According to the results of the groundwater quality investigation about 230 holes all over the country, the groundwater which was in excess of standard grows larger every year and closed holes increased to 23,457 holes in 1997 from 15,724 holes in 1996. This is the major reasons that water quality contamination, shortage of water quantity, increasing of salinity and so on. There are 7 groundwater salinization sources which are considered as most important on a regional level. And among theses the Cheju Island groundwater salinization sources are (1) halite solution, (2) natural saline groundwater, (3) sea-water intrusion. The method of taking an isotopes is one of research methods of the origin of groundwater salinization and is used in so many studies because it has very high confidence. 18O, 2H, 3H, 14C and so on in an isotopes are frequently used in the method of them. Consequently on this study we analyzed major ions and 3H in groundwater, sea-water and rain of the eastern part of cheju island known as contaminated site from long time ago to examine the origin of groundwater salinization. Relation ratios of the major ions versus chloride ion shows similar tendency to sea-water. This indicates that sea-water entered the groundwater layer. And amount of 3H in holes of the land side is higher than that of the sea side. Relation of chloride ion versus 3H indicates negative character. Therefore we can think that the reason of groundwater salinization of this part is natural saline groundwater and halite solution by relation.

Butyltin compounds (BTs) in seawater, sediments and organisms (Thais clavigera, Liolophura japonica and Cellana nigrolineata), were quantitatively determined to evaluate their distribution inside Songsan Harbor of Cheju Island. In addition, imposex in T. clavigera was used to assess the effect on organisms of BTs. Analysis of the samples collected in seawater, sediments (March, June and August) and organisms (May, July and August) in 1998, confirmed the contamination of BTs in the aquatic environment inside Songsan Harbor. The main BTs species in seawater and sediments was monobutyltin (MBT), tributyltin (TBT), respectively, irrespective of survey time. In organisms, TBT and dibutyltin (DBT) were detected in similar concentrations for T. clavigera and L. japonica, but for C. nigrolineata, DBT concentration was the highest. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serious effect on the sensitive organisms upon chronic exposure. The relatively high correlations (r>0.83) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paint and their sources were negligible. The sedimentary organic matters did not have influence on the distribution of BTs in marine environment, and lipid content in T. clavigera did not show a correlation with TBT concentrations. The rate of occurrence of imposex in T. clavigera was 100 %, and the relative penis length index (RPLI) and the relative penis size index (RPSI) which represent the degree of imposex were 79.7%, 58.1%, respectively. Measurement of imposex in T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of BTs.

The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater. spring water are analyzed. The concentration of Cl- and Na-+K- contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, HCO3, Na-Cl-HCO3 and Ca-HCO3. The concentration ratio of SO4- to Cl- is 0.1354(R2=0.972) at this area. This value is very similar with Dittomer's ratio of 0.13. For Na-, K-, and Mg2+ versus Cl-, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4㎞ at Kosung-Susan area. The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of Na- observed at field is 25∼45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500μmhos/㎝ is located at 4∼5㎞ point at Kosung-Susan area and 2.5㎞ point at the other area. The equation of correlation between Cl- concentration and EC values is Cl-=0.1927EC-16.683 for the area lower than 500μmhos/㎝ and Cl-=0.2773EC for the area beyond 500 μmhos/㎝.

The purpose of this paper is to present the environment change of Cheju Island as land development process using GSIS(Geo-Spatial Information System) technique. We implemented the process based on the maps of soil color, underground water pollution points, land use, land development planning and land sight seeing supported by Cheju Province Office. To use the maps for GSIS data, first we transformed the picture data of the office into raster structured picture data using scanner. Second, the coordinate system was added to raster data using 1/50000 geographic map. Third, we estimated land planning process using GSIS technique(overlay and reclass technique). The results showed that land development effected the natural environment(forest, green field, farm land). However, the chemical pollution and land sight seeing was not so much effected by the land development that was found.

To study the residue of organophosphorus pesticides in the ocean environment on the Cheju island, EPN[O-ethyl-O-4-nitrophenyl phenylphosphonothioate] and monocrotophos [Dimethyl-1-methyl-2-methy] carbamoylvinylphosphate] of organophosphorus pesticides are surveyed on coastal environment of Cheju city and Wimi in May and October 1996. The qualified limit detection of EPN and monocrotophos are 0.005ng/mL and 0.006ng/mL., in the water by GC-FPD, respectively. The qualified limit detection of EPN and monocrotophos are 0.010ng/g and 0.012ng/g in the solid such as sediment and sea organism by GC-FPD, respectively. EPN and monocrotophos are not detected in seawater and sediment. Moreover EPN and monocrotophos are neither detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). EPN, monocrotophos used in the farm on the Cheju island are not residued in the coastal environment in the Cheju island.

The adsorption and leaching of organophosphorus pesticides (phenthoate, diazinon, methidathion) were investigated in Namwon soil(black volcanic soil), Aewol soil(very dark brown volcanic soil) and Mureung soil(dark brown nonvolcanic soil) sampled in Cheju Island. The Freundlich constant, K value, was 52.4, 31.3 and 27.7 for phenthoate, diazinon and methidathion in Namwon soil, respectively and decreased in the order of phenthoate, diazinon and methidathion among the pesticides. The K value of phenthoate was 52.4, 15.9 and 5.9 for Namwon, Aewol and Mureung soil, respectively and was the highest for Namwon soil with very high organic matter content and cation exchange capacity(CEC). The Freundlich constant, 1/n, showed a high correlation with organic matter content, i.e., its value was less than unity for organic matter rich soil(Namwon soil) and greater than unity for organic matter poor soil(Mureung soil). Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 74∼86%. The leaching of pesticides was less for phenthate with high K values, and more for methidathion with low K values among the pesticides. It was slower for Namwon soil with high K values, and faster for Mureung soil with low K values among the soils.

제주산 감귤의 유통방법에 따른 선도 변화를 조사하고 저온유통의 효과를 검토하였다. 유통 중 성분변화는 상온(17)유통이 저온(5)유통에 비해서 중량감소는 6% 증가, vitamin C는 1.91mg 감소, 당산비는 20% 증가함을 보였다. 상온유통에서 중량감소로 인하여 당산비가 높아져서 (16.11에서 21.75) 감귤의 맛과 선도가 감소된다. 현행 감귤수송은 상온유통을 하고 있으나 고품질 감귤에는 부적합한 것으로 나타나며 고품질 소량생산 지향의

Based on the X-ray powder diffraction (XRD) and M ssbauer spectroscopy, the thermal behavior and phase transformations of two clays are investigated for raw and fired conditions, which are collected from Kwangryeongli and Ildo district in Cheju Island. M ssbauer spectra at room temperature and 20for two clays show that paramagnetic Fe3- is the structural iron of the layer silicate and ferrihydrite, and superparamagnetic goethite has about 50% of total iron contents. The XRD peaks of hematite for the fired clays appear from 800℃ in Kwangryeongli clay and from 600℃ in Ildo district clay, respectively. The structural Fe2+ was completely oxidized into Fe3- at 400℃ for Kwangryeongli clay and 500℃~600℃ for Ildo district clay, respectively. The structural Fe2+ was completely oxidized into Fe3- at 400℃. For the temperature ranging from 400℃ to 700℃~800℃, two fired clays exhibit the dehydroxylation of the clay mineral. A disintegration of the clay mineral structure is observed from 700℃~800℃ to 1100℃, followed by the onset and spread of vitrification process. It is also shown that well-crystallized hematite phase is formed at the temperature higher than 1100℃ and the relative absorption area decreases, which might be related to the recrystallization of alluminosilicate matrix.

In order to investigate the adsorption characteristics of organochlorine pesticides chlorothalonil and dicofol with soil colors and regions for soils of an orange orchard, the soils were sampled at 3 regions, respectively, among black volcanic, dark brown volcanic, and brown nonvolcanic soils. Every soil has a higher clay proportion (49-75%) in soil texture and the organic carbon content and cation exchange capacity with soil decreased in the following sequence: Black volcanic > Dark brown volcanic > Brown nonvolcanic soils. Especially those in black volcanic soils were much higher than others. The retention time, quantitative detection limit, and extractian, efficiencies of chlorothalonil and dicofol were 2.82min, 1.5ng/mL, 93.6% and 3.64min, 4.5ng/mL, 94.2%, repectively. The Freundlich constant, Kd, was higher in dicofol compared to chlorothalonil and in the black volcanic soils that have higher organic carbon content and cation exchange capacity. The Freundlich constant, 1/n, was in the range of 0.76-0.89 in the black volcanic soils that have a higher organic matter(16.4-19.8%), whereas it was in the range of 1.02-1.13 in the brown nonvolcanic soils that have a lower organic matter(2.4-3.4%), and so it was considered that 1/n was dependent on the organic matter.

This study was carried out to investigate the chemical characteristics of rainwater sampled in Cheju City from July 1994 to June 1996. Concentrations of major Ions (Cl^-, SO_4^2-,NO_3^-, Na^+, K^+, Ca^2+, Mg^2+ and NH_4^+) were determined. The pH of rainwater, calculated from the volume weighted H^+ concentration, was found to be 5.61, indicating extensive neutralization of the acidity in the rain. The relative magnitude of average ionic concentrations followed the relation Cl^-> SO_4^2-> Na^+> Ca^2+> NH_4^+> NO_3^-> Mg^2+> K^+. The ions associated with sea salt, namely Na^+ and Cl^-, dominated the total concentration of ions in the rainwater and the SO_4^2- ion accounts for 20% of total concentration. [H^+]/[nss-SO_4^2-+NO_3] ratio and a multiple regression for SO_4^2- and NO_3^- ions against H^+, Ca^2+ and NH_4^suggested that all of SO_4^2+ and NO_3^- in rainwater was not necessarily associated with H_2SO_4, anf HNO_3, but might also occur in combination with NH_4^+ or Ca^2+. The monthly mean concentrations of SO_4^2-, Ca^2+ and NH_4^+ in spring time was higher than those in other seasons. These results may be attributed to the fertilizer application as the local sources and the yellow sand phenomina as a regional-scale sources.

The conditions of cold stroage of Citrus unshiu Marc. var. okitsu produced in Cheju were investigated. The changes of peel moisture contents soluble solids, total sugar, vitamin C and density were slightly occured, and decay ratio was below 20% on keeping freshness relatively till late of March during cold storage. After thats decayed citrus fruits were increased gradually mainly from cold injury with lower temperature and high humidity. The loss of fruit weight, decrease of fruit hardness, and decrease of acid content were occured gradually during cold stroage. Because of the difficulty of long term storage for Citrus unshiu, the conditions and periods of cold storage would be determined after considering the physicochemical properties of fruits every year.

Total carotenoid contents, color values and spectrum characterization in the range of UV of fruit juice and organic acid and free sugar contents determined by HPLC were investigated on 10 varieties of Cheju citrus fruits. Carotenoid contents of juice were 0.47-9.20/ml which showed higher with Dangyooja while showed lowest content with Meiwa Kumquat. Lightness (L) of juice was highest in Meiwa Kumquat, and in the order of Sankyool, Navel orange and Hungjin. Redness(a) and yellowness(b) were in the order of Dangyooja, Natsudaidai, Sambokam and Kinkoji. The maximum absorption wavelengths if citrus Juices were variable at 269.5-285.5nm according to varieties and it was observed that were changed by mixing with Juices of other varieties. Major organic acids of citrus juice were citric and malic acid, and citric acid was 64.4-95.1% of total organic acids. Ascorbic acid was high in Navel orange, Sudachi and Dangyooja, and low in Meiwa Kumquat and Hungjin. Major free sugars were sucrose, glucose and fructose. Sucrose was 49.2-75.2% of total free sugars, and high in Sankyool and Meiwa Kumquat. Glucose and fructose were high in Meiwa Kumquat and Navel Orange.

Physicochemical properties and the conditions of cold storage of kiyomi clangor(Citrus unshiu x sinensis) produced in Cheju were investigated. Firmness, edible part ratio, soluble solids, and acid content were decreased gradually with incurasing fruit size. Carbohydrates in juice were consisted of 65.12% sucrose, 19.65% fructose, and 15.23% glucose The main organic acrid In juice was 57.4% of citric acid, and others were lactic acid, malic acid, oxalic acid and fumaric acid, respectively. Weight loss were occured very. slowly to about 6% till late of May, but decayed fruits were occurred very slowly to about 6% till late of May, but decayed fruits were arisen to about 8% at 3, and about 13% at 5 of storage temperature. The changes of peel moisture content, soluble solids, total sugar, vitaamin C, and density of fruits were slightly occured during cold storage. Cold storage at 3 and 87% relative humidity kept freshness of citrus fruits for a long-term without damage of cold injury.

Total carbohydrates of Kumquats was 14.69% Kumquats, Citrus natsudaidai, and C. platgmama contained 18.3, 11.1 and 13.0%, of soluble solids, and 42.39, 32.09 and 20.13mg/100g, of vitamin C, respectively. Acid contents of C. natsudaidai and C. plafmama harvested on March 1995 in south Cheju were 2.52% and 0.89% . In preparing of Kumquats-tea, combination of 50% honey and sugar, 5% oligo-sugar, 32% Kumquats slice, 13% juice of C. natsudaidai were the best recipe for sensory evaluation. In C. natsudaidai-tea, combination of 5∼10% peel slice treated at 90 for 1min, 50∼60% concentration of sugar and 35∼40% of flesh of C. natsudaidai were good. for sensory evaluation. Microbial growth was not observed in the sterilized products for more than one month at 30.

This study was conducted for the efficient utilization of a scoria, which is abundantly found in Cheju island, as adsorbent and the scoria was examined for its performance in clarification of adsorption of heavy metal ions. The order in heavy metal ions adsorbed on scoria was; Pb^+>Cd^2+>Cu^2+>Ag^+>Co^2+>Zn^2+>Cr^3+>Cr^6+. This tendency was relatively consistent with the decreasing order of radius of hydrated metal ion. Also, the smaller scoria size and the larger amounts of scoria showed higher removal efficiency for heavy metal ions. The same scoria size showed more effective removal efficiency for heavy metal ions at lower initial concentration than at higher initial concentration. The adsorption abilities of original scoria and chemically treated scoria were compared. Adsorption isotherm of scoria was generally obeyed to Freundlich formula than Langmuir formula and Freundlich constant, 1/n was obtained in the range of 0.2∼0.4.

In order to determine the quality of Citrus unshiu(medium cultivar of satsuma mandarin) produced in Cheju, citrus fruits sampled at sorting places and harvested directly on citrus tree in south and north area of Cheju were analyzed. The fruits were grown in size till early of November, and soluble solids were increased continuously after that. Compared with the quality of citrus fruits as a factor of soluble solids, firmness, total sugar, pH, and color index, the optimum harvest periods were supposed to be reasonable from early of December for C. unshiu Marc. var. yonezawa and C. unshiu Marc. var. hayashi, Fruit weights and peel thickness had a linear correlation with increasing fruit size, but soluble solids and acid contents had not a correlation. The selection of C. unshiu variety was needed to determine by the properties of storage.

Surface heat balance of the northern sea of Cheju Island for summer in 1993 and 1994 is analyzed using the observation data obtained by Marine Research Institute, Cheju National University. Each flux elements at the sea surface is derived from the marine meteorological reports with application of an aerodynamical bulk method for the turbulent heat fluxes, and empirical formulae for the long-wave radiation heat fluxes. The flux divergence of oceanic heat transport and the rate of heat storage in the ocean are estimated as residual. The features of the surface heat balance are mainly decided by the solar radiation flux and the latent heat flux for 1994. But the Bowen Ratios were large for 1993. This means that the sensible heat fluxes were nearly equal to the latent heat fluxes for 1993. In this period, mean flux divergence of oceanic heat transport is about 130 W/㎡.