• Spatial Information Research
• /
• v.11 no.2
• /
• pp.101-117
• /
• 2003

High resolution satellite image analysis has been recognized as an effective technique for monitoring local land-cover and atmospheric changes. In this study, a new high resolution map for land-cover was generated using both high-resolution IKONOS image and conventional land-use mapping. Fuzzy classification method was applied to classify land-cover, with minimum operator used as a tool for joint membership functions. In separateness analysis, the values were not great for all bands due to discrepancies in spectral reflectance by seasonal variation. The land-cover map generated in this study revealed that conifer forests and farm land in the ground and tidal flat and beach in the ocean were highly changeable. The kappa coefficient was 0.94% and the overall accuracy of classification was 95.0%, thus suggesting a overall high classification accuracy. Accuracy of classification in each class was generally over 90%, whereas low classification accuracy was obtained for classes of mixed forest, river and reservoir. This may be a result of the changes in classification, e.g. reclassification of paddy field as water area after water storage or mixed use of several classification class due to similar spectral patterns. Seasonal factors should be considered to achieve higher accuracy in classification class. In conclusion, firstly, IKONOS image are used to generated a new improved high resolution land-cover map. Secondly, IKONOS image could serve as useful complementary data for decision making when combined with GIS spatial data to produce land-use map.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.21 no.3
• /
• pp.104-120
• /
• 1979

I. Title of the Study Studies on the Development of Improved Subsurface Drainage Methods. -Drainage Performance of Various Subsurface Drain Materials- II. Object of the Study Studies were carried out to select the drain material having the highest performance of drainage; And to develop the water budget model which is necessary for the planning of the drainage project and the establishment of water management standards in the water-logged paddy field. III. Content and Scope of the Study 1. The experiment was carried out in the laboratory by using a sand tank model. The drainage performance of various drain materials was compared evaluated. 2. A water budget model was established. Various parameters necessary for the model were investigated by analyzing existing data and measured data from the experimental field. The adaptability of the model was evaluated by comparing the estimated values to the field data. IV. Results and Recommendations 1. A corrugated tube enveloped with gravel or mat showed the highest drainage performance among the eight materials submmitted for the experiment. 2. The drainage performance of the long cement tile(50 cm long) was higher than that of the short cement tile(25 cm long). 3. Rice bran was superior to gravel in its' drain performance. 4. No difference was shown between a grave envelope and a P.V.C. wool mat in their performance of drainage. Continues investigation is needed to clarify the envelope performance. 5. All the results described above were obtained from the laboratory tests. A field test is recommended to confirm the results obtained. 6. As a water balance model of a given soil profile, the soil moisture depletion D, could be represented as follows; $$D=\Sigma\limit_{t=1}^{n}(Et-R_{\ell}-I+W_d)..........(17)$$ 7. Among the various empirical formulae for potential evapotranspiration, Penman's formular was best fit to the data observed with the evaporation pans in Jinju area. High degree of positive correlation between Penman;s predicted data and observed data was confirmed. The regression equation was Y=1.4X-22.86, where Y represents evaporation rate from small pan, in mm/100 days, and X represents potential evapotranspiration rate estimated by Penman's formular. The coefficient of correlation was r=0.94.** 8. To estimate evapotranspiration in the field, the consumptive use coefficient, Kc, was introduced. Kc was defined by the function of the characteristics of the crop soil as follows; $Kc=Kco{\cdot}Ka+Ks..........(20)$ where, Kco, Ka ans Ks represents the crop coefficient, the soil moisture coefficient, and the correction coefficient, respectively. The value of Kco and Ka was obtained from the Fig.16 and the Fig.17, respectively. And, if $Kco{\cdot}Ka{\geq}1.0,$ then Ks=0, otherwise, Ks value was estimated by using the relation; $Ks=1-Kco{\cdot}Ka$. 9. Into type formular, $r_t=\frac{R_{24}}{24}(\frac{b}{\sqrt{t}+a})$, was the best fit one to estimate the probable rainfall intensity when daily rainfall and rainfall durations are given as input data, The coefficient a and b are shown on the Table 16. 10. Japanese type formular, $I_t=\frac{b}{\sqrt{t}+a}$, was the best fit one to estimate the probable rainfall intensity when the rainfall duration only was given. The coefficient a and b are shown on the Table 17. 11. Effective rainfall, Re, was estimated by using following relationships; Re=D, if $R-D\geq}0$, otherwise, Re=R. 12. The difference of rainfall amount from soil moisture depletion was considered as the amount of drainage required. In this case, when Wd=O, Equation 24 was used, otherwise two to three days of lag time was considered and correction was made by use of storage coefficient. 13. To evaluate the model, measured data and estimated data was compared, and relative error was computed. 5.5 percent The relative error was 5.5 percent. 14. By considering the water budget in Jinju area, it was shown that the evaporation amount was greater than the rainfall during period of October to March in next year. This was the behind reasonning that the improvement of surface drainage system is needed in Jinju area.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.1
• /
• pp.104-115
• /
• 1992

The rice culture techniques included 'Jodosukyungbeob'(旱稻水耕法 : culture techniques of early-ripening paddy rice), 'Mandosukyungbeob' (晩稻水耕法) : culture techniques of late-Ripening paddy rice 'Handobeob'(旱稻＆lt;山稻＆gt;法 : culture techniques of upland rice), 'Myojongbeob'(苗種法 : culture techniques of paddy rice by transplanting), 'Kunangbeob'(乾秧法 : culture techniques of rice by transplanting which rears seeding in dry paddy) and 'Sudogunpanongbeob'(水稻乾播農法 : culture techniques of paddy rice seeding in dry field). Especially, 'Kunangbeob' and 'Sudogunpanongbeob' were originally developed in Korea as seen in 1600s(Kyoungje : 經濟) and early 1800s (Yoji : 要旨). In 'Jodosukyungbeob' it took 9 days for seed dipping, water-sprouting and prevent damage by birds, each for 3 days in China, but in Korea seed dipping in water took 3 days and the rest of the procedures were flexibly established. In matured soils, practices were fall plowing right after harvest, recognition of effective tillering and additional fertilization use of human manure, and stimulation of sprouting by lime application. The unique culture techniques adequate for Korean situations were practiced, which included weed control after draining accurately for 3 to 4 times, draining at mid season for improving wind and drought tolerance, rice harvesting at appropriate time for preventing grain shattering, and seeding in rows. 'Mandosukyungbeob' was improved techniques contrast to those of China, and the major contents were selection of proper varieties, good stand establishment by seeding high rates, induction of vigorous tillers, and adoption of 'Jokjongbeob'(足種法 : seeding method by foot). Also, one of the most prominent rice cultures by our ancestors was 'Kunpanongbeob' that was systemized form habitual practice of Pyongan Province. The unique technique actualized was 'Hando [旱稻(山稻)]' culture technique which was the combinations of 'Jokjongbeob', root stimulation method, and disaster-tolerant mixture cropping with adoptation of variety theory, although it was originated from China. The transplanting techniques has come before 'Jikseol'($\ulcorner$直說$\lrcorner$) and its merits were sufficiently realized. However, this method was basically prohibited from the early Chosun dynasty because extremely bad harvest was expected under drought conditions and insufficient conditions of water storage. But, it was permitted in the areas that contained water all the times and in case of large-scale farming especially. Most of rice culture was transplanted in the end of the Chosun dynasty because transplanting was continuously spreaded in the three southern provinces of Korea. Under these circumstances, transplanting technique was improved from the early to the end of the Chosun dynasty by weed control, fertilizing, water management, and quadratic transplanting. Based on these techniques, agricultural productivity was improved 5 times by that time. 'Kunpanongbeob' was created and developed properly for Korean conditions that is dry in early season and flooding in late season. This was successively developed and established into transplanting technique of nursery seedling.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.29 no.6
• /
• pp.327-340
• /
• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• Korean journal of applied entomology
• /
• v.12 no.3
• /
• pp.115-120
• /
• 1973

An experiment was carried out to investigate possible use of several systemic insecticides as seed treatment to control some insect pests of rice, barley and soybean. The insecticides were impregnated with active carbon dust and $2\%$ water solution of methyl cellulose as skicker. The seeds were dressed with the insecticides: Fussol (Monofluoroacetamide), Dimethoate (0, 0-dimethyl-S-(N-methyl carbamoylmethyl) phosphorodithioate), Metasystox (0, 0-dimethyl 0-2 ethylthioethyl phosphorodithioate), Dimecron (0, 0-dimethyl (diethylamide-1-chlorocrotonyl) Phosphate). The seeds were treated at the rate of $4\%$ by grain weight. Effects of seed treatments with systemic insecticides on the seed germination and insecticidal effectiveness were tested. Fer rice, no seed germination was observed in Fussol treatment. Dimethoate, Metasystox and Dimecron showed a slight reduction in germination when seeds were sown 1 day after treatment, but they showed gradual reduction in germination when seeds were sown 20 and 45 days after treatment. Especially Diriethoate treatment showed significant reduction in germination after 20 and 45 days of storage. All the insecticides reduced seedling stands of barley somewhat. No plant emergence was observed in Fussol treatments after 25 and :to days of storage. In case of the 40 days of storge in barley seed treated with Dimethoate, Hetasystox and Dimecron there was no gignificant reduction in plant emergence except Fussol treatment. Dimethoate was highly toxic to the soybean seed viability. However, there was no significant reduction in the soybean germination after 1 day of storage. in Fussol, Metasystox and Dimecron treatments After 25 days of storag in Fussol and Dimethoate treatments, no plant emergence was observed, and there was $13.3\%$ emergence in Metasystox treatment, and $93.0\%$ emergence in Dimecron treatment. Dimethoate treatment in rice seed(variety Suwon # 82) showed $90\%$ mortality at the twentieth day and $33.3\%$ at the thirtieth day after sowing against the green rice leafhopper, Nephotettix cincticeps But no visible effectiveness was observed in Metasystox and Dimecron treatments. Dimethoate treatment in barley seed resulted in low population density of aphids. Rhopalosiphum spp. Final observation on the number of eggs per plant was made at the fiftieth day after sowing; 2 in Dimethoate, 4 in Fussol, 6 in Metasystox, 7 in Dimecron, and 13 in check plots. All the insecticides tested resulted in good insecticidal effectiveness against the aphids, Aulocorthum solani on soybean plant at the ninth day infestation after sowing. Dimethote, Metasystox, and Dimecron treated soybean plants was still effective in controlling the aphids to the eighteenth day infestation.

• Journal of Bio-Environment Control
• /
• v.26 no.3
• /
• pp.158-166
• /
• 2017

The object of this study was to improve tomato seedling quality in low temperature(below 7, $10^{\circ}C$ during night time or daily mean air temperature was $18^{\circ}C$) by application of silicate fertilizer. Six different silicate fertilizer concentrations (8, 16, 32, 64, 128, and 256mM) or water as the control were applied to tomato seedlings twice a week for 20 days. Positive effects were observed in the growth parameters of the seedlings treated with 16 and 32mM silicate fertilizer; the most effective concentration of silicate at which seedlings showed the best performance was 16mM. However, a high concentration of silicate (256mM) caused negative effects on the growth. The transpiration rate decreased alongside with the increase of silicate concentration up to 32mM, possibly due to the increased stomatal diffusive resistance. Silicate stimulated the growth and development of tomato seedlings, resulting in increased growth parameters and root morphology. However, no significant differences were observed among treatment numbers of soil-drenching wuth the silicate (6, 10, or 20 times with 16mM) for 20 days, suggesting that silicate treatment with 6 times may be sufficient to induce the silicate effects. The application of 16mM of silicate fertilizer reduced relative ion leakage and chilling injury during low temperature storage. In addition, the seedlings treated with silicate fertilizer recovered faster than those without silicate treatment after low temperature storage.

• Korean Journal of Plant Resources
• /
• v.25 no.1
• /
• pp.156-168
• /
• 2012

Chrysanthemum is a cut flower species that normally lasts for 1 to 2 weeks, in some cases 3-4 weeks. This has been attributed to low ethylene production during senescence. Reduction in cut flower quality has been attributed to the formation of air embolisms that partially or completely blocks the water transport from the vase solution to the rest of the cut flower stem, increasing hydraulic resistance which may cause severe water stress, yellowing, wilting of leaf, and chlorophyll degradation. Standard type chrysanthemum can be harvested when buds were still tightly closed and then fully opened with the simple bud-opening solution. Standard type chrysanthemum can also be harvested when the minimum size of the inflorescence is about 5-6 cm bud which opened into the first flower full-sized flower. While spray varieties can be harvested when 2-4 most mature flowers have opened (40% opening). Cut flowers are sorted by stem length, weight, condition, and so on. Standard chrysanthemum is 80 cm length for standard type and 70cm for spray type. Pre-treatment with a STS, plant regulator such as GA, BA, 1-MCP, chrysal, germicide, and sucrose, significantly improved the vase life and quality of cut flowers. It is well established that vase solutions containing sugar can improve the vase life of cut chrysanthemum. Chrysanthemum is normally packed in standard horizontal fiberboard boxes. Chrysanthemum should normally be stored at $5{\sim}7^{\circ}C$. Precooling resulted in reduction in respiration, decomposition, and transpiration activities as well as decoloration retardation. There was significant difference between "wet" storage in 3 weeks and "dry" storage in 2 weeks. In separate pulsing solution trials, various germicides were tested, as well as PGRs to maintain the green color of leaves and turgidity. Prolonging vase life was attained with the application of optimal solution such as HQS, $AgNO_3$, GA, BA and sucrose. This also retarded senescence in leaves of cut flower stems. Fresh cut chrysanthemum can be transported using a refrigerated van with $5{\sim}7^{\circ}C$. Increasing consumption and usage of cut chrysanthemum of various cultivars would require efficient transport system, and effective information exchange among producer, wholesaler, and consumer.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.19 no.1
• /
• pp.4296-4311
• /
• 1977

This study was conducted to derive an Instantaneous Unit Hydrograph for the accurate and reliable unitgraph which can be used to the estimation and control of flood for the development of agricultural water resources and rational design of hydraulic structures. Eight small watersheds were selected as studying basins from Han, Geum, Nakdong, Yeongsan and Inchon River systems which may be considered as a main river systems in Korea. The area of small watersheds are within the range of 85 to 470$\textrm{km}^2$. It is to derive an accurate Instantaneous Unit Hydrograph under the condition of having a short duration of heavy rain and uniform rainfall intensity with the basic and reliable data of rainfall records, pluviographs, records of river stages and of the main river systems mentioned above. Investigation was carried out for the relations between measurable unitgraph and watershed characteristics such as watershed area, A, river length L, and centroid distance of the watershed area, Lca. Especially, this study laid emphasis on the derivation and application of Instantaneous Unit Hydrograph (IUH) by applying Nash's conceptual model and by using an electronic computer. I U H by Nash's conceptual model and I U H by flood routing which can be applied to the ungaged small watersheds were derived and compared with each other to the observed unitgraph. 1 U H for each small watersheds can be solved by using an electronic computer. The results summarized for these studies are as follows; 1. Distribution of uniform rainfall intensity appears in the analysis for the temporal rainfall pattern of selected heavy rainfall event. 2. Mean value of recession constants, Kl, is 0.931 in all watersheds observed. 3. Time to peak discharge, Tp, occurs at the position of 0.02 Tb, base length of hlrdrograph with an indication of lower value than that in larger watersheds. 4. Peak discharge, Qp, in relation to the watershed area, A, and effective rainfall, R, is found to be {{{{ { Q}_{ p} = { 0.895} over { { A}^{0.145 } } }}}} AR having high significance of correlation coefficient, 0.927, between peak discharge, Qp, and effective rainfall, R. Design chart for the peak discharge (refer to Fig. 15) with watershed area and effective rainfall was established by the author. 5. The mean slopes of main streams within the range of 1.46 meters per kilometer to 13.6 meter per kilometer. These indicate higher slopes in the small watersheds than those in larger watersheds. Lengths of main streams are within the range of 9.4 kilometer to 41.75 kilometer, which can be regarded as a short distance. It is remarkable thing that the time of flood concentration was more rapid in the small watersheds than that in the other larger watersheds. 6. Length of main stream, L, in relation to the watershed area, A, is found to be L=2.044A0.48 having a high significance of correlation coefficient, 0.968. 7. Watershed lag, Lg, in hrs in relation to the watershed area, A, and length of main stream, L, was derived as Lg=3.228 A0.904 L-1.293 with a high significance. On the other hand, It was found that watershed lag, Lg, could also be expressed as {{{{Lg=0.247 { ( { LLca} over { SQRT { S} } )}^{ 0.604} }}}} in connection with the product of main stream length and the centroid length of the basin of the watershed area, LLca which could be expressed as a measure of the shape and the size of the watershed with the slopes except watershed area, A. But the latter showed a lower correlation than that of the former in the significance test. Therefore, it can be concluded that watershed lag, Lg, is more closely related with the such watersheds characteristics as watershed area and length of main stream in the small watersheds. Empirical formula for the peak discharge per unit area, qp, ㎥/sec/$\textrm{km}^2$, was derived as qp=10-0.389-0.0424Lg with a high significance, r=0.91. This indicates that the peak discharge per unit area of the unitgraph is in inverse proportion to the watershed lag time. 8. The base length of the unitgraph, Tb, in connection with the watershed lag, Lg, was extra.essed as {{{{ { T}_{ b} =1.14+0.564( { Lg} over {24 } )}}}} which has defined with a high significance. 9. For the derivation of IUH by applying linear conceptual model, the storage constant, K, with the length of main stream, L, and slopes, S, was adopted as {{{{K=0.1197( {L } over { SQRT {S } } )}}}} with a highly significant correlation coefficient, 0.90. Gamma function argument, N, derived with such watershed characteristics as watershed area, A, river length, L, centroid distance of the basin of the watershed area, Lca, and slopes, S, was found to be N=49.2 A1.481L-2.202 Lca-1.297 S-0.112 with a high significance having the F value, 4.83, through analysis of variance. 10. According to the linear conceptual model, Formular established in relation to the time distribution, Peak discharge and time to peak discharge for instantaneous Unit Hydrograph when unit effective rainfall of unitgraph and dimension of watershed area are applied as 10mm, and $\textrm{km}^2$ respectively are as follows; Time distribution of IUH {{{{u(0, t)= { 2.78A} over {K GAMMA (N) } { e}^{-t/k } { (t.K)}^{N-1 } }}}} (㎥/sec) Peak discharge of IUH {{{{ {u(0, t) }_{max } = { 2.78A} over {K GAMMA (N) } { e}^{-(N-1) } { (N-1)}^{N-1 } }}}} (㎥/sec) Time to peak discharge of IUH tp=(N-1)K (hrs) 11. Through mathematical analysis in the recession curve of Hydrograph, It was confirmed that empirical formula of Gamma function argument, N, had connection with recession constant, Kl, peak discharge, QP, and time to peak discharge, tp, as {{{{{ K'} over { { t}_{ p} } = { 1} over {N-1 } - { ln { t} over { { t}_{p } } } over {ln { Q} over { { Q}_{p } } } }}}} where {{{{K'= { 1} over { { lnK}_{1 } } }}}} 12. Linking the two, empirical formulars for storage constant, K, and Gamma function argument, N, into closer relations with each other, derivation of unit hydrograph for the ungaged small watersheds can be established by having formulars for the time distribution and peak discharge of IUH as follows. Time distribution of IUH u(0, t)=23.2 A L-1S1/2 F(N, K, t) (㎥/sec) where {{{{F(N, K, t)= { { e}^{-t/k } { (t/K)}^{N-1 } } over { GAMMA (N) } }}}} Peak discharge of IUH) u(0, t)max=23.2 A L-1S1/2 F(N) (㎥/sec) where {{{{F(N)= { { e}^{-(N-1) } { (N-1)}^{N-1 } } over { GAMMA (N) } }}}} 13. The base length of the Time-Area Diagram for the IUH was given by {{{{C=0.778 { ( { LLca} over { SQRT { S} } )}^{0.423 } }}}} with correlation coefficient, 0.85, which has an indication of the relations to the length of main stream, L, centroid distance of the basin of the watershed area, Lca, and slopes, S. 14. Relative errors in the peak discharge of the IUH by using linear conceptual model and IUH by routing showed to be 2.5 and 16.9 percent respectively to the peak of observed unitgraph. Therefore, it confirmed that the accuracy of IUH using linear conceptual model was approaching more closely to the observed unitgraph than that of the flood routing in the small watersheds.

• Journal of the East Asian Society of Dietary Life
• /
• v.18 no.4
• /
• pp.446-454
• /
• 2008

The traditional Korean drink "Jehotang", which is one of the most commonly prescribed drugs for treatment of the heat stroke accompanied by high fever, severe sweat and thirst, it is effective far quenching thirst strengthening the stomach, stopping diarrhea and regulating intestinal function. It is also known to play a role in activating the growth of useful microbes in the intestine and in multiplying intestinal immune cells. Thus, this study investigated all aspects of the drink in an effort to develop a new functional beverage. In the course of this study, the analytical research into the literature concerning Jehotang an error in the secrets of preparing the drink. The Japanese apricot, which was given the botanical name, "Prunusmume", should only be used with the flesh (scientifically referred to as "Fructusmume"), which is fumigated with straw fire before drying. and the seed should be thrown away. The honey should only be used after it is heated with a gentle fire, before removing the white foam that farms on its surface to make the "Yeonmil". Two kinds of cooking processes were found in the ancient literature. One procedure boiling down the powered Fructus mume mixed with the Yeonmil, while the other procedure involved preparing the Fructus mume's water by adding water to it and blending the water with the Yeonmil and the rest of the raw ingredient before boiling them down. The current procedure, in which the cooking is done in a double boiler, has been widely adopted to its simplicity. The finished Jehotang is put in porcelain, kept at room temperature, and consumed after mixing with cold water.

• Korean Journal of Environmental Agriculture
• /
• v.22 no.1
• /
• pp.16-25
• /
• 2003

Manun Reservoir, located in Andong district has the capacity of 2 million tons in irrigation water supply with the drainage area of $23.8\;km^2$. Manun Reservoir is over fifty year old, and shallow in depth. The ratio of drainage area (DA) to reservoir surface area (SA) as an effective physical parameter on water quality was 56.1 and was higher than those of other agricultural reservoirs. The ratio of reservoir storage (ST) to SA in Manun Reservoir was 4.79, and the mean depth was below 8m. Both ratios of DS/SA, total area (TA)/ST and ST/SA in Manun Reservoir were relatively higher than those in other agricultural reservoir and natural lakes in Korea. These physical parameters in Manun Reservoir, however, had a eutropic potential significance. Average of COD, IN, and TP in Manun Reservoir were 11.1 mg/L 1.426 mg/L, 0.093 mg/L, respectively. In the inflow stream of Manun Reservoir, the TN ($1.426{\sim}3.809\;mg/L$) was higher than those in reservoir. Only Lyngbya spp. was dominant in phytoplankton for this study period and Gymnodinium spp., Peridinium spp., and Cryptomonas spp. were dominant in zooplankton. According to the Carlson's trophic status index, Mnnun Reservoir was eutrophic in 1996, 1997, and 1999, and hypertrophic in 1998.