Applying Minimum Night Flow to Estimate Water Loss Using Statistical Modeling: A Case Study in Kinta Valley, Malaysia

The average percentages of non-revenue water (NRW) for Malaysia and for the state of Perak in 2010 were 36.37 and 29.44%, respectively. These average percentages have led to lower income generation. This could create constraints on maintenance and operation of water reticulation systems. In this study, the appropriate time band of minimum night flow (MNF) and the actual water loss or amount of NRW for the district of Kinta in Perak, Malaysia were investigated. Flow and pressure in 361 zones in Perak were monitored for 24 h using PrimeWorks software. From the 361 zones, 30 study zones were randomly selected. The 30 study zones were geographically divided into three groups, with each group having 10 zones. Statistically, one-way analysis of variance (ANOVA) was used to test the variations in MNF among the three groups. The data of the flow for the 30 zones were screened from 1:00 to 5:00 am for the past 4 years. The frequency of MNF occurrences was analyzed every 15 min. The results show that the majority (84.2%) of the frequencies of MNF occurrences in the 30 study areas occurred from 2:15 to 4:15 am, whereas minimum frequencies were observed at 1:00, 1:15, and 5:00 am.

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Statistics in the Service of Science: Don't let the Tail Wag the Dog

10.31234/osf.io/kxhfu ◽

2021 ◽

Author(s):

Henrik Singmann ◽

Gregory Edward Cox ◽

David Kellen ◽

Suyog Chandramouli ◽

Clintin Davis-Stober ◽

...

Keyword(s):

Statistical Modeling ◽

Statistical Models ◽

Mixed Models ◽

Model Comparison ◽

Bayes Factors ◽

Causal Mechanisms ◽

Science Models ◽

Scientific Goal ◽

Coordination Function

Statistical modeling is generally meant to describe patterns in data in service of the broader scientific goal of developing theories to explain those patterns. Statistical models support meaningful inferences when models are built so as to align parameters of the model with potential causal mechanisms and how they manifest in data. When statistical models are instead based on assumptions chosen by default, Attempts to draw inferences can be uninformative or even paradoxical—in essence, the tail is trying to wag the dog.These issues are illustrated by van Doorn et al. (in press) in the context of using BayesFactors to identify effects and interactions in linear mixed models. We show that the problems identified in their applications can be circumvented by using priors over inherently meaningful units instead of default priors on standardized scales. This case study illustrates how researchers must directly engage with a number of substantive issues in order to support meaningful inferences, of which we highlight two: The first is the problem of coordination, which requires a researcher to specify how the theoretical constructs postulated by a model are functionally related to observable variables. The second is the problem of generalization, which requires a researcher to consider how a model may represent theoretical constructs shared across similar but non-identical situations, along with the fact that model comparison metrics like Bayes Factors do not directly address this form of generalization. For statistical modeling to serve the goals of science, models cannot be based on default assumptions, but should instead be based on an understanding of their coordination function and on how they represent causal mechanisms that may be expected to generalize to other related scenarios.

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Study of non-revenue water status and enforcement measures to reduce water loss: case study in villages of Kermanshah Province of Iran

Chinese Journal of Population Resources and Environment ◽

10.1080/10042857.2017.1406744 ◽

2017 ◽

Vol 15 (4) ◽

pp. 351-356 ◽

Cited By ~ 2

Author(s):

Seyyed Alireza Mousavi ◽

Iraj Shahbazi ◽

Hosna Janjani ◽

Rastegar Veysinejad ◽

Ali Asgar Sobhani ◽

...

Keyword(s):

Water Loss ◽

Water Status ◽

Non Revenue Water ◽

Reduce Water Loss

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Statistical modeling the effect of sediment physicochemical properties on the concentration of heavy metal (case study: Musa Creek, SW Iran)

Environmental Earth Sciences ◽

10.1007/s12665-018-7289-6 ◽

2018 ◽

Vol 77 (3) ◽

Cited By ~ 3

Author(s):

Maryam Ghazanfari Shabankareh ◽

Hakimeh Amanipoor ◽

Sedigheh Battaleb-Looie ◽

Javad Dravishi Khatooni

Keyword(s):

Heavy Metal ◽

Physicochemical Properties ◽

Statistical Modeling ◽

Metal Case ◽

Sw Iran

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Water Crossover Reduction in DMFC Utilizing Hydrophobic Anode MPL

ASME 2008 6th International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2008-65019 ◽

2008 ◽

Author(s):

Christian E. Shaffer ◽

Chao-Yang Wang

Keyword(s):

Water Transport ◽

Water Loss ◽

Transport Model ◽

Flow In Porous Media ◽

Cathode Side ◽

Two Phase ◽

Direct Methanol ◽

Lower Permeability ◽

Phase Transport

Reducing the water crossover from anode to cathode is an important goal for direct methanol fuel cell (DMFC) technology, especially if highly concentrated methanol fuel is to be used. A well-documented way to reduce this water loss to the cathode side is by using a hydrophobic cathode microporous layer (MPL). Recently, however, it has been demonstrated that in addition to a cathode MPL, the use of a hydrophobic anode MPL further reduces the water loss to the cathode. In this work, we use a two-phase transport model that accounts for capillary induced liquid flow in porous media to explain physically how a hydrophobic anode MPL acts to control the net water transport from anode to cathode. Additionally, we perform a case study and show that a thicker, more hydrophobic anode MPL with lower permeability is most effective in controlling the net water transport from anode to cathode.

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Leakage estimation in water networks based on two categories of night-time users: a case study of a developing country network

Water Science & Technology Water Supply ◽

10.2166/ws.2013.201 ◽

2013 ◽

Vol 14 (2) ◽

pp. 329-336 ◽

Cited By ~ 2

Author(s):

P. K. Amoatey ◽

R. Minke ◽

H. Steinmetz

Keyword(s):

Demographic Characteristics ◽

Total Water ◽

Night Time ◽

Water Utility ◽

Active Population ◽

Water Closet ◽

Minimum Night Flow ◽

Social Habits ◽

District Metered Area

The proportion of total water loss that is due to leakages and bursts in a district metered area in the Baifikrom supply network in the Central region of Ghana was investigated using the minimum night flow method. Legitimate customer night use was estimated specifically for the study area based on social habits, active population at night and demographic characteristics of two categories of night-time users identified – water closet users and ventilated improved pits users. It was estimated that 12% of the daily supply volume was lost through leakage indicating that apparent losses constitute 28%. This suggests that the water utility has to investigate the components of apparent losses and plan measures to reduce them in addition to reducing leakage.

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