Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea’s SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.

In this study, we propose a flow velocity evaluation scheme based on pressure measurement in pressurized pipeline systems. Conservation of mass and momentum equations can be decomposed into mean and perturbation of pressure head and flowrate, which provide the pressure head and flowrate relationship between upstream and donwstream point in pressurized pipeline system. The inverse impedance formulations were derived to address measured pressure at downstream to evaluation of flow velocity or pressure at any point of system. The convolution of response function to pressure head in downstream valve provides the flow velocity response in any point of the simple pipeline system. Simulation comparison between traditional method of characteristics and the proposed method provide good agreements between two distinct approaches.

Multi-regional water supply system, which installed for supplying multiple water demands, is characterized by large-sized, long-distance, tree-type layout. This system is vulnerable to long-standing service interruption when a pipe breaks is occurred. In this study, a numerical method is proposed to calculate drainage time that directly affects time of service interruption. To begin with, governing equations are formulated to embed the delayed drainage effect by the friction loss, and to resolve complicated connection of pipelines, which are derived from the continuity and energy equations. The nonlinear hydraulic equations are solved by using explicit time integration method and the Newton-Raphson method. The developed model is verified by comparing the result with analytical solution. Furthermore, the model’s applicability is validated by the examples of pipelines in serial, in parallel, and complex layout. Finally, the model is utilized to suggest an appropriate actions to reduce the deviation of draining time in the C transmission line of the B multi-regional water supply system.

Pressure monitoring is expected to be expanded in a water distribution system according to accelerated development of smart water network management technologies caused by appearances of affordable digital infrastructures like computing, storage and bandwidth. However, the placement of pressure sensors has been determined by engineer’s technical decisions since there is no well-defined criteria for deciding a suitable location of pressure sensor. This study presents a placement method of pressure sensors based on the consideration of allowable error in calibrating water network analysis modeling. The proposed method is to find a minimum set of pressure sensors for achieving a reliable management of water transmissions main and increasing the efficiency of their real-time operation. In the case study in Y area’s transmission main, the proposed method shows equally distributed pressure sensors in terms of hydraulics. It is expected that the proposed method can be used to manage transmission mains stably and construct a robust real-time network analysis system as a minimal criteria.

It has been widely accepted that the pressure management of water distribution systems using pressure reducing valves(PRVs) would be an effective method for controlling leakages. A pressure reducing valve (PRV) regulates outlet pressure regardless of fluctuating flow and varying inlet pressure, thereby reducing leakage and mitigating the stress on the water distribution system. However, the operation of a PRV is vulnerable to its mechanical condition and hydraulic operability. In this research, the effect of PRVs installed in water distribution system are evaluated in terms of hydraulic pressure reduction and mechanical performance by analyzing measured pressure data with statistical approach. A statistical approach using the moving average filter and frequency analysis based on fourier transform is presented to detect abnormally operated PRVs that have been densely installed in water distribution system. The result shows that the proposed approach can be a good performance evaluation method by simply measuring pressures for the PRVs.

Deposits discharged through the cleaning mainly were cement mortar, bitumen paintings and rust pieces, and fragments of perforation, stones and gravels. Deposits were more removed through swabbing pig cleaning rather than air scouring cleaning on the whole. However, air scouring cleaning were not influenced by the constraint conditions such as a change in the diameter or the presence of the valve in water mains compare to swabbing pig cleaning. So, it was thought that air scouring cleaning might be more favorable to water distribution network cleaning in the future. After the cleaning, water quality including residual chlorine and turbidity also was improved because of the removal of a significant amount of the deposits. Therefore, if the cleaning is continuously and regularly implemented in water mains, it is expected that it will help to recover the reliability and to preserve the health of water quality.

Tuberculation and slime accumulated in water mains play an important role in modifying water quality of drinking water. Therefore, in this study, it was investigated that what materials were accumulated, and what components were included in the tuberculation and slime of water mains. The Various tuberculation and slime sample were collected from the 12 water mains to analyze their physical and chemical properties and crystal structure. As a analysis method, VSS(Volatile suspended solid), SEM(scanning electron microscope), EDS(Energy Dispersive X-ray spectroscope), ICP(Inductively Coupled Plasma Mass Spectrometer) and XRD(X-Ray Diffractomete) were used. The results of analysis on the samples, the representative materials were verified such as iron corrosion products, the fine sand particles generated during backwash, fine particles of activated carbon, aluminum used in coagulation process, and manganese included in raw water.

The flushing is important to maintain good water quality in water main. It is a technique of using water velocity to remove sediments in water distribution system. The variety of water quality problems can occur in a distribution system, so too can a variety of benefits be gained by system flushing. In order to effectively perform the flushing, the contaminants to be removed to set up and it can be solved, it is necessary to ensure the proper flow rate. In this study, the removal of contaminants present in the inner water pipe attached loose deposits such as fine particles of granular activated carbon, sand and iron corrosion product sought to derive flow rates. Thus, the constant observation of using pilot plant scale water distribution plant for the movement of floating characteristics of particles were assessed.

Water discolouration and increased turbidity in the local water service distribution network occurred from hydraulic incidents such as drastic changes of flow and pressure at large consumer. Hydraulic incidents impose extra shear stresses on sediment layers in the network, leading to particle resuspension. Therefore, real time measuring instruments were installed for monitoring the variation of water flow, pressure, turbidity and particulates on a hydrant in front of the inlet point of large apartment complex. In this study, it is attempted to establish a more stable water supply plan and to reduce complaints from customers about water quality in a district metering area. To reduce red or black water, the water flow monitoring and control systems are desperately needed in the point of the larger consumers.

수돗물의 공급과정에서 발생되는 상수관망의 누수는 소중한 수자원의 손실, 공급에너지의 추가적인 소요 등 사회경제적인 손실을 초래한다. 본 연구에서는 관로 상에 설치되어 실시간으로 계측되는 유량자료를 이용하여 누수를 감시하는 모형을 적응 칼만필터 기법을 이용하여 제시하였다. 제안된 누수감시 알고리즘에서는 수돗물 사용량의 시간적 변화와 요일적 변동을 고려함으로써 예측의 신뢰도를 향상시키는 방안을 제시하였다. 또한 기존의 칼만필터 기법에 혁신과정을 추가하여 잡음의 공분산에 대한 자동보정을 통하여 예측의 정확도를 개선하였다. 개발된 모형은 사인형태의 가상 유량자료에 대한 모의실험을 통하여 적응 칼만필터 기법의 예측 정확도를 기존의 칼만필터 기법과 비교하였으며, JE시의 2개 소블록 유량자료에 대한 현장 적용성 평가를 실시하였다. 본 연구의 결과는 관로의 파열에 의한 누수 및 비정상적인 용수사용량에 대한 감시를 통하여 상수관망의 효율적인 운영관리에 적용될 수 있을 것으로 기대된다.

수돗물의 생산 및 공급과정에 소요되는 에너지에 대한 체계적인 분석 및 평가는 최근의 전력부족 사태와 온실가스 감축의 필요성에 따라 관심이 증가되고 있다. 본 연구에서는 기존의 연구에서 제시한 결과에 대한 검토를 통하여 실용적으로 적용 가능한 에너지 분석기법 및 평가기법을 제시하였다. 본 연구에서는 EPANET2의 수리해석 결과를 이용하여 에너지를 평가할 수 있는 모형을 MATLAB 플랫폼 기반 하에서 개발하였다. 제안된 기법은 상수관망의 입지, 관로의 상태, 누수정도 등에 따라 시설물이 내재적으로 가지는 에너지 관리효율과 운영효율을 분리하여 평가할 수 있는 성능평가 지표를 제시하였다. 개발모형은 시험관망과 실제관망에 대하여 각각의 상수관망 구성요소에 대한 에너지 분석 및 평가결과를 제시함으로써 적용성 평가를 실시하였다. 본 연구의 결과는 상수관망 에너지 관리의 최적화를 도모함으로써 피크시간대의 전력수요 관리 및 에너지 절감형 상수도 시스템 계획 및 운영에 활용될 수 있을 것으로 기대된다.

본 연구에서는 3차원 점성 흐름에 적용될 수 있는 비정수압 자유수면 모형을 수평방향 직교 곡선좌표계에서 개발하였다. 개발된 수치모형은 엇갈린 격자를 사용함으로써 발생되는 자유수면에서의 경계조건 종결 문제를 수면층 방정식을 도입하여 해결하였으며, 난류의 유동 해석을 위한 폐합식으로 등방성의 k-ε 난류모형을 이용하였다. 본 연구에서 운동량방정식은 이송-확산항만으로 중간단계의 유속을 예측하고, 압력 및 중력을 포함하는 생성항과 연속방정식을 결합하여 다음 시간단계의 유동장을 결정하는 계산 단계 분리법을 이용하였다. 수치모형의 적용성 평가를 위하여 폐쇄된 2차원 수조에서의 취송류, 급경사를 가지는 2차원 수로에서의 흐름, 원심력에 의한 이차류 흐름특성 분석을 위한 3차원 급변 만곡류에 대한 모의를 실시하였다. 수치모의 예측치는 수리모형 실험값과 수위, 유속, 난류특성 등에서 일치하는 양상을 보이는 것이 확인되었다.