• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.437-446
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• 2012

As a part of establishing suitability classification for forage production, use of the national soil and climate database was attempted for Italian ryegrass (Lolium multiflorum Lam., IRG) in Gangwon Province. The soil data base were from Heugtoram of the National Academy of Agricultural Science, and the climate data base were from the National Center for Agro-Meteorology, respectively. Soil physical properties including soil texture, drainage, slope available depth and surface rock contents, and soil chemical properties including soil acidity and salinity, organic matter content were selected as soil factors. The crieria and weighting factors of these elements were scored. Climate factors including average daily minimum temperature, average temperature from March to May, the number of days of which average temperature was higher than $5^{\circ}C$ from September to December, the number of days of precipitation and its amount from October to May of the following year were selected, and criteria and weighting factors were scored. The electronic maps were developed with these scores using the national data base of soil and climate. Based on soil scores, the area of Goseong, Sogcho, Gangreung, and Samcheog in east coastal region with gentle slope were classified as the possible and/or the proper area for IRG cultivation in Gangwon Province. The lands with gentle or moderate slope of Cheolwon, Yanggu, Chuncheon, Hweongseong, Pyungchang and Jeongsun in west side slope of Taebaeg mountains were classified as the possible and/or proper area as well. Based on climate score, the east coastal area of Goseong, Sogcho, Yangyang, Gangreung and Samcheog could be classified as the possible or proper area. Most area located on west side of the Taebaeg mountains were classified as not suitable for IRG production. In scattered area in Chuncheon and Weonju, where the scores exceeded 60, the IRG cultivation should be carefully managed for good production. For better application of electronic maps.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.56-63
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• 2018

The management of Combined Sewer Overflows(CSOs) and Separated Sewer Overflows(SSOs) discharge directly to the effluent system in an untreated state, which occurs when the facility capacity is exceeded due to heavy rain, has become an important issue in recent years as the heavy rain becomes a regular phenomenon. Despite the continuous development of filtration technology, targeting densely populated urban areas, CSOs are rarely applied. Therefore, this study was carried out to optimize the process to apply CSOs in a pilot-scale horizontal flow filtration system with a rope-type synthetic fiber. The research was carried out in two steps: a preliminary study using artificial samples and a field study using sewage. In the preliminary study using an artificial sample, head loss of the filter media itself was analyzed to be approximately 1.1cm, and the head loss was increased by approximately 0.1cm as the linear velocity was increased by 10m/hr. In addition, the SS removal efficiency was stable at 81.4%, the filtration duration was maintained for more than 6 hours, and the average recovery rate of 98% was obtained by air backwashing only. In the on-site evaluation using sewage, the filtration duration was approximately 2 hours and the average removal efficiency of 83.9% was obtained when belt screen (over 450 mesh) was applied as a pre-treatment process to prevent the premature clogging of filter media. To apply the filtration process to CSOs and SSOs, it was concluded that the combination with the pre-treatment process was important to reinforce the hydraulic dimension for the stable maintain of operation period, rather than efficiency. Compared to the dry season, the quality of incoming sewage was lower in the rainy season, which was attributed to the characteristics of the drainage area with higher sanitary sewerage. In addition, the difference in removal efficiency according to the influent quality of the wet season and dry season was small.

• The Korean Nurse
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• v.36 no.1
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• pp.59-76
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• 1997

The purposes of this study were to identify the contents and satisfaction level of the patients received home care service, and to compare the differences of the contents by the characteristics of the patients. Seventy eight patients received home care service from 1st Jan. to 30th Sept., 1996 were data-collected to analyze the contents and outcomes of home care service. Sixty-nine patients currently receiving home care service were participated to evaluate the satisfaction level of home care service. The data were analyzed using mean, standard deviation, $x^2$ test, and ANOVA by SPSS $PC^+$ program. The findings of this study were as follow : 1. The contents & outcomes of home care service 1) The mean age of the subjects was 64.4 years: 58% of them were female. Those who living in Seoul were 83% and the rest of the subjects was living in Kyung-Gi. 2) The subjects who had one diagnosis were 41%. Over 60% of them had the disease of neurologic & sensory system. 3) The mean number of visit was 6. Only one visit was 22%. The mean time of care was 79 minutes. Duration of visit from 31 minutes to 60 minutes were 47 %. The subjects who terminated the visit because of death were 67.3%. 62% of the persons who referred them to the home care service were nurses. 4) The pain after the service was more relieved than before. The amounts of intake, the degree of bed sore, edema & fracture after the service were more improved than before. Health status after the service was improved in general. 5) There were significant differences between initial and last conscious level in tracheostomy care & oxygen inhalation care. There was significant difference between initial and last degree of activity in blood sugar check. 6) There were significant differences on the number of visit in assessment of the status, evaluation & observation, vital sign check, skin care, injection, medication, bed sore care, colostomy care, relaxation therapy for pain relief, patient education, family care, exercise therapy, position change, supply of disinfected equipments and infection control. There were significant differences on visiting time in nasogastric tube care, drainage tube care and oxygen inhalation care. 2. The satisfaction level of home care service 1) 50% were male. Over 60 years of the subjects was 61 %. Those who living in Seoul were 82%. 2) The subjects who had one or two diagnosis were 32% respectively. 55% of the persons who referred them to the home care service were nurses. 3) Total level of satisfaction of home care service was very high. 4) The older the age, the higher the satisfaction level. The larger the number of visit, the higher the satisfaction level. 5) The subjects who were in cloudy state were higher level of satisfaction than in alert or coma state. The subjects whose activity were normal or who needed assistance were higher level of satisfaction than bedridden or immobilized subjects. These findings suggested that the patients had substantial need for posthospital care. They tended to be elderly and to have experienced the wide range of health problems associated with aging, chronicity, including limitations in activities, and other serious health problems. So, the nationwide home care systems beyond the limit of demonstration program by local association and the development of the effective financial system of home based health care are necessary for the clients who are in need of home care.

• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.1-13
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, it is necessary to install the facilities that can cope with the initial stormwater. Most researches have been conducted on the design of facilities applying the Low Impact Development (LID) and the reduction effect on rainfall runoff to examine with 1D or 2D numerical models. However, the studies on the examination about flow characteristics and stability of pipe network systems were relatively insufficient in the literature. In this study, the stability of the pipe network system in rainwater storage tank was examined by using 3D numerical model, FLOW-3D. The changes of velocity and dynamic pressure were examined according to the number of rainwater storage tank and compared with the design criteria to derive the optimal design plan for a rainwater storage tank. As a results of numerical simulation with the design values in the previous study, it was confirmed that the velocity became increased as the number of rainwater storage tank increased. And magnitude of the velocity in pipes was formed within the design criteria. However, the velocity in the additional rainwater storage pipe was about 3.44 m/s exceeding the allowable range of the design criteria, when three or more additional rainwater storage tanks were installed. In the case of turbulence intensity and bottom shear stress, the bottom shear stress was larger than the critical shear stress as the additional rainwater storage was increased. So, the deposition of sediment was unlikely to occur, but it should be considered that the floc was formed by the reduction of the turbulence intensity. In addition, the dynamic pressure was also satisfied with the design criteria when the results were compared with the allowable internal pressure of the pipes generally used in the design of rainwater storage tank. Based on these results, it was suitable to install up to two additional rainwater storage tanks because the drainage becomes well when increasing of the number of storage tank and the velocity in the pipe becomes faster to be vulnerable to damage the pipe. However, this study has a assumption about the specifications of the rainwater storage tanks and the inflow of stormwater and has a limitation such that deriving the suitable rainwater storage tank design by simply adding the storage tank. Therefore, the various storage tank types and stormwater inflow scenarios will be asked to derive more efficient design plans in the future.

• Journal of Korea Water Resources Association
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• v.40 no.11
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• pp.887-898
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• 2007

A physically based semi-distributed model, SWAT was applied to the Chungju Dam upstream watershed in order to investigate the spatial and temporal characteristics of watershed sediment yields. For this, general features of the SWAT and sediment simulation algorithm within the model were described briefly, and watershed sediment modeling system was constructed after calibration and validation of parameters related to the runoff and sediment. With this modeling system, temporal and spatial variation of soil loss and sediment yields according to watershed scales, land uses, and reaches was analyzed. Sediment yield rates with drainage areas resulted in $0.5{\sim}0.6ton/ha/yr$ excluding some upstream sub-watersheds and showed around 0.51 ton/ha/yr above the areas of $1,000km^2$. Annual average soil loss according to land use represented the higher values in upland areas, but relatively lower in paddy and forest areas which were similar to the previous results from other researchers. Among the upstream reaches, Pyeongchanggang and Jucheongang showed higher sediment yields which was thought to be caused by larger area and higher fraction of upland than other upstream sub-areas. Monthly sediment yields at the main outlet showed same trend with seasonal rainfall distribution, that is, approximately 62% of annual yield was generated during July to August and the amount was about 208 ton/yr. From the results, we could obtain the uniform value of sediment yield rate and could roughly evaluate the effect of soil loss with land uses, and also could analyze the temporal and spatial characteristics of sediment yields from each reach and monthly variation for the Chungju Dam upstream watershed.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.6-11
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• 1989

This investigation was conducted to get basic informations on land consolidation works and soil management for arable land. The characteristics of geometrical features of mapping units in the detailed soil maps of Korea were measured from 70 soil series (565 soil phases) by using a picture analysis system. The results obtained were as follows: 1. The mean values of the mapping units in extent, periphery, diameter of long axis and short axis, roundness and number of acute angles were 22.0ha, 2.267m, 911m, 0.104, and 3.5, respectively. It was suggested that "Simplicity Index of Mapping Unit", $=\frac{Extent\;in\;ara}{Length\;of\;boundary\;periphery\;in\;meter}{\times}\frac{1}{number\;of\;acute\;angle}$ be valuable to judge the complexity degrees of mapping units. 2. The size of mapping unit among physiographyic position was shown in order of Alluvial plains > Fluviomarine plains > Terraces > Hills > Fans > Mt. foot slopes > Valleys, and the simplicity index of mapping units also showed similar order of the extent. 3. The size and the simplicity index of the soils developed on plains with silty textured imperfectly drained were higher than the soils developed on sloped land with loamy textured. As the slopes getting steeper or relatively better in soil drainage, the size and the simplicity index became smaller. 4. The relationship between the simplicity index and the size of the farm unit divides by the land consolidation works was positively correlated. And it was concluded that the parcelling of the farm unit divides by the planning of land consolidation should be based on the soil boundaries of the detailed soil maps for mechanized or collaborated farming.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.301-310
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• 2023

Ferrihydrite is an iron oxide mineral that is easily found in the natural environment, including acid mine drainage, and has a low crystallinity and high specific surface area, resulting in high reactivity with other ions, and can remove environmentally hazardous substances. However, because ferrihydrite is a metastable mineral, there is a possibility of releasing adsorbed ions by phase transformation to other minerals having low surface area and high crystallinity. In this study, the adsorption characteristics of arsenate, chromate, and selenate on ferrihydrite and the oxyanion removal efficiency of ferrihydrite were studied considering mineral phase transformation. At both pH 4 and 8, the adsorption of oxyanions used in the study were in good agreement with both Langmuir and Freundlich adsorption models except for selenate at pH 8. Due to the difference in surface charge according to pH, at pH 4 a higher amount of ions were adsorbed than at pH 8. The adsorption amount were in the order of arsenate, chromate, and selenate. These different adsorption models and adsorption amounts were due to different adsorption mechanisms for each oxyanions on the surface of ferrihydrite. These adsorption characteristics were closely related to changes in the mineral phase. At pH 4, a phase transformation to goethite or hematite was observed, but only a phase transformation to hematite was observed at pH 8. Among the oxyanion species on ferrihydrite, arsenate showed the highest adsorption capacity and hardly caused phase transformation during the experimental period after adsorption. Contrary to this, chromate and selenate showed faster mineral phase transformation than arsenate, and selenate had the lowest retardation effect among the three oxyanions. Ferrihydrite can effectively remove arsenate due to its high adsorption capacity and low phase transformation rate. However, the removal efficiency for other two oxyanions were low by the low adsorption amount and additional mineral phase transformation. For chromate, the efficient removal is expected only at low concentrations in low pH environments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.587-597
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• 2023

We evaluated the eutrophication of Saemangeum Lake, which causes abnormal growth of algae, using the Carlson index. Eutrophication characteristics of Saemangeum Lake were analyzed. For the study, water quality surveys were conducted at 7 stations in Saemangeum Lake every month in 2021. The concentration of Chl.a was slightly higher in the Mankyeong water system in winter, and slightly higher in the Dongjin water system in spring and summer, but overall, except for some periods, the concentration was similar to or lower than the lake water quality environmental standard of class 3. COD showed water quality similar to or above the lake quality environmental standard of grade 4 in both the Mankyeong and Dongjin water systems in the summer and Autumn. TOC concentrations were within lake water quality standard 3 at all sites. Total phosphorus concentrations exceeded the lake water quality standard of Class 4 and were higher in January and August after rainfall. In the correlation analysis between water quality factors, the correlation of organic matter, total phosphorus, and total nitrogen to salinity was relatively high. This reflected the water quality characteristics of freshwater, brackish water, and seawater areas due to seawater inflow through the drainage gate and freshwater inflow through upstream rivers. According to the characteristics of eutrophication fluctuations in Saemangeum Lake by trophic state index, the indices of Chl.a, SD, and TN showed water quality in the early stage of eutrophication, while the TP index showed a severe eutrophication state. The magnitude of the eutrophication index among water quality components was TSI(TP) > TSI(TN) > TSI(SD) > TSI(CHL) in all water systems. Quadrant analysis of the deviation of TSI(CHL) from TSI(TP) and TSI(SD) on a two-dimensional plane showed that there was no limiting effect of total phosphorus on algal growth in all water systems. In addition, the factors af ecting light attenuation appeared to be dominated by small particulate matter from outside sources.

• Proceedings of the KSEEG Conference
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• 2001.05b
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• pp.42-63
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• 2001

The detail survey on the Songsanri tomb site including the Muryong royal tomb was carried out during the period from May 1 , 1996 to April 30, 1997. A quantitative analysis was tried to find changes of tomb itself since the excavation. Main subjects of the survey are to find out the cause of infiltration of rain water and groundwater into the tomb and the tomb site, monitoring of the movement of tomb structure and safety, removal method of the algae inside the tomb, and air controlling system to solve high humidity condition and dew inside the tomb. For these purposes, detail survery inside and outside the tombs using a electronic distance meter and small airplane, monitoring of temperature and humidity, geophysical exploration including electrical resistivity, geomagnetic, gravity and georadar methods, drilling, measurement of physical and chemical properties of drill core and measurement of groundwater permeability were conducted. We found that the center of the subsurface tomb and the center of soil mound on ground are different 4.5 meter and 5 meter for the 5th tomb and 7th tomb, respectively. The fact has caused unequal stress on the tomb structure. In the 7th tomb (the Muryong royal tomb), 435 bricks were broken out of 6025 bricks in 1972, but 1072 bricks are broken in 1996. The break rate has been increased about 250% for just 24 years. The break rate increased about 290% in the 6th tomb. The situation in 1996 is the result for just 24 years while the situation in 1972 was the result for about 1450 years. Status of breaking of bircks represents that a severe problem is undergoing. The eastern wall of the Muryong royal tomb is moving toward inside the tomb with the rate of 2.95 mm/myr in rainy season and 1.52 mm/myr in dry season. The frontal wall shows biggest movement in the 7th tomb having a rate of 2.05 mm/myr toward the passage way. The 6th tomb shows biggest movement among the three tombs having the rate of 7.44mm/myr and 3.61mm/myr toward east for the high break rate of bricks in the 6th tomb. Georadar section of the shallow soil layer represents several faults in the top soil layer of the 5th tomb and 7th tomb. Raninwater flew through faults tnto the tomb and nearby ground and high water content in nearby ground resulted in low resistance and high humidity inside tombs. High humidity inside tomb made a good condition for algae living with high temperature and moderate light source. The 6th tomb is most severe situation and the 7th tomb is the second in terms of algae living. Artificial change of the tomb environment since the excavation, infiltration of rain water and groundwater into the tombsite and bad drainage system had resulted in dangerous status for the tomb structure. Main cause for many problems including breaking of bricks, movement of tomb walls and algae living is infiltration of rainwater and groundwater into the tomb site. Therefore, protection of the tomb site from high water content should be carried out at first. Waterproofing method includes a cover system over the tomvsith using geotextile, clay layer and geomembrane and a deep trench which is 2 meter down to the base of the 5th tomb at the north of the tomv site. Decrease and balancing of soil weight above the tomb are also needed for the sfety of tomb structures. For the algae living inside tombs, we recommend to spray K101 which developed in this study on the surface of wall and then, exposure to ultraviolet light sources for 24 hours. Air controlling system should be changed to a constant temperature and humidity system for the 6th tomb and the 7th tomb. It seems to much better to place the system at frontal room and to ciculate cold air inside tombs to solve dew problem. Above mentioned preservation methods are suggested to give least changes to tomb site and to solve the most fundmental problems. Repairing should be planned in order and some special cares are needed for the safety of tombs in reparing work. Finally, a monitoring system measuring tilting of tomb walls, water content, groundwater level, temperature and humidity is required to monitor and to evaluate the repairing work.