine zone, so that Nakdong delta have been formed. Analysis and synthesis of from hundreds of boring data of the delta area reveal that progression of delta formation have been accompanied with the development of barrier islands. If the barrier islands had grown as forming a plural row, then their intervals have posteriorly filled with another fluvio-marine deposits. Besides, it shows that delta deposits are essentially alluvial. However, at the periphery of the delta, intervention of fine marine deposits is frequently found.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.236-245
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• 2007

Feeding habits of Liobagrus andersoni were investigated in a tributary of the Namhan river from October 2005 to October 2006. L. andersoni was considered as an entirely bottom-feeding carnivore based on it's stomach contents. Because, the diet of L. andersoni was mainly aquatic insect such as Ephemeroptera, Trichoptera, Diptera. The most important prey was Ephemeroptera species. Small sized individuals (<50 mm SL) fed mainly on small prey organisms such as Baetis. However, larger Ephemeroptera and Trichoptera were heavily selected with increasing fish size. The relative proportion of food items was changed with season. The prey materials were more various at summer and autumn than winter. L. andersoni eaten Ephemeroptera intensively in spring and summer but eaten Trichoptera and Chironomidae in winter. Feeding activity of L. andersoni was started after sunset and was most active at midnight, but the activity was reduced after sunrise and during day period. So it was considered that L. andersoni was a nocturnal stalkers.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.333-339
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• 2019

The Red swamp crawfish Procambarus clarkii is native to the southern United States and inhibits all over the world including the United States, Asia, Africa and Europe. In Europe, it is known to disrupt ecosystems such as competition with native crayfish. In this study, habitats of red swamp crawfish were identified in Jiseok stream (15.5 km section) and Daecho stream (6.1 km section) of Youngsan river. A total 33 red swamp crawfish were captured. A female captured in Jiseok stream carried 215 newly hatched red swamp crawfish in her the burrow. As a result of the analysis of the habitat environment, the water temperature was ranged of 2.4~32.8℃, conductivity was 53.4~502.3 μS cm^-1 and DO was 0.74~22.64 mg L^-1. As a result of measuring HOBO, the temperature ranged from -9~48.1℃, showing a change of 57.1℃ throughout the year. The variation of the water temperature throughout the year from 2.9~33.9℃ was found to be 31℃. Red swamp crawfish have a high adaptability and a wide range of environmental resistance, and report a sharp increase in newly invaded areas, negatively affecting indigenous organisms. In addition, it can be used as a medium for the spread of diseases and parasites, so prompt investigation and research should be carried out.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.3
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• pp.230-240
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• 2009

The ESCORT model is applied at Mokpo coastal zone to analyze the effect of fresh water discharge released from the gates of the Youngsan River sea-dyke. Applicability and validity of both 2-D and 3-D hydrodynamic modules could be guaranteed by simulating hydrodynamic feature with ebb dominance characteristics. Then, effects of the released discharge on the hydrodynamics are investigated. And analysis of the effects on diffusion phenomena show that 3-D model is essential for such diffusion modelling. Moreover, vertical salinity distributions near the gates are examined, and the influence range of fresh water is also estimated, which shows that dilution of fresh water is going on slowly because of poor flushing.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.398-404
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• 1999

Factor analysis technique was employed to screen the principal indicators influencing soil and water qualities in the intensively cultivated areas of the Han River Basin. Soil chemical parameters were analyzed for the soil samples collected at intensive farming area in Pyungchang-Gun, and water quality monitoring data were obtained from the agricultural small catchments of Han River Basin during 1996 and 1997. Among the $11{\times}11$ cross correlation matrix, 29 correlations were significant out of 55 soil quality indicator pairs. The overall Kaiser's measure of sampling adequacy(KMS) value was acceptable with 0.60. Most indicators except iron were acceptable. Among soil indicators, the first factors showing high factor loadings were pH, Ca and Mg. The factor loading was the highest for Ca. The second factor could be characterized as phosphate and micronutrient. The third factor was organic matter and EC, and the fourth factor was potassium and Fe. Out of 190 water quality indicators, 86 correlations were significant. Overall KMS value was 0.74, but the KMS values for pH, TSS, Cd, Cu and Fe were lower than 50. The first factor of EC accounts 27.1 percents of the total variance, and showed high factor loadings with Na, Ca, $SO_4$, Mg, K, Cl, $NO_3$, and T-N. The second factor showed high loadings with Zn, Fe, Mn and Cd. The third to seventh factors could be characterized as $PO_4$, TSS, inorganic nitrogen, pH and T-P, and Cu factors, respectively. The factor score for EC was the highest in Kuri, followed by Chunchon, Dunnae and Daegwanryng. The factor score for heavy metals were the highest in the Daegwanryng. The results demonstrated that the factor analysis could be useful to select the most principal factor influencing soil and water qualities in the agricultural watershed.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.641-644
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• 2008

This paper investigated the plant and raw material of the ready-mixed concrete company which could supply to the second Lotte World on Pusan. the results were summarized as following. Almost plants were mainly using Twin shaft mixer which was 210m$^3$/hr and horizontal type. There was different the number of admixture silos at each plants, and they were separated by types. The mixtures mainly consisted of the ordinary portland cement, fly ash and blast furnace slag. For favorable quality control, each materials had to carry from same factories, and the monitering standard for quality control should be prepared. The coarse aggregates were used with many different producing districts, so they were only used from Y caused by exclusion of quality difference. The crushed, washed and river sands were generally used as fine aggregates, so the fine aggregates which could be possible to supply stable quality were chosen. This study used Poly Carbonic Acid Admixture which was developed to satisfy maintenance of performance till 2 hours and 10MPa at 15 hours.

• Journal of agricultural medicine and community health
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• v.22 no.2
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• pp.239-252
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• 1997

A questionnaire survey including stool examination for the parasite ova, skin test, and enzyme-linked immunosorbent assay (ELISA) of the liver fluke to find the factors related with the prevalence of the parasite infestation was done toward 118 residents living in three villages of Song-jung, Yi-jung, and Chim-gok of Okok-myun, Goksung County, South Cholla Province. The results are as follows : 1. The prevalence of Clonorchis sinensis ova by the stool examination was 46.6%. The sensitivity and specificity of skin test to egg-positive cases were 63.5% and 68.9%. The sensitivity and specificity of ELISA to egg-positive clonorchiasis were 100% and 34.9%. 2. The prevalence of Clonchiasis was higher in male than in female. 45~64 year old group was the highest among age groups, and the longer the duration of living in the present residence was, the higher the prevalence was shown statistically significantly (p<0.01). 3. The present drinker had higher prevalence of Clonorchiasis significantly than the past drinker or non-drinker, and the more the frequency of drinking the higher the prevalence was shown significantly (p<0.05). 4. Those who took raw fish had significantly higher than persons who didn't take it or take cooked fish(p<0.05) and prevalence showed the tendency to be increased as the frequency to take raw fishes increased significantly(p<0.05). 5. Those who had taken a raw sweet fish(Plecoglossus altivelis) or snake-headed fish(Ophicephalus argus) showed significantly higher prevalence of infection with liver fluke than persons who didn't take the raw fish. 6. While 56.4% of persons infected with Clonorchiasis answered that they were healthy, only 13.0% of the subjects were careful for their health, and 41.8% experienced tests to diagnose liver flukes before they were examined by this survey. 7. While 56.4% of infected persons thought the prevalence was high in their community, 54.0% were afraid to be infected, 47.1% thought the infection might destroy their health, 25.5% took treatment drugs, and 18.2% took raw fish continuously after treatment. The above results confirmed that Goksung area was highly prevalent in Clonorchiasis, so it was necessary to push effective preventive program against liver fluke infection together with the program to diagnose and treat existing infected persons.

• The Journal of the Petrological Society of Korea
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• v.20 no.1
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• pp.39-59
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• 2011

To get the geologic information data such as rock resources, industrial ground, development planning and so on, distribution ratios of constituent rocks with geologic age and rock type were obtained in Gyeongnam, Ulsan and Busan areas by ArcGIS 9.3 program, digital geologic and geomorphic maps of 1 : 250,000 scale. Geologic ages and rock types in the Gyeongnam area can be divided into 6 and 40, respectively. Their distribution ratios of the geologic ages are decreasing in the order of Cretaceous, Precambrian, Quaternary, Jurassic, Triassic and Tertiary. They show the wide ranges of 1.35-57.36%, and the former makes the most dominant ratio. Major rock types are 24 ones, all of which occupy the ratio of 94.58% and relatively narrow ranges of 1.15-13.64% in the area. Among them, andesite and andesitic tuff shows the more or less dominant ratio, and separately develops in the northeast, mid east and south parts of the area. In the Ulsan area, geologic ages and rock types can be divided into 3 and II, respectively. Their distribution ratios of the geologic ages are decreasing in the order of Cretaceous, Quaternary and Triassic. They show the very wide range of 6.90-79.21%, and the former makes the most prevailing ratio. Major rock types are 9 ones, which totally occupy the ratio of 98.63% and more or less wide ranges of 1.50-39.01% in the area. Among them, Jindong formation shows the most dominant ratio, and widely develops in the inner and eastern part of the area. In the Busan area, geologic ages and rock types can be divided into 3 and 10, respectively. Their distribution ratios of the geologic ages are decreasing in the order of Cretaceous, Quaternary and Tertiary. They show the wide ranges of 6.73-47.02%, and the two former makes the most dominant ratio of 88.03%. Major rock types are 6 ones, all of which occupy the ratio of 93.02% and relatively wide ranges of 4.07-47.02% in the area. Among them, alluvium forms the most dominant ratio, which mostly develops in the lower Nagdong River, West Nagdong River and Suyeong River.