• Korean Journal of Remote Sensing
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• v.32 no.3
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• pp.221-234
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• 2016

In Korea, most industrial parks and major cities are located in coastal areas, which results in serious environmental problems in both coastal land and ocean. In order to effectively manage such problems especially in coastal ocean, water quality should be monitored. As there are many factors that influence water quality, the Korean Government proposed an integrated Water Quality Index (WQI) based on in situmeasurements of ocean parameters(bottom dissolved oxygen, chlorophyll-a concentration, secchi disk depth, dissolved inorganic nitrogen, and dissolved inorganic phosphorus) by ocean division identified based on their ecological characteristics. Field-measured WQI, however, does not provide spatial continuity over vast areas. Satellite remote sensing can be an alternative for identifying WQI for surface water. In this study, two schemes were examined to estimate coastal WQI around Korea peninsula using in situ measurements data and Geostationary Ocean Color Imager (GOCI) satellite imagery from 2011 to 2013 based on machine learning approaches. Scheme 1 calculates WQI using estimated water quality-related factors using GOCI reflectance data, and scheme 2 estimates WQI using GOCI band reflectance data and basic products(chlorophyll-a, suspended sediment, colored dissolved organic matter). Three machine learning approaches including Random Forest (RF), Support Vector Regression (SVR), and a modified regression tree(Cubist) were used. Results show that estimation of secchi disk depth produced the highest accuracy among the ocean parameters, and RF performed best regardless of water quality-related factors. However, the accuracy of WQI from scheme 1 was lower than that from scheme 2 due to the estimation errors inherent from water quality-related factors and the uncertainty of bottom dissolved oxygen. In overall, scheme 2 appears more appropriate for estimating WQI for surface water in coastal areas and chlorophyll-a concentration was identified the most contributing factor to the estimation of WQI.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3943-3955
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• 1975

The purposes of this study are to evaluate the utilization characteristics of electrical power consumption, to grasp the present trends in the use of electrical equipments, to estimate the demand factor and load factor being held, and to evaluate the efficiency of electical uses for the recently electrified farms cultivating paddy rice. For the purposes, 109 sample farms located in eleven villiages electrified in six different years from 1968 to 1973, were chosen at random and investigated on 35 items concerning to electrical uses and wiring systems. The survey was carried out in 1975, in the vinicity of Suweon city. The results are summarized as follows: i) The average annual power consumption on sample farms is considered to be low, being 242.9 Kwh. in 1974, and varied according to the different electrified year and size of cultivated land, respectively. It has significant positive correlation to the area of farm, too. ii) Between the number of year of electrical uses and the power consumption, there is very significant positive correlation, which could be expressed as Y=43.041+16.108 X, where X represents the number of years of electrical uses. The annual increment of power consumption is much greater at the beginning of the electrification than that at the later years, its average being approximately 20 percent. However, it is recommended that any estimation of long-term increments should be carefully investigated. iii) The monthly power consumption varies considerably throughout a year, in which the heaviest farm load occurs in November. Observing the seasonal variation of consumption, the winter-time is the heaviest season while the summer is the lowest. The result implies house lighting is chief contribution to the present electrical consumption on the farms. Comparing the variation of monthly consumption ratios between the sample farms and industries, the electrical uses on the farms are independant of the industrial uses, and further, the agricultural uses are of inverse pattern to the farms from the results that there is negative correlationship between them, iv) The number of electrical equipments used on the farms are occupied chiefly by lighting sources. Next to the lighting sources, household appliances of small quantity and some motors are used. The mean electrical quantity is about 1, 127.4 watt, which corresponds to about 37.6 per cent to the contracted quantity. The composition of quantity is chiefly occupied by the electrical motor of about 1.5 hp., single-phased. The number of the annual utilization hours of each equipment is tabulated in Table IV-5. In contradiction to the high utilization of lighting sources and small household appliances, the motor is poorly used for approximately 22 hours in a year. v) More than 55 per cent of farms want to purchase new electrical equipments such as small household appliances and electrical motors in their number. The impulse of purchasing such items is stimulated by the contacts to the mass media and their knowledge on such equipments. Consequently, the increase of electrical uses could be prompted by such trials as education and demonstration. vi) The demand and load factors on the farms vary considerably according to the greater variation of the power consumption, daily or monthly. The daily demand factor is 22.4 per cent and load factor 18.6 per cent, while the annual demand factor is 1.3 per cent and load factor 70 per cent approximately. Therefore, the low efficiency of construction cost requires re-evaluation of the present contracted quantity of 3 Kw. or increase of electrical uses. vii) The electrical energy on the farms devoted chiefly to lighten the farm residences does not contribute to the farm incomes. Consequently, the cost of electrical consumption presses considerably upon the farm economy. Therefore, there is great need to build up the electrical uses on the farms through the development of new works and techinques to utilize any electrical equipments on the production of farm products. Further more, such the development should be related to increase the actual income of the farm consumers.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.37-45
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• 2006

Recently, wood-framed houses has been built in the Korea for pension. Wood is good material for human healthy, while the construction lumbers are treated with preservative such as CCA (chromated copper arsenate), which contain some toxic elements for human body. However, if the waste woody biomass treated with various heavy metals, which has been collected from house construction or demolition, was fired in the field, and incinerated or landfilled after mass collection, such components will result in the toxic air pollutants in the burning or land fills, and spreaded into other areas. So the careful selection of wood and chemicals are required in advance for house construction, in particular, for environment-friendly housings. Therefore, this study was carried out to determine the content of toxic heavy metals in woody materials such as domestic hinoki and imported hemlock treated with CCA for housing materials, and the post-treated wood components such as organic fertilizer, sludge, dry-distilled charcoal and carbonized charcoal, to be returned finally into soil. The results are as follows. 1) The chemical analysis of toxic trace elements in various solid biomass required accurate control and management of laboratory environment, and reagents and water used, because of the error of data due to various foreign substances added in various processing and transporting steps. So a systematic analyzers was necessary to monitor the toxic pollutants of construction materials. 2) In particular, the biomass treated with industrial biological or thermal conditions such as sludge or charcoals was not fully dissolvable after third addition of $HNO_3$ and HF. 3) The natural woody materials such as organic fertilizer, sludge. and charcoals without any treatment of preservatives or heavy metal components were nontoxic in landfill because of the standard of organic fertilizers, even after thermal or biological treatments. 4) The CC A-treated wood for making the construction wood durable should not be landfilled, because of its higher contents of toxic metals than the criterion of organic fertilizer for agriculture or of natural environment. So the demolished waste should be treated separately from municipal wastes.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1125-1147
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• 2014

This study was conducted to develop the health evaluation indicator of pond wetland in order to enhance the quality of eco-experience in rural area. The methods for development of evaluation indicator were consisted of 3 stages; 1st, the precedent assessment protocol was applied to 10 pond wetlands in farm villages, and eco-experience expert survey was conducted to selection the evaluation item and criteria at 2nd and 3rd stages. In the results of applying the precedent assessment protocol, we found out two problems; 1) the evaluation result of value determination and conservation value were too simple, and 2) the score by evaluation items were nearly the same, because evaluation criteria in not precisely for application in rural area. These results were reflected to expert survey. According to the 1st survey results, they suggested that 4 items should be maintained, and 3 items should be deleted, and 2 items should be modified among a total of 9 times. Therefore, it was modified into the evaluation protocol having a total of 8 items. According to the 2nd survey results, the selected evaluation items were generally proper. With regard to items for assessing the health condition of pond wetland, we selected a total of 8 items; (1) Connectivity to forest, (2) Connectivity between water body and wetland connection, (3) Number of Vegetation, (4) Surround land use, (5) Interspersion of Vegetation, (6) Crossing Structure, (7) Wetland size, and (8) Outlet structure. In addition, it was suggested that accessibility, visibility, and trash were need for utilization of pond wetland as a place for eco-experience. It is expected that the selected evaluation indicator can help to utilize the pond wetland as an eco-experience space in rural area, and maintain the pond wetland as a space for conservation of biodiversity.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.333-340
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• 2015

Because soils in reclaimed lands nearby coastal areas have much higher salinity and moisture content than soils in inland area, parts of greenhouses embedded in such soils are exposed to highly corrosive environments. Owing to the accelerated corrosion of galvanized steel pipes for substrucrture and structure of greenhouses in saline environments, repair and reinforcement technologies and efficient maintenance and management for the construction materials in such facilities are required. In this study, we measured the corrosion rates of the parts used for greenhouse construction that are exposed to the saline environment to obtain a basic database for the establishment of maintenance and reinforcement standards for greenhouse construction in reclaimed lands with soils with high salinity. All the test pipes were exposed to soil and water environments with 0, 0.1, 0.3, and 0.5% salinity during the observation period of 480 days. At the end of the observation period, salinity-dependent differences of corrosion rate between black-surface corrosion and relatively regular corrosion were clearly manifested in a visual assessment. For the soils in rice paddies, the corrosion growth rate increased with salinity (0.008, 0.027, 0.036, and $0.043mm{\cdot}yr^{-1}$ at 0, 0.1, 0.3, and 0.5% salinity, respectively). The results for the soils in agricultural fields are 0.0002, 0.039, 0.040, and $0.039mm{\cdot}yr^{-1}$ at 0, 0.1, 0.3, and 0.5% salinity, respectively. The higher corrosion rate of rice-paddy soil was associated with the relatively high proportion of fine particles in it, reflecting the general tendency of soils with evenly distributed fine particles. Hence, it was concluded that thorough measures should be taken to counteract pipe corrosion, given that besides high salinity, the soils in reclaimed lands are expected to have a higher proportion of fine particles than those in inland rice paddies and agricultural fields.

• Journal of the Korean GEO-environmental Society
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• v.15 no.4
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• pp.5-11
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• 2014

Recently, there have been various lifeline installations constructed in the underground space of urban area due to the effective use of land. For newly installed lifelines or the management of the installed lifelines, many construction activities of excavation and backfilling are observed. Around these area, there are possibilities of collapse or excessive settlement due to the leaking of the pipe or unsatisfactory compaction of backfill material. Besides, construction costs can be saved since the on-site soils are used. The application of this liquidity filling material is not only to the lifeline installation but also to underpin the foundation under the vibrating machinery. On the evaluation of the applicability of this method to this circumstance, the strength should be investigated against the static load from the machine load as well as the vibration load from the activation of the machine. In this study, the applicability of the liquidity fill material on the foundation under the vibrating machinery is assessed via uniaxial compression and resonant column tests. The liquidity filling material consisting of the on-site soils with loess and kaolinite are tested to investigate the static and dynamic characteristics. Furthermore, the applicability of the reclaimed ash categorized as an industrial waste is evaluated for the recycle of the waste to the construction materials. The experimental results show that the shear modulus and 7 day uniaxial strength of the liquidity filling material mixed with reclaimed ash show higher than those with the on-site soils. However, the damping ratio does not show any tendency on the mixed materials.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.5
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• pp.103-115
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• 2016

This study aims to analyze the properties of cold air production and its flow of Nakdong-Jeongmaek(mountain ranges), and to suggest management strategies for Nakdong-Jeongmaek in order to enhance the green air conditioning functions of Jeongmaek. For this purpose, three study sites including Gudeoksan Mountain and the vicinity in Busan, Goheonsan Mountain and the vicinity in Ulsan, and Unjusan Mountain and the vicinity in Pohang were selected. The results found that cold air flow and its height of the three study sites were analyzed based on topographic properties and land use. Management strategies for preserving and enhancing their temperature reduction functions were suggested. The cold air produced in the vicinity of Gudeoksan was not fully developed and spread because of the high-density development at the border of Jeongmaek. Since high pressures of development are expected at the border, high conservation policies are required. In the vicinity of Goheonsan, where the agricultural complex and industrial park are located, cold air flows well throughout the entire study site thanks to fully developed cold air in the wide, flat valley. Hence, plans to maintain the current cold air flow are required, and conservation plans to mitigate future developments are also needed in the flat valley. The cold air in Unjusan and the vicinity with its complex and narrow mountain valleys gradually develops into valley bottoms. In order to take advantage of the terrain, the valley near the cold air production areas are preserved. In particular, special plans are required to prevent damage to the cold air layer near Youngcheonho Lake, where the highest height of cold air was recorded due to the closed and lower terrain feature. This study could support the establishment of systematic management plans of Nakdong-Jeongmaek to preserve and enhance its green air conditioning functions.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.593-612
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• 1996

This study concern with the changes of street from the Choseon Dynasty to present days around Old-Boundary in Taegu, analyzing the backgrounds of change factors and development trends of the Taegu City. The basis element of a city structure is the street. Therefore, in this study, a chage of street space of a city was investigted. Historically, Taegu was a walled city and had a Mono-nucleus which was restricted by the castle, and served as a starting point of formation of spatial structuure. The form of the artery street took a "T" pattern, othe streets were formed in irregular shapes. As the city grew gradually, the castle was removed on account of diversification in traffic network, change of socio-economic organization in traffic network, change of socio-economic organization, formation of industrial bases and functional distribution. CBD of this city has been located within the area surrounded by these streets. This is a kind of general pattern of traditional walled cities through the world in both Western and Oriental societies. A s the begining of this centry, a 'Dark Ages' descended upon Korea because the country was under the Japanese-Korean Annexation, and, throughout this period, the urban planning was planned exclusively for Japanese. The street pattern within residential areas of Korea took the maze type, in contrast with Japanese residential areas which showed grid pattern of streets. This is another general pattern of almost of all colonial cities especially in Asia. High class residential areas were planned and built by Japanese, and they were located within 5-10 minutes' on-foot distance from the CBD hard core. This high prestige has continued until the 1980s when it occurred land use succession which commerical functions invaded into residential areas. Back in the colonial period, there was a between two hetrogeneous groups due to the fact that the Japanese lived mainly oriented the new railway system but that Koreans still lived along the old highway system which ran through the Korea Peninsula. Street netwook formed in the above process has maintained its shape without great changes after the liberation form the Japanese Colony. Taegu has, accordingly, developed ring-radial network system which has been a combination of radial and ring facilities. The present conditions of street patterns in Taegy mainly depend on 4 rings and 8 radius, with grid pattern street able to be found in Old Boundary.

• Journal of the Korean Geographical Society
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• v.43 no.4
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• pp.449-465
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• 2008

Coastal lagoon has experienced a natural geomorphic development process which has been aggraded after the climax of transgression in Holocene. This study estimates superiority on landscape conservation of lagoons and degree of landscape changes during the 20th century as conservation ratios of area and shore length, and analyzes the causes of the changes and classifies the lagoons based on the data by case study of the major 7 coastal lagoons(Hwajinpo, Songjiho, Gwangpoho, Yeongrangho, Maeho, Hyangho, and Gyeongpoho) in the middle East Coast of the Korean Peninsular. Based on the conservation ratios of area and shore length, the areal change is in order of Songjiho($0.56km^2$, 92%), Hwajinpo($2.06km^2$, 90%), Yeongrangho($0.96km^2$, 86%), Hyangho($0.32km^2$, 76%), Gyeongpoho($0.90km^2$, 52%), Maeho($0.14km^2$, 50%), and Gwangpoho($0.07km^2$, 32%), and the shore length change is in order of Hwajinpo(11.90km, 100%), Hyangho(3.34km, 90%), Yeongnangho(7.21km, 89%), Gyeongpoho(7.11km, 79%), Songjiho(5.56km, 79%), Gwangpoho(1.16km, 62%), and Maeho(2.16km, 58%). Therefore, the characteristics of landscape changes of the lagoons in the study area can be represented in order of Hwajinpo(Al), Hyangho(A2), Yeongrangho(A3), Songjiho(A4), Gyeongpoho(B4), Gwangpoho(B5), Maeho(B6). Serious process for land use and industrial development has changed landscape around lagoons decreasing the area of coastal plains dramatically up to this century. Because small lagoons such as Maeho and Gwangpoho have experienced severe transformation and destruction, and Gyeongpoho was transformed into artificial lake for urbanization and tourism, they show dramatic landscape change.

• 한국해양학회지
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• v.18 no.1
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• pp.29-42
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• 1983

This stidy was intended to investigate the heavy metal contents in the bottom sediments of the continental shelt around the Jeju Island and ot the southern coastal area of the Korean Peninsula. For this study 39 bottom sedinent samples were taken from the study area using Phleger gramity corer and Snapper. The average contents of heavy metals were 59.1 ppm Zn, 362.6 ppm Mn, 63.8 ppm Cr, 15.7 ppm Pb, 10.0 ppm Co, 28.9 ppm Ni, 10.5 ppm Cu, and 2.7% Fe in the surficial sediments around the Jejr Island; and 79.ppm Zn, 384 ppm Mn, 8.6 ppm Pb, 17.8 ppm Ni, 23.2 ppm Cu, and 1.59 % fe in those of nearsgore of the southern coastal area respectively. The heavy metal contents were higher in the northwestern part around the Jeju Island compared to those in other region. However, these tendencies were not the result of pollution, but of the differences of grain size of the sedimenrs. In the nearshore of the southern coast, the heavy metal contents did not show any geographical tendency. However, those of Masan and Jinhae Bays wew higher than those of the other region. These seemed to be caused by waste disposal from the industrial compsex located at the adjacent land. Nevertheless these values of heavy metal content except for Zn and Cu in Masan Bay and inner bay of Jinhae are lower than the average values of the each world-wide data of the nearshore sedimentl. The pair correlations of the cach heavy metal elements were calculated by regressino analysis using VAX 780 computer. the following pair elements, such as Zn-Cu, Ni-Cu, Fe-cu, Cr-Cu, Co-Zn, Ni-Zn, Cr-Zn, Ni-Co, Fe-Co, Cr-Co, Fe-Ni, Cr-Ni and Cr-Fe show closely posetive linear correlations in the sediments around the Jeju Island. In general, the heavy metal content increases in proportion to the increase of the mean values of the grain size of the sediments around the Jeju Island. In the southern coastal area, in gineral, thepair correlations of each heavy metal elements did not southern coastal area, in general, the pair correlatttttions of rach heavy metal elements did not show any positive correlation except for the positive linear correlations of Cu-Zn, Cu-ni and Ni-Mn. It is interpreted as a result of the differences of the physecochemical environment of the sampling sites and also of the influences of the ondustrial wastes from the manufacturing factores located at the coastal zone of the study area.