Risk assessment on Jeju Special Self-Governing Province(JSSGP)’s water supply facilities and establishment of adaptation measures for climate crisis factors were implemented. JSSGP’s vulnerability to the climate crisis was high in the order of drought, heat wave, heavy rain and strong wind. As a drought adaptation measure, policies of water saving and revenue water ratio improvement were considered. As for the heat wave adaptation measure, the introduction of an advanced water treatment process was suggested in response to the increase of algae cell number which resulting in taste and odor problem. As for heavy rain adaptation measures, the installation and operation of automatic coagulant injection devices for water purification plants that take turbid surface water were proposed. As a measure to adapt to strong winds, stabilization of power supply such as installation of dual power line was proposed in preparation for power outages. It is expected that water facilities will be able to supply high-quality tap water to customers even under extreme climate conditions without interruption through risk assessment for climate crisis factors and active implementation of adaptation measures.

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project’s target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

This study aims to explore the appropriate water pressure control of water supply pipeline to reduce water losses of water supply network in Jinan-gun. The current water pressure status of each 5 blocks and the impact of optimized water pressure on improving revenue water rate were investigated. In order to obtain the flow rate and water pressure data of each small block, a smart hub is set in the pressure reducing valve chamber at the inlet of the small block, and a smart water pressure meter is installed in the fire hydrant and the faucet of the customer. For the pressure reducing valves installed for water pressure management system of each block, the diameter calculation standard and type of the pressure reducing valve are determined, and the application reasons are put forward. The analysis results of water pressure management for each small block in Jinan-gun show that the pressure control equipment and water pressure management need to be improved in four small blocks. The water flow rate in Jinan-eup and Sangjeon-myeon increases from 57.2% to 87.6% when the water pressure control is completed.

In this study, we collect water control valves that have had accidents due to existing cracks, etc. are collected, and propose investigation items for strengthening the valve structural safety evaluation through a series of analyzes from valve specifications to physicochemical properties are proposed. The results of this study are as follows. First, there was a large variation in the thickness of the body or flange of the valves to be investigated, which is considered to be very important factor, because it may affect the safety of the valve body against internal pressure and the flange connected with the bolt nut. Second, 60% of the valves under investigation had many voids in the valve body and flange, etc. and the decrease in thickness due to corrosion was relatively large on the inner surface in contact with water rather than the outer surface. It is judged that the investigation of depth included voids is very important factor. Third, all valves to be investigated are made of gray cast iron foam, and therefore it is judged that there is no major problem in chemical composition. It is judged that the chemical composition should be investigated. Fourth, as a physical investigation item, the analysis of metal morphology structure seems to be a very important factor for nodular cast iron from rather than a gray cast iron foam water valve with a flake structure. As it was found to be 46.7~68.8% of the standard recommended by KS, it could have a direct effect on damage such as cracks, and therefore it is judged that the evaluation of tensile strength is very important in evaluating the safety of the valve.

This study has been conducted to investigate the North Korea water supply system. For this purpose, laws and regulations concerning the North Korea water utilities were analyzed. According to this study, the water supply system of North Korea is similar to that of South Korea. The major difference between these two systems lies in the national water supplier: South Korea has the national water supplier as well as the municipal suppliers, while there is no national water supplier in North Korea. It is noted that the North Korean water utilities depend on outside suppliers for resources necessary for water production such as electricity, chemicals, spare parts, etc. This could damage the North Korean water utilities. If required resources were not delivered properly (deficient quantity and/or at delayed timing), the water suppliers would encounter difficulties in water production.

본 연구에는 가뭄의 유발 요인으로 강수량, 기온, 상대습도 등의 기상현상을 활용하고 가뭄 피해로 인한 대응 요소로서 대체수원, 제한급수, 운반급수 등의 비상급수를 적용하여 AI기반 가뭄 대응 정보 구축 방안을 구성하였다. AI 머신 러닝 기법 중 널리 사용되는 의사결정나무 모형을 통하여 예측 기법을 수립하였다. 연구 대상 지역은 비상급수 활용 빈도가 높고 종관기상관측소가 존재하는 충주시, 안동시, 의성군을 선정하였다. 자료 기간은 2014년부터 2019년까지의 자료를 이용하였으며, 가뭄 유발 기상요인으로 ASOS의 강수량 및 기온, 습도를 이용하고 가뭄 피해 요소로 국가 가뭄정보 포털의 비상급수 현황 자료를 활용하였다. 모형 학습 결과 정확도가 약 0.97, F1-Score가 약 0.5로 나왔으며, 이는 비상급수가 필요한 상황과 그렇지 않은 상황을 97%의 확률로 예측할 수 있음을 의미하며, 비상급수가 필요했던 표본만을 대상으로 했을 경우 약 50%의 확률로 예측이 가능한 것을 의미한다. 따라서 의사결정나무 모형을 적용하여 예측 정확도를 분석한 결과 가뭄 대응 비상급수 준비지역 예측을 위한 적용성이 높은 것으로 평가되었다. 그러나 본 연구에서는 기상 조건만을 가뭄 유발 요인으로 반영하였기 때문에, 공급수량 부족 등의 요인을 추가적으로 검토할 필요가 있으므로 가뭄과 연관된 요소인 저수지 용량 등을 추가하고 비상급수 이외의 피해 요소 역시 확장하여 연구를 개선하고자 한다.

It is investigated in this study how the water supply system has been developed in North Korea. Articles published in the Rodong Newspaper (North Korea official newspaper) were mainly reviewed for this purpose. It was found in this study that the development of the water supply system in the North Korea was affected by their socioeconomic situations. Their water supply development was categorized into six groups in this study since the first water supply system built in Pyongyang (1910); Occupation period (1910~1945); Introduction period (1946~1950); Restoration period (1951~1960); Advancement period (1961~1970); New village period (1971~1974); Depression period (1974~).

이 연구는 GFRP관을 상수도관으로 사용하기 위해 테스트베드를 설치하여 지중매설된 관의 구조적 거동에 미치는 영향을 조사하였다. 또한, GFRP관의 역학적 성질을 조사하고 관 강성을 추정하였다. KS규격에서 제시하고 있는 허용드로우와 고압력(사용압력의 1.5∼2.0배), 트럭하중을 적용시켜 관 내부와 외부의 복합하중이 작용할 경우 관 내압의 변화와 관의 거동을 확인하였다. 그 결과, 상수관으로 GFRP관을 장기 사용하여도 충분한 내압을 가지고 있음을 확인하였다.

The purpose of this study is to analyze outcome of the project to improve old water supply facilities in Airforce Base to improve water revenue rate. To achieve the objective of this study, First, literature review is conducted to clearly define the concept of water revenue rate improve project. Second, WASCO project on 2 Airforce base review and smart water management pilot project on 1 Airforce base is conducted. Third, economical analysis of project is conducted to examine the outcome. As a result, WASCO and smart water management pilot project on Airforce base was effective to improve water revenue rate. Finally, the improvements were suggested after investigating the key factors on water revenue rate improve project. In the future, this study will be used as a baseline for developing water revenue rate improve project.

Due to global climate change, mega-droughts have occurred frequently. Since long-term droughts make it difficult to secure the water resources, water supply needs to be restricted in a reasonable manner. In the event of limited water supply, the waterworks need to develop a restricted water supply strategy. This study showed that analyzing daily water supply could be used to respond to the first stage of a drought. According to an analysis of Korea's major water authorities, there was about 7~21% of room for daily minimum water supply in case of a drought. Restricting the water supply by lowering pressure is a good strategy for local water authorities with high water leakage rate since leakage is inversely dependent with pressure. For this method, it is necessary to quantify water deficiency and pressure at each node using a simulation. Since DDA-based software is not possible to predict changes in demand at nodes with pressure reduction, WaterGEMS, a PDA software, was used to quantitatively predict water shortages and pressures at each node. Locations where water is deficient need to install booster pumps or to be dispatched with water tank truck and bottled water. Without these support, lowering pressure could not be an option for water works. This paper suggests a method for waterworks to plan a drought by lowering pressure to restrict water supply using daily water supply analysis and PDA based simulation.

In this study, a model to optimize residual chlorine concentrations in a water supply system was developed using a multi-objective genetic algorithm. Moreover, to quantify the effects of optimized residual chlorine concentration management and to consider customer service requirements, this study developed indices to quantify the spatial and temporal distributions of residual chlorine concentration. Based on the results, the most economical operational method to manage booster chlorination was derived, which would supply water that satisfies the service level required by consumers, as well as the cost-effectiveness and operation requirements relevant to the service providers. A simulation model was then created based on an actual water supply system (i.e., the Multi-regional Water Supply W in Korea). Simulated optimizations were successful, evidencing that it is possible to meet the residual chlorine concentration demanded by consumers at a low cost.

Due to global climate change, Korea is experiencing flooding and drought severely. It is hard to manage water resources because intensive precipitation during short periods and drought are commonly occurred in Korea, recently. Severe drought occurred in 2015 and 2017 in the islands, and coastal and inland areas in Korea, and the citizens experienced decreased water supply and emergency water service by using bottled water. Therefore, the Korean government provided additional governmental funds such as the grant of drought disaster. In this study, we tried to calculate the cost of water for drought response based on the cost of tap water for the regional local governments in Korea and the grant of drought disaster by the Ministry of the Interior and Safety in Korea, etc. The estimated costs of water for drought responses in coastal and inland areas which have a chance to apply alternative water sources such as brackish or seawater desalination and water reuse in Korea were higher than in other areas in Korea. Additionally, as the novel approach of drought response, the 300 m3/day-scale desalination vessel was suggested to provide desalinated water for the islands in Korea. The estimated expenses of water supply for the target island areas (Sinan-gun and Jindo-gun) by the desalination vessel was lower than those by emergency water service by using bottled water.

Pipe for water supply is one of the important parts that supply water to home, factory and so on. Water leakage in pipe for water supply due to deterioration, ground sinking and earthquake leads to enormous economical loss. Therefore, pipe for water supply should be designed to satisfy the requirement of, for instance, structural stability and fatigue durability. The purpose of this study was to investigate the fatigue durability of flexible joint for relaxing the impact due to earthquake and ground sinking. For this purpose, flexible joint was simulated using dynamic characteristics and fatigue life. As the results, the problem of fatigue durability may occur when flexible joint and pipe for water supply are treated as rigid body in simulation. Thus it means that the role of packing in flexible joint is very important and packing should be designed as optimal conditions that are considered fatigue durability as well as waterproof.

The results of internal temperature. productivity and immunity analysis of the laying hen house by the thermal environment and the supply of cold drinking water were as follows. The external temperature was changed from the minimum of 18℃ at night and the maximum of 36℃ during the day, and the internal temperature of the laying hens varied from 20~31℃. Thermal imaging analysis showed that the body temperature of the laying hen decreased by 2.4℃ with the supply of drinking water. The laying hen amount increased 2.36g and laying hen rate increased 3.62%p. Albumin increased 6.1%, decreased AST 15%, and decreased cholesterol 12.7%. Immune activators increased and T cells and B cells increased to increase immunity.

The pipe for water supply is essential part among SOC (Social Overhead Capital) fields. Pipe for water supply is mainly damaged by deterioration of pipe, earthquake, ground sinking and so on. The leakage of water have been led to enormous economical loss in our country. The purpose of this study was to investigate the structural stability of flexible joint for relaxing impact due to earthquake and ground sinking. For this purpose, flexible joint was simulated using tensile load and internal pressure. As the results, flexible joint for structural stability was needed the tensile load of below 3 ton and internal pressure of below 60 kgf/cm2. However, it is considered that real flexible joint should be applied more high safety factor than that of simulation result because of combined stress.

This study would present a risk analysis method to evaluate stable tap water supply in a multi-regional water supply system and propose a measure for the evaluation of the effect of the conjunctive operation of the multi-regional water supply system using this. Judging from the vulnerability for the crisis response of the entire N. multi-regional water supply system, as compared to the result of Scenario 1 in which no conjunctive pipes were operated, it was found that in Scenario 2, in which conjunctive pipes were partially operated, the vulnerability of crisis response decreased by about 30.6%, and as compared to Scenario 3, the vulnerability of crisis response decreased by 86.2%. In setting a plan for stable tap water supply in N multi-regional water supply system, using the estimated value and the method for the evaluation of the vulnerability of crisis response by pipe, by interval and by line, it is judged that this can be utilized as a basis for the judgment of the evaluation of the operation or the additional installation of conjunctive pipes.