OpenFlows | Water Infrastructure - WaterSight - Automatic Demand Adjustment

Product(s):	WaterSight
Version(s):	10.00.
Area:	Documentation

Overview

If you don't have a calibrated model, WaterSight can automatically calibrate your model demands. There are two options available: update demands by using a global pattern or updating demands by using a different pattern for each zone. When selecting zone by zone, the user can also choose which zones to be considered.

WaterSight will automatically compute a pattern for the global system or for each zone based on the real system total flow or each zone flow and will automatically apply it to the nodes belonging to the respective zone. For better accuracy it is recommended to use the option to update demands zone by zone.

Requirements

In order to update demands by setting a global pattern, it is required that all inflows, outflows and storage sensors for the system total zone are defined (information configured in the Zones configuration page) and transmitting data into WaterSight (make sure sensors are defined in the Sensors configuration and that the On-Premise tool (OFOSC) is working).

In order to update demands zone by zone, it is required that:

Zones are uploaded and configured, with all inflows, outflows and storage sensors associated (if exist). Take a look at the zones configuration help page for more information.
After Zones are uploaded and configured, please check that zones flow and patterns are available, by looking at the Zones graphs in the Network Monitoring dashboards.
The WaterGEMS model that is uploaded in WaterSight needs to contain the same zones (with the same names) and those need to be assigned to the respective model nodes. For the model nodes with no zones assigned or with zones different that those defined in WaterSight, patterns and demand adjustments will be ignored (only base demand and units demands will be taken into account).

Calibrating demands: Demand & Patterns (Global)

WaterSight will automatically compute a global pattern for the entire system, and will automatically apply this global pattern to all nodes of the network. The total demand for each node is obtained by adding up all base demands and unit demands (unit demands multiplied by number of units) defined in the WaterGEMS model and then by multiplying this final node demand by the global pattern automatically computed by WaterSight.

The global system pattern is automatically calculated by the software and takes into consideration the following:

The global system zone flow corresponds to the sum of all inflows, subtracted by all outflows, and by taking into account also the storage variation inside the system;
Last month of historical zone flow data is used to calculate a pattern for the global system zone (dimensional values);
Global pattern, including a one week forecast, is calculated using a machine learning algorithm, together with advanced data analytics methods. Bad data, including outliers and spikes are removed from the analysis and a different pattern for week days and weekends is computed;
Global pattern with dimensional values is transformed into a global multiplier (or dimensionless pattern) and applied to each node of the model;

The global system dimensionless pattern (global demand multiplier) covers all simulation window period defined by the user in the Numerical model settings (hindcast + forecast). The global dimensionless pattern also differentiates between weekday, Saturday and Sunday. For example if the simulation window covers a Friday and a Saturday, the global demand multiplier for Friday and Saturday will be quite different.

Another important aspect to mention is that the global pattern is continuously and automatically being updated in real time (whenever new data arrives into WaterSight) using always last month of historical data. This means that the global pattern for today is slightly different than the global pattern of the previous day and will be slightly different from tomorrow global pattern.

Calibrating demands: Demand & Patterns (Zone-by-zone)

The zone pattern is automatically calculated by the software and always updated in real time, as summarized below:

Step 1 - Each zone flow corresponds to the sum of all inflows, subtracted by all outflows, and by taking into account also the storage variation inside the zone;
Step 2 - Last month of historical zone flow data is used to calculate a pattern for each zone (dimensional values), together with machine learning algorithm and advanced data analytics methods
Step 3 - Each zone pattern, including forecast, is calculated using a machine learning algorithm, together with advanced data analytics methods. Bad data, including outliers and spikes are removed from the analysis and a different pattern for week days and weekends is computed;
Step 4 - Each zone pattern with dimensional values is transformed into a zone multiplier (or dimensionless pattern) and applied to all the nodes that belong to the respective zone;

The zone dimensionless pattern (zone demand multiplier) covers all simulation window period defined by the user in the Numerical model settings (hindcast + forecast). The zone dimensionless pattern also differentiates between weekday, Saturday and Sunday. For example if the simulation window covers a Friday and a Saturday, the zone demand multiplier will include both days and Friday and Saturday will be quite different.

Another important aspect to mention is that zones pattern are continuously and automatically being updated in real time (whenever new data arrives into WaterSight) using always last month of historical data. This means that the zone pattern for today is slightly different than the zone pattern of the previous day and will be slightly different from tomorrow pattern. This is particularly useful when there are significant changes in zone demands such as winter and summer, or when zones boundaries are changed. In these cases also a new pattern is automatically obtained and multiplied to each of the nodes, without any user intervention.

The user can analyse each zone dimensional pattern automatically calculated by WaterSight by acceding to the Zone details graph (under Network Monitoring page). The pattern used in the model is the represented with the grey line (P50). This is the dimensional pattern that will be automatically transformed into a dimensionless pattern (zone demand multiplier) used to multiply all existent node demands of the hydraulic model, in case this option is enabled in the Numerical Model settings. The user also has the option to export the zone dimensional patterns to CSV by clicking in the Download button located on the top right of the graph

To check and confirm that the model accuracy improved, the user should can go to the real time simulation page and click in any sensor icon that is measuring flow (represented by a wi-fi symbol). Sensors icons highlight that a specific hydraulic element has a valid sensor signal associated to it, and therefore model and measured results can be compared. Below an example where a PRV modelled flow (at blue) is compared with the measured flow from SCADA, at black (with the zone demand adjustment option enabled).

If you want to compare this new result with the status quo condition (with no demand adjustments calculated by WaterSight, this means using the exact same configurations defined in the WaterGEMS model) please go to the Numerical Model settings (inside the administration) and set the demand adjustment option to "No update". Then wait for the next model run, and accede to the same model element by clicking in the wi-fi symbol. Compare again model and simulated results.

For more information about how demands and patterns are calculated, see this article:Patterns and Demand Forecasts Calculation

Using AMI Data

In case AMI data is available for the Large Customers, WaterSight can use that data to automatically update the patterns for those specific customer meters in the model and a remainder flow pattern - given by the difference of the total zone flow and the sum of all large customers flow - will be applied to the rest of all customers of the model that are within the zone. More information can be found here - AMI for Hydraulic Model.

Troubleshooting: Why is the model flow very different from the real flow?

In case there are significant differences between model flow (blue line in graph above) and real flow (black line in graph above) first make sure that the option to enable automatic zone demand adjustment (zone by zone) is enabled in the Numerical Model settings (inside the administration).

If this option is enabled next step is to check if all the junctions in the WaterGEMS model that belong to that zone have the zone field assigned or if the zone name matches exactly the one defined in WaterSight. Note that for the model nodes with no zones assigned or with zones names different that those defined in WaterSight, patterns and demand adjustments will be ignored and the model base demand and units demands will be taken into account. This means for example that if a junction that belongs to a specific zone does not have a zone assigned in WaterGEMS and has a consumption of 10 l/s, and assuming the real average zone flow is 20 l/s, those 10 l/s will be added, which will contribute to a final zone average zone flow in the model of 30 l/s (instead of 20), which is not correct.

Figure 1- Assigning zones to the junctions in the WaterGEMS model. Example of junction J-713 with no zone assigned.

Exporting WaterSight patterns for further analysis

Besides this, it is also possible to export and further analyze the dimensionless pattern generated by WaterSight. Please go to Realtime Simulation page > Previous Simulations and download the latest simulation.

Then open the sqlite file in WaterGEMS, go to Components > Patterns. Patterns automatically generated by WaterSight are automatically exported and can be analyzed in WaterGEMS. Pattern names are automatically generated based on the zone names in WaterSight.

Note: The pattern automatically generated in WaterSight and exported to WaterGEMS comprises the all simulation period defined in WaterSight (which can be more or less than 24 hours). Because week day and weekend patterns generated by WaterSight can be significantly different, in case the simulation period comprises a Friday and Saturday for example, two different patterns (for weekday and weekend) are combined into a single one automatically. Also note that in WaterGEMS it is required the starting multiplier of the pattern to be exactly the same value as the last multiplier, therefore this additional and last value is added only when exporting to the WaterGEMS file, but it is not being considered in the WaterSight simulations.

Additional and more refined analysis can be further done by the user. If for example some zones have some large customers which the pattern is well known, the user can create these large customer patterns in WaterGEMS and assign them specifically to those large consumers, being all other nodes with the zone patterns generated by WaterSight. Then upload that WaterGEMS model again into WaterSight, and make sure that now the "No Update" demand adjustment option is disabled (in the Numerical Model settings, inside the administration) so that the patterns that are in WaterGEMS are now considered.

For more information about patterns or forecasts, please click here.

WaterSight - Automatic Demand Adjustment