Daily potential evapotranspiration was estimated using meteorological data which are observing regularly such as rainfall, temperature, humidity, wind speed, and duration of sunshine. Penman method is used practically in estimating evapotranspiration at present, and its regional coefficients were derived at 19 stations in the Korean Peninsular. Because meteorological data are observing at 77 stations under the Korea Meteorological Administration, the methodology of estimating evapotranspiration using meteorological data will be able to be applied in more regions than Penman method.

The purpose of this study was to investigate the effects of ponding depth treatment on evapotranspiration in paddy fields. Three poding depth treatments, very sallow, shallow, and deep were used. The experimental plots were three $80m{\times}8m$ rectangular plots. Daily values of rainfall amount, ponding depth, irrigation water, drainage water, evapotranspiration, and infiltration were measured in the field. The ponding depth was continuously observed by observed nstaff during the growing season. The ET was measured by 1m diameter PVC lysimeters. Irrigation water volume was measured by 75 mm pipe flow-meters and the drainage water volume by 75 mm pipe flow-meters and a recording parshall flume. The results showed that irrigation water depths were 688.9 mm, 513.6 mm, and 624.4 mm in 2001, and 356.9 mm, 428.6 mm, and 513.2 mm in 2002 in very shallow, shallow, and deep ponding, respectively. The evapotranspiration were 465.0 mm, 484.1 mm, and 415.1 mm in 2001 and 461.3 mm, 476.3 mm, and 470.6 mm in 2002 in very shallow, shallow, and deep ponding, respectively.

Operation of experimental site on the rural water is necessary to research on the effective development and management of agricultural water. Hydrological data on the watershed runoff, reservoir storage, irrigation and drainage are measured and accumulated. For the monitoring system of the experimental site, four rainfall gauging stations and twenty-six water level gauging stations are established and operated. Analysis of measured data are processed for rainfall amount and intensity, water level and discharge.

Hasa TM/TC system is composed of one control center, two reservoirs, six pumping stations and twelve canal systems. For this system we developed water management program which includes flood forecast program, drought reduction program, irrigation scheduling program and database program. With these program we expect that operators can improve the irrigation efficiencies of the irrigation systems due to the timely irrigation on a right place, in a proper quantity and reduce the cost of maintenance and reduce flood and drought damages of the Hasa district. In agricultural engineering respect, the databases including water level, rainfall, the amount of flowing can be useful to the researcher who make a study of hydrology and hydraulics in rural area. Water management program records all of the TM/TC data to MOB format file per 10 minutes.

Many methods are available to measure leaf area index(LAI) directly and are variations of either Leaf area index(LAI) and leaf angle distribution are widely used indices of canopy structure that are difficult to measure directly. Direct measurements of canopy structure are tedious and labor intensive in small canopies and nearly impossible in large forest canopies. This study introduced fundamental theories in LAI measurements and applied that for several crops.

The aim of the present study was the evaluation of methods for estimating the vegetation information in the field on the basis of spectral reflectance measured farm field, in particular the estimation of Leaf Area Index(LAI). Variability in tissue optical properties was wavelength-dependent. For rice and bean, the lowest variation was in the visible spectral region and the highest in the near-infrared. The structural attributes of ecosystems determine the relative contribution of tissue and canopy factors that drive variation in a reflectance signal.

In order to investigate effect of irrigation on soil moisture and soybean growth, a experimental plot, which was shielded from precipitation was established. Four different irrigation rates were applied and soil moisture variations were monitored with TDR. Soybean yield and product quality are under scrutiny.

The purpose of this study is to develope a indicator for agricultural water use. Agricultural water is challenged by the increase of water use in the sectors of urbanization and industry and social pressure to use water in sustainable and environmentally sound way. The development of agricultural environment indicators is divided into 13 sectors, among which agricultural water use indicators include amount and intensity of agricultural water use, efficiency of agricultural water use, shortage or surplus of water use, water stress, etc.. Agricultural water use indicators provide basic data for sustainable and environmentally sound agricultural development, and also help policy decision makers to solve water shortage problems through water policy and water management measures by making the most of the total available water resources.

It is to show the problems of the existing techniques to estimate agricultural water demand and to suggest the new methods considering the water demand for non-irrigated area and decrease of water loss in canal. It is to suggest the methods to improve the techniques for estimating agricultural water demand and to analyze the water demand and supply according to the facilities capacity. Until now, the concept of per the unit used to estimate agriculture water demand is useful to estimate demand, but is insufficient to cope with the variations of conditions in future. And the paddy area of government is not realistic against a trend of decrease. Water demand decrease is caused by constructions of irrigation facilities as constructing of irrigation canal, but application loss ratio is fixed. Increase of the water demand owing to the increase of the yield per the unit area is also the actual condition which is not considered. The guide-line must contain these contents for a demand estimate.

It is unreasonable to calculate the amount of agricultural water use by applying unit demand method, because it is different from other water use due to the return flow and reuse in the recycle of watershed. Data from irrigation pumping station and reservoir were analysed. Factors for water balance are precipitation, evapotranspiration, percolation, runoff, and management loss, etc. Here in the study, the amount of agricultural water was defined in the way of three different categories. First one is "Gross water" including evapotranspiration, percolation, and management loss. Second one is "Agricultural water" including Gross water and effective rainfall. Third one is "Broad water" which is abstracting the return flow from Agricultural water.

Irrigation canal systems were evaluated based on documentations and field survey. Field survey was conducted for main canals using GPS, with respect to canal characteristics such as canal material, presence of weed, potential inflow of sediment, sedimentation, and so forth. Methodology described in this paper could be used for planning maintenance practices.

Measuring of Water Losses in irrigation canals have been done in 4 irrigation area. Four concrete canals and nine earth canals have been measured by the inflow-outflow method. The results obtained in this experiment were that the loss rates in the main irrigation canal and the secondary irrigation canal were 11.54%, 19.29% respectively. And the loss rates in concrete irrigation canals were 4.77%.

This study presents an evaluation of the mechanical pipe flowmeter at low hydraulic heads. Three flowmeters each of 75mm and 25mm diameter were used. The Flowmeter was tested with experimental open channel apparatus. Relationship between flowmeter values and bucket values was good. The 75mm diameter flow meter showed small relative errors with hydraulic heads above 9cm. The 25mm diameter flow meter showed small relative errors with hydraulic heads above 2cm. The Irrigation flow measurement using the mechanical pipe flowmeter of 75mm diameter in paddy fields needs hydraulic head above 9cm, which is easy to get in tertiary canals.

Developed power off automatic stanch that keep floodgate upper stream water level changelessly for curtailment of operation by manpower and electricity lead-in equal early investment expense that manual system floodgate and electric motion floodgate have. Human strength does not need in floodgate operation as that power off automatic floodgate open and close floodgate automatically by buoyancy and also, another thing power does not need. Before establish floodgate, effect that get to waterway when behaves repair calculation of correct waterway and decide size of floodgate accordingly and establish floodgate must do examination analysis fussily. power off automatic floodgate night soil that get between countermeasure is the urgentest low-down in reply because can do mistake in operation by phenomenon and so on about water resources by different plate shape change through a model experiment examine closely need to.

We constructed climagraphs for 16 regions of Korea by using the average monthly minimum air temperature, maximum air temperature and global radiation. We characterized the outside climate requirements corresponding to the climate requirements of crops in greenhouses. The climagraphs allow to decide the appropriate climate periods for greenhouse cultivation without heating and cooling equipment. These graphs may be used for analyzing climatic characteristic of a given area, selecting the suitable region and greenhouse and making a rational plan for greenhouse cropping in Korea. We found difficulty in deciding the beginning and end of greenhouse heating and cooling period due to insufficient references.

This study was conducted to secure the structural safety and to build fundamental data for development of controlled environment facilities in ginseng cultivation. Shading structures of ginseng cultivation were classified with materials, structural forms, and detailed setups. They are wood or steel pipe, single or multi span, and frame or cable type. For structures having representative forms and dimensions, modeling for structural analysis was builded by SAP2000. And there was almost no farm carrying out the environmental management specially.

The objectives of this study are to analysis structural characteristics of small scale vinyl house and to develope structural analysis program for optimum design. The variation of maximum section forces along the structural characteristics, location and number of purlin was analyzed in vinyl house. It was concluded that the developed structural analysis program could be used usefully for optimum design of small scale vinyl house.

이 연구는 흙으로 만든 전통적인 저장고를 검증하기 위하여 흙담저장고를 축소 제작하고 농산물의 저장조건에 많은 영향을 미치는 온도와 습도의 변화를 9월 4일부터 10일까지 7일동안 측정하고 분석하였다. 그 결과를 요약하면 다음과 같다. 1. 흙담저장고는 외부 기온보다 일일 $3.5^{\circ}C{\sim}8.5^{\circ}C$ 낮게 유지되고 변화폭이 $2.5^{\circ}C{\sim}5^{\circ}C$로 작아 농산물 저장 조건에 맞추기 위한 에너지 투입이 줄어들 것으로 기대된다. 2. 습도는 높게 유지되고 변화폭이 $4%{\sim}9%$로 습기(물)만 저장고 내에 제공하면 충분히 저장조건에 맞는 80% 이상을 유지하기 쉬울 것으로 기대된다. 3. 흙담저장고에 실제로 농산물을 저장하였을 경우에 저온저장고에 맞추어져 있는 저장 조건들이 상당량 바뀔 것으로 보인다. 이는 오래동안 보관하는 저온저장고와는 달리 농산물의 맛, 신선도 등 품질면의 향상으로 이어질 가능성도 있어 이에 대한 시험과 검증이 필요할 것으로 보인다.

This research was carried out to show the method of preserving high-grade farmland or Agricultural Development Area to contribute to the self-sufficiency of food as well as promotion of industrialization and urbanization, which has reduced 22,000 ha of farmland per year during last 10 years. However, in securing housing estate areas, the farmland conservation policy conflicts with housing supply policy for demands on more comfortable dwelling life for people, which leads to serious situation in Capital Circle of living more than 50 % of total national population. Therefore, this presents the method of fulfillment both the farmland conservation policy for self-sufficiency of food and the housing supply policy for proposition of securable residential areas.

The Sea dike tidal closure works has traditionally ended in the failure. Therefore, the success of the tidal closure in Hwaong in the sea near Inchon where has the greatest tidal gap in our country deserves to consider its meaning. While its process was going on, we had the difficulty like bad weather, unexpected ground settlement, flow velocity beyond the imagine, etc. Moreover, environment group's rush was so fierce that the works could have been delayed. This works showed that not only technical aspects but also social problems(environment group's rush and public discontents) were important factors in accomplishing the works. Finally, all of the difficulties were overcome and the tidal closure works were successful. So, This success is the best example in a kind of the another works in itself.

This paper presents the result of the Water Erosion Prediction Project(WEPP) watershed scale model's application for prediction of sediment yield from a watershed which is comprised of hillslopes and channels and analyses of the soil loss from hillslopes and channels with crop practice and shape. To evaluate the model's application, the model is applied to a watershed that comprised of six hillslope and one channel, and the result was a good agreement with the observed values. The soil loss from hillslope was increased as the hills lope was under fallow conditions and slope length was longer. The soil loss from the channel was increased at the downstream for the concentration of flow.

Among 172 wastewater treatment plants, eighty eight plats are found to be qualified for potential wastewater resources applicable to agricultural irrigation. The total effluent capacities are 4,042 thousand tonnes per day, which may be used to irrigated paddy fields of $156\;km^2$. Preliminary surveys have been made to inquire farmers and water managers about their preference for wastewater reuse. All of them expressed their willingness to accept the wastewater reuse. The surveyed water managers suggested microbiological treatments be made and exclusive prove for safety of wastewater irrigation be prerequisite to the practices. Further surveys with experts and water managers throughout the nation are needed before any conclusions are made.

This study was carried out to investigate the actual state of management for tourism farms of Chuncheon City. Also, it was evaluated whether the selection of suitable place was done for the existing tourism farms with GIS. Especially, it was analyzed for the distance and time used by visitors of tourism farms. The directions for the efficient agricultural land uses and selection of suitable places were suggested for the tourism farms being opened in the future with these analyses.

So far, the water management have separately been accomplished by water supply, flood control, and environmental river management. In spite of sustainable policy of water resource development, flood & drought damage, poor water accident, and deterioration of river ecosystem have continuously occurred. It means that it is difficult to improve those problems with the present systems and institutions. So, it is time to discuss to change the present water management system of administrative sense into the one classified by the watershed in order to understand problems of water resource in the regional basis. First, a integration of similar branch office in organization and a work specialization should be driven in the government. Second, it is desirable to develop the water resources according to the inherent characteristics of the watershed.

Recent years have been widely discussed rural amenity as well as ecological restoration, green tourism, friendly nature, environmental preservation and so on as a way of addressing the various issues in sustainable rural development. This paper explores what the evaluation items on rural amenity is to sustain the identity of rural villages. After a review of the related preceding researches we suggested two alternatives of the amenity evaluation items in rural village's level. The one is the amenity evaluation items which consists of 3 factors and 17 items on basis of three functional space such as a living place, a working place, and a protected and enjoying place in rural villages. The other's amenity evaluation items has 6 factors and 14 items from a viewpoint of the functional integrated space in rural villages.

In this study, flood influence analysis in the downstream of Sung-Ju dam was simulated using HEC-RAS model. Input data for the simulation was which measured water level, water velocity, stream section etc. HEC-RAS model could be applied to steady flow or gradually varied flow in natural or artificial stream. HEC-RAS model which can simulate real-time changing water level and compute water surface curve was supplied to show the standard influent amount of Sung-Ju dam. Through this study the submerged damage of Sung-Ju dam's downstream would be minimized.

A naturally favorable consolidated Drainage canal which had been completed in August 2000 was observed over two years with surrounding environment, fauna and flora, alternation of fauna. Research data for understanding ecological change were vegetation, water quality, fishes and amphibia. Through these researched data, biotope data would be established basically. Creation of Biotope which is related to naturally favorable consolidted ecological change of canal was considered on this study.

The rural population has been continuously decreased since the standards of living in rural communities is relatively lower than in urban. In other words, rural area has become less attractive for settlement. The concept of 'rural amenity' was introduced, to increase interests in the development of rural area. But, there has not been proper theories and methods to evaluate the amenity. In this study, rural amenity was classified and the elements of rural amenity was evaluated using statistical methods. The results of this study could be useful to assess the effects of the polices on improving rural amenities.

Remodeling of agricultural facilities can be defined as follows; it is received newly social needs which calamity is reduced, its function is improved, ecosystem is maintained, water-friendly space is preserved. By those remodeling, environment water and tour water with role as a place of rest and leisure sports, and so forth can be ensured. Therefore, on this study, we would propose the approach of the repair and enhancement of agricultural facilities which can reflect those social demands.

국내 느타리버섯 재배 농가 중 64%가 부업형이고, 재배사 한 동의 규모도 $40{\sim}70$평 정도로 다양할 뿐만 아니라 농가당 재배규모가 적어 영세성을 면치 못하고 있는 실정이다. 이중 간이식 재배사가 70%정도를 차지하고 있어, 버섯의 가격이 가장 비싼 여름철에는 재배를 할 수 없는 실정이다. 또한 지역별, 규모별로 환경조절 설비에 대한 적정기준 뿐만 아니라 재배사 관리지침 둥도 전무한 상태이고, 오직 재배와 환경조절 설비는 경험에 의 존하고 있었다. 재배사를 신축할 경우에도 전문시공업체가 거의 전무한 상태였다. 앞으로 연중재배 시스템을 도입하여 고품질 버섯을 재배하여 국제경쟁력을 높이려면, 이러한 문제점들이 우선 선결되어야 할 것으로 판단된다.

The uplift capacity and displacement of an earth anchor for improving the wind resistance of the 1-2W type plastic film pipe on greenhouse was tested using the steel circular vertical earth anchor with various diameters and embedded depths (L) in dry sand. The diameter (B) of the model anchor is 90mm, 120mm, 150mm, respectively. The model tests were performed embedded depth ratios (L/B) ranging from $1{\sim}3$ in loose density. In the case of diameter 90mm, as the uplift loading increased, the uplift capacity also increased until the loading was reached to ultimate uplift capacity. After that, the uplift capacity was continually increased or decreased until the experiment was finished. In general, the ultimate uplift capacity was different depending upon the anchor diameter and embedded depth ratios.

The purpose of this study was to disclose the problems of structural safety of small scale vinyl house through investigation of actural state of plastic greenhouses by region and growing crops and the objective of a field survey is to develop safety structural model of small scale vinyl house which accounts for the most part of local horticultural facility in order to reduce damage caused by strong wind and heavy snow repeatedly every year.

A simulation by the TOPAS model, two dimensional finite difference model was performed on the flows through drainage lock gate for the Saemangeum tidal reclamation project. Analysis focus on the changes of intertidal zone areas according to the operation scheme of the gate. The intertidal zone areas were analyzed as $66{\sim}70\;km^2$ when the opening of the gate was 300 m. It occupied about $85{\sim}90%$ of intertidal zone areas compared to that the Mangyung sea basin was opened without sea-dike. It appeared to be the most effective in terms of securing enough intertidal zone areas when the gate was operated as inflowing sea-water after 2 day's drainage.

The monitoring system for integrated management of on-site wastewater treatment plants(biofilter) was designed and its operation program was developed. In design process, the research on monitoring parameters which will be able to represent condition and operation of the pilot plants was accomplished, and these parameters came to reveal with ORP(Oxidation-Reduction Potential), water level, pump and power on/off. Proposed monitoring system is composed with measurement, control, communication and display device, and PCB(Prototype Circuit Boards) and microcontroller (PIC16F877) technique are applied to its design of control device for performing specific function. also, The operation program of PC setup is developed in order to provide a convenience to the manager.

A layout planning of the rural village must consider regional, environmental and historical background, at the view of future-oriental. The study is Ryongsan-chon, that common the Korean rural village in China. It has a good environment for agriculture but lacking facilities for life. The layout plans that consider the characteristic of in-China, and Korean made out.

This study is performed to properties of low heat concrete using blast furnace slag powder and gypsum. The test result shows that the air content is in the range of $4.1%{\sim}5.1%$, the unit weight is in the range of $2,306kg/m^3{\sim}2,334kg/m^3$. The compressive strength of concrete mixed blast furnace slag(BFS) low than ordinary portland cement(OPC) at the curing age of 7days, but it is high or same at the curing age of 28days. And the natural gypsum shows superior compressive strength than the chemical gypsum.

This study is performed to evaluate the properties of ECO-permeable polymer concrete with blast furnace slag powder and stone dust. The unit weight is in the range of $1,821kg/m^3{\sim}1,955kg/m^3$, the unit weights of those concrete are decreased $15%{\sim}20.8%$ than that of the normal cement concrete. The highest strength is achieved by ECO-permeable polymer concrete filled blast furnace slag powder 50% and stone dust 50%, it is increased 36% by compressive strength, 119% by tensile strength and 217% by bending strength than that of the normal cement concrete, respectively. The coefficient of permeability is in the range of $5.6{\times}10^{-2}cm/s{\sim}8.1{\times}10^{-2}cm/s$, and it is largely dependent upon the mix design.

The purpose of this research was to evaluate on the properties of fresh and hardened high-performance concrete(HPC) incorporating high-reactivity metakaolin(HRM). Setting time, heat of hydration, compressive strength, resistance to chloride-ion penetration, and repeated freezing and thawing test were carried out in order to investigate the properties of fresh and hardened state concrete. The properties of the HRM concrete were also compared with those of the portland cement concrete and silica fume(SF) concrete. The laboratory test results indicate that HRM material can be used as a supplementary cementitious material to produce high-performance concrete.

This study was developed high-quality a large size precast channel structure using polymer concrete to improve quality of the product as well as to enhance construction quality. Practical precast channel structure design and manufacture procedure for the high polymer concrete were described in this paper. Precast PC represent the fastest growing segment of the polymer concrete industry. The fast curing, high strength, and low impermeability permit thin section and rapid reuse of moulds. Precast channel structure will carry out structural experiment and analysis.

This study was performed to find out the regression function to calculate the modulus of elasticity of concrete mixed by river coarse aggregate. The distribution of the group of core strength made a normal curve and the effect factor in the modulus of elasticity was 0.97 at the concrete compounded by river coarse aggregate.

The effects of polymer-cement ratio, antifoamer agent content and shrinkage-reducing agent content on the drying shrinkage of polymer-modified mortars using redispersible polymer powder are examined. As a result, irrespective of the antifoamer content, the drying shrinkage of the polymer-modified mortars using redispersible polymer powder tend to decrease with increasing polymer-cement ratio and shrinkage-reducing agent content. Such a drying shrinkage development is due to the effect of reducing water from incorporation of EVA redispersible polymer powder and antifoamer agent.

In this study, the effects of the number of coat and immersion period on strength properties, waterproofness and chemical resistance of painted and immersed cement mortars using two admixture were examined. Test results showed that the flexural and the compressive strengths of the coated and immersed cement mortars increase with increasing number of coat and immersion period. The water absorption of the coated and immersed cement mortars tended to decrease with increasing number of coated and immersion period. In the case of the change of weight and the immersion period for the solutions, a decreasing tendency was shown as the immersion period increases regardless of solution, with a little variation.

This study is performed to examine the dry Hwangtoh mortar. The unit weight is in the range of $1,891kg/m^3{\sim}2,037kg/m^3$, it tend to decrease with increase using the Hwangtoh. The compressive and bending strength are in the range of $105kgf/cm^2{\sim}353kgf/cm^2,\;18kgf/cm^2{\sim}66kgf/cm^2$, respectively. The mortar of using Hwangtoh 20% is showed the highest strength ratio.

This study is performed to properties of ready mixed concrete (RMC) in site. The unit weight of the B company's RMC is range from $2,308kg/m^3\;to\;2,355kg/m^3$ and that of the J company's RMC is range from $2,288kg/m^3\;to\;2,310kg/m^3$. The compressive strength of B company's RMC of curing age of 7 days is range from $191kgf/cm^2-232kgf/cm^2$ and that of curing age of 28days is $273kgf/cm^2{\sim}306kg/cm^2$. The compressive strength of J company's RMC of curing age of 7 days is range from $151kgf/cm^2{\sim}177kgf/cm^2$ and that curing age of 28 days is range from $215kgf/cm^2{\sim}234kgf/cm^2$. The B and J company's air content is range of $3.2{\sim}5.2%$. The content of Chloride of the Band J company's is range from each $0.026kg/m^3{\sim}0.046kg/m^3\;and\; 0.034kg/m^3{\sim}0.069kg/m^3$, respectively.

In this research, a basis test on steel fiber concrete's material property was carried out and optimum design as well as material property was examined. In corroboration of it, the compressive strength was compared with the tensile strength and this paper tried to get the initial load of flexural cracking and the ultimate load in the positive-negative moment section through the static test of beam. The addition rate of the steel fiber, 0.75 SFRC specimen was failed at $65{\sim}75%$ of the static ultimate strength and it could be concluded that fatigue strength to two million cycle was around 75.2%.

This study is performed to examine the engineering properties of polyprofilene fiber reinforced high flowable concrete. For the estimation of the flow ability and filling ability, the slump flow, box height difference and L-shape filling appearence are measured and compared. The test result shows that the slump flow and L-shape filling appearence is decreased with increase containing polyprofilene fiber and box height difference is increased with increase containing polyprofilene fiber. Also, compressive strength is decreased with increase containing polyprofilene fiber.

This study is performed to properties of strength of concrete using recycled aggregate. The compressive strength is in the range of $232kgf/cm^2{\sim}375kgf/cm^2$, the tensile strength is in the range of $27kgf/cm^2{\sim}35kgf/cm^2$, and bending strength is in the range of $58kgf/cm^2{\sim}67kgf/cm^2$ at the curing age of 28days. The test result shows that the strengths tend to decreased with increase using recycled aggregate.

This study is performed to examine physical and mechanical properties or neutralization treatment point and curing methods of ECO-cencrete using rice straw ash. Tests for void ratio, compressive and bending strength with neutralization treatment point and curing methods are performed. The test result shows that the void ratio is decreased with increasing content of rice straw ash. But, the compressive and bending strength is increased with increasing content of rice straw ash. The greatest strength is appeared when neutralization is treated at the curing age of 6 days.

This study is performed to examine the non-destruction properties of the Hwangtoh mortar. The absorption ratio is in the range of $8.25%{\sim}18.16%$, it tend to increase with increase using the stone dust and Hwangtoh. The pulse velocity and dynamic modulus at the curing age 7 and 28days are in the range of $2,290m/s{\sim}4,140m/s,\;2,976m/s{\sim}4,219m/s\;and\;105{\times}10^3kgf/cm^2{\sim}293{\times}10^3kgf/cm^2,\;137{\times}10^3kgf/cm^2{\sim}318{\times}10^3kgf/cm^2$, respectively. They tend to decrease with increase using the stone dust and Hwangtoh.

This study is performed to develop of planting block using rice straw ash for Protection of Inclined plane. For the planting, porous concrete block is demanded ability to passing water and air through void of block. In this paper, material used for porous concrete block is cement, rice straw ash, and coarse aggregate(5-10, 10-20, 5-20mm). Planting block size is 23*23*4cm and kinds of planting are Tall fescue, Lespedeza cyrtobotrya and Lespedeza cuneata. The results measured for three months show that possible planting of various kinds for porous concrete block.

This study is performed to examine the flowability and filling ability of steel fiber reinforced high performance concrete. For the estimation of the flowability and filling ability, slump flow, box height difference and L-shape filling appearence are measured and compared. The test result shows that the slump flow is $60{\pm}5cm$ to make no difference with containing steel fiber, box height difference is increased with increasing steel fiber and L-shape filling appearence is to bad with increasing steel fiber. But, proper containg of steel fiber is considered to be applied for high performance concrete without decreasing of slump flow and filling ability.

The construction method of a dirt-walled house is studied in order to develop eco-friendly store house. A dirt-walled house is constructed based on wall frame(Korean traditional style). The main material is soil (mud).

This study is performed to examine the physical and mechanical properties of cement mortar with Hwangtoh and fly ash. The unit weight is in the range of $2,068kg/m^3{\sim}2,137kg/m^3$ and $1,899kg/m^3{\sim}2,045kg/m^3$, the compressive strength is in the range o $92kgf/cm^2{\sim}458kgf/cm^2$ and $88kgf/cm^2{\sim}316kgf/cm^2$ and the pulse velocity is in the range o $3,195m/s{\sim}4,255m/s$ and $2,670m/s{\sim}3,953m/s$ in water and dry curing, respectively. Also it is decreased with increase of the content of Hwangtoh.

This study was carried out to investigate the characteristics of the field-saturated hydraulic conductivity$(K_{fs})$ and matric flux potential$({\Phi}_m)$ measured by the Guelph Permeameter at the Backokpo watershed in the Han river and at the Bangdong watershed in the Keum river. And the Alpha $({\alpha})$ value which is the ratio of $K_{fs}$ to ${\Phi}_m$ were determined and the ${\alpha}$ values along with the defined soil series could be utilized to classify the soil in the Korean watershed into the SCS hydrologic soil groups.

The analysis of characteristics of pumping in the small tube well for agriculture were surveyed. Study area was located at the Galsinri in Yesangun near the yedang reservoir. Agricultural electricity using rates for pumping, ground water level and volume of pumping was monitored every week. Pump working ratio and pump efficiency during period of transplanting of rice showed 48.5%, 58.4% respectively.

This research seeks to derive the design rainfalls through the L-moment with the test of homogeneity, independence and outlier of data on annual maximum daily rainfall in 38 Korean rainfall stations. To select the fit appropriate distribution of annual maximum daily rainfall data according to rainfall stations, applied were Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) probability distributions were applied. and their aptness was judged Dusing an L-moment ratio diagram and the Kolmogorov-Smirnov (K-S) test, the aptitude was judged of applied distributions such as GEV, GLO and GPA. The GEV and GLO distributions were selected as the appropriate distributions. Their parameters were estimated Targetingfrom the observed and simulated annual maximum daily rainfalls and using Monte Carlo techniques, the parameters of GEV and GLO selected as suitable distributions were estimated and. dDesign rainfallss were then derived, using the L-moment. Appropriate design rainfalls were suggested by doing a comparative analysis of design rainfall from the GEV and GLO distributions according to rainfall stations.

This study was conducted to estimate the design flood by the determination of best fitting order of LH-moments of the annual maximum series at six and nine watersheds in Korea and Australia, respectively. Adequacy for flood flow data was confirmed by the tests of independence, homogeneity, and outliers. Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Pareto (GPA), and Generalized Logistic (GLO) distributions were applied to get the best fitting frequency distribution for flood flow data. Theoretical bases of L, L1, L2, L3 and L4-moments were derived to estimate the parameters of 4 distributions. L, L1, L2, L3 and L4-moment ratio diagrams (LH-moments ratio diagram) were developed in this study.

This study was conducted to estimate the design flood by the determination of best fitting order for LH-moments of the annual maximum series at fifteen watersheds. Parameters of GEV distribution and flood flows of return period n years were derived by the methods of L, L1, L2, L3 and L4-moments. Frequency analysis of flood flow data generated by Monte Carlo simulation was performed by the methods of L, L1, L2, L3 and L4-moments using GEV distribution. Relative Root Mean Square Error (RRMSE), Relative Bias (RBIAS) and Relative Efficiency (RE) using methods of L, L1, L2, L3 and L4-moments for GEV distribution were computed and compared with those resulting from Monte Carlo simulation. At almost all of the watersheds, the more the order of LH-moments and the return periods increased, the more RE became, while the less RRMSE and RBIAS became. Consequently, design floods for the applied watersheds were derived by the methods of L3 and L4-moments among LH-moments in view of high confidence efficiency.

Design rainfall using LH-moments following the consecutive duration were derived by the regional and at-site analysis using the observed and simulated data resulted from Monte Carlo techniques. RRMSE, RBIAS and RR in RRMSE for the design rainfall were computed and compared in the regional and at-site frequency analysis. Consequently, it was shown that the regional analysis can substantially more reduce the RRMSE, RBIAS and RR in RRMSE than at-site analysis in the prediction of design rainfall. RE for an optimal order of L-moments was also computed by the methods of L, L1, L2, L3 and L4-moments for GEV distribution. It was found that the method of L-moments is more effective than the others for getting optimal design rainfall according to the regions and consecutive durations in the regional frequency analysis. Diagrams for the design rainfall derived by the regional frequency analysis using L-moments were drawn according to the regions and consecutive durations by GIS techniques.

A formula of watershed evapotranspiration by Penman or Thonthwaite or Lowry-Johnson was used to measure its quantity of evapotranspiration until now. These formula were derived for Foreign country and, it is rather difficult to apply the above formulas to the Korean watershed. These measuring methods are merely used to measure the monthly quantities of evapotranspiration. At the research CE of a coefficient of evapotranspiration for a watershed were newly presented, which was utilized for the calculation of Beken's formula in the DAWAST model.

The Soil Conservation Service (SCS) developed a unique procedure for estimating direct runoff from storm rainfall. But, It is very difficult to estimate accurately flood hydrograph by SCS method, because the initial ion of Ia(0.2Sa) itself has lots of systematic errors and there is no investigation on Ia in the Korean watershed. The maximum storage capacity of Umax is calibrated in the DAWAST model and is related to the present ability of rainfall to be infiltrated into the unsaturated soil. Effective rainfall for design and real-time flood hydrograph can be estimate more reasonably by introducing new Ia relationship made from the rainfall-runoff data observed in the Korean watersheds.

This model is the daily streamflow model of the Korean watersheds has been developed to simulate the daily streamflow with the data of daily rainfall and pan evaporation. Parameters of this model are the water balance parameters composed Umax, Lmax, FC, CP, and CE and the routing parameters composed $U_i,\;k_1\;and\;k_2$. Among these parameters, CE value is applied one fixed value during the year and coefficient of initial ion K is empirically determined by 0.2. The object of this research is to improve the DAWAST model by application of the monthly value of CE for evapotranspiration and the revised K value for the initial abstraction.

A hydrologic gauging network include a real-time measuring equipment was established within the Balhan watershed. Rainfall, stream water level, flow velocities were monitored at the six gauging stations. For stream flow gauging stations, the stage-discharge relationships were developed. The flow rate of the Balan watershed was 83.60% in 2001 and 48.79% in 2002.

이 연구는 지하수개발사업 타당성 분석을 지원하기 위한 Desk GIS에 기반한 지하수사업기초조사지원 시스템을 개발하는 것이 목적이다. 개발된 시스템을 이용하면, 신규 개발 예정관정에 대하여 GIS안에서 모의 양수실험을 할 수 있으며, 기설관정의 채수영향반 경과의 중첩여부, 오염원 등과 비교하여 지하수관정개발사업의 허가여부를 판단할 수 있다. 농업기반공사 등 지하수 관련 부서들이 전사적으로 지하수 관련자료를 공유할 수 있으며, 자료의 정확성, 신뢰성 그리고 최신정보를 공유할 수 있을 것이다.

Yi-dong experimental basin is operated for research on the rural basin characteristics and accumulation of a long term data by hydrological observation equipments. It is basin area 9,440ha, length 14.4km and slope 0.67%. Hydrological observation network is constructed of rainfall meter 4points, reservoir storage level 3points and river water level 2points.

The ground water regime analysis method, numerical analysis method, water budget method, and baseflow analysis method have been used for estimating ground water recharged quantity. This study, adapting water budget concept of unsaturated zone, and saturated zone of the DAWAST model, proposed a new method to estimate ground water recharged quantity.

Turbidity currents, often develop after heavy storm events, deliver various non-point pollutants and tend to lead eutrophication, depressed dissolved oxygen, and sedimentation in reservoirs. Field observations were performed to investigate the flow regimes of turbidity currents and their impact on reservoir water quality in Daecheong Reservoir. A 2D laterally-averaged hydrodynamic and water quality model was applied to simulate the temporal and spatial distributions of turbidity in the reservoir, and evaluated by comparing with the field data.

Watershed boundary and stream network can be extracted from DEM(Digital Elevation Model) using GIS software such as ARC/INFO or ArcView Spatial Analyst. However, there exist many errors in the generated watershed boundary and stream network just by operating sink removal function of the present software. This paper present the error reducing method to delineate watershed boundary and generate stream network especially in plane areas by using stream burning techniques known as Fillburn and Agree bum. These preprocessing techniques of DEM dramatically decreased the errors comparing with the results by no-bum DEM.

An artificial neural network model was developed to analyze and forecast real time river runoff from the Naju watershed, in Korea. Model forecasts are very accurate (i.e., relative error is less than 3% and $R^2$ is great than 0.99) for calibration data sets. Increasing the time horizon for validation data sets, thus making the model suitable for flood forecasting, decreases the accuracy of the model. The resulting optimal EBPN models for forecasting real time runoff consists of ten rainfall and four and ten runoff data (ANN0410 and ANN1010 models). Performances of the ANN0410 and ANN1010 models remain satisfactory up to 6 hours (i.e., $R^2$ is great than 0.92).

Geographic Information System (GIS) has advantage of analyzing spatial distributed data and handling spatial data for hydrologic analysis. Hydrologic Engineering Center's Hydrologic Modeling System(HEC-HMS) with HEC-GeoHMS was used to analyze flood runoff at agricultural small watershed. HEC-GeoHMS, which is an ArcView GIS extension designed to process geospatial data for HEC-HMS, is a useful tool for storing, managing, analyzing, and displaying spatially distributed data. Hydroligical component including peak discharge, time to peak, direct runoff, baseflow for Balhan study watershed, which is located in Whasung city, Kyunggi province, having an area of $29.79km^2$, were calculated using the HEC-HMS model with HEC-GeoHMS.

For real-time flood forecasting and effective control flood at the Youngsan estuary dam, the Flood Forecasting and Control User Interface System II (FFCUS II) has been developed. This paper describes the features and application of FFCUS II. FFCUS II is composed of the database management subsystem, the model subsystem, and the graphic user interface. The database management subsyem collects rainfall data and stream flow data, updates, processes, and searches the data. The model subsystem predicts the inflow hydrograph, the tide, forecasts flood hydrograph, and simulates the release rate from the sluice gates. The graphic user interface subsystem aids the user's decision-making process by displaying the operation results of the database management subsystem and model subsystem.

In this study, a topography based hydrologic model (TOPMODEL) was tested on the Anseong-cheon watershed. Pit in watershed was removed by liner trend surface interpolator. The DTM Analysis program is used to derived a distribution of ln($a/tan{\beta}$) values from DEM (Digital Elevation Model) using the MDF (Multiple Direction Flow) algorithm of Quinn et al (1995). Current TOPMODEL program limits are number of time step, ln($a/tan{\beta}$) increment, delay histogram ordinate and size of subcatchment pixel maps. Therefore, TOPMODEL is not suitable for application of large watershed. Muskingum method and watershed division enhance grid pixel resolution for rainfall-runoff simulation accuracy.

The purpose of this study is to evaluate the hydrological impact due to temporal land cover change urbanization of Anseong-cheon watershed $(585.09km^2)$. WMS (Watershed Modeling System) HEC-1 was adopted, and burned DEM with $200{\times}200m$ resolution and soil map reclassified by hydrologic soil groups were prepared. Land cover for 1985, 1990, 1995 and 2000 were classified by maximum likelihood method, using Landsat MSS and TM imageries. Calibration and verification of HEC-1 were conducted using 4 storm events. Peak flow at Pyeong taek station increased $25.9m^3/sec$ during the past 15 years due to paddy and forest decrease. Streamflow impact by just paddy area decrease and forest area decrease were also analysed keeping watershed CN values unchanged of the given year, respectively.

Semi-two dimension numerical models were applied to study on the hydraulic and sedimentologic characteristics of upstream and downstream channel section in Dal stream. The feature of this paper is (1) to analyse the effects of bed changes by sediment transport formulas, (2) to analyse the effects of bed changes by stream tube. The simulation results of Meyer-peter and Muller formula for long-term bed changes are good when compared to the measured data.

The EPIC model was applied to assess the environmental impacts of two contrasting tillage systems (conventional versus ridge tillage). The model was calibrated with field data and validated with another set of data. The errors between the 12-year predicted and observed means or medians were less than 10% for nearly all of the environmental indicators, with the major exception of a nearly 44% over prediction of the N surface runoff loss for Watershed 2. The predicted N leaching rates, N losses in surface runoff, and sediment loss clearly showed that EPIC was able to simulate the long-term impacts of tillage and residue cover on these processes.

This study is that analyzes the flood damages caused by rainfall during typhoon and how inundated area should be affected. Using HEC-HMS for analyzing rainfall-runoff and GIS (Geography Information System) for analyzing inundated area and volume. Each model was applied to Seopyung area for runoff effect analysis. As the result, Damaged area was magnified gradually according to the increase of rainfall and GIS was good for calculating the exact flood damage area at varied time.

This paper reviews depositional environments, consolidation characteristic of marine deposits along the Nam-Yang river mouth and then analytical solution of self-weight consolidation is made to find consolidated state. This area has been deposited through the short geological age(22year). It's deposition rate is as high as 70cm/year and the height of deposition may be $3{\sim}12m$. It's known that this area is in the under-consolidated state from OCR and analytical solution. It is conclude that the under-consolidated state should be considered in prediction of consolidation settlement.

This study was performed to evaluation the consolidation behavior of agricultural reservoir in the very soft ground. The final settlement prediction methods by Hyperbolic and Asaoka methods were used to compare with the degree of consolidation estimated by exess pore water pressure. The dissipated excess pore water pressure during embankment construction and peak excess pore water pressure on the completed embankment were suggested for the estimation of the degree of consolidation. It was concluded that the degree of consolidation estimated from dissipated excess pore water pressure was more reliable than that from the peak excess pore water pressure.

The compression index, $C'_c$ and the swelling index, $C'_s$ which are obtained from the e-log p curve of the consolidation test, are used to calculate the consolidation settlement. In this research, $C'_c$ and the two new methods of $C'_s$ i.e. $C'_{s1}$, $C'_{sm}$ for remolded clays were examined with the $({\omega}_0-{\omega}_p)$ and $(e_0-e_p)$ which are satisfied with the condition and the type of soil. Moreover, the relationships of $C'_{s1}$, and $C'_{sm}$ versus $C'_c$ were obtained.

To analyze the settlement characteristics of short-fiber reinforced soil(SFRS) under dynamic loading, a series of tests with loading condition of 5 Hz frequency and 500,000 cycles were performed. The materials used for tests are a soil of SM type and short-fibers with polypropylene and monofilament or fibrillated type. From the tests, average plastic settlement of SFRS at PPF38(0.3%), PPF38(0.5%), PPM60(0.2%) is low. Elastic settlement of SFRS is low at PPM60(0.2%) and is high at PPF60(0.5% ).

Recently, attempts to use indigenous plants have been made for the recovery of nature of slopes and making permanent vegetation group, harmonizing with surroundings from the ecological perspective. For surface failure prevention of slopes, indigenous plants are known as superior to those of exotic grasses, but studies how much indigenous plants influence shear strength of soil is lacking. Therefore, in this study, strength increasement of the root-soil system were investigated for four indigenous plants.

In the present study, in order to apply a cyclic viscoelastic-viscoplastic constitutive model to multi-layered ground conditions during large earthquake, the numerical simulations of the 1995 Hyogoken Nanbu Earthquake at Port Island, Kobe, Japan, were performed by the seismic respons analysis. From the seismic response analysis, it was verified that a cyclic viscoelastic-viscoplastic constitutive model can give a good description of the damping characteristics of clay accurately during large event which induces plastic deformation in large strain range.

Traditional methods of earth reinforcement consist of introducing strips, fabrics, or grids into an earth mass. Recently, discrete fibers are simply added and mixed with the soil, much the same as cement, lime or other additives. The advantages of randomly distributed fibers is the maintenance of strength isotropy, low decrease in post-peak shear strength and high stability at failure. In this study, new composite reinforcement structures which consist of geotextile and randomly distributed discrete fibers were examined their engineering properties, such as shear strength of the composite reinforced soil. The increments of shear strength of composite reinforced soils were the sum of increments by fiber and woven geotextile respectively.

The purpose of this study is to evaluate the loss volume of base soil materials with the grain size range of filter materials for agricultural reservoir. The test results show that the loss volume is increased with the hydraulic pressure, and the amount of loss volume for same sample is different with the filter range.

This study, soil sampling includes disturbed weathered granite soils from 8 different sites and disturbed weathered non-granite soils from 5 sample sites, put a purpose on finding for a utility possibility and practical use in this study. As a result of this study, internal friction angle & cohesion indicate which are from re-mold of samples by compaction seem to be able to use a compared to an field data. It is considered that strength parameter of disturbed weathered granite soil in the field is a useful reference.

The dredged soils of rural streams can be treated with cement for recycling. It is very important to know whether the treated soils have achieved some required qualities for further treatments if the soils are mixed with cement. In this study, fall-cone test was used to examine changes in workability and compactibility during an curing time of soil-cement mixture. Test results showed that fall-cone apparatus can be satisfactorily used for this purpose. Although there was some difference of initial curing time and cement contents, the engineering properties of treated soils were little affected.

In this paper, dynamic properties of fiber reinforced soils were investigated at shearing strains between $10^{-4}%\;and\;10^{-1}%$ using resonant column test. Resonant column test has been widely used as a primary laboratory testing technique in investigating dynamic soil properties expressed in term of shear modulus and material damping. At strains above elastic threshold, the variations of shear modulus(G) and damping ratio(D) were investigated. Based on test results, the small strain shear modulus($G_{max}$) and damping ratio($D_{min}$) were determined and the effects of confinement on $G_{max}$ and $D_{min}$ were characterized.

In this study, the clay samples collected in the area Mokpo carry out laboratory soil test. Under three different curing $temperature-20^{\circ}C,\;50^{\circ}C,\;80^{\circ}C$ and 4 terms of curing day -1day, 7days, 14days, 40days for each, the remolded and reconsolidated samples had been made. To find out an aging effects and geotechnical characteristics between undisturbed samples and reconsolidated samples, laboratory tests were preformed. In the results, it was found that mechanical properties of undisturbed natural samples were similar to high temperature reconsolidation clay. The curing temperature influence on simulating aging effect more than the curing day does and the best curing condition are $80^{\circ}C$, 27days.

A in-situ experiment was performed to evaluate the pullout resistance capacity of chains which is used as a reinforcement of reinforced earth wall. It was also considered that chain was combined with a bar or L-type steel angle by the transverse reinforcement member in the experiment. As a result of experiment, it is expected that chain can be safely used as reinforcements of reinforced earth wall, although it is concerned that a theoretical estimation of the pullout resistance capability of chain is too conservative.

The WASP model was applied to Bokha stream with 8.4km of its main stem located in Ichon-gun, Kyonggi province in Korea. The stream was divided into 26 segments with each of 400m length, and 5 segments were embraced boundaries of its tributaries. The parameters of the model were calibrated by the trial and error method to minimize differences between observed and simulated concentration of water quality constituents. The correlation coefficients for DO, $NO_3-N,\;PO_4-P$ and organic P showed high values providing the ability of simulation. The correlation coefficients for BOD and $NH_3-N$ showed low values in both calibration and verification test.

In spite of considerable advances in water quality control measures within lake, many basic questions concerning an eutrophication still remains unanswered and it becomes obvious that an extensive limnological database is needed for the inter-comparison between bodies of water and for the assessment of the status of lake water quality. In order to diagnose the water environment and assess the changes of the water quality, Wangkung irrigation reservoir was investigated by a long-term monitoring program for the physical, chemical and biological water quality parameters. In addition, these data was used to determine the design elements of natural purification facilities.

To provide the basic information for the water quality improvement of the Sumjin River Basin, the water qualities of the Chooryeong-chon watershed were investigated from May in 1999 to September in 2002.

It is reported that Korea is a county of water shortage. The government make plans to construct dam to cope with this problem. But, it become difficult to construct dam, because of public opinion of residents and objection of environmentalist. In the sense, the government set up new policy of demand-management which means water saving. It is known that the efficiency of agricultural water is so poor that the first target to save water is focussed on agricultural water. In the study, the function of agricultural water was evaluated and it is found that it is not a waste, but a good ability on eco-system by return flow.

Wetland systems are widely accepted natural water purification systems around the world in nonpoint sources pollution control. In this study, the field experiment to reduce nonpoint source pollution loadings from agricultural drainage and polluted stream waters using wetland and pond system was performed. The removal rate of $BOD_5$, TSS, TN, TP, and $Chl-{\alpha}$ was 52%, 90%, 56%, 59%, and 81%, respectively. Performance of the experimental system was compared with existing data base (NADB), and it was within the range of general system performance. Overall the water quality improvement was apparent in wetland and pond system.

The purpose of this study is to construct an Environment Database Management System (EDMS) for the Saemangeum watershed based on the linkage of Water Quality Model, i.e. QUALKO and WASP model, and GIS database to estimate water quality effectively in this area. There are two major river systems on this study area, the Mangyeong and the Dongjin rivers. Input data are automatically generated through the calculation of the pollutant loading and inflow concentration from the point and non-point sources. The developed system is composed of three different phases, such as pre-process, model performance and post-process. The Model performance is supported by the database at pre-process phase and model performance results were shown in the graphs and attribution data at post-process phase. The measured data from the Mangyeong and the Dongjin rivers are used to evaluate the applicability of EDMS. The EDMS shows higher reliability, and it is expected to contribute to the effective management and improvement of water quality modeling in the Saemangeum watershed since the system reduces complications of using a model in DOS operating environment and increases the accuracy of water quality analysis.

We investigated net outflow load and unit load of pollutants from a paddy fields area in dry year 2001. Amount of irrigation water in 2001 was about 61-63% of that in previous years 1999 and 2000 due to drought. The net outflow load and unit load of pollutants in 2001 were negative, showing that paddy fields acts as sink of pollutants due to function of water quality purification. The relationship between unit load of pollutants and net surface outflow (= surface outflow - irrigation water) showed positive correlation. The results showed that abatement of surface outflow by appropriate water management contribute to reduce surface outflow load from paddy fields.

The objectives of the paper are to develop the total maximum daily loads simulation system, TOLOS that is capable of estimation annual nonpoint source pollution from small watersheds, to monitor the hydrology and water quality of the Balhan HP#6 watershed, and to validate TOLOS with the field data.

The objectives of the paper are to develop the infra-technologies for reclaiming the effluents from wastewater treatment plants and reusing for agriculture water. The Suwon wastewater treatment plant has been selected for wastewater reuse tests and the water quality and treatment efficiencies are investigated. Three levels of wastewater treatments that are the effluent from the plant, sand filtering, and ultra-violet treatment are applied in the pilot system. The randomized block method was applied to wastewater application to paddy rice with five treatments, three blocks, and two replica. The control was the plots with groundwater irrigation, the other treatments are to use polluted stream flow by pumping, in addition to three wastewater treatments. The block test plots and field plots have been monitored for the water quality, soil pollution, and health hazards during the crop stages.

Discharge characteristics of pollutant loadings from sewage systems were estimated in the catchment area of a reclaimed area - Saemangeum -. Pollutant loadings were estismated according to the discharge pattern of small treatment facilities. BOD pollutant loadings produced by population were 84,380kg/day, which were composed of nightsoil 35% and sewage 65%.

Two irrigation districts, Maekok and Byungjum 1 which are irrigated with polluted stream flow, and one control district Kichun, that is supplied from a reservoir complying with the water quality standard are selected for water quality monitoring to identify the effects of polluted irrigation on crop yields, environments, and health hazards for farmers. The water quality at Maekok and Byungjum 1 districts are worse than the control district, and continuous water quality monitoring are needed for the wastewater reuse for agriculture.

The electrical conductivity, EC is a major indicator of soil salinity. Measuring EC of saturation-paste extract of soil, ECe, is the standard way to evaluate soil salinity. However much of the data on soil salinity have been obtained by measuring the EC of the 1:5 soil-to-water extract, EC(1:5) or salts contents(%) which multiplied by conversion factor. And, thus we attempted to collect and analysis 90 soil samples at 9 reclaimed tidelands in Korea and to derive a relationship between ECe and dilution factor at ECe and EC(1:5), $DF_{1:5}$ of 3 soil textural conditions and 6 salinity conditions. Regression equations between ECe and $DF_{1:5}$ were obtained $ECe=1.4701ln(DF_{1:5})+5.0974(r^2=0.97^{**})$ in case of more than 50% silt contents, $ECe=2.1399ln(DF_{1:5})+5.3462 (r^2=0.99^{***})$ in case of below 50% silt contents, and $ECe=1.5927ln(DF_{1:5})+5.2486 (r^2=0.98^{***})$ in all cases, and then we suggested the $DF_{1:5}\;and\;DF_%$ of 3 soil textural conditions and 6 salinity conditions.

In this presentation, the methods that is appropriate to remediate the farmland contaminated by petroleum hydrocarbon was considered using the case histories of the abroad. As a result of a consideration, most remediation procedures were based risk assessment and management, risk-based procedure. It is also useful to use natural attenuation mechanism to remediate petroleum-contaminated sites. However, more research efforts are demanded for developing a cost-effective and efficient technologies.

Global warming is one of the major international concerns and renewable energy development and utilization are getting more attention recently. One of the competitive renewable energy alternatives is biomass. This paper describes the major concepts of gasification and fuel gas applications.

VFS는 침전물, 영양물질, 농약 등이 지표수로 유입하는 것을 감소시킬 수 있는 유용한 BMP이다. VFS의 식생의 종류는 목초, 관목 및 나무가 있으나 우리 나라와 같이 비점원오염 관리를 목적으로 하는 경우에는 목초가 가장 적당한 식생이다. VFS의 효과는 토양특성, 배수면적, 지형과 지변경사, 식생의 품질과 토지이용과 기후에 지배된다. 그리고 주기적인 VFS의 관리는 비점원오염을 관리하는데 중요한 요소이다. 식생의 정화능력을 이용한 VFS는 비점원오염 관리에 매우 효과적인 것으로 밝혀지고 있다. 그러나 VFS 독자적인 적용보다는 저류지와 같은 다른 기법과 동시에 적용하는 복합적인 관리대책을 강구하는 것이 더 효과적이다. VFS의 폭은 토양 특성, 배수면적, 지면 경사, 식생의 종류, 토지 이용도 등에 따라서 다르나 대체로 10m 정도가 적당할 것으로 사료된다. 그러나 보다 신뢰성 있는 VFS의 설계기준은 실제 시공과 사후 효과분석을 통하여 많은 자료를 축적한 후에 얻을 수 있을 것이다.

Deterministic and probabilistic approaches to the design of ultraviolet (UV) disinfection system for water reclamation are reviewed and discussed. The high inactivation of TC, FC and E. coli by UV disinfection was demonstrated and the inactivations of TC, FC and E. coli were 97%, 98% and 99%, respectively. Within the range of 0.3-4.5mWs/cm, the effect of UV does on the inactivation ratio was not observed. However, in the highest wattage of UV lamp, 39W, the inactivation ratio of TC, FC and E. coli was 100%, regardless of the UV does so the UV density was more effective on inactivation ratio of TC, FC and E. coli rather than UV does. Under the 0.4 mWs/cm and 16W of UV lamp, the effect of dissolved organic matter and turbidity on the inactivations of TC, FC and E. coli could not be observed in this study within the range of 0-60mg/L and 0-40 NTU respectively.

This study has been carried out to analized of long term changes of water quality with regard to main pollutant sources in agricultural reservoirs on the basis of data during 1996-2001. The major source was domestic wastewater(DWW) and water pollution by non-point sources(NPS) is increasing as time goes. It was determined that Seasonly average values of DWW were pH $7.6{\sim}8.7$, COD $7.0{\sim}9.4$, T-N $0.74{\sim}2.07$, T-P $0.05{\sim}0.62$, Live-stock wastewater(LWW) were pH $7.5{\sim}8.9$, COD $5.5{\sim}9.8$, T-N $0.57{\sim}1.91$, T-P $0.04{\sim}0.13$, NPS were pH $7.1{\sim}8.3$, COD $3.1{\sim}5.2$, T-N $0.29{\sim}1.44$, T-P $0.02{\sim}0.07$. Fluctuation of DWW and LWW were very wide and variable long term patterns of them were similar. Trophic states by Carlson Index of DWW and LWW was classified as eutrophic to hypretrophic from chl-a, T-P concentration.

The purpose of this study was to get the change of stream water quality in upper stream of Dong-jin river stream, water samples were taken at samling site during 6 month with from march to August in 2002. The water temperature and pH of stream water were ranged $9.0{\sim}29.4^{\circ}C,\;6.48{\sim}9.33$, respectively. The COD values of stream water was ranged from 0.60 to 19.06. The content of T-N and T-P were $1.88{\sim}6.74mg/L$, $ND(not detcted){\sim}0.50mg/L$ by the livestock wastes and agricultural activity, respectively. Also, suspended solids of stream water was ranged $0.4mg/L{\sim}322.0mg/L$. The contents of heavy metal Zn, Cu, and Pb were $ND{\sim}0.070mg/L,\;ND{\sim}0.012mg/L,\;and\;ND{\sim}0.043mg/L$, respectively. Cd was not dected in all the samples.

A subwatershed within Juam Lake was monitored to identify hydrologic and water quality characteristics. Rainfall record was collected and flow rate measurement and water quality sampling were conducted periodically at the watershed outlet. Hydrologic response and pollutant load characteristics were analyzed based on observed data.

By the explosive increase of population and industrialization the security of water resources is required, and water resource pollution problem is emerging as a serious social issue. For the ongoing Saemankeum project, lots of efforts are being put together to manage the water quality of the Saemankeum above a certain level, and it is sure that water quality management problem of main inflows from Mankyung River and Dongjin River is very important. Based upon the water quality data of Mankyung River this report examines its correlative characteristics by water quality sampling point factors and the water pollution resource factors, and subjects to provide elementary data for efficient water quality management of Mankyung River.

In recent, industrialization increases the level of pollution load in sea areas, and the inflows of pollutants to public sea areas cause sudden and wide-range of influence to the water quality and the ecosystem. To prepare for these kinds of unpredictable water pollution issues, the necessity is emerging to build an automatic water quality monitoring system, which can monitor and alarm the water quality changes of the subject sea areas. For the ongoing installation plan of the automatic water quality monitoring system around the Saemankeum sea area, this report compares and analyzes its installation conditions as well as the physical and chemical characteristics of the in-situ type and the water-sampling type of the automatic water quality monitoring equipments, and subjects to provide elementary data for the system installation in the Saemankeum.

In this study, we investigated concentrations and loads of nutrients in the paddy plots with conventional and environmental farming method. For two experimental plot, type of fertilizer for basal dressing was different but total applied fertilizer rates was almost identical. The nutrient concentrations in irrigation and percolated water were almost constant, while the ponded water significantly increased after fertilizer application. The nutrient concentrations in ponded water at long distance from inlet was higher than those at short distance due to longer detention time.

Characteristics of pollutant load during irrigation and non-irrigation periods was investigated for streamwater from a rural watershed. Water was sampled and discharge was measured at 5-days intervals at outlet of study area. The mean concentrations of TN and TP in an irrigation period are higher than in an non-irrigation period, while mean COD concentration in an irrigation period is lower than in a non-irrigation period. For increasing discharge during an irrigation period, TN concentration increase, TP concentration is nearly unchanged, and COD concentrations decreases.

In this study, the effect of DEM resolution (15m, 30m, 50m, 70m, 100m, 200m, 300m) on the hydrological simulation was examined using BASINS (Better Assessment Science Integrating point and Nonpoint Source) for Heukcheon watershed (303.3km2) data from 1998 to 1999. Generally, as the cell size of DEM increased, topographical changes were observed as the original range of elevation decreased. The processing time of watershed delineation and river network needed more time and effort on smaller cell size of DEM. The larger DEM demonstrated had some errors in the junction of river network which might effects on the simulation of water quantity and quality. The area weighted average watershed slope became lower but the length weighted average channel slope became higher as the DEM size increased. DEM resolution affected substantially on the topographical parameter but less on the hydrological simulation. Considering processing time and accuracy on hydrological simulation DEM mesh size of 100m is recommended for this watershed.

Development and application of nonpoint pollutant source model need pertinent runoff simulation for expecting good simulation result of yield of nonpont pollutant and it's move. this study purpose was compare to runoff height among Observed of Regression, HSPF and SWAT in hukchun basis loacated Gyeonggi province yangpeong-gun in two years($1998{\sim}1999$). Result, runoff height were Regression, SWAT, HSPF is 2578.96, 2526.44, 2547.21mm respectively, Nash-Schutcliff' simulation efficiency, compare to observed, was 70.22, 73.71% respectively so two simulation run off height was pertinent. If Regression method use excess observed arrange, it include error. so it's importance using pertinent arrange of observed runoff height.

This study is to application the TANK modle for Ponding depth and discharge, T-N, T-P simulation from paddy field area. Simulation coefficient of correlation for Ponding depth and discharge, T-N, T-P were 0.89, 0.60, 0.99, 0.91 respectively. advanced purposes are development of agriculture runoff character modeling and application of best management practice with this study model.

Land application is one of the desirable management practices for animal wastes. Majority of livestock farms adopt composting and land applications for the management of animal waste in this country. Meanwhile, there are only a few studies related with the effects of land application on pollutant loading. This study investigates the water quality characteristics in a rural watershed with intensive livestock farming. The results indicate that major constituents of water quality are substantially increased at the sites near livestock farms and compost incorporated fields during the rainfall-runoff periods. There are no significant differences of water quality parameters among the sampling sites during no rain periods.

This study was conducted to show how to manage the water quality of Kyung-an river. The water quality and hydrologic data were obtained at the main river and branch streams in Marc $h{\sim}April$ 1998. First of all, we surveyed the contribution of branches for the pollution of water quality at Kyung-an river. It was in order of Kongiam(25.5%)>Yong-in Pollutant Treatment Complex (15.26%)^gt;Shin-won(13.99%)>Buen(11.86%)>Yangji(8.68%)>Yooun(7.43%)>Kwang-ju Pollution Treatment Complex(5.50%)>Osan(5.04%). The hydrological model using mass balance and BOD reduction formula suggested that if the quality of water Yoo-un and Shinn-won stream (branch streams of Kyung-an River) which is lowest in the basin is controlled adequately and outlet water from Yong-in pollutant treatment complex is adequately treated, the quality of Kyung-an river will be improved by 90% compared to current level.

The effect of fertiltzer application on ponded and percolation water in rice paddy were investigated at the experimental plots during irrigation period. We laid out three experimental plots such as 150% Excessive, 100% Standard and 70% Reduced. The concentration of T-N and T-P in ponded water were increased rapidly after application. The concentration of T-N and COD in percolated water increased with fertilizer application rates, while T-P concentration were almost constant.

The purpose of this study Was to investigate the effects of ponding depth treatment on water balance in paddy fields. Three ponding depth treatment, shallow, traditional, and deep were used. Daily values of rainfall amount, ponding depth, irrigation water, drainage water, evapotranspiration, and infiltration were measureed in the field. The results showed that irrigation water depths were 198mm, 195mm, and 355mm in shallow, traditional, and deep ponding, respectively. The three treatments did not show any statistical difference in growth and yields. Shallow depth treatment showed the largest yield.