Fig 1.
Drainage map of the sewage network of part of Vellore City, India.
This map was utilized in this applied scenario and identifies the organization and IDs of major drainage branches. This map is used to define the fixed parameters (Table 1), which identify the length of each branch and each branch’s parent branch(es) in order to represent the direction of wastewater flow. This map provides a visualization of the conceptual map used by the model to track wastewater flow along the sewage network. Blue arrows indicate the direction of flow toward the convergence point. Note: not all branch IDs are shown to improve readability. Drainage map from https://es.world/map/vellore for drainage lines [29]. Street map from OpenStreetMap contributors. (2024) [Data file from 2023-06-02] Retrieved from https://www.openstreetmap.org/export—map=13/12.9049/79.1300 [43]. Terms: https://www.openstreetmap.org/copyright.
Table 1.
Model Parameters for theoretical applied scenario.
Fig 2.
Diagram of the model processing steps.
Each simulation box represents one of n simulations, for which values for distributed parameters are randomly selected from parameter distributions. Within each simulation, the model iterates over m iterations and stores calculations for pathogen concentrations and detection probability at the end of day m. Once n simulations are completed, the model computes averages for pathogen concentrations across all simulations (and associated standard error and confidence intervals). The model then computes average detection probabilities (and associated standard error and confidence intervals as described in 2.6 Probability of Detection and in S2 Text).
Table 2.
Model Inputs for Sensitivity Analyses.
Fig 3.
Mean probability of detection along each branch at each hour of the day.
For each branch, detection probability is averaged across all 10-meter sections at each hour.
Fig 4.
System map with five potential sampling branches.
A) Potential sampling locations that emphasize different sampling priorities. B) A visual comparison of the average probability of detection along each sampling branch at 0900. Drainage line data from https://es.world/map/vellore.
Table 3.
Five example sampling branches along the theoretical wastewater system.
Fig 5.
Detection probabilities at five potential sampling branches.
A. Probability of detection at each hour and along each section of the five potential sampling branches described in Table 3. B. Probability of detection along the section of the branch with the maximum detection probability, over the course of 24 hours.
Fig 6.
Comparison of system maps across twelve different scenarios described in Table 2.
Each subset map provides a visual comparison of the average probability of detection along each branch at 0900. Drainage line data from https://es.world/map/vellore.
Fig 7.
Probability of detection at five sampling points in the wastewater system across 12 different sensitivity analysis scenarios.