관개조직의 정확한 운영과 적적한 관리에 있어 조절 시스템은 대단히 중요하다. 일본 농업토목학회는 관개조직 조절을 조사하는 위원회를 가지고있다. 이 위원회는 조절 시스템을 위한 편람을 만들려고 한다. 편람을 만드는데 있어서이 조절 시스템의 개념을 여기에서 다루고자 한다.

일본의 농촌지역에서의 수질보전과 생활개선을 위해 일본 농림수산성이 보조하는 농촌 오폐수처리사업을 소개한다. 특히 사업 시행의 배경, 사업의 장점 , 오폐수 처리기술과 문제점, 사업조직들을 다룬다.

부족 (또는 적자) 조절관개는 용수절약 및 작물수량 증수를 위한 주요 방법중의 하나이다. 부족조절관개는 작물과 물의 관계에 근거를 두고 있다. 부족조절관개의 이론은 Shaanxi 및 Gansu 성에서의 실험자료을 이용하여 분석되었다. 부족조절관래에서의 실용상의 문제점은 ; 작물-물관계의 불확실성, 부족조절관개에서의 적정 생육기와 물부족의 정도, 관개조직과 기술에 대한 부족조절관개의 필요조건등이다.

In the practice , ET was mainly estimated by Blaney-Criddle or FAO Penman method. But these methods were found to frequently overestimate ET. And calculation of effective rainfall by empirical formula is hardly to explain drop property and soil texture. Since 1990, FAO recommended the adoption of Penman-Moneteith combination method as a new standard for reference ET. Purpose of this study is establish new estimate method of upland crop requirements. We asopt P-M method to estimate ET and set up soil moisture balance equation to equation to calculate effective rainfall and irrigation water requirements. We expect that this new method rise efficiency to upland water management.

From 1997 irrigation water withdraws has been surveyed for the purpose of river operation and management . Recently , the River Law was revised (1999.2.8) and obligate to water users to report their proposed and actual water withdrawals. If we can save more water from rice paddy area, we can use more water for municipal and industrial activity and we can expect water quality should be improved in the river. So the role of irrigation water use efficiency is more and more important.

An object-orient watershed runoff model was formulated using the SCS curve number method and routing routines. The four objects included in the model were rainfall , hydrologic unit, reservoir, and channel. Each object considers the data and simulation method to depict the runoff processes. the details of which were presented and discusses in the paper. The resulting model was applied to the HS #3 watershed of the Balan Watershed Project, which is 412.5 ha in size and relatively steep in landscape. The simulated runoff hydrographs from the model were close to the observed data.

The study has been performed to estimated the quantity of ground water recharge using the DAWAST model for water balance analysis in the Youngsan & Sumjin watersheds. The mean safe yield of ground water is annually 41.3mm, corresponding to 85 $\times$106 ㎥ at the Naju station in the Youngsan watershed, and 76.6mm corresponding to 343 $\times$ 106 ㎥ at the Songjung station in the Sumjin watershed. It is remarkable because safe yield of ground water are estimated 44 to 64 % less than the quantities estimated in the other researches.

The purpose of this study is to design the framework of DSS (Decision Support System) for drought mitigation with internet and web interface. The users who apart from central government always connect to its main server via iternet. And web interface and browser operable models make it possible to analze data related with drought and planning for drought mitigation . Thereby, it need to build a database system , which manages data update from the users, and develop java-applet programs to assist decision making. The framework of DSS might be nicely adapted to the planning and decision making for the agricultural drought migigation.

Upland Irrigation Network Analysis System(UINAS) used Object-Oriented Programming (OOP). The results of using OOP is definition of objects and class hierarchy for UINAS, Objects of UINAS are consist of the Pipe , Sprinkler, Valve , Pump, Tee , Bend and Contractions. The classj hierarchy have cooperative design for FEM in analysing the irrigation network. Therefore UINAS have a flexiblility in additioning the network components.

The water requirement of crops in paddy fields is composed of evapotranspiration and infiltration. The determination of effective rainfall has the great significance for the irrigation managements and system design. There are numerous methods to estimate effective rainfall. The FreeBoard Model(FBM), ond of them , is popular because it can describe the algorithm of effective rainfal with simplified and general formation. The purpose of this study is to evaluate effective rainfall by field measurement , to compare this closely with the results from freeboard model and modified freeboard model , and to find out which of two models is more consistent with the results obtained by measurements.

A Web-based information system from the Korea Agricultural Water Use Laboratory AWUL, has been developed to provide with regional water management information and guidance for the operations of irrigation reservoirs through the World Wide Web(WWW). Twenty-six reservoirs are selected as the reference reservoirs for regional water management , and the real-time operation guide may be issued the grwoing seasons. The information available from the system includes the wether forecasting , drought analyses, and reservoir operation data for those reference sites. For a specific reservoir, the manager may access the system to obtain the water requriement, irrigation secheduling , and reservoir operations that fit best to the irrigation district.

The evaluation of the effective rainfall is important in the desgin and operation of irrigation systems. But the difinition of the effective rainfall and the method for the estimating effective rainfall is various for each purpose . In this paper, the effective rainfall was defined as amount of rainfall which is remained in the effective soil depth that can be use to consumptive use of crop during growing season. The sol moisture was measured by Neutron prob for the effective rainfall estimation, and theexperiment was conducted for mulched and non-mulched condition of lysimeter during growing season. By the result of analysis and the former definition, the effective rainfall was estimated to be 37.2% for the mulched lysimeter and 40.7% for the non-mulched lysimeter.

This study is performed to select irrigation design year from 10-year return period 7-month(April to October) precipitation amount and compare reference crop evapotranspiration at 13 regions by REF-ET model. 1. Seven-month growing season average reference crop evapotranspiration values showed low values of 4.1 ∼4.2mm /day by FAO-24 Corrected Penman method, and 3.6 ∼3.7mm/day by FAP-24 Blaney Criddle method in Chinjin and Ulsan, high values of 4.9mm/day by FAO-24 Corrected Penman method , 4.1mm/day by FAO -24 Blaney Criddle method in Mokpo and Pohang. 2. Estimated seven-month growing season average reference crop evapotranspirations are 4.6mm/day by FAO-24 Corrected Penman method, 3.9,mm/day by FAO-24 Balney Criddle method, 4.0mm/day 1985 Hargreaves method, respectively.

In 2000 FFIA , FIA, RDC are united into new corporation. This corporation will manage rural water with TM/TC(Tele-Monitoring/Tele-Control) system. Most systems which were adopted in TM/TC system were Closed Control System which use exclusive network and protocol . Closed Control System can not support new corporation's requirement in water management system. Therefore, new corporation should adopt Open Control System as standard rural water management system. Open Control System support Fieldbus technology, TCP/IP various protocols, programming model, OPC which is essential to the water management program, and so on.

Unused irrigation water due to delievery losses and management losses. and ground water releases from infiltration in the paddy irrigation system are eventually returned to the stream. They are called as irrigation return flow. It affects the discharge of drought flow in the down strenamflow. And it may contain chemicals, and threaten streamflow quality . Thus, the accurage estimation of irrigation return flow is important to the streamflow modeling and water resources planning , and also to the control of agriculutral nonpoint source pollution . The irrigation return flow of pumped water was investigated in the Keum river watershed.

The daily irrigation water intakes from five reservoirs were measured and the water management characteristics analyzed . During the irrigation seasons in 1998 , the total water supply rates ranged from 534 to 864 mm, and thedelivery losses varied from5 to 17 pervent. Major factors affecting the water supply rates were rice transplanting and water management , and rainfall distributions during the growing seasons. The consumptive uses and effective rainfall from each researvoir were compared satisfactorily with the simulated results from the Daily Irrigation Reservoir Operation Model , DIROM.

The state of drought was evaluated by the operation rule curve. From the present percentage of reservoir storage and the operation rule curve, it could be determined to ristrict the irrigation water supply to a certain level and eventually to overcome the shortage of water in the irrigation reservoir.

Evapotranspiration is one of the important water budget components . An experiment was conducted to measure evapotranspiration. Three lysimeters were used to measure daily evapotranspiration. Lysimetrically measured values were compared with estimated values of various methods in REF-ET model , and then crop coefficient was computed.

The management method of the irrigation facilities are different with management agency , type, user, purpose of use, and the accuracy of data applied for the grasp of present situation and maintenance is of a low grade. Therefore the information management system is needed to classify and systematize the data. The purpose of this study is to prepare the digital map of Chonbuk FLIA district, to construct the database of the irrigation facilities , to develop the information system for the management using World Wide Web, to supply and be able to use easily to whomever needs it.

Writers were attendee at the meeting which was held at Yanbian University Science & Technology in China from Aug. 2nd to 5th. During the meeting Study tour was conducted along the Duman River at the China side. Writers lookded the hill slop along the Duman River, Hoeyoung City, and Musan City , Status on Farmland developmnet in N, Korean could be observed.

The purpose of this study is to find sedimentation patterns variation before and after Saemangeum reclamation. Water circulations are calculated diagnostically from the observed water temperature and salinity data and wind data and tidal residual current. Three dimensional movements of injected particles due to currents, turbulence and sinking velocity are tracked by the Euler-lagrange methoed. Calculated sedimentation patterns of riverine material are highly similar to the observed ones.

The objective of this paper is to provide an overview of the coastal zone managment system in the USA , France, Netherlands and Korea with an emphasis on the present state and problem of coastal zone management . Based on each country's experience , environmental techniques and methodologies has provided valuable information that can be used to carry out future , similar enacts laws of caastal zone management . The problem an dthe posture of the costal zone management of Korea are presented and a matter necessary for managing the coast and the problem in the future are presented.

The land reclamation area of Saemangeum(Kunsan) is located between 126$^{\circ}$10' E~126$^{\circ}$50' E and 35$^{\circ}$35' N~356$^{\circ}$05'N at the western coast of the Korean peninsula. The are many small islands including extensive areas of semi-diurnally flooded and dewatered tidal flats. The reclamation area of Saemangeum has a range of 5.6m spring tide and the maximum tidal current speed is about 1.41m s-1 in ordinary spring tide. Most of the sediments deposited on the tidal flats are transported from the Geum river, the Manjyung river and The Dongjin river. The soil in this area consists of silty sand with the depth of 10m to 30m . The wind in winter is strong from the direction of northwest. In the past twenty years, land reclamation projects for agricutural purpose or industrial cocmplex have been mostly implemented along the western coast of Korea. Saemangeum coastal area is being constructed the33km sea dike and 40, 100ha reclamation area. The purpose of this study is to find the residual circulations in four seasons after the dike construction by a robust diagnostic and prognostic numerical model. Heat flux at the sea surface in January ,May , August , October was asopted on the basis on the daily inflow of solar radiation at the earth surface, assuming an average atomospheric transmission and no clouds , as a function of latitude and time of year(George L.P.J.E William, 1990). The discharge from the Geum , the Mankyung and the Dongjin rivers was adopted on the basis of experience formula of river flow in January , May ,August, October (The M. of C.Korea, 1993) . Water temperature and salinity along the open boundaries are obtained from the results of field observation s.

This study was performed to analyze dealinization effects on gypsum treatments in reclaimed tidelands and to obtain the basci data for developing prediction techniques f desalinization to be applicable in the begining of tideland reclamation. In this study , the reclamation experiments with 4 treatments were conducted through the leachig method, using the samples of silt soil and silt loam soil collected in 5 units of tideland reclamation projects. The electrical conductivity , exchangeable sodium percentage and hydraulic conductivity were analyzed in order to investigate the effects of desalinizatino for reclaiming the tidelands with high salt concentration.

The reclamation area of Saemangeum (Kunsan) located between 126$^{\circ}$10' -126$^{\circ}$50'E and and 35$^{\circ}$35'N -36$^{\circ}$05'N at the western coast of Korea. The construction of the 33km sea dike is building in the Saemangeum area. When the construction of the sea dike in the coastal region takes plase, there exists a certain amount of soil which is diffused by the tidal current. Behavior of the soil diffusion usually depends on its intrinsic characteristics, bathymetry, construction method and used mchinery. The amount of soil at the construction acts as a pollutant which is the cause of changing the marine environment. When the soil material is diffused , it may form a layer which obstructs the light passing into the sea and causes the extinction or alteration of the living beings on the sea bottom. The settlement of soil material could change the sea bottom deposit. The purpose of MITIGATION is to harmonize the development and the conservation of environment, to restrict environmental destruction and to reproduce the enviroment damaged by the construction in the coastal region. The purpose of this study is to find the method by which we minimize the anti-function of development in the coastal region. Tide and tidal current are calculated using a two-dimensional numerical model before the construction of sea dike in Saemangeum Bay. The numerical results are compared well with field observations. On the basis of these results, we caculated the tide and tidal current after the construction of the sea dike in order to investigate the change of the tide and tidal current after the construction of the sea dike. Moreover, we calculated the tide and tidal current after the construction of submerged breakwater in order to preserve the enviornmental condition of creature habitat . We compared the tide and tidal current before and after the construction of submerbed breakwater, to investigate the possbility of MITIGATION in the fisheries.

The purpose of this study is to investigate on tideland recalamation project as a part of situation on farm land improvement measures in North Korea. By using satelite image data beyond the national boundaries, it makes possbile to analyze tideland reclamation projects, and owing to the developed software and procedure we can analyze data regardless of difference in data acquistion date. Satellite image data LANDSAT JEARS-1 data are mainly used, and analyzing software ER Mapper, ERDAS , IDRISI are used . Reclamation survey result made by the ministry of unification in 1994 were examined by means of remote sensing using satellite image data. The results are ; Completed and/or partly completed project are 24, 596ha and planned are about 142, 223 ha, 166, 819 ha in total. However, they already reported about 300 thousand ha would be reclamined from the sea in early 1980.

The purpose of this study is to find on the Current Change and Residual current in Final closing section of Seamangum the sea dike . The M2 current was calculated in two case of the two and three point Final closing section. The residual currents are calculated diagnositically from the observed water temperature and salinity data and wind data and tidal residual current.

In a mean time, arrangement of a arable land is lead by government with same way, same type. It means that there are no considering on characteristic features of region and aspect of ecological environment that can experess its natural charactersistics. Because whenever there is needed to be arranging , most of structure are made by a ward office from a desgin to a execution so that cause many public resentment and durability is very short by a inappropriateness its maintenance. The purpose of this study is divided into four parts ; First, to form the naturally favorable waterside spaces by performing the basic water controlling funtions of the irrigation channel and the drainage channel. Second, to provide the meeting place of the residents and to restrore the ecological system by means of the formation of the naturally favorable waterside spaces. Third, to lead to the optimal design and maintenance that residents want by inviting the residents to participate at the begining stage of planning. A district of this study is located on Songsam(13-14 zone), Samseung-Lee Ganam-Meon Yeoujoo-Gun Jyonggi Province and a length of section is 420m. This study came up with the following results. First, estabished the type of design and area of the area by means of the collected residents' opinions. Seconds, changed the straight line water channel already designed to the curve water channel . Third changed the structure materials of the steel concrete structure to the natural materials . Fourth, change dthe design by area for the ecological system and the meeting place of the residents. Fifth, divided the whole area into fourth area in order to satisfy the residents' requests.

In order to make the reasonable irrigation planin the reclaimed paddy fields, the estimation of irrigation water requirements by soil textures and water management methods for the normal growth of crops is very important. This study was carried out to determine leaching water requirements before cultivating crops. For the purposes of this study, the physical and chemical properties of soil sampels used in the desalinication experiments were analyzed and change of salinity by supplying water and leaching water were investigated in the experimental field with lysimeters.

In this study, a computer program considering iniial imperfectiionof axiymmetric reinforced concrete shell which show plastic deformation by large external loading was developed . Initial imperfection of wall was assumed as 'sine curve' which can be expressed as Wi =W0 sin(n$\pi$/1y). The developed model was applied to the analysis of dynamic response of axisymmetric reinforced concrete shell when it has initial imperfection . The initial imperfection of 0.0, -5.0 and 5 cm and steel ration 0 , 3 and 5% were tested for numerical examples.

The purpose of this study is to investigate the natural frequencies and mode shapes of beam-columns on the non-homogeneous foundaion. The beam model is based on the classical Bernoulli-Euler beam theory. The linear foundation modulus is chosen as the non-homogeneous foundation in this study . The differentidal equation goeverning free vibrations of such beam-columns subjected to axial load is derived and solved numerically for calculting the natural frquencies and mode shapes. In numerical fivekinds of end constraint are considered, and the lowest four natural frquencies and corresponding mode shape are obtained as the non-dimensional forms.

In this study , Computer programs for the optimum and automation desgin of reinforced concrete box culvert were developed. It was shown that even though the strarting points and optimization method are different the objective function and optimum design variables converge to a value within a close range respectively, and consequently the optimum design program developed in the study is reliable and stron. 3D-design drawing can be drawn using automation desgin computer program developed in this study.

In this study New design automation method of R/C structure based on the finite element method and the analogy evolution ary procedure was developed . This system is the efficient tool to support Reinforcement Arrangement of R/C structure. The anology evolutionary procecure is similar to the evolutionary procedure proposed by Xie and Steven.

The purpose of this paper is to investigate the natural frequencies and mode shape of columns immersed in fluid. The beam model is based on the classical Bernoulli-Euler beam theory which neglects the effects of rotatory inertial and shear deformation. The eccentricity and rotatory inerital of the tip mass are taken into account . The governing differential equations forr the free vibrations of immersed columns are solved numerically using the corresponding boundary conditoins. The lowest four natural frequencies and corresponding mode shapes are calculated over a range of non-dimensional system parameters : the ratio of fluid depth to span length, the mass ratio, the dimensionless mass moment of inertial, and the eccentricity.

Most of the irrgation structures are shortage of feasible facility management. The surveyed data to irrigation structures related to maintenance record were built and interface program between GIS and database were developed . It was conducted to develope a system for safe appraisal and repair works on agricultural irrigation structures. The system assisting onsite field investigation and determining the typical rehabilitation method of typical agricultural structural problems such as fractures and cracks of members was developed.

In this study , the variation of dry density and unconfined compressive strength were investigated, calcium carbonate, quicklime, portland cement, 19mm monofilaments and fibrilllated fibers were used as reinforcement materials. And calcium chloride was added to cement and calcium carbonate reinforced soil mixture in order to accelerate setting and hardening speed. It appears that dry density is highest in calcium carbonate reinforced soil mixture with 9% of mixing rae. According to increasing the amount of fibers, in soil mixture , the dry density decreased. The more the amount of monofilament fibers is the higher the compressive strength. But the compressive strength is decreased in fibrrillated fiber added soil mixture with more than 1.0% of mixing rate.

In this study, by using the natural language processing of the field artificial intelligence, automated index was performed . And then, the Natural Language Processor for Constructing Database (NALPDB) has been developed. Furthermore, the Design knowldege Information Relational DataBase (DIREDB) has been also developed, which is designed to interlock the knowledge base. DIREDB processes both the documented design-data , like a concrete standard specification, and the design knowledge frrom an expert. DIREDB is also simulates the design space of structures accordance with the production rule, and thus it is determined that DIREDB can be used as a engine to retrieve new knowledge and to implement knowldege base that is necessary to the development of automatic design system.

The distinguished geological characteristic of Taegu area is consist of anisotropic shale or sedimentary rock. Therefore if rocks are used for construction, it would've some difficulties of reuse showing the aspect of resource engineering. We made physical and mechanic properties for rock discrimination and then whether it had utilization worth or not. So we studied the engineering propriety through the aggregate tests based on rock's in laboratory. The last passed aggregate were D, E and B1 at KS and the rest couldn't use the place where weather phenomenon is caprice. This sis for base-line data of aggregate development research before the porpriety investigation for aggreagte of excavated rock in Taegu area.

In this study, a computer program was developed for analysis of the orthotropic curved ring sector plates. In the developing program , the thin-plate theory and multi-base coordinate system was adopted. The effect of design factors-boundary conditions, loading conditions, steel ratio, open angle, radius of curvature and relative flexural rigidity between slab and edge-beam-on the behavior of the circular ring sector plates were discussed. Also, the practical limitations was proposed to replace the problem of the orthotropic sector plate by equivalent rectangular plage.

At this study, we investigated the chemical component and the mineral granular composition of sedimentary rock and others where were distributed in Taegu area and compared correlations with each data through the various physicla and mechanical characteristic test. As the result, d and E, they are kinds of granite, which contain much albite than others were proved to be strong by mechanical tests and the correlation moduli were proved to be more than 0.8 except P wave velocity-Poisson's ration relation when examined Elastic moduluous -Poisson's ration, P, wave velocity-Uniaxial compression strength, Elastic modulous -Uniaxial compression strength and Uniaxial compression strength-Poisson's ration correlation function graph.

This study is performed to evaluate an elastic properties and acid-resistance of concrete using pine needle ash(PNA). Materials used for this experiment are PNA , normal portland cement, natural fine and coarse aggregate. Test results show that the highest ultrasonic pulse velocity , dynamic and static modulus of elasticity is achieved by 5% PNA filled PNA concrete, which has showed similar with those of thei normal cement concrete. Acid-resistance of PNA concrete is increased with increase of the contnet of PNA , it is 1.29 times of the normal cement concrete by 5% PNA fille PNA concrete an d2.57 times by 15% PNA filled PNA concrete . Accordingly , PNA concrete wil greatly improve the properties of concrete.

Recently , the use of steel fibers has been increased in flexural members and beams of concrete structures ; such as bridge decks, highway roads, runway of airport , buildings , ete.. An experimental investigation of the shear behavior of high-strength reinforced concrete beams using input steel fiber was conducted. However only a few experimental tests have been carried out under static loading . The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking , crack patters, fracture modes. The load versus strain and load versus deflection relation were obtained from the static test.

This study is performed to evaluate slump , air content, compressive strength and length change ratio of non-shrinkage high strength ocncrete is achieved by 10% expansive additive contained. The length change ration of non-shrinkage high strength concrete which is in water curing, shows 0.055% expansion in 10% expansive additive contained concrete and 0.308 expansion in 20% expansion additive contained concrete when it is curing 28 days.

This research was performed to evaluate the longitudinal length change ratio of concrete used the expansive admixture. As the results of this study, the compressive strength was shown the highest value at the used 10% expansive admixture both of the dry and wet curing condition. And the length change ration was shown higher 0.0316% and 0.0529 % than that of control in wet and dry curing condition. But this value was not enough to recover the shrinkage occuring by dry shrinkage. According to this study , we have obtained 10% on normal portland cement concrete as the optimum replacement ration of expansive admixture.

After researching the physical properties of the concrete included Rice Husk Ash(RHA concrete) and workability of fresh concrete admixed RHA, we have tested durability of RHA-concrete against freeaing and thawing in the winter using rapid freezing and thawing test method(KS F 2456) . There aretwo hypotheses to explain the failure mechanism of a freezing and thawing action. First, the hydraulic pressure in the pores of freezing concrete make an internal stress of concrete structures outbreaking micro crack in the face of concrete, Second, Frost action causing damage to cement paste repeatedly come from soil frost action, freezing water in the capillaries. Initial Relative Dynamic Modulus of Elasticity (DME) was biggest in cae of unit binder weight 600kgf/㎥ and relative dynamic modulus of elasticity increased until 300cycles. In general , initial relative DME was proportional to unit binder weight . Relative DME was decreased in proportion to unit binder weight in the case of 300, 400, 500kgf/㎥ , but relative DME fo the others remained more than 90% until 300 cycles. It was not good effect of intermixed RHA to concrete in case of below unit binder weight 300kgf/㎥ and the resistance of freezing and thawing was not good either.

Over 4.1 billion metric tons of non-hazardous solid wastes are generated in the United States anually. Therefore, there is a need to reuse or reprocess as many products or by -products as possible. In this report, the aggregates produced from Naval Shipyard and Charlexton area dredge spoils are designated as NC and DS, respectively. The major objective of this portion was to determine the feasibility of the use of these aggregates in concrete mixtures. According to test results, the unit weight of concrete mixtures containing NC and DS (vitrified glass) was lower than the control mixture, and the control mixture produced higher compressive and bending strength compared to mixtures containing vitrified glass. However the mixtures containing vitrified glass still could be used in the field based on the minimum criteria set for the mix desgin.

This study has been performed to obtain the mechanical properties of specialty cellulose fiber reinforced concrete. Flexural test is proceeded by third-point loading method and the size of the test specimens is 15${\times}$15${\times}$55mm. The effect of differing volume fraction (0.08%, 0.1%, 0.15%) were studied. The results of tests of the specialty cellulose fiber reinforced concrete were compared with plain and polypropylene fiber reinforced concrete. Results indicated that specialty cellulose fiber reinforcement showed an ability to increase the flexural strength.

This study is basic research to improve quality of asphalt concrete mixture, to preserve environment, and to recycle waste vinly. The mixing method and proper content of waste vinyl were determined through preliminary mix design. This study performed mix designs using 2 type gradations of aggregate in addtion content of wate vinly. Marshall stability at optimum asphalt content of asphalt concrete mixture addtin wate vinly was satisfied with the specification of the Ministry of Construction and Transportation , and its values indicated that dense grade asphalt concrete mixture containing waste vinyl were higher than common dense grade mixture (control). From this study, it was confirmed that addtion of waste vinyl improved quality of asphalt concrete mixture.

This study is performed to evaluate the physical and mechanical properties and acid-resistance of oyster shell concrete. The result shows that the unit weights of concrete with oyster shell are decreased by 1∼2% than that of the normla cement concrete. The highest strength is achieved by 2.5% oyster shell filled oyster shell concrete, it is increased compressive strength by 4% , tensile strength by 6% and bending strength by7% than that of the normal cement concrete, respectively . The acid-resistanceis increased with increase of the content of oyster shell. It is 1.6 times of the normal cement concrete by 15% oyster shell filled oyster shell concrete. Accordingly, oyster shell concrete will improve the properties of concrete.

This study is performed to evaluate an elastic properties of rice straw ash concrete . The following conclusions are drawn ; The ultrasonic pulse velocity is in the range of 4.084 ∼4.336㎧, which has showed abuot the same compared to that of the normal cement concrete. The highest ultrasonic pulse velocity is showed by 5% rice straw ash filled reice straw ash concrete. The dynamic and static modulus of elasticity i sin the range of 294 ${\times}$103 ∼ 347 ${\times}$103 and 266${\times}$ 103 ∼347${\times}$ 103 kgf/$\textrm{cm}^2$ , respectively. It is showed about the same compared to that of the normla cement concrete. The poisson's number of rice straw ash concrete is less than that of the normal cement concrete . The stress-strain curve of concrete which is contained rice straw ash within 10% appear slowly and over 10% appear almost straightly.

The objective of this stu요 was to develop a polymer mortar guide block for the blind handicapped people. A high strength and a long durability polymer concrete using unsaturated polyester resin was used to developed the block and to improve the exiting cement mortar guide bloc. Physical and mechanical properties of the polymer mortar guide block were investigated with respect to absorptivity, impact strength, bending strength compared to those of the conventional cement guide block. The polymer mortar guide block was proven to have properties , indication that the block have better industrial applications.

This study was performed to evaluate the physical properties of reinforced soil-mixture powder. Soil was used to be powder that passed by the No. 200 mech and the reinforcement as calcium carbonate, quicklime and portland cement used for this study to improve soil. We resulted from fineness , setting time, and compressive strength test of reinforced soil-mixture powder. We've got the two conclusions . The first , in case that we were used reinforced soil-mixture powder included some portland cement, the higher the mixture rates of the reinforcement , the wider the difference theoretical data with experimental data. The second, the setting time of reinforced soil-mixture powder is faster than soil powder itself and the reinforcement for promoting strength was proved that calcium carbonate was proper than others if we compared it with other reinforcment.

This study was initiated to develop a precast polymer concrete panel production method and to describe some engineering properties of FRP (Fiberglass Reinforced Plastics) reinforced polymer mortar. Specimens with different panel thickness and FRP reinforcement were prepared and tested and analyzed with respect to structural behaviors. Cracking moment was mostly affected by the thickness and reinforced FRP. Data of the study could be widely applied to the designing and planning of production processes of many polymer concrete products of which all or some of the components are composed with thin panels.

It is necessary to evaluate the location suitability for protected horiculture to plan new protected horticulture facilities in rural areas. Evaluation models for location suitability of protected horticulture in three selected regions ; suburban , plain mountainous were constructed by method of analytic hierarchy process (AHP). Evaluation models were to three case study areas,location characteristics of protected horticulture were shown in each regional features.

In practicing the refinement project of agriuctural production basys, many researches have been done until now, but they are not reused because management is not easily accomplished. We analysed and designed the Components of refinement project by the object -orientation technique, and presented a method of accumulation and management of object's data using relational database. In result, management of new data is easy and reusibility are increased compared to structural analysis technique.

Providing the reasonable construction cost at the initial stage of the rural development project, is a kety factor of the each step of project , such as propriety analysis , cost planning , design, and planning the progress of work. The explainable construction cost can be estimated at the early stage using the actual cost data by statistical analysis. In this study, the influence factors are extracted by factor analysis with the actual cost data of rural development project, object cost model is developed by multiple regression analysis, and verify the developed cost model by Monte-Carlo simulation .

The revision of domestic laws is in progress according to the UN Convention on the Law of the Coastal Zone Management . Along with it, the governmental policies related to maritime environmental preservation, especially around coastal zones and public works have been promoted based on enviornment, swiftly changed from the old function-based style. Therefore, this report will point out the important aspects which should be considered whenever there is any project on the coastal zones, suggest and classify projects of reviving the nationwide coastal zones, and show how to planning , check and evaluate the necessary technologies for reviving the coastal zones. This research will track down the coastal zone management method based on the natural enviornment as one of the necessary process to check the coastal zone enviornment for effective operating of the coastal zone management equipment method, starting on August 9, 1999, and report the technologies related with it.

Mountain agricultural land should become to the land use considering natural environmental conditions with characteristics of natural suitability . In this study , an evaluation of natural suitability was done for Pyongchang-gun , Kangwon-Do which has a lot of mountain agricultural lands using GIS according to the kind of land use (paddy, field, ordinary upland field, grassland, orchard land, forest).

This study aimed at developig the questionnaire design/analysis system for village appraisals. Based on the standard questionnaire pool, this study is developing a software that can automatically design questionnaire sheet, input and analyze the survedy data, finally output the anlayzed results on PC enviornment. And the system developed in this study will be completed through modification works by the verifying research on case study areas.

In this study , the system was developed for design procecure of agriultural engineering. For development of the system, design reports of Rural Development Corporation were analyzed, the components using in system were searched, and the user interface was developed. It was found that the development of this system would be used for design procedure using design information based on RDBMS.

In this paper, we attempted to eatablish questionnaire items for evaluation of residential satisfaction level by factor analysis, and the model was developed as a function of primary component of questionnaire items. For development of residential satisfaction model, items are selected by factor analysis adn regression coefficient is estimated by the multiple linear regression analysis.

The purpose of this study was to investigate the air flow characteristics of the rock bed storage for solar-heated greenhouse design, Heat storage material was gravels and experiments were performed under different outside temperature condition. The results of this study will be used for design of experimental solar-heated greenhouse.

This study were performed to find the cooling effect and to provide design data during summer season for the Pad& Fan system of greenhouse . The temperature variation along the greenhouse width were analyzed. Also, the effect of the pad location and fan capacity on the cooling of the greenhouse were analyzed. While Pad &Fan systems were operating the temperatures in greenhouse were very different along the meausring locations. It is recommeded that PAD location and FAN capacity should be considered to design the Fan and Pad system in order to provide greenhouse the optimum temperature condition.

This study was performed to find the recycling performance and to provide design data during recycle solid composting system to reduce bulking agent cost, Dairy manure amended with rice hulls and recycled compost was composted in a laboratory -scale vessel by continuous aeration for 10 days. The temperature and ammonia emission variations according to the ratios of bulking agents during the primary aeration stage were surveyed. Also, the influence of fresh compost quality on the recycling performance were anlayzed. While recycled composting system were operatured. The temperature in compost was maintained in the range of 40∼60$^{\circ}C$ needed for biodegradation and death of pathogenic organisms, but the ammonia emission was different by the ratios of recycled compost. The ammonia emission increased due to the low C/N ratio(17.6), high pH value(8.1) of the recycled compost.

This study was performed to figure out an optimum water environment and to obtain the fundamental data related with saving labor and water consumption for the chinese cabbage being grown in greenhouse . The productivity of cabbage cultivated in boty pots and floor were compared to each other in the aspects of height and weight depending on the soil saturation levels. Obtained results are as follows. ; In case of pot cultivation , the height as well as weight of cabbage in 80% soil saturation level(P80) were measured to be larger than those in the other 2 soil saturation leves (P100 and P60). The weight of floor cultivated cabbages were relatively larger than that of pot cultivated ones. In accordance with saturation ration, the general trend of water consumption rate was maximum in P80 and was decreased in the order of P80 , P100 and P60. And the average indoor temperature as well as the plant growth rate were found to be closely related with water consumption rate.

This study was performed to find an efficient method to overcome extremely high temperature within greehhouse in summer season. The actual states of practical use for greenhouse in hot summer season were investigated. About 21.6% of the investigated greenhouse farms were no cultivation, and most greenhouse farms were cultivating under the very inferior environment . To examine thermal enviornment of greenhouse according to cooling or assistant cooling , greenhouses were treated with natural ventilation, shading, roof sprinkling , and evaporative cooling with air cool fan. Shading and operating air col fan showed a drop in temperature of 3.8∼4.2$^{\circ}C$ as compared with natural ventilation, and most greenhouse air temperatures were maintained below 35$^{\circ}C$.

The simulation and experiments were conducted to anlayzed the vaiation of the temperature and humicity in the wintering beehouses which had two kinds of the insulator materials of urethane foam and sandwich panel individually . It was found that inside temperature of sandwich panel beehouse was similar to the urethane foam at the same outside temperature by the simulation results. The variation of the inside temperature and humidity for the urethane foam was less than the sandwich panel.

The experiment was conducted to predict air movements and to analyzxe the ventilation characteristics in ventilated greenhouse. Relatively high wind velocity was checked near windward inlet, but near leeward outlet and indoor very low wind velocity near to zero was checked . Despite of much influent air, indoor temperature was watched as high values uniformly due to inadequate air flow in greenhouse and low ventilation efficiency of the greenhouse.

It was neede to know the amount of PAR to predict the growth of crops, and the quantity of total radiation to control the temperature by shading screen in the greenhouse. Experiments have been conducted to determine the correlation between the hourly PAR and total solar radiation the transmisson of PAR and total solar radiaiton oat canopy location, and the relationship between the illuminaance and total solar radiation. Additional experiments are needed to confirm thses experimental results.

This research was performed to study the actual behavior of 1-2W type pipe greenhouse under the influence of typhoon by measuring the vairous strains instructural materials. These results can eventually be utilized in the desgin criteria as well as in the modification of conventional equaltion for calcu more realistic wind loads. Tehfirst data under the influence of Typhoon Olga arrived in Jinju on Aug. 1999. Were obtained by strain gage with 10 sensor points. According to the data obtained, the typical variation ofstrain depending on wind patter could be observed. The strains in structural frame were fluctuated very sensitively depending on the direction and magnitude of wind velocity. But some of the data were lost or missed by system's failure. A kind of inherent vibration pattern of greenhouse pipe frame was observed from the plotted data, but this phenomenon is not so clear as to be separated from the overall fluctuation so far. This experimental research is expected to be continued as a long term project to measure and analyze the strain pattern of structural frame depending on the various locations and section characteristics by wasy of adopting more efficientg instrument with sufficient number of measuring points and accuracy.

Salt accumulation is one of themajor problems in soils under protected cultivation . Since protected cultivation does not have rainfall or excessive irrigation, salt accumulaiton inthe soils is inevitable. In this study, characteristics of salt accumulation in soil column were ivestigated, and a salt-extracting method was tested to see its effectiveness. The results showed that the concentration of salt in top soil layers increased and electrical conductivity as thesalt concentration decreased especially in the top soil layer .When extraction medium was applied.

This study is to analyze the causes of flood damage in Imjin river basin inAugust , 1999. and to propose the measure to reudce such flood damage. The northern part of Kyonggin Province in the basin was severely damaged by flood due to the heavy rainfall for 4 days from 31 July to 3 August, whioch was recordedas 1,032mm. The heavy rainfall worth recording was one of main cuasese of such damage, but unsuitable river improvement and basin management were also important causes. The flood proptection works such as flood control reservoir and riverlevee were not contructed or sufficient in spite of the unflavorable geographical conditions of Imjin reiver. In case of irrigatiion faciliteis, 43 pumping stations in 3 FIAs were severely damaged due to inundation of the pump and switch boxes. The protection works for pump room should be improved to reduce the damage due to inundation.

The objective of this study is to analyze hydrologic recessiioon curve at the outlet of the ssangchi basin. For the development of recession equation, the initial discharge(Q0) and the recession parameters are estimated . It is shown that the accurate estimates of recession curve is easily obtained . The obtained parameters can be related to the basin characteristics, drainge area, and the total stream length so that they can be used for the development of the regional low flow estimation model.

Hydraulic model tests are performed to find economical and hdrqulically stable design of cooling water intake channel of steam power plant. The result of tests show that the standard distributiion of y-components in the chamber of CWP(circulating Water Pump) are recommended below 3.5 to maintain hydraulic stability, so that this value is considered as the design criteria. Common basin is necessary to improve the hydraulic stability of inflow, however the longer basin does not always improve the hydraulic stability , and the optimal length of basin can be found in some range. From the results the flow stability maintained the best condition when the length of basin is 7.2m. Beside the standard tests the auxiliary tests like edge , baffle, trapezoidal section and increase of pump capacity are carried out based on the optimal condition foudn in the standard tests. From the series of tests the economical and hydraulically stable design of intake channel was proposed.

The purpose of the study were to detect and evaluate the land use and changes on the Balan Watersheds, located southwest of Suwon, using the Thematic Mapper(TM) data. Three sests of TM taken in 1985 , 1993 and 1996 were used and the changes in the land use analyzed and compared. The suupervised and unsuperivised classification methods were adoppted to classify five land-cover categories ; Paddy , upland , forest , residential , and water. Future ladn use patterns were simulated using a Markow chain method, and the change ratios presented.

This study was conducted to derived design floods by Generalized Extreme Value(GEV) distributiion for the annual maximum series at ten watersheds along Han, Nagdong, Geum , Yeongsan and Seomjin river systems. Adequency for the analysis of flood data used in this study was established by the test of Independence, Homogeneity , detection of Outliers. Coefficient of variation , skewness and kurtosis were calculated by the L-Moment, and LH-Moment ratio respectively. Parameters were estimated by the Method of L-Method of LH-Moment. Design floods obtained by Method of L-Moments and LH-Moments using different methods for plotting positions in GEV distributions and were compared with those obatined using the Method of L-Moments and LH-Moments by the Relative Mean Errors and Realtive Absoulte Errors. It was found that desgin floods derived by the method of L-Moments and LH-Moments using Cunnane plotting position foumula in the GEV distribution are much closer to those of the observed data in comparison with those obtained by methods of L-moments and LH-moments using the other formula for poltting postions from the viewpoint of Relative Mean Errors and Relative Absoulte Errors. In view of the fact that hydraulic structures indcluding dams and levees are generally usiong design floods with the return period of two hundred years or so, design floods derived by LH-Moments are seemed to be more reasonable than those of L-Moments in the GEV distribution.

One of the purpose of the reservoir operation is minimizing theinnudation area in the downstream reaches during flood period.l To execute the gate operation properly , it requires lots of real-time data such as rainfall, reservoir level, and water level in the downstrea. Gate operation model was developed with the flood discharge obtained from real-time flood forecasting model and the criterion prepared from the past history of gate operation. Water level in the downstream would be increased by the releasing discharge from the spillway and the area of paddy land flooded in a certain detph and time would be estimated usnig GIS map. Gate operation model was applied to the Yedang reservoir, and the flooded area, depth and time in the paddy land was estimaged.

To extract hydrologic information more easily , the pre-processor for hydrologic model using Geographic Information System was developed . This model was applied to the Balan-reservoir watershed which is located at the southwest of Suwon. For estimation SCS curve number, landuse map and hydrologic soil group map were collected from digital map and reconnaissance soil map respectively. The estimated curve number from the GIS technique was 73.

The time paramters most frequently used in hydrology are the tuime of concentration, lag time , time base, time to equilibrium , time to peak, time of travel, and residence time. Especially the time of concentraion constitute an important part of operating rainfall-runoff modeling and determining critical rainfall intensity. In the result of simulation , we discoved that SCS foumula has the highest value with length, Kerby with height and SCS with slop respectively, while only Kraven formula has the lowest value in them. With concerning to relative sensitivty, the time of concentraion was marked the constant effect according to increase of length and slope level, and the length has much more effect than the slope relatively in parameters.

Three of the most important factors governing liquid transmission inunsaturated soils are field-saturated hydraulic conductivity, Kfs matric flux potential , ${\Phi}$m and sorptivity, S. The Guelph Permeameter is an in-hole constant-head permeameter, employing the Mariotte Principle. The study was carried out to investiate the characteristics of the water hsed average infiltration coefficient measured by the Guelph Permeameter at the Backokpo watershed in the Han river and at the Bandong watershed in the Keum river.

Recently rainfall and water evel are monitored via on -line system in real-time bases. We applied the on-line system to get the rainfall and waterlevel data for the development of the real-time flood forecasting model based on SCS method in hourly bases. Main parameters for the model calibration are concentration time of flood and soil moisture condition in the watershed. Other parameters of the model are based on SCS TR-%% and DAWAST model. Simplex method is used for promoting the accuracy of parameter estimation. The basic concept of the model is minimizing the error range between forcasted flood inflow and actual flood inflow, and accurately forecasting the flood discharge some hours in advance depending on the concentration time. The flood forecasting model developed was applied to the Yedang and Topjung reservoir.

In order to assess the estimtions of CN for a small agricultural watershed using the satellite image, TM image from Landsat-5 was classsified by MLC. CN for each pixels in the image was estimaed using the results. For the estimation enhancing , it was tried that each land use area in a pixel was estimated by the mixel assumption and the averaged CN by weight areas. Those resutls were applied for the actual hydrologic analyses were highly concerned with the observed runoff discharge and more enhanced on the mixel assumption.

A modified SCS TR-20 model that may be applied to a watershed having rice paddies as a land use type, was formulated and applied to a gauaged watershed. The model was applied to the Balan watershed of 26$\textrm{km}^2$ in size for estimation strorm hydrographs . And the simulation results from the model were also compared with thoses from the SCS model. The results showed that paddy fields play an important role to reduce peak runoff. When fractions of paddies are left to fallow conditions or when rice crop is replaced by other, the peak runoff was found to increase up to 10 to 20 percentg . The reduction rates in peak runoff appear to become greater for heavier storms or higher antecedent moisture conditions.

This study was carried out to derive optimal design drought flows by the Weibull-3 and Wakeby distributions for the annual drought flows series at seven watersheds along Han, Nagdong, Geum, Yeongsan and Seomjin river systems. L-coefficient of variation , L-skewness and L-kurtosis were calculated by the L-moment ratio respectivley. Parameters were estimated by the Methods o fL-Moments with continuous duration. Design drought flows obtained by Methods of L-Moments using Weibull plotting positions formula in the Weibull-3 and Wakeby distributions were compared by the Relative Mean Errors(RME), Relative Absolute Errors (RAE) and Root Mean Square Errors(RMSE). It has shown that design drought flows by the Wakeby distribution using method of L-moments are much closer to those of the observed data in comparison with those obtained by the Weibull-3 distribution using method of L-moments.

While there are to estimating design discharge , we are in trouble with how to separate area, Because discharges will be different depending on the shape of area even though there are same size of area . This study is for a reasonable presentation of design discharge method where there are changing characteristcs of area with SCS and Clark theory by sung HEC-1 Model. While we were Estimating desgin discharge with separating area in a relation to Time of Concentration(Tc) with SCS , Clark method, we found that if there are no variation of Tc the value of a discharge is not changed where shapes of area are different though. And from the result of analysis with SCS and Clark method, we ascertained that discharge by the SCS method was more bigger than that of the Clark where Area is less than 100ha. On the other hand, Clark method is more bigger in the more 1000ha.

The objective of this study is to identify the applicability of land cover image classified by remotely sensed data ; Landsat TM merged by SPOT for hydrological applications such as SCS runoff estimation . By comparing the calssified land cover image with the statistical data, it was proved that hey are agreed well with little errors. As a simple application , SCS runoff estimation was tested by varying rainfall intensity and AMC with Soilmap classfied by hydrologica soil map.

yongdam multipurpose is under construction to divert a part fo Geum riverlfow to Mankyung watershed and to supply the domestic water to the Chunju region and produce the hydro-electricity. Generally construction of dam by the method of inther-region water transfer affects the quantity and quality of water inthe down streams and reservoirs. The impact of operation plan of Yondgam dam on the quantity and quality of water in the Guem river and Daechung dam was investigated .It was recommended that the discharge of water transfer from one watershed to another should be minimized as much as possible.

The real strength evvelope for soils without cemetation goes through the origin and is curved. The Mohr -Coulomb failure criterion with the strength parameters c' and ø' from conventional tests overestimates the shear strength available at low normal stresses. The results of laboratory tests interpreted in terms of the Mohr-Coulomb failure criterion are not appropriate for evaluation of surficial slope stability , because the range of effective normal stresses in the field are not used in the laboratory tests.

The model using homogenization technique based on energy concept for the prediction of the failure criterion of staple fiber mixed soil was developed to increase the practice and the application of staple fiber as a reinforcement for improving soft ground and agrictural structures. Parameters of the model are aspect ration and volumetric ocntnet of fiber, cohesion and internal friction angle of soil, adhesiion intercept of soil and fiber. It is judged that the model developed in this study is applicable to the soil composed of clay, silt and sand mixed by linear types of fiber such as steel bar, steel fiber , natural fiber etc..

In Soft ground of south-western coast of our country necessity of marine indutrial complex and container facility has been remarkable. Site construction for habor facility is one of the most urgent problems. Consolidation of dredged fill has become important task. In addition, volume change of dredged fill should be examined carefully. This study dealt with consolidation of dredged fill by PCDDF and in order to secure trafficability of heavy equipment for surface treatment should be studied.

Yielding is an important feature of the stress-strain behavior of clays. This study was performed to estabilish the yielding curves and properties for a marine caly from Jangheung. Chonnam Province . A series of tests was done by means of the various stress path tests. Results of the tests are as follows ; 1) The laboratory -determined Ko is very similar to that applied to the Jaky equation. 2) The shape of yielding curve is nealry symmetrical about the p' axis like other natural clays. 3) The critical state parameters, Mc and Me are the same for compression and extension tests which contrasts with the results of the isotropically consolidated soils. 4) The state boundary suface using the critical state paratmers can resresent the normalized yielding curve obtained by various stress path experiments.

This study has been done to investigate the characteristics of synthetic fiber reinforcement sol with fully satruated . To this end, consolidated undrained triaxial test was performed on synthetic fiber reinforcement soil using the soft clay and plypropylene fiber . From the results of test, it was formed that the mixing ratio for weight and the aspect ratio of synthetic fiber have an effect on the shear characteristic of synthetic fiber rinforcement soil. Especially shear paramter C has line relationship for mixing ratio of fiber, and øhas parabolic relationship for mixing ratio of fiber.

This study were performed to investigated the behavior of excessive pore water pressure with embankment of soft clay. The dissipation behavior of excessive pore water pressure in the improved and non-improved area was used to compare and alyze with lateral displacement , and to investigated the applicability of the methods for stability evaluatio of soft clay. The behavior of excess pore water pressure could be used to the fundamental data for stability evaluation, and the evaluation of the stability of embankment was recommended to use the indlination of curve rather than critical line.

To analyze the characteristics of unconfined compressive strength of reinforced soil bricks made of clayey and sandy mixed with cement, lime, staple fiber and their combinatioin , a series of unified comparessive tests was performed. The resutls are summarized as follows ; 1) Reinforcing effect of reinforced clayed soil and that of soil brick of sandy soil mixed with cement and staple fiber is 8 times greater than no reinforced sandy sol. Therefore, the reinforcing effect seems to be greater in sandy soil than in clayey soil . 2) Lime shows a negative reinforcing effect in clayed soil but a little reinforcing effect in sandy soil. 3) It is appeared that strain at failure of soil brick reinforced with staple fiber is greater than that of unreinforced brick regrardless of soil's type.

An experimental investigation was carried out to study the feasibility of using the stabilized sludge, as a backfill and cutoff-water materials for embanckment structures. for stabilizing of sludge, hydrated lime and quick lime was used as additive , and a series of tests was performed on the sludge and the stabilized sludge to examine their physical properties, compaction, compressive strength, hydraulic conducivity and consolication characteristics. From the test results, the physical and mechanical properteis of the stabilized sludge weremore improved as compared with the sludge. Especially from the viewpoint of physical porperty , consolidation or settlement and cutoff-water , quick lime is more effective than the hydraged lime as tabilizatio addtivie. But , viewpoint of compaction and shear strength, hydrated lime is more effective than the quick lime as stabilization additive. As a result of this study, it was founded that the stabilized sludge can be developed the backfill and cutoff-water materials , improved the stabilizing method of sludge.

Recently , the hydraulic fill method is commonly used in many reclamation projects due to lack of fill materialss. The method of hydraulic fill i recalmation is executed by transporting the mixture of water -soil particles into a relcaimed land through dredging pipes, then the dredged soil particels settle down in thewater orflow over an out flow weir with the water. The amount of the volume reductions of dredged soil is considered the sum of the overall settlement by descication shrinkage and self-weigth consolidation and the loss of soil particles flow over a weir. In the present study, hydrometer analysis was performed with the soil samples obtained bofore and after dredging to estimate the amount of soil particles residual at reclaimed area and the loss of soil particles , then it was suggested the method of determining the loss ratio of dredged soils from the tests results. The hydrometer analysis of in-situ soil samples showed that the loss ratio of dredged soils is lowest at the nearest point to dredge pipe and highest at the nearest point of out flow weir.

This study was carried orut considering the aspect of economical and measuring time to investigate through the literature review of the test methods and advantage -disadvantage of infilltrometer and porous probe test apparatus. SSRI and BAT permeameter could obtain results within relatively short time and measure low permeability. SDRI is able to obtain values the accuracy and representative of the overall in-situ. BAT permeameter is to suitable because it can obtain the values accurately and quickly . Therefore the apparatus cost can be to disregard. In-situ measurement using in-situ hydralulic conductivity test equipment is able to do for the engineer to quickly identify and remediate problem areas due to construction or material changes.

For many soft ground embankment projects , instrumentation programs for stability and settlement management is being essential . This usually leads to generate large volume of data, which can be used for further research. Database technique is most effective method for data management . Data produced by soft ground embankment instrumentation can not be used by itself but must be reproduced using geotechnical analysis technique. In this study, a intelligent database system for softground called IDSIM was developed to examine applicability intellgent database. . The IDSIM analysis instrumentation data automatically and present results by Web/DB interface successfully.

In this study, a series of test was conducted to show the characteristics of freezing -thawing process on soilcrete using the soft clay in a redevelopment paddy area, was treated with cement and several additives such as Beestar, CaSO4 , MgO, and polypropylene fiber, From the results of test, it was found that first addtivies -cement and beestar-was effective for compressive strength, and the resistance against freezing -thawing process was improved by secondary additives, in the order their effectiveness, i.e. CaSO4 , Synthetic fiber, MgO and Beestar.

An attention has been draw to converter slag which in use of it for improvement of soft ground. It has never considered about it. Associated with above fact, it should be carefully examined that the permeability with time delayed of converter slag, the chemical characteristics of converter slag and conversion of laminar flow in to turbulent flow in converter slag and the use of it be scrutinized.

The objectives of the study are to investigate thermal conductivity(TC) and coefficient of thermal transmission (CTT) according to the type of soils, the presence of reinforceemnt, temperature, relative humidity and to analyze experimentally the characteristics of thermal transfer of reinforced soil wall. Results are summarized as follows ; 1) Clayey soil has high value of TC and CTT than sandy soil. 2) TC and CTT of reinforced soil wall is about 6∼17% higher than those of reinforced one, 3) It is founded that the effect of relative humidity on the soil wall is important at the same temperature and 4) As the temperature is high, it is appeared that TC and CTT are high.

Three floating islands have been constructed for water quality improvement for a polluted irrigation reservoir. Phragmites australis was considered as the suitable aquatic macrophyte of the floating island. From April to August in 1999, the net primary productivity of Phragmites australis was 3,530gDM/㎡. Uptake rates of nitrogen and phoshorous by Phragmites australis planted in the floating island could be estimated to 10.2kg/d/ha and 0.8kg/d/ha, respectively. The floating islands worked well as a habitat of fish and prawns. Therefore, the floating islands could be evaluated a good measure ofwater quality improvement for irrigation reservoir.

This study was carried out to investigate the paddy soil and water quality in Boryung freshwater reservoir watershed during the non-cropping season. Soil pH of the Boryung freshwater reservoir watershed were 5.39∼5.78. Total-N and P contents were high by the accumulation of chemical fertilizer partly. Heavy metal content of paddy soils were natural background level. Water pH of the Boryung freshwater reservoir watershed ranged from 6.82 to 8.64. Total-N content affected by a livestock wastes and sewage water were the higher than that of others and total-P content showed below 0.1mg/L. Nitrate nitrogen contents was very high according to the influence a livestock waste and sewage water partly. Heavy metal contents of wateers were natural background level.

This study was conducted for the purpose of assessing the pollutant removal possibilities of sedimentation pool formed by deep dredging of a reservir inlet. Water quality data were collected in the Masan reservoir, whose inlet has been dredged deep like sedimentation pool. The average concentration of chemical oxygen demand(COD), total nitrogen(T-N) adnd total phosphorous(T-P) in the deep dredged area were 8.3∼28.4mg/$\ell$ (COD), 2.0∼6.0mg/$\ell$(T-N), 0.17∼1.34mg/$\ell$(T-P), which were 3.3% (COD) , 30.6%(T-N) and 46.4%(T-P) higher than those of middle part of the reservoir. From these results, it was considered the deep dredged area in the inlet of reservoir might play a key role to improve reservoir water quality.

The objective of this study are to examine the feasbility of reuse treated sewage effluent ofr agricultural water, and to obtain basic data for estabilishment of rational agricultural water quality standard. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale applicatiion, further study is recommended on the secific guidelines of major water quality components and publc health.

The effect of fertilizer applicatioin on ponded and percolation water in paddies were evaluated at the field plots of the Chungbuk National University for irrigation period. The chemical fertilicers were applied to the study polts at an average application rate of 77, 110, 165kgN/ha, respectively. The concentration of T-N , T-P and COD in ponded water greatly depends on the amount and timing of fertilizer applied. Therefore, the decrease in the amount of fertilizer and proper water management may be needed to decrease in the amount of fertilizer and proper water management may be needed to reduce the runoff loading.

The organic matter flow in rural watershed in Chongwon-gun , Chungbuk, was evaluated, The study watershed is about 67$\textrm{km}^2$ in area and its population was 7,000 in 1996. The amount of inflow in the study area exceeds the amount of outflow by 534kg/ha , and the livestock feed account for 90 percent of the amount of inflow. The loading of organic matter by livestock waste amounts to 51 percent of total loading to agricultural land and the enviornment. The increase in recycling of livestock waste is essential for the management of orgainc matter in the rural watershed.

We threat sludge by heating methods with low pollution and high efficiency. Organic and inorganic components in Sludge can be almost removed through the heaging treatment process, and thefinal products are called artifical aoil or artificial media which are depended on temperature control. It can be recycled on the agricultural sites. Because it contained sort of organic matters while high heaging process with addition. To use them as agricultural materials, it need to know their characteristic transform in the nature. So we have planting bean and corn for two years with standard planting methods and to anticipate changing characteristics of artificial media and artificial soil by staying it natural condition, analyze it physical and chemical characteristics. This study will be contributed to reduce mass enviornmental problems by the treatment of Sludge and make it possible application for a agriculture use.

This study estimated average yearly watershed pollutant loading by using SWMM(Storm Water Management Model) which is one of the nonpoint source quality models. Two sites were measured discharge and water quality at dry period and wet period. The rainfall data is used from 1989 to 1998 . During a decade, the average year watershed pollutant loading, which is SS, BOD5 , TN, TP, were 2.39E+06kg, 0.92E +05kg, 2.53E+05kg, 2.66E+04kg respectively. During dry period, SS, BOD5 TN, TP loadings were 1.89E+05kg, 1.7E+05kg, 1.04E+05kg, 1.11E+04kg, and during wet period 1.89E+05kg, 1.17E+05kg, 1.04E+05kg, 1.11E+04kg respectively so wet period loading are more than dry day loadings.

Stream and groundwater qualities of two rural watershes in the upper North Han river basin were monitored for 14months. Six to eight stream sampling sites and two to there groundwater monitoring wells were chosen and water samples were regularyl collected and analyzed with respect to total nitrogen(T-N), total phosphorus(T-P) and total suspended solids(TSS). Monitoring data were graphically analyzed with respect to time.Rainfall amout and intensity seemed to have an impact on stream T-N and T-P concentration changes. TSS concentrations were generally lower than the first class stream water quality standared, Both stream and groundwater qualities near livesstock feetlot areas were degraded indicating the feedlots have an impact on water quality.

This study was initiated to collect background pollutant data for rural watersheds. The effluent/run-off polutant load and run-off ratio of the study areas were calculated and the two types of regression equations, L=a$.$Q+b and L=c$.$Qd where L and Q are the pollutant load(L) and discharge (Q), were derived. We acquired that the correlation coeffcients of the two types of regression equations were over than 90% except for BOD . Therefore, L-Q equations would be a measure to predict water quality of rural watersheds.

For the assessment of the level of stream pollution, SWAT-WASP model linked with GIS was applied to a respresentative rural watershed and evaluated for its applicability through calibration and verfication using observed data. Using daily water yields, sediment yields and nutrient discharge simulated by SWAT model, WASP input file was build. Point source pollutant and water quality change in stream was considered in WASP model. For the model applicatiion , digital maps were constructed for watershed boundary, ladn-use , soil series , digital elevation, and topographic data of Bok-Ha watershed using GRASS. The model application results showed that the simulated runoff was in a good agreement with the observed data and indicated reasonable applicability of the model.

When it rains, soil erosion occurs and soil particles move into the reservoirs or stream . Nutrients and contaminants, which are adsorbed on soil particles, flow into waterbody and are leached into water. Then they effect on water quality and eutrophicaltion of reservoirs. In this study , corrleation of SS to COD was surveyed , and that of SS to T-P was also done. R2 values in wet period were almost over 0.8, but were very low in dry period . THis shows that concentrations of COD and T_P will be assumed by using SS concentrations in wet period in stream.

The fishways on Namdae-cheon and Osib-cheon and the use of migratory fishes were investifated from July 1998 through Jung 1999. There are three types of fishways on these rivers. Those are baffled fishways, fish ladder, and fish ladder with gabion. Namdae-cheon has 7 baffled fishways and 19 fish ladder, and Osib-cheon has only fish ladder with gaboin. On Namdae-cheon 1,195 fishes of 24 species were collected. Amog these fishes 241 fishes of 9 species were anadromous fishes occupying 38% in species and 19% in number. On Osib-cheon 1,015 fishes of 24 species were collected. Among these fishes 240 fishes of 5 species were anadromous fishes occupying 21% in species and 24% in number. On Namdae-cheon the species number and auundance decreased gradually upstream. The poor structure of fishways seems to have worked as an obstacle to the upstream migration of fishes on Namdae-cheon. On Osib-cheon all the observed fish species except three -spined stickleback(Gasterosteus aculeatus aculeatus) which stay and spawn around downstream of river could migrate upstream. The good structure of fishways on this river is thought to have helped upstream fish migration.

In general ,wastes of livestock are covered 1% in the total wastes in Korea. But, actual pollutant loading rates by an organic material are 18% which will be serious problem in fresh water lake. An aim of this study is analyzing water quality in Bo-Ryeoung fresh water lake which are arounded by a lot of small livestock area, so that look for how to manage water quality of fresh waterlake.

This study is to modify the EUTRO5(sub-model of WASP5) for applying river water quality simulation. Because previous version of EUTRO5 has unique kinetic constant for all segement on each constituent, EUTRO5 is not adequate for some river simulation. As this version have each kinetic constant for all segment on each constituent, it will be suitable for model application with rapid changing geometry and kinetic purification of upstream river.

Discharge characteristics of organic materials and nutrients were estimated in the catchment area of relaimed area-Saemankeum-. Discharge load of BOD5 was high in the domestic system, while nitrogen and phosphorous were discharged mainly from the livestock system and the land . Load was so dependent on the precipitation that it increased in the rainy season, particulary in nitrogen and phosphorus. Loads from nonpoint sources in this area were higher compared with others.

The effects of nonpoint source pollutants from a small agricultural alluvial watershed on groundwater quality were investigated and analyzed in this study . Water quality factors of pH, electric conductivity(EC), total nitrogen(T-N), nitrate nitrogen(NO3-N), ammonium nitrate(NH4-N), and total phosphorus(T-P) concentrations were monitored at the watershed located in Shinbook-myon , Chunchon, Kangwon-Do, Korea for 2 years. Groundwater samples of about 2 liters from 7 to 20 farm wells were regulary collected and analyzed with respect to the water quality factors which were again anlayzed with respect to time and land uses of residential , agricultural , livestock feedlot, greenhouse, and natural areas.

Concentration and discharge have been intensively monitored at the drainage canal in a paddy field area during storm-periods. Among 4 storm runoffs, the No. 2 and No. 3 runoff was in the fertilizer application period. The specific load-specific discharge equation L=aQ\ulcorner have different characteristics for the pollutants. The coefficient of b generally shows values of more than 1 for T-N, about 1 for COD\ulcorner, and less than 1 for T-P. For same specific discharge, No. 2 runoff shows higher specific load than other runoffs. For the coefficient of determination of the L-Q equation, COD\ulcorner is higher than T-N and T-P. The mean concentration of direct runoff, significantly depending on the storm events, is 0.6 to 8.3mg/ιfor T-N, 0.05 to 0.51 mg/ι for T-P, and 10.0 to 18.3 mg/ι for COD\ulcorner.

In intensive agriculture, exceeded chemical fertilizer application would increase the concentration of nitrate nitrogen in groundwater. Consequently, it could bring the eutrophication in lakes and streams. The present study examined runoff loading of nitrogen and phosphorus from the paddy field during non-cropping season. The runoff loading of total-N, ammonia-N, nitrate-N and total-P were 12.96kg/ha, 5.42kg/ha, 1.52kg/ha and 1.41kg/ha. When the runoff loading of nutrients was compared by runoff water and sediments. About 70-80% of total-N by runoff water and the rest 20-30% by runoff sediments were flowed into streams. But 60-70% of total-P by runoff sediments and the rest 30-40% by runoff water were flowed into streams. The phosphorus compounds, which were flowed into streams by runoff sediments and then sedimented, keep exchanging with water at water body in undelivered condition. And it moves gradually into water layer. This process can cause eutrophication continually and repeatedly in water environment. So, a sound program is needed to reduce soil erosion from farmlands.

The purpose of this study is to obtain land classification map by using remotely sensed data; Landsat TM and SPOT panchromatic, and to compare their results with statistical data and digitized coverage from topographic paper map. The classification was conducted by maximum likelihood method with training sets. The best result was obtained from the Landsat TM merged by SPOT Panchromatic, that is, similar with statistical data. This is caused by setting more precise training sets with the enhanced spatial resolution by using SPOT Panchromatic. The classified map may be useful as a fundamental data to estimate pollutant load in regional scale of agricultural watershed.

RUSLE was applied to estimate annual soil loss from two small agricultural watersheds in Kangwon-do, Korea. GIS input parameters were prepared by using DEMs and soil maps prepared by the NGIS project and Rural Development Adminstration, respoctively. RUSLE parameters were prepared based on existing data and equations. Estimated annual soil loss was graphically presented to easily visualize the large soil loss area. Uplands and vineyards proved to be the two greatest sources for soil erosion. It was suggested to develop effective management practices to reduce the soil erosion from uplands and vineyards.

It has been acknowledged that fertilizer and animal waste have different ratio of \ulcornerN/\ulcornerN which is presented as a symbol of $\delta$\ulcornerN, and that the values of $\delta$\ulcornerN for fertilizer and animal waste are placed less than +8 $\textperthousand$ and higher than +10$\textperthousand$, respectively. By this reason, the demarcation range for the source nitrogen mass ratio is between +8$\textperthousand$ and +10$\textperthousand$. In this study, we would suggest a possible method to trace the major pollution basis using the nitrogen isotope analysis method for management of water quality.

In this study, a decision support system (DSS) was developed to calculate optimal wastetreatment cost, treatment level and treatment quantity of various pollutants for applying for in rural basin. The DSS includes a gegraphic informatino system (GIS), relational database system (RDBS), water quality models(Loading function , WASP5), watershed pollution load calculation module(SPLC), optimal water quality management plan to satisfy the water quality regulations. The system can be modified by user to trace the optimal condition for decision. The effort was conducted to apply the developed DSS to select the for optimal water quality management plan small rural basin called Kwanri Stream.

The performance of a small on-site wastewater treatment system consisting of an anaerobic septic tank and upgraded absorbent biofilter was investgted . The anaerobic septic tank was used as a pre-treatment of the absorbent Biofitler instead of the primary clarifier. The treatment capacity of the system was examined by changing the hydraulinc loadings to the Absorbent Biofilter as 2.5㎥/day , 4.5㎥/day, 6.0㎥/day, respective. The effluent from the septic tank was fed into the Absorbent Bilfilter. Based on the experimental results, the quality of treated wastewater satisfied the regulation and the BOD and SS was removed down to approximately 5mg/$\ell$ and 1mg/$\ell$, respectively.