Performance Of Water Supply System Research Articles

The socio-technical short-term implications of drinking water hoarding on supply reliability

ABSTRACT Panic buying during crises, like the initial hoarding of toilet paper amid COVID-19 restrictions, is mainly driven by social and emotional factors influenced by risk perception and social media content. Similarly, unreasonable drinking water hoarding, i.e., simultaneous withdrawal of water by a large number of customers, can influence the performance of water supply systems (WSS). Decreasing performance (e.g., more friction losses and therefore a smaller outflow rate at faucets) can cause a negative feedback loop that might trigger further water hoarding behaviours. This research explores the socio-technical implications of water hoarding in crisis situations within a WSS. An analysis of an Alpine WSS in Austria reveals that up to 40% of households, with a filling rate of 0.1 L/s (bathtub filling), can hoard without performance drop and negative feedback. Beyond this threshold, impacts become noticeable, leading to inadequate water supply for some households, causing disruptions and negative feedback loops. This emphasizes the need for information campaigns to counter false information, preventing emotional triggers. In conclusion, the research highlights the interplay between technical and social factors in crisis water demand management, stressing the importance of informed interventions to mitigate hoarding behaviour and maintain efficient WSS operation.

Enhancing Sustainability in Italian Water Supply Pipes through Life Cycle Analysis

The primary concern regarding the sustainability of the urban water cycle remains the performance of water supply systems. This, in turn, is determined by the functionality and sustainability of the system components, such as the pipe networks, pumps, and other appurtenances, which must be analyzed from an environmental perspective. The aim of the present study is to analyze the sustainability of two different types of water supply pipe materials that are commonly used, polyvinyl chloride and high-density polyethylene, using a comparative Life Cycle Analysis methodology. The functional unit was established in accordance with the water supply system that serves an Italian metropolitan city with a dimension of 9240 km, as one meter of water supply infrastructure, with 40 years as a life span. A cradle-to-gate analysis was conducted, starting from the production phase of the water pipelines to the maintenance phase, excluding the end of life and disposal phases. The chosen methodology was CML, justified by the fact that the results are more understandable and reproducible. Results comparison revealed a higher environmental impact during the production phase, while the maintenance phase had a very low impact. Notably, PVC pipe in comparison with HDPE material had a higher impact, except in two categories of impact: abiotic depletion and photochemical oxidation. The study contributes to the future development of alternative approaches for sustainable and eco-efficient water supply infrastructure designs and materials.

Assessment of Water Supply System Performance Indicators Based on the Customer Bill-Based Approach

Significant efforts have been undertaken over the last two decades by governmental organizations and local and international non-governmental sectors to improve water supply and sanitation structures; however, there are significant challenges to the town's growth and expansion. Chiro town's population is increasing, and the community is affected by water and excreta-borne diseases as a result of a lack of proper sanitation facilities and a water supply system. In this study, billed data from Chiro Town water supply service enterprise customers have been used to assess the performance of the water distribution network over ten years (2011-2020). The findings show that the Town's water coverage is 62.9%, the water demand is 8,121.6m3/day, and the computed annual water production is 4,222.3m3/day. Residents of the town have complained about a lack of access to improved drinking water supplies, low water consumption, and sanitation facilities, particularly in the community of those who live in the town's borders and practice open defecation. For all domestic use, 16.32% and 83.68% of respondents used unprotected and protected water sources, respectively. This study suggested that strong sectoral coordination, community involvement, and sufficient financial resources were required to identify the root causes and provide an efficient water supply system in the study area.

TRNSYS simulation study of the operational energy characteristics of a hot water supply system for the integrated design of solar coupled air source heat pumps

To address the issues with solar water heating systems taking up a lot of space, unstable hot water supply, air source heat pumps susceptible to frost in the winter, and low energy efficiency. The TRNSYS tool is employed in this work to simulate a solar-coupled air source heat pump system. The heat pump operation is first investigated using the inverse Carnot cycle. The performance coefficient is then calculated by the second law of thermodynamics without considering the pipeline's pressure drop and heat loss. The output temperature of the hot water that the heat pump circulates is then determined. The daily hot water needs can be estimated roughly based on information about solar radiation. The heat balance equation for flat plate solar collectors was used to compute the intensity of solar diffused radiation. The Berlage calculation was used to determine the solar radiation received on the collector's surface. After a qualitative analysis of the heat from the heat source, the efficiency of the linked heat pump and the conventional air source heat pump was compared. Analyzing the water temperature change graph for each month's data reveals that the system can achieve 50 °C during the water supply time each month. The heat pump's annual energy consumption is 6252.01 kWh, while the system's annual energy consumption is 9100.47 kWh. The study findings may be used as a guide to improving the design and management of the whole system. In addition, they may improve the solar water supply system's performance.

A Risk-Based Framework to Evaluate Infrastructure Investment Options for a Water Supply System

Increasing water demand due to socio-economic development often requires structure-level interventions, e.g., infrastructure expansion of water supply systems to bridge the gap between demand and water supply. Evaluating different expansion options is critical to making informed decisions. This study focuses on evaluating infrastructure investment options from the reliability perspectives of a water supply system. The evaluation framework is comprised of probabilistic demand projections, stochastic streamflow generation, a mixed-integer programming, and system performance evaluation. Different “industry understood” performance metrics, e.g., annual reliability, maximum delivery capacity, the probability of unsuccessful status, and the magnitude of potential water shortage, can be employed to evaluate the performance of water supply systems. This framework has been applied to Tampa Bay Water, a regional supply agency on the west coast of Florida, United States. The probabilistic demand projections for the future (2021–2040) consider socio-economic projections and climate conditions based on the statistics of historical observations. The Latin Hypercube Sampling algorithm is used to capture the bivariate distribution of supply and demand. This mixed-integer programming is a daily system optimization that minimizes operational cost and considers operational constraints and preferences, e.g., water withdrawal permits, facility production capacity, and water production preferences. Current infrastructure capacity and operational conditions are defined as the baseline scenario. Two additional planning scenarios of expanding the treatment capacity of a surface water treatment plant by 75,708 m3/day [20 million gallons per day (mgd)] and 113,562 m3/day (30 mgd) in the year 2028 are investigated. Results reveal that annual reliability would increase with the expansion of surface water treatment plant capacity. The spatio-temporal supply and demand variability determines that the firm yield from the surface water treatment is less than its expanded production capacity. Except for low demand realizations in the future, the duration and magnitude of potential water shortage could be reduced in both scenarios with engineering intervention. Although this framework is demonstrated for a regional water utility in Florida, it can be applied to other water supply systems around the world.

Evaluation of water supply system performance affected by climate change with MODSIM modeling and reservoir efficiency indicators

Evaluation of water supply system performance affected by climate change with MODSIM modeling and reservoir efficiency indicators

Mathematical Methodology in the Seismic Resilience Evaluation of the Water Supply System

Abstract This paper has collected more than one hundred papers about resilience at home and abroad, summarised and analysed the meaning and evaluation methods of resilience and then summarised the key issues. Through research on these papers, we found that the current evaluation method for the water supply system seismic resilience is divided into two aspects: on the one hand, it’s based on the seismic performance of water supply system, where the system itself evaluates the resilience absorbs the earthquake resistance level. On the other hand, the assessment is based on the post-earthquake recovery ability of the water supply system, namely the recovery time, recovery degree, recovery path and the resilience level of resources input. Based on past seismic safety of the water supply system and research on post-earthquake recovery ability, the meaning of water supply system in seismic resilience should include two aspects of seismic safety and post-earthquake recovery ability. From using the seismic safety evaluation method also and post-earthquake recovery ability in two angles, this paper gives a comprehensive multiple evaluation index framework of the evaluation model and points out that water system earthquake state resilience evaluative criteria and the requirements of the current seismic code should match.

Selecting the Best Approach to Modeling the Performance of Water Supply System Using the Combination of Rough Set Theory with Multi-Criteria Decision Making

Selecting the Best Approach to Modeling the Performance of Water Supply System Using the Combination of Rough Set Theory with Multi-Criteria Decision Making

Evaluation of the Performance of Water Supply System in Wolaita Sodo Town, Snnpr, Ethiopia

Wolaita Sodo town suffering the shortage of safe water supply service due to increasing population. The aim of study was evaluating the performance of water supply system to develop strategies to improve the situation for the future. It was carried out using six performance indicators suggested by International Water Association (IWA) this was analyzed by SIGMA lite and user perception data that analyzed by SPSS. As study indicates, average consumption for about 73% of households was less than 20 liter/capita/day. Most of the households (i.e. 53%) were dependent on public tap, vendors and unprotected spring as a primary water source. About 22% of households depend on neighboring water vendors and pay high price (i.e. average of 70.6 ETB/month) for poor drinking water source. Among the six IWA indicators of water supply service; operational indicators and quality of service indicators fully showed a good performance. However, from water resource indicators (consumer satisfaction & production/person/day); from personnel indicators (employees/connection), all physical indicators and from financial indicators (water tariff) need some improvement. Generally as the results of the study shows, there was a shortage of water supply service in the town due to the problem of existing water supply system. Keywords: Access, demand forecast, performance indicators, Performance evaluation, water supply services, DOI: 10.7176/CER/13-1-02 Publication date: January 31 st 2021

Socio-Hydrological Modelling to Assess Reliability of an Urban Water System under Formal-Informal Supply Dynamics

Increasing water scarcity in developing world cities combined with poor performance of water supply systems has led to an increasing reliance on informal water supply systems. Although the availability of informal supply provides a coping mechanism that enables water consumers to be resilient to failures in water supply, the longer-term effects on formal water supply systems (FWSS) are uncertain, with a potential reduction of tariff recovery (RT), and in turn a service provider’s financial sustainability. This motivates an analysis of the coevolving dynamics and feedbacks involved in water systems where formal and informal components co-exist. Investigating Hyderabad, Pakistan as a case study, a dynamic socio-hydrologic system model is built, comprised of a formal system’s water and fund balance, consumer behaviour and infrastructure conditions. Simulations are executed on a monthly basis at a household level and for a 100-year period (2007–2107) using data available from years 2007–2017. Demand shift to informal is observed to be weakly associated with lower recovery rates, with household income as a major predictor. The FWSS’s financial balance, predominantly driven by infrastructure condition, appears to be less sensitive to recovery of a tariff to generate sufficient revenue.

Water resource management strategy for urban water purposes in Dili Municipality, Timor-Leste

ABSTRACT There are various factors in Dili’s water system responsible for the water scarcity problem in the city. Hence, there is a need for strategic plans which could be used as guidelines in improving its water system. The objective of this study was to formulate a strategic plan for water resource management in Dili. The process commenced with the identification of external and internal factors. The Analytical Hierarchy Process (AHP) was used to weight the score at the input stage. The alternative strategies were formulated with the Strengths, Weaknesses, Opportunities, and Threats (SWOT) matrix. Furthermore, the Quantitative Strategic Planning Matrix (QSPM) was used to select the priority strategy at the decision stage. Based on the results, a total of 13 internal and 13 external factors were identified, while five alternative strategies formulated. Moreover, the selected strategy as the priority for implementation has the capacity of developing the water resource management infrastructure in Dili, as well as improving the water supply system performance in meeting the urban water demand.

Impact of Optimized Pump Scheduling on Water Quality in Distribution Systems

AbstractPump scheduling can improve performance of water supply systems, but it may have a different effect on water quality. The target of this article is to examine optimized pump schedules’ impa...

Water Supply System Performance Improvement in the Town of Pirot Using Water Balance IWA Methodology and Numerical Simulations

Water Supply System Performance Improvement in the Town of Pirot Using Water Balance IWA Methodology and Numerical Simulations

Dynamic Optimization Model for Improving Urban Water Supply System Fragility with Uncertain Streamflow

With uncertainties in available water resources, the performance of water supply systems must be assessed and optimized to meet future sectoral demands. This study develops a dynamic model by evaluating fragility, which comprises three indexes: reliability, resiliency and vulnerability. With the aim of mitigating the negative stressors that lead to system collapse, dynamic multisectoral water supply optimization is conducted. To mitigate the negative impacts of water scarcities on system fragility over the long term, the performance of dynamic systems must be assessed. Optimization can shift the water supply system fragility (WSSF) to a robust or even an antifragile state. A real-world case study in Northeast China is conducted over ten-year intervals. Based on the optimized model, several managerial insights are given to the policy makers of the Tianjin Binhai New Area (TBHN) to cope with streamflow uncertainties. Finally, scenario analysis and sensitivity analysis are conducted, and the results indicate that as water availability decreases, both reliability and vulnerability decrease, which further increases system fragility. In addition, the reliability of the system greatly contributed to system antifragility compared with the contributions of resilience and vulnerability.

Urban water supply system optimization and planning: Bi-objective optimization and system dynamics methods

Sustainable, low-cost, environmentally conscious development is a major challenge for urban water supply systems. This study considers household and industrial water demand and establishes a bi-objective model to balance the economic and environmental cost of a three-stage urban water supply system including water production, distribution, and treatment processes. Considering different attitudes toward the increasing imbalance between water demand and supply, three hypothetical scenarios are designed based on which three sets of data on water demand and wastewater production volumes are defined. Then, a two-step method is applied to obtain solutions to decision variables (potable water use rate and wastewater untreated rate). After optimization, a system dynamics model is applied to test water supply system performance under short-, medium-, and long-term planning scenarios. Finally, the model is applied to Singapore to test its feasibility. The proposed bi-objective model provides managerial insights into the use of alternative water resources. For example, in 2020, water demand is simulated as 5.63×108m3. After optimization using the proposed model, the quantity of alternative water is 2.5×108m3 (water from the local catchment), 2.5×108m3 (imported water), 5.31×107m3 (desalinated water), 4.05×107m3 (NEWater for indirect potable use), and 8.10×107m3 (NEWater for direct non-potable use). Total water supply is 6.75×108m3, which means there is some redundancy in water supply. Further, three indexes—supply-demand ratio, economic cost, and environmental cost—help to identify the suitable planning period: the medium-term focus is the most appropriate option as it promises water adequacy for over 15 years and has lower energy costs and less negative environmental impact during the evaluation years. In addition, this study proves the influence of decision makers’ preferences on contradictory objective functions (economic cost minimization and environmental negative impact minimization). Overall, the proposed model balances a trade-off between the risk of an increasing future supply-demand imbalance and current water adequacy. Lastly, the proposed model offers a paradigm to identify a sustainable planning period.

Assessing Future Impacts of Climate Change on Water Supply System Performance: Application to the Pozzillo Reservoir in Sicily, Italy

Climate change induced by greenhouse gas emissions is expected to alter the natural availability of water, affecting domestic, agricultural and industrial uses. This work aims at assessing the possible future impacts of climate change on precipitation, temperature and runoff, and to simulate the effects on reservoir demand–performance curves. To this aim, a modeling chain is set up, based on the combined use of regional climate models (RCMs) and water supply system simulation models. The methodology is applied to the Pozzillo reservoir, located in Sicily (Italy), which has experienced several droughts in the past. We use an RCM model that, based on a previous study, has proved to be the most reliable in the area, among those of the EURO-CORDEX initiative. RCM precipitation and temperature monthly time series are used to generate future reservoir inflow data, according to two representative concentration pathways, RCP4.5 (intermediate emissions scenario) and RCP8.5 (high emissions scenario) and a two-step bias correction procedure. Simulation of the reservoir indicated that, due to reservoir inflow reduction induced by climate change, performances of the Pozzillo reservoir are predicted to decrease significantly in the future, with impacts of RCP8.5 generally higher than RCP4.5.

Fuzzy Reliability-Vulnerability for Evaluation of Water Supply System Performance

The reliability of water supply system is a critical factor in the development and the ongoing capability to succeed in life and people's health. Determining of its, with high certainty, for performance of water supply system is developed to ensure the sustainability of system. Reliability (Re) plays a great role in evaluation of system sustainability. The probability approaches have been used to evaluate the reliability problems of systems. The probability approach is failed to address the problems of reliability evaluation that comes by subjectivity, human inputs and lack of history data. This research proposed two models; I) traditional model: fuzzy reliability measure suggested by Duckstein and Shresthaand then developed by El-Baroudy; and II) developed model: fuzzy reliability-vulnerability model. The two models implemented and evaluation of water supply system by using two hypothetical systems (G and H). System (G) consists of a single pump and System (H) consists of a two parallel pumps. Triangular and trapezoidal membership functions (MFs) are used to investigate of the reliability measure to the form of the membership function. The results agree with expectations that the reliability of parallel component system {ReH (0.53)} is higher than the reliability of single component system {ReG (0.47)}. Moreover, the result by using fuzzy set reduces the effect of subjectively in process of decision-making (DM). The fuzzy reliability vulnerability is able to handle different fuzzy representations and different operation environment of system

Impact of operating rules on planning capacity expansion of urban water supply systems

ABSTRACTWater utilities often rely on industrial water supply (e.g. desalination) to complement natural resources. These climate-independent sources of supply allow operators to respond quickly to varying operating conditions, but require them to choose operating strategies, or rules. How does such operational flexibility impact the performance of water supply systems? How might it affect long-term plans for capacity expansion? Possibly significantly, as demonstrated by the analysis of a water supply system based on Singapore. First, we simulate the dynamics of the system under multiple rainfall and operating scenarios to understand the extent to which the operators’ behavior affect system performance. Results show that different operating rules can have comparable impact on the variability in system performance as hydrological conditions. Then, we show that small changes in the operating rules can lead to substantial changes in the capacity expansions, such as the size of a new desalination plant.

Assessment of regional drought risk under climate change using bivariate frequency analysis

Since water supply failure is one of the primary impacts of drought, drought risk should be quantified in the context of a lack of available water. To assess the drought risk, water supply system performance indices such as reliability, resiliency, and vulnerability are usually introduced as they correspond to primary drought characteristics, i.e., frequency, duration, and magnitude. In this study, we developed a drought risk index (DRI) through weighted averaging the performance indices derived using bivariate drought frequency analysis. We suggested two types of DRI: observed DRI (DRI_O) and designed DRI (DRI_D). DRI_O was calculated using an observed (or synthesized) time series of water shortages. DRI_D was estimated from the bivariate drought frequency curves, which are the probabilistic magnitudes of water shortages corresponding to a particular duration. The historical maximum drought event that represents the maximum DRI_O has generally been used as the target security level. However, we could establish a practically applicable target security level considering that the future water supply failure risk is represented by DRI_D. We defined regional drought safety criteria in this study by comparing DRI_O and DRI_D. Application of the criteria to the Nakdong river basin in South Korea showed that W1 (Byeongseongcheon) and W4 (Hyeongsangang) had the lowest and highest drought risk, respectively, and the drought safety criteria showed an average range of 5–20 years.

Uncertainty Propagation of Hydrologic Modeling in Water Supply System Performance: Application of Markov Chain Monte Carlo Method

AbstractIt is imperative for cities to develop sustainable water management and planning strategies in order to best serve urban communities that are currently facing increasing population and wate...