New ideas

Sharing threshold events via the Delft-FEWS web services

Sharing threshold events via the Delft-FEWS web services


The current Delft-FEWS web service already exchange data with external applications. A wide variety of queries can be submitted to the Delft-FEWS web service to get appropriate responses to be further processed into other applications like web sites, data viewers, data management systems etc. build by others.

An important element of a (flood) forecasting system is the collection of threshold events which are captured in a dedicated table of the Delft-FEWS central database. A threshold event is a combination of a location, parameter, threshold-indicator, threshold crossing type (up crossing, down crossing) and the time of crossing. This information is vital to visualize warnings (e.g. on the Delft-FEWS Map) or to trigger tasks (export, send e-mail).

Thresholds events can also be used for post-analysis of flood events to assess if there were 'false alarms' when the forecast timeseries was indicating a threshold crossing, but the actual measurement timeseries did not. Threshold events are often used for model validation and calibration purposes.

The new idea presented here is to extend the Delft-FEWS web service with this threshold event information. Example responses users can get when querying the web services are e.g. :

  • Number of threshold events in a certain period (for a specific timeseries)

  • Number of threshold events of a certain severity (for a specific timeseries)

  • Elapsed time between up crossing and corresponding down crossing (for a specific threshold event)

More use cases can be defined at a later stage

The estimated costs to implement this is: €7.000.- which includes: code developments and review, testing and documentation. This feature is known under reference FEWS-22933 and is on the waiting list for Delft-FEWS 2020.02 (Expected release date: November 2020).

Would you like more information about this idea and/or considering co-financing this development, please contact the expert(s) mentioned below.

New ideas