• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.79-89
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• 2004

Remote sensing technique is a probable means to estimate distribution of actual evapotranspiration in connection with regional characteristics of vegetation and landuse. The factors controlling evapotranspiration from ground surface are air temperature, humidity, wind, radiation, soil moisture and so on. Not only the vegetation influences directly the evapotranspiration, but also these factors strongly influences the vegetation growth at the area. Therefore, it can be expected that evapotranspiration is highly correlated to vegetation condition. The normalized difference vegetation index (NDVI) showed excellent ability to get the vegetation information. The NDVI is obtained using NOAA/AVHRR have been studied as a tool for vegetation monitoring. In this paper, a simple method to estimate actual avapotranspiration is proposed based on vegetation and meteorological data.

• Journal of Soil and Groundwater Environment
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• v.12 no.6
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• pp.78-91
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• 2007

The groundwater chemistry is heavily influenced by land use. This study has investigated the groundwater quality and contamination characteristic associated with land use. Contamination index ($C_d$) was estimated for evaluating and areal distribution of groundwater contamination degree. Groundwater samples collected from 216 locations in the study area show great variability in chemical composition. Electrical conductance ranges from 100 to $31,360\;{\mu}S/cm$. The pH values are between 4.6 (acidic) and 8.57 (weak alkaline). The water types predominantly represent the $Ca-HCO_3$ and $Ca-Na-HCO_3$ types, whereas, in the residential and business areas, the water type is shifted to (Na, Ca)-Cl type with rich concentration of Cl. The $C_d$ values of the study area range from 1.1 to 117.6 with a mean of 9.56.

• Water for future
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• v.10 no.1
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• pp.53-70
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• 1977

The analysis performed here is aimed to increase the familiarity of hydrologic process especially for the small basins which are densely gaged. Kyung An and Mu Shim river basins are selected as a representative basin according to the criteria which UNESCO has established back in 1964 and being operated under the auspice of Ministry of Construction. The data exerted from these basins is utilized for the determination of characteristics of procipitation and runoff phenomena for the small basin, which is considered as a typical Korean samall watershed. The study found that the areal distribution of preciptation did not show any significant deviation from the point rainfall. Since the area studied is less than 20 km#, the pointrainfall may be safely utilized as a representative value for the area. Also the effect of elevation on the precipitation has a minor significance in the small area where the elevation difference is less than 200m. The methodology developed by Soil Conservation Service for determination of runoff value from precipitation is applied to find the suitability of the method to Korean river basin. The soil cover complex number or runoff curve number was determined by comsidering the type of soil, soil cover, land use and other factors such as antecedent moisture content. The average values of CN for Kyung An and Mushim river basins were found to be 63.9 and 63.1 respectively under AMC II, however, values obtained from soil cover complex were less than those from total precipitation and effective precipitation about 10-30%. It may be worth to note that an attention has to be paid in application of SCS method to Korean river basin by adjusting 10-30% increase to the value obtained from soil cover complex. Finally, the design flood hydrograph was consturcted by employing unit hydrograph technique to the dimensionless mass curve. Also a stepwise multiple regression was performed to find the relationship between runoff and API, evapotranspiration rate, 5 days antecedentprecipitation and daily temperature.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.39-45
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• 2010

Quantification of carbon absorption and understanding the human induced land use changes (LUC) forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by LUC through remote sensing technology. The Landsat imagery four time periods was classified with the hybrid classification method in order to quantify carbon absorption by LUC. Thereafter, for estimating the amount of carbon absorption, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated with the crown width extracted from digital forest cover type map. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the IPCC guideline, was used to convert the stand biomass into the amount of carbon absorption. Total carbon absorption has been modeled by taking areal estimates of LUC of four time periods and carbon factors for land use type and standing biomass. Results of this study, through LUC suggests that over a period of construction, 7.10 % of forest and 9.43 % of barren were converted into urban. In the conversion process, there has been a loss of 6.66 t/ha/y (7.94 %) of carbon absorption from the study area.

• Water for future
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• v.29 no.2
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• pp.179-190
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• 1996

The characteristics of water quality in the downstream of the Han River were analyzed by statistical techniques. Basic characteristics, areal and temporal variations, and correlations of water quality data were investigated. Monthly water quality data have been investigated systematically by exploring data analysis, including time series plot, summary statistics, distribution test, time dependence test, seasonality test and flow relatedness test. Results show that water quality data in this river have seasonality. And applicability of stochastic models such as Thomas-Fiering model and ARMA(1,1) model was identified. From the examination of water quality data related to discharge, it was found that DO and SS are sensitive to water temperature rather than discharge, while BOD and COD are sensitive to discharge at dry seasons. Seasonal periodicities were identified in all water quality variables from the cross correlation analysis.

• Economic and Environmental Geology
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• v.35 no.5
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• pp.479-490
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• 2002

The aim of this study is to evaluate the contributions of each hydrogeological factors to groundwater recharge ratios in order to determine areal estimates of recharges in entire inland area of South Korea. For this purpose, various statistical analyses and overlay techniques of GIS were conducted fur entire area and 4 river basins of South Korea. As a result, the spatial distribution of recharge, South Korea were visualized.

• Journal of Korea Water Resources Association
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• v.47 no.5
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• pp.469-482
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• 2014

This study developed a Bayesian spatial regional frequency analysis, which aimed to analyze spatial patterns of design rainfall by incorporating geographical information (e.g. latitude, longitude and altitude) and climate characteristics (e.g. annual maximum series) within a Bayesian framework. There are disadvantages to considering geographical characteristics and to increasing uncertainties associated with areal rainfall estimation on the existing regional frequency analysis. In this sense, this study estimated the parameters of Gumbel distribution which is a function of geographical and climate characteristics, and the estimated parameters were spatially interpolated to derive design rainfall over the entire Han-river watershed. The proposed Bayesian spatial regional frequency analysis model showed similar results compared to L-moment based regional frequency analysis, and even better performance in terms of quantifying uncertainty of design rainfall and considering geographical information as a predictor.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.67-94
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• 1995

A total of 394 plant species in 74 families planted in home gardens, public building gardens, campuses of elementaiy, middle, and high schools, and universities, recreation areas, city parks, loeal and national ways, and highways from 1.21 local areal in Korea were surveyed- A comparison of the surveyed species to nation-widei.y growing species in those areas were studied. the results obtained were as follows : 1. The ratio of evergreen to deciduous plant species was 38.1:61,9 and that of tree:scrub:vine was 54:40.9:5.1. 2. The ratio of evergreen to deciduous plant species was 27.5:72.5 among total 276 land-scape plant species surveyed in Seoul and Kyongki-do province. The ratios were 32:68 in Kwangwon-do, 36.1:63.9 ill Chungchongbuk-do, 37:61 iii Chungchongnanl-do, 36.4:63.6 in Kyungsangbuk-do, 39.2:60.8 고 Kyungsangaaal-do, 35.7:64.5 in Jollabuk-do, 40.6:59.4 in Jollanam-do, and 43.1 :56.9 in Cheju-do. This results tell that more evergreen species are growing in the southern than in northern region in Korea. 3. Plants with 100% frequency in national planting were 8 species inclubing Forsythia koreana 91-99% were 6 species including Taxus cuspidata, 81-90% were 13 species including Magnolia liilflora, 71-80% were 10 speces including Buxus microphylla val, koreana, 61-70% were 13 species including Thuja occiduntakus, 51-60% were 15 species including Pius thunbergii, 41-50% were 15 species including Kerria japonica, 31-40% were 17 species including Cryptomeria japonica, 21-30% were 28 species including Viturnum awabuki, and below 20% were 267 species including Koelreuteria paniculata. 4 Uppermost north latitude of planting distribution of major temperature species was sum- marized as follows: Although it has been reported that Cryptomeria japonica is possible to grow in areas around -47, the result from this study shows that Cryptomeria japonica grows normally in Choonchun Seoul, Samchuck, and Kwangryeung, etc. , and is possible to grow normally in the areas with approximately -6$^{\circ}C$ in an average temperature in January, where are -2$^{\circ}C$ colder than the reported temperature, but locally warm Phyllostachys bambusoides is distributed to Mt. Kumkang and Mt. Sulak, and also planted in Seoul, Kwangryeung, and Chunchon.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.123-139
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• 1995

The megalopolis citizens are reevaluating the expectant value and the perception of leisure aceording to increasing the level of their incomes, The leisure of citizens is increasing in the aspect of quantity and quality of life nowadays In the site planning of leisure, the concrete understanding about people's choice of a leisure site will be the most important thing, not only for the aspect of improvement of the quality of life but also efficiencies of the land use The purposes of chi study are firstly, to find out the factors which are influenced on a choice of Outdoor leisure facilities in neighbourhood unit and to Compare the Characteristics Of Choice models between the three metropolitan areas, secondly, to predict a limitation of use areal according to the change of a needed time based on the metropolitan's standard choice model For the choice model establishment this research used Logit Model which has been used in the field of the traffic, the tourism and the economics. This research made the results which find out the influencing variables with needed times, the accessibility and the percentage of facilities. The lindtations of use areas come out the results which are predicted according to the change of needed times as a most influencing factors. The range of each preferred leisure facility is about 956 meter distant in the neighbourhood park about 644 meter distant in the pocket park about 604 meter distant in the recreation center, about 628 meter distant in the tennis court about 974 meter distant in the private hob by facility and about 528 meter distant in the library from the apartment unit The recreation center and the library are nearer facilities than the other facilities. But these facilities are surveyed to be more or less influenced by an interesting progran, a context of events and the level of useful facilities, etc.

• Journal of Radiation Protection and Research
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• v.13 no.2
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• pp.29-40
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• 1988

A spectrum-exposure rate conversion operator G(E) for a portable HPGe detector used for field environmental radiation survey was theoretically developed on the basis of a space distribution function of gamma flux emitted from a disk source and an areal efficiency of the detector. The radiation exposure rates measured using this G(E) and the portable HPGe. detector connected to a portable multichannel analyzer were compared with those measured by a 3' ${\phi}\;{\times}$3' NaI(Tl) scintillation detector with the reported G(E) and a pressurized ionization chamber. A comparison of the three results showed that the result obtained using the HPGe detector was lower than those determined using the NaI(Tl) detector and ionization chamber by 17% to 29%, The difference obtained is close to that reported in literature. The method developed here can be easily applicable to obtain a G(E) factor suitable to any detector for detecting the exposure rate of environmental gamma radiation, since the spectrum-exposure rate conversion operator can be calculated by a hand calculator.