These measurements were made on a trip from the Canal Basin in Exeter to Exmouth. The first part of the trip was along the Exeter Canal, followed by a portage to the River Exe just south of St James' Weir. The River was followed downstream to Exmouth with a coffee stop at Topsham.
The trip was undertaken on a falling tide with light north eastery winds.
| Label | Time | Height |
|---|---|---|
| A | 08:57 UTC | leave Exeter Quay |
| B | 09:15 UTC | arrive Blue Bridge .. start portage |
| - | 11:08 UTC | High Tide at Topsham |
| C | 09:33 UTC | portage to St James' Weir |
| D | 10:09 UTC | pass Countess Wear Sewage Works |
| E | 10:35 UTC | stop at Topsham |
| - | 11:08 UTC | leave Topsham |
| F | 11:36 UTC | arrive at Turf Locks |
| G | 11:39 UTC | leave Turf Locks |
| H | 12:37 UTC | arrive Exmouth |
By combining observations made from the kayak the with position-time information from a GPS the location of each measurement can be determined. These values can then be plotted on an interactive map.
In the maps below measurements from the kayak are presented as colour coded circles. By clicking on a circle the actual measurements can be examined.
The following images show the measurements from each sensor in the area around Countess Wear Sewage Works.
Each map shows an area 1km wide. At this time the kayak was moving south eastwards.
... click on an individual image for a full size version ...
... click on an individual graph for a full size version ...
Photo of the sewage outlet at Countess Wear. The outlet is just north of the pylons shown on the maps above. The outflow appears as a series whorls about 3 metres away from the southern bank.
The following graphs show the measurements made as a function of time. The points marked A, B, C etc. show the points labelled in the Trip Timings table above.
... click on an image for a full size graph ...
Note: After 10:17 the nitrate measurements are compromised by the increasing salinity values (these are shown in red).
After this time the shape of the nitrate curve mirrors that of the salinity one.
