Submitted by Steve Turner on
The rating plots shown for peak flow stations on the NRFA website have been updated to include AMAX as well as gaugings.
The new feature allows you to view where the AMAX flow values sit on the rating at each NRFA Peak Flow site. As default, all AMAX values across the period-of-record are shown first, and by using the time slider they will plot on the graph as you move through time.
The plots also show the check gaugings carried out at the site, and you can use the zoom and pan tools to explore the plot, for example you may want to get a better view of the gaugings where there is a cluster. Hovering over AMAX will give the flow value and year, whilst hovering over ratings will give information about the limb, and hovering over gaugings gives the date, stage and flow. You can also download an image of the rating plot.
Where available the rating plots will also show AMAX1, QMED and the bankfull stage.
View the interactive rating plot by visiting a peak flow page (e.g. 54004) and choose 'Peak flow rating information' in the Data type drop down menu.
The static plots are still available on the website, just click the tab above the rating plot. Users should be aware that the stage-discharge equations applied to the peak flow data are not always the same as those applied in the main hydrometric Measuring Authority archives and those used to calculate the NRFA daily flow data.