• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.875-889
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• 2021

This study compares and analyzes the Soil and Water Assessment Tool (SWAT) and Terra MODIS (Moderate Resolution Imaging Spectroradiometer) as coniferous, deciduous and mixed forest with Yongdam Dam upstream (904.4 km²). The hydrologic evaluation period was set to 10 years from 2010 to 2019, and the applicability of the 8-day MOD15A2 Leaf Area Index (LAI) data, 3 TDR (Time Domain Reflectometry) (GB, JC, CC), and 1 Flux Tower (DU) evaporation volume (YDD) data was simulated. As a result, the R² of coniferous forest, deciduous forest and mixed forest are 0.95, 0.89, 0.90, soil moisture and evaportranspiration stations R² were analyzed at 0.50 to 0.55 and 0.51, respectively, with R² at 0.74, RMSE 2.75 mm/day, NSE 0.70 and PBIAS 14.3% for Yongdam inflow. Based on the calibrated and validated watersheds, the annual average evaportranspiration was calculated as coniferous 469.7 mm, deciduous 501. mm and 511.5 mm mixed forest, total runoff were estimated at coniferous 909.8 mm, deciduous 860.6 mm and 864.2 mm mixed forest. In the case of annual average evaportranspiration, it was evaluated that deciduous were high, but in the case of streamflow, it was evaluated that coniferous were high. Unlike other hydrologic with similar patterns throughout the year, the average annual evapotranspiration was about 7% higher than coniferous due to the higher evapotranspiration of deciduous with high leaf area index in summer and fall. In addition, deciduous were 9% and 6% higher for surface runoff and lateral flow, but the groundwater of coniferous was 77% higher. Therefore, it was confirmed that the total runoff was in order of coniferous, mixed forest, and deciduous.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1615-1633
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• 2023

Sargassum horneri is one of the floating algae in the sea, which breeds in large quantities in the Yellow Sea and East China Sea and then flows into the coast of Republic of Korea, causing various problems such as destroying the environment and damaging fish farms. In order to effectively prevent damage and preserve the coastal environment, the development of Sargassum horneri detection algorithms using satellite-based remote sensing technology has been actively developed. However, incorrect detection information causes an increase in the moving distance of ships collecting Sargassum horneri and confusion in the response of related local governments or institutions,so it is very important to minimize false detections when producing Sargassum horneri spatial information. This study applied technology to automatically remove false detection results using the GOCI-II-based Sargassum horneri detection algorithm of the National Ocean Satellite Center (NOSC) of the Korea Hydrographic and Oceanography Agency (KHOA). Based on the results of analyzing the causes of major false detection results, it includes a process of removing linear and sporadic false detections and green algae that occurs in large quantities along the coast of China in spring and summer by considering them as false detections. The technology to automatically remove false detection was applied to the dates when Sargassum horneri occurred from February 24 to June 25, 2022. Visual assessment results were generated using mid-resolution satellite images, qualitative and quantitative evaluations were performed. Linear false detection results were completely removed, and most of the sporadic and green algae false detection results that affected the distribution were removed. Even after the automatic false detection removal process, it was possible to confirm the distribution area of Sargassum horneri compared to the visual assessment results, and the accuracy and precision calculated using the binary classification model averaged 97.73% and 95.4%, respectively. Recall value was very low at 29.03%, which is presumed to be due to the effect of Sargassum horneri movement due to the observation time discrepancy between GOCI-II and mid-resolution satellite images, differences in spatial resolution, location deviation by orthocorrection, and cloud masking. The results of this study's removal of false detections of Sargassum horneri can determine the spatial distribution status in near real-time, but there are limitations in accurately estimating biomass. Therefore, continuous research on upgrading the Sargassum horneri monitoring system must be conducted to use it as data for establishing future Sargassum horneri response plans.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.126-134
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• 1999

To provide the basic information for the water improvement and control of water resource in Nakdong river districts, the physico-chemical characteristics of water in four main streams and three branch streams of the river were investigated through 36 times totally, one time per each month from January in 1995 to November in 1997. The pH values of each sites in main or branch stream of Nakdong river was pH $6.3{\sim}9.3$ range, pH range of Jukpo and Namji area at spring and fall was almost over pH 8.5, which was exceeded the water quality standard for agriculture. DO values of Nakdong river was almost $8.0{\sim}13mg/l$, except for Kangchang area in downstream of Kumho river. BOD values in Dasa area where was prior to mixing of Kumho river was $1.5{\sim}4.8mg/l$, which was under the water quality standard for agriculture(8mg/l), but BOD values followed mixing of Kumho river was over the permit standard of agricultural water as $3.8{\sim}8.9mg/l$ in Koryung, $3.4{\sim}8.4mg/l$ in Jukpo and $3.3{\sim}7.8mg/l$ in Namji according to time or season. Especially, BOD values at Gangchang area in Kumho river were $7.6{\sim}18.5mg/l$, which was over the water quality standard for agriculture and so Kumho river was a main pollutant: source of Nakdong river. COD values of main stream of Nakdong river was over the permit standard of agriculture(8mg/l) as $5.2{\sim}13.5mg/l$ in Koryvng, $5.0{\sim}12.7mg/l$ in Jukpo and $5.0{\sim}12.2mg/l$ in Namji according to time or season. And COD values was much high rather than BOD values and its gap of concentration was increased along with downstream. $NH_4-N$ of main stream of Nakdong river followed mixing of Kumho river($0.5{\sim}13.1mg/l$) was the highest affected in Koryung($0.18{\sim}5.0mg/l$) and detected much more in winter than in summer. T-N in Koryung($4.96{\sim}12.06mg/l$) followed mixing of Kumho river was significantly high rather than $2.86{\sim}4.86mg/l$ in Dasa, $4.20{\sim}8.20mg/l$ in Jukpo and $3.18{\sim}8.64mg/l$ in Namji, which was almost over the permit standard of agricultural water(1.0mg/l). T-P in Koryung($0.10{\sim}0.58mg/l$) also was significantly high rather than those $0.07{\sim}0.36mg/l$ in Jukpo and $0.08{\sim}0.4mg/l$ in Namji as over the standard of agricultural water(0.1mg/l). The concentration of T-N or T-P in Nakdong districts was trended of increasing in every year.

• Journal of Acupuncture Research
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• v.17 no.1
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• pp.55-66
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• 2000

The following results have been obtaind after examing 72patients with facial paralysis who were hospitalzed and treated through the time period of December 1st, 1996 to November 30th, 1999 at the Department of Acupuncture and Moxibustion of Seoul Oriental Medicine, Kyungwon University. During the examination, those 72 patients were divided into two groups, and One group was treated by oriental-western treatment, the other group was treated by oriental treatment. Oriental treatments were acupuncture and moxibustion, herb medicine, physical treatment and hygienic treatment. The one of main western treatments is steroid therapy. The results were obtained as follows : 1. In regard to signs at the first medical examination, lacrimation was showed highest number and facial paralysis, dysgeusia, hyperacusis were showed in numerical order. 2. In regard to prescription of oriental herb medicine, Kamissangbotang(加味雙補湯) was prescribed in greatest numbers and Boyangwhanotang(補陽還五湯), Kamiboiktang(加味補益湯), Ligigepungtang(理氣祛風湯) were prescribed in numerical order. 3. In regard to treatment number, 10~19 times for treatment was showed highest number and 1~9 times, 20~29 times, 40~49 times were showed in numerical order . 4. In regard to mean treatment times about injury region and main sign, the effect of oriental-western treatment was showed as follows: lacrimal gland disorder, hyperacusis, dysgeusia, facial paralysis were treated for 15.1, 27, 13.2 and 21.4 times, repectively. The effect of oriental treatment was showed as follows: lacrimal gland disorder, hyperacusis, dysgeusia, facial paralysis were treated for 34.8, 22.1, 33.8 and 16.3 times, respectively. 5. In regard ta the effect of treatment about injury region and main sign, oriental-western treatment was showed as follows: cases of lacrimal gland disorder were showed 1 of excellent case, 1 of fair case, 5 of good cases. In hyperacusis patients, there was showed 1 of fair case. In dysgeusia patients, there was showed 1 of excellent case, 3 of fair cases, 1 of good case. In facial paralysis, there were showed 5 of fair cases. Oriental treatment was showed as follows: In lacrimal gland disorder, the excellent were 4 cases, the fair were 10 cases, the good were 3 cases and the poor were 4 cases, In hyperacusis, the fair were 5 cases, the poor 2 cases. In dysgeusia, the excellent were 4 cases, the fair were 1 case, the good were 1 case and the poor was 1 case, In facial paralysis, the excellent were 9 cases, the fair were 4 cases, the good 3 cases and the poor were 3 cases. 6. The effect of total treatment was as follows: 30 cases were showed fair effect, 19 cases were showed excellent effect, 13 cases were showed good effect and 10 cases were showed poor effect. 7. In regard to attack factor, overlabour was showed highest number and wind-cold, mental stress, trauma, ear disease, common cold, dental diseae, reason unknwon were showed in numerical order. 8. In regard to premonitory symptoms, non significant symptoms were in 38 cases, the pain of peri-stylomastoid region were in 38 cases and headache, dysaesthesia of periorbit, dysgeusia, stomatitis, eyelid tic were showed in numerical order. 9. In regard to sex, male were 33 cases and female were 39 cases. The distribution of age was disclosed that thirty, forty, fifty, seventy, sixty, twenty and below twenty years were revealed in turn. Sex and paralytic side were showed as follows: male-left were 15 cases, male-right were 18 cases, female-left were 19 cases and female-right were 19 cases. In regard to attack frequence in month, March was showed highest number and January, April, May, August, October, etc were showed in numerical order. In regard to attack frequence in season, spring was showed highest number and winter, summer, fall were showed in numerical order, but attack frequence between four seasons wasn't showed significant difference.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.77-91
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• 2008

In this study, we developed a technique of applying DRASTIC, which is the most widely used tool for estimation of groundwater vulnerability to the aqueous phase contaminant infiltrated from the surface, and a groundwater flow model jointly to assess groundwater contamination potential. The developed technique is then applied to Buyeo-eup area in Buyeo-gun, Chungcheongnam-do, Korea. The input thematic data of a depth to water required in DRASTIC model is known to be the most sensitive to the output while only a few observations at a few time schedules are generally available. To overcome this practical shortcoming, both steady-state and transient groundwater level distributions are simulated using a finite difference numerical model, MODFLOW. In the application for the assessment of groundwater vulnerability, it is found that the vulnerability results from the numerical simulation of a groundwater level is much more practical compared to cokriging methods. Those advantages are, first, the results from the simulation enable a practitioner to see the temporally comprehensive vulnerabilities. The second merit of the technique is that the method considers wide variety of engaging data such as field-observed hydrogeologic parameters as well as geographic relief. The depth to water generated through geostatistical methods in the conventional method is unable to incorporate temporally variable data, that is, the seasonal variation of a recharge rate. As a result, we found that the vulnerability out of both the geostatistical method and the steady-state groundwater flow simulation are in similar patterns. By applying the transient simulation results to DRASTIC model, we also found that the vulnerability shows sharp seasonal variation due to the change of groundwater recharge. The change of the vulnerability is found to be most peculiar during summer with the highest recharge rate and winter with the lowest. Our research indicates that numerical modeling can be a useful tool for temporal as well as spatial interpolation of the depth to water when the number of the observed data is inadequate for the vulnerability assessments through the conventional techniques.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.4
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• pp.65-77
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• 2012

This study examined changes in land cover for the past 25 years in Busan and subsequently evaluated heat island potential by using land surface temperature and observation temperature data. The results were as below. The urban area of Busan increased by more than 2.5 times for the past 25 years from 1975 to 2000. It was believed that an increase in the pavement area of city within such a short period of time was an unprecedented phenomenon unique to our country. It could be assumed that urban heat island would be worsened through this process. After analyzing the land temperature according to the land cover, it was shown that there were noticeable changes in the temperature of urban & built-up and mountain & forest areas. In particular, the temperature rose to $36{\sim}39^{\circ}C$ in industrial areas during the summer, whereas it went down to $22{\sim}24^{\circ}C$ in the urban areas at whose center there were mountains. It was found that heat island potential according to the level of land cover had various values depending on the conditions of land cover. Among the areas of urbanization, the industrial area's heat island potential is 6 to $8^{\circ}C$, and the residential and commercial area's is $0{\sim}5^{\circ}C$, so it has been found that there is high possibility to induce urban heat islands. Meanwhile, in the forest or agricultural area or the waterside, the heat island potential is $-6{\sim}-3^{\circ}C$. With this study result, it is possible to evaluate the effects of temperature increase according to the urban land use, and it can be used as foundational data to improve urban thermal environment and plan eco-friendly urban development.

• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.216-237
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• 2017

Thermal effluent of the hot spring has long been a field of interest in the relationship between temperature gradient and freshwater algae in geology, limnology and aquatic ecology throughout the world. On the other hand, many artificial hot springs have been developed in Korea, but the research on them has not been still active. This study was performed every month from December 2015 to September 2016, to elucidate the spatiotemporal effects of thermal wastewater effluent (TWE) on the ecosystem of benthic algal assemblage in four stations(BSU (upstream), HSW (hot spring wastewater outlet), BSD1~2 (downstream)) of the upstream reach of the Buso Stream, a tributary located in the Hantan River basin. During the survey, the influencing distance of temperature on TWE was <1.0 km, and it was the main source of N P nutrients at the same time. The effects of TWE were dominant at low temperature and dry season (December~March), but it was weak at high temperature and wet season (July~September), reflecting some seasonal characteristics. Under these circumstances, the attached algal communities were identified to 59 genera and 143 species. Of these, the major phylum included 21 genera 83 species of diatoms(58.0%), 9 genera 21 species of blue-green algae (14.7%) and 25 genera 32 species of green algae (22.4%), respectively. The spatiotemporal distribution of them was closely related to water temperature ($5^{\circ}C$ and $15^{\circ}C$) and current ($0.2m\;s^{-1}$ and $0.8m\;s^{-1}$). In the basic environment maintaining a high water temperature throughout the year round, the flora favoring high affinity to $PO_4$ in the water body or preferring stream habitat of abundant $NO_3-PO_4$ was dominant. As a result, when compared with the outcomes of previous algal ecology studies conducted in Korea, the Buso Stream was evaluated as a serious polluted state due to persistent excess nutrient supply and high thermal pollution throughout the year round by TWE. It can be regarded as a dynamic ecosystem in which homogeneity (Summer~Autumn) and heterogeneity (Winter~Spring) are repeated between upstream and downstream.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.63-75
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• 2016

For safe water supply, residual chlorine has to be maintained in tap-water above a certain level from drinking water treatment plants to the final tap-water end-point. However, according to the current literature, approximately 30-60% of residual chlorine is being lost during the whole water supply pathways. The losses of residual chlorine may have been attributed to the current tendency for water supply managers to reduce chlorine dosage in drinking water treatment plants, aqueous phase decomposition of residual chlorine in supply pipes, accelerated chlorine decomposition at a high temperature during summer, leakage or losses of residual chlorine from old water supply pipes, and disappearances of residual chlorine in water storage tanks. Because of these, it is difficult to rule out the possibility that residual chlorine concentrations become lower than a regulatory level. In addition, it is concerned that the regulatory satisfaction of residual chlorine in water storage tanks can not always be guaranteed by using the current design method in which only storage capacity and/or hydraulic retention time are simply used as design factors, without considering other physico-chemical processes involved in chlorine disappearances in water storage tank. To circumvent the limitations of the current design method, mathematical models for aqueous chlorine decomposition, sorption of chlorine into wall surface, and mass-transfer into air-phase via evaporation were selected from literature, and residual chlorine reduction behavior in water storage tanks was numerically simulated. The model simulation revealed that the major factors influencing residual chlorine disappearances in water storage tanks are the water quality (organic pollutant concentration) of tap-water entering into a storage tank, the hydraulic dispersion developed by inflow of tap-water into a water storage tank, and sorption capacity onto the wall of a water storage tank. The findings from his work provide useful information in developing novel design and technology for minimizing residual chlorine disappearances in water storage tanks.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.1
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• pp.1-10
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• 1999

To find out the way to be able to prolong the grazing years of mixed pasture under Cheju summer-hot weather, an experiment designed with split plot (main plot : 3 cutting-plant height such as 15cm, 30cm and 45cm and sub plot : 4 white clover varieties such as Regal, Tahora, Brown and SRVR) was carried out at Cheju Agricultural Experiment Station during the period from Sept. 1994 to Oct. 1996 Dry matter yield in 15cm plant height in cutting dates has shown significantly lower increase than those in 30 and 45cm(P<0.05). There was highiy significant increase in dry matter yield of Brown plot when compared with other varieties of white clover in 2nd year(P<0.01). There was no difference on botanical composition of mixed sward as affected by plant height in cuttings dates in 2nd year. The percentage of white clover tends to lower in white clover varieties Brown and SRVR when compared with Regal and Tahora. The rate of weed was not affected by plant height in cutting dates and white clover variety in mixed pasture at last cutting time of 2nd year. In 15cm plant height, concentration of ADE and NDF was the lowest one while P contents was the highest one(P<0.01). Potassium contents was the lowest one in 30cm plant cutting height(P<0.05), and nitrogen showed statistically interaction between plant cutting height and white clover variety(P<0.01). White clover variety was no effective on concentration of constituents in mixed pastures. In conclusion, white clover variety SRVR harvested at 15cm plant height is effective on nutrient value of pasture and balance of grass and white clover in botanical composition.

• Journal of Animal Environmental Science
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• v.10 no.3
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• pp.141-154
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• 2004

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which the electrical power is not available. The average so]ar radiation energy is 3.488 kWh/($m^2{\cdot}day$) in Korea. In this study, the automatic control logic and system of the water pump driven by the radiation energy were studied, designed, assembled, tested and analyzed for realizing the solar powered water pump. The experimental system was operated automatically and the cycle was continued. The average quantity of the water pumped per cycle was about 5,320 cc. The cycle time was about 4.9 minutes. The thermal efficiency of the system was about $0.030\%$. The pressure level of the n-pentane vapour in flash tank was 150$\%$450 hPa(gauge) which was set by the computer program for the control of the vapour supply. The pressure in the condenser and air tank during cycles was maintained as about 600 hPa and 1,200 hPa respectively. The water could be pumped by the amount of 128kg/($m^2{\cdot}day$) with the efficiency of $0.1\%$ and the pumping head of 10 m for the average solar energy in Korea.