The fundamental basis for the predction graphs is to give a real time estimate of imminent river levels, using a simple relationship between the river level at Alford and that at the prediction site.

There are two points on the river Don that prediction graphs have been calculated for, Haughton and Milton Meadows

1. Haughton, just up river from Port Elphinstone. This site was chosen as a test site, as there is historical data available from the SEPA river guages. Using data supplied by SEPA, the river level at Alford was compared to that at Haughton. A series of river level events were recorded at Alford and then subsequently identified at Haughton, a relationship was then plotted and the time between Alford and Haughton recorded. By plotting the events on a graph and then adding a 'best fit' line, a formula can be derived that will allow a prediction at Haughton, given any river level at Alford.

2. Milton Meadows, this site was chosen due to the flooding event on the 7/8 January 2016. Although Milton Meadows lies between Haughton and Alford, the same relationship cannot be used due to local effects, such as the road bridge. During high river levels, the bridge affectively acts as a funnel and then a dam - this causes the river levels at Kemnay to rise at a different rate to that elsewhere. The river level monitor will provide data for this relationship.

How to use the prediction graphs:

Be aware:

• The prediction graphs automatically update when SEPA update their website river levels data.

• The prediction graphs simply predict what will happen at Haughton/Milton Meadows based on what is happening at Alford.

• The prediction graphs will not predict localised effects down stream from Alford.

• From recent calculations the prediction for Milton Meadows will be 3 hours.