• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.6
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• pp.504-511
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• 1990

Weather data acquisition and potential evapotranspiration (PET) calculation procedure were investigated to support the agricultural development efforts in the mid-altitude mountainous region of Cheju Island. Automated weather stations (AWS) were installed at two points representing the east and the west of the study area. A personal computer was employed to collect the near-real time weather data from AWS through the public telephone line. Hourly data were available for solar radiation, air and soil temperature, relative humidity, wind speed and direction, and precipitation. Based on the data for the month of June 1989, daily climatic features were comparatively analyzed for the two areas and the Penman equation was used to calculate PET. Air temperature was higher by 1 to 2 degree C in the east due mainly to the higher solar radiation and partly to the Fohn effect caused by the daytime southwesterly blowing over Mt. Halla. Diurnal march of soil temperature lagged by 4 hours behind that of air temperature and the diurnal range for 10cm subsurface soil was 3 degree C. Wind was consistently stronger and a marked sea-land breeze circulation was detected in the west. Calculated PET values were higher in the east by 6% than in the west. Overall values from the east and the west of the mid-altitude mountainous region were higher by 30% than those of the coastal region, which were estimated from the Class A Pan evaporation measured by the Korea Meteorological Service Offices.

• 한국해양학회지
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• v.28 no.3
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• pp.241-258
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• 1993

To investigate the sedimentary environments on the coastal areas of Imja to Nakweol islands which show very complex shorelines and several zonal sand ridges in NE-SW direction, southwestern coast of Korea, a total of forty samples were taken by a grab sampler and sedimentological and micropaleontological studies on those samples were carried out. The present study area are classified into muddy sandy gravel, sand, city sand, sandy silt and silt facies. With statistical moment parameters such as mean, sorting, skewness and ketosis for the sediments in the study area, the sediments are generally categorized as shallow sedimentary facies. The characters that are observed in quartz grains among the sandy sediments of the study area imply the existence of high energy environments, temporal exposures in atmosphere and the mixing of clastic sediments of the several different origins. In the sediments of the study area, one genera belonging to six silicoflagellata species and five genera belonging to five nannoplankton species were detected. On the basis of the micro-organism assemblage, the study area seems to be influenced by active reworking dominantly under warm water masses. In addition, organic matter ad carbonate contents in the sediments did not show a definite relation with the occurrences of the micro-organisms in the study area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.254-264
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• 1990

Using the meteorological data, surface weather map, and oceanographic data for 5 years(1984-1988). I investigated the characteristics of the fog occurrence and the role of the inshore in Pusan about the fog occurrence. And the meteorological data and sea surface temperature(SST), which were observed in July, 1989 in Suyoung Bay, were compared with those in Pusan. The fogs in Pusan concentrate in May, June and July. And at fog occurrence time the principal wind directions are Southwest(SW) winds, which easily supply with water vapor, and a series of Northeast(NE) wind. At the fog days pressure patterns are pattern 7 in spring time (March, April, and May) and pattern 10 and pattern 13 in summer time (June, July, and August). Also the advection fog(sea fog) is closely related with the relationship between warm and cold advection in 850~700mb and cold and warm SST rather than the increase of the instability of atmosphere in 850~500mb. The fogs in Taegu, which is the inland region, mainly occur at dawn in fall time due to the strong night radiation fog. On the other hand in Pusan the coastal region, the fogs occur from late spring time to summer time (May, June, and July). Because there is the abundant supply of the water vapor from the ocean owing to a series of South(S) wind at this time. Then the atmosphere, which has high relative humidity, reaches easily the supersaturation by the radiation cooling. In Suyoung Bay and Pusan the meteorological observation data, SST and fog days are almost similar. And I think that the mechanism of the fog occurrence nearly accords with both regions.

• Journal of the Korean association of regional geographers
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• v.5 no.1
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• pp.151-162
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• 1999

This study is a comparative analysis of sea level and 500hPa surfaces between dry year and wet year, which are selected by variability of precipitation and standardized anomalies in Korea in early autumn. While the amount of precipitation of early autumn decreases, the variability of precipitation increases rapidly reflecting the strength and weakness of Kaul Changma front and the occurrences of the typhoonic precipitation. The regional distribution of the variability of precipitation shows west-high, east-low pattern in which the east coast and the southeastern coast shows low, but high in the southwestern coast. In the anomalies distribution of sea-level and 500hPa surfaces, during dry year, the northern part of Siberia and the core area of North Pacific high shows negative anomalies, on the contrary, there were positive anomalies in wet year at the same areas. In addition, at the 500hPa level, while the Korean peninsula was located at the west of deep trough with low zonal index in dry year, the peninsula was influenced by weak trough with high zonal index showing strong zonal flow in wet year. During dry year the height of 500hPa surface is low at the north of $40^{\circ}N$, but high in wet year. In consequences, this study identified that the occurrences of dry year and wet year were influenced by the seasonal variations of the strength and the weakness of North Pacific high and Siberian high.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.82-95
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• 2011

The objective of this paper is to analyze the GIS-based water cycle system: rainfall, evapotranspiration, surface run-off of Gyeongsanam-do for the effective rainwater management. The rainfall(1999~2008) analyzed by a spatial interpolation method, showed relatively higher amount in Hadong-gun, Sanchung-gun, and Sacheon-gun on the southwest coast than in Changnyeong-gun, Miryang-si, and Changwon-si in the mideast inland. The evapotranspiration was calculated by the three independent variables: air temperature, landuse, and NDVI(normalized difference vegetation index). The analysis showed that Namhae-gun had the highest evapotranspiration of 93.71mm, and Jinhae-si and Changwon-si had the lowest values of 81.78mm and 84.37mm. The surface run-off was analysed by a run-off equation based on the SCS hydrologic soil classification and landuse. The amount of surface run-off showed that Hadong-gun had the highest value, of 90.40mm, and Geochang-gun had the lowest, of 46.69mm. The analysis results of the GIS-based water cycle system will be used to support the establishment of the effective rainwater management plan in Gyeongasngnam-do.

• Journal of the Korean association of regional geographers
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• v.6 no.2
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• pp.57-69
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• 2000

The purpose of this study is to identify distributional characteristics of autumn droughts in occurrence frequency and to analyze synoptic characteristics on the surface pressure fields and 500hPa levels for autumn droughts in Korea. The regional distributions of autumn droughts in occurrence frequency vary according to the monthly regional distributions of the precipitation variabilities in Korea. In september, the southwestern and the mid western parts of Korean Peninsula have high rate of drought frequency, while the eastern coast regions have low rate of it. It means that the regional distribution of the drought frequency in september indicates west-high and east-low pattern. In October, the regional distribution of the drought frequency shows low variations on regions, but in November the inland areas have low rate of drought frequency, whereas the coastal areas have high rate of it. Negative anomalies appear on the surface and 500hPa level, around Korean Peninsula during the drought period of early autumn. Positive height anomalies areas are extended from the Sea of Okhotsk to the central part of the North Pacific Ocean. It indicates that the occurrence frequencies of blocking high and ridge are high around the Sea of Okhotsk. When the pressure system, such as migratory anticyclone, stays around the Korean Peninsula, a drought occurs. In late autumn drought, the positive anomalies appear in the west and the negative anomalies in the east are generated, respectively and therefore, zonal wind is strong around Korean Peninsula. In consequence, occurrences of droughts in early autumn have a different mechanism from those of late autumn.

• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.41-50
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• 2009

Water levels in groundwater monitoring wells of Jeju Island were analyzed using parametric and non-parametric trend analyses. Number of used monitoring wells in the analysis are 94 among totally 106 monitoring wells and the monitoring period is greater than single year, from 2001 to 2009. For the trend analysis, both parametric (linear regression) and nonparametric (Mann-Kendall trend test and Sen's trend test) methods were adopted. Results of the linear regression analysis on daily basis indicated that about 58.5% of the monitoring wells showed a decreasing trend, and analysis using monthly median indicated that about 79.8% showed a decreasing trend. The Mann-Kendall trend test and Sen's trend test with monthly median values in confidence levels of 95% and 99% showed the same analysis results. In confidence level of 95%, 32% were decreased, 3% were increased and the remains showed no trend. However, in confidence level of 99%, 16% were decreased, 2% were increased and the remains showed no trend. The largest decline rates of water levels were detected mainly at the coast of the northwestern and southwestern parts, which is expected to closely related to the increased pumping in the urban area and tourist resort.

• Journal of the Korean earth science society
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• v.40 no.2
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• pp.149-162
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• 2019

In the macro-tide open coast of the Korean western coast, typhoon effects were investigated in terms of variations on topography, surface sediment, and sedimentary environment, which appeared before and after the typhoon Kompasu of 2010. The Kompasu of small size and strong intensity landed on the southwestern coast of the Korean Peninsula and passed across the inland between September 1st and 2nd in 2010. Topography and surface sediments before and after the typhoon were measured and sampled along the survey line of 22 sites in the Gochang Donghori intertidal flat. The intertidal area was divided into high tidal zone, middle tidal zone, and lower tidal zone on the basis of mean high water level, mean sea level, and mean low water level. Topographic variation before and after the typhoon represented deposition of average 0.03 m in high tidal zone, erosion of average -0.15 m in middle tidal zone, and erosion of average -0.39 m in lower tidal zone, respectively. Surface sediments of the intertidal flat consisted mainly of fine to medium sands, and the ratio of fine sand was the largest both before and after the typhoon. Surface sediments after the typhoon became finer in mean grain size showing well sorting rather than those before the typhoon.

• Korea journal of population studies
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• v.26 no.1
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• pp.1-30
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• 2003

This paper attempts to explore the effects of ecological and socioeconomic factors on the level of mortality and the changing trends of such effects during the period of 1990∼2000. For this purpose the population census data and micro-data from the vital statistics for years 1990, 1995 and 2000 were used. As indicators of mortality, the crude death rate(CDR), the standardized death rate(SDR) and the longevity rate were calculated for 170 'Si' s and 'Gun's. Using GIS, this paper first presents the mortality and longevity maps for years 1990, 1995 and 2000. Then ANOVA and regression analyses are carried out in an effort to generalize the effects of ecological and socioeconomic factors on the CDR, the SDR and the longevity rate. When the mortality and longevity maps are examined, three indices of mortality are found to be markedly high in the southwest coastal regions of Cholla-Nam-Do. By contrast, Seoul and Pusan metropolitan areas show substantially low level of mortality and longevity in these indices. It is also found that the regional differentials in the SDR and the longevity rate show a trend of becoming smaller after 1990. The research, however, does not find any linear relationship between the SDR and the longevity rate. The causal mechanisms of the two indices are found to be different. The results of the ANOVA and the regression analysis reveal that the locational factors of both mountainous and farming regions tend to increase the CDR and SDR while both coastal and farming regions disclose a tendency of increasing the longevity rate. The level of statistical significance of these analytical results is found to be weaker when socioeconomic factors such as education, income, marital status, availability of medical care, and sanitary conditions of the region are taken into account. The regional differentials in the mortality level seem to have a clear relationship not only with the socioeconomic factors but also with the age structure influenced by the age selectivity of migration during the past 40 years.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.423-433
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• 2019

In order to predict the seabed topography change due to the construction of offshore wind power structures in the west-southern sea of Korea, field observations for tides, tidal currents, suspended sediment concentrations and seabed sediments were carried out at the same time. These data could be used for numerical simulation. In numerical experiments, the empirical constants for the suspended sediment flux were determined by the trial and error method. When a concentration distribution factor was 0.1 and a proportional constant was 0.05 in the suspended sediment equilibrium concentration formulae, the calculated suspended sediment concentrations were reasonably similar with the observed ones. Also, it was appropriate for the open boundary conditions of the suspended sediment when the south-east boundary corner was 11.0 times, the south-west was 0.5 times, the westnorth 1.0 times, the north-west was 1.0 times and the north-east was 1.0 times, respectively, using the time series of the observed suspended sediment concentrations. In this case, the depth change was smooth and not intermittent around the open boundaries. From these calibrations, the annual water depth change before and after construction of the offshore wind power structures was shown under 1 cm. The reason was that the used numerical model for the large scale grid could not reproduce a local scour phenomenon and they showed almost no significant velocity change over ± 2 cm/s because the jacket structures with small size diameter, about 1 m, were a water-permeable. Therefore, it was natural that there was a slight change on seabed topography in the study area.