The Ruagagh Valley

The Interactive map

This interactive map is built in layers which can individually be switched on and off. The map can be zoomed in and out by use of the + and – buttons in the top left, or by the use of a mouse wheel.

The measure icon (under the '+' and '-') will activate when clicked. Left click to start a line of measuring, double click to stop that line of measuring; and click again on the icon to turn off measuring. Lengths are displayed in metric units.

The legend for all layers is found by moving the mouse pointer over the icon in the top right. The map is displayed within it's own frame and can be moved by dragging with the mouse left button.

Clicking anywhere on the map will raise a popup box that describes the layers active at that point.

Yellow lines indicate glacial lineations (mainly striations, and mainly on elevated ground) , purple lines indicate glacial outflow channels identified by the BRITICE project, and green lines glacial outflow channels. Red lines are roads, including tracks, drives, yards, and paths. Black spots indicate locations to be visited on the field trip, or features of interest; red spots are locations which are illustrated by photographs; and yellow spots are ringforts (raths or cashels).

Up to four photographs of the landscape features are displayed when a red spot is selected. Each photograph can then be selected to open in a new browser tab if required.

When the map first opens some layers are switched off - use the layers menu to switch the layers on or off as desired.

  • Townlands – a lot of townland borders follow streams and rivers which are better exposed when townlands are switched off.
  • Contours - these are invaluable in illustrating elevation - but there are four different sets of contours available. All have been generated by a contour algorithm from height data in the original surface data model. The contours will be different depending on the accuracy of the model they are based on - Satellite data is accurate to 30 m (contours at 2 m and also 10 m intervals), Digital Terrain Model to 5 m, and Digital Surface Model to 1 m (both DTM and DSM are contoured at 2 m intervals). Using the DTM 2 m contours with the DSM removes a lot of superfluous data and produces smooth and accurate contouring.
  • Other available layers are Deglaciation Landforms, Quaternary Sediments, Glacial Features, and Bedrock Geology – these four layers complement each other but can also mask each other.

Click here to go to the Interactive Map

The Area of the Map

The map covers an area 4.8 km north to south by 5.4 km east to west – a total of almost 26 km2 – of lowland West Cork. Orientation is with North at the top - the slight skew is a result of the Coordinate System of the rectangle that I selected to display.

There are two areas of hillshaded relief (exaggerated in the vertical by 5x to accentuate relief), the larger area is from the Digital Terrain Model (DTM) based on a grid of 5 m. Inside that is an area from the Digital Surface Model (DSM) based on a grid of 1 m. The DSM is directly from the original photogrammetry, and the DTM was then derived from that, with some loss of accuracy as can be seen. Both were obtained from Blue Sky, a survey company that has taken photogrammetric survey of the whole of Ireland. Contours at an interval of 2 m have been generated. The DTM does not contain the data for trees and buildings, and so the contours based on the DTM are as a consequence much clearer. Use the layer menu to switch various layers on and off - have the DTM 2m contours switched on and the DSM contours switched off.

The initial purpose of obtaining the DSM was to identify the mounds in this valley with a view to identifying further mounds of glacial sediment. The mound of (glacial?) lake sediment with gravel on the side of the mound, from which gravel is being extracted and which therefore enables a view of the interior of the mound, is at the eastern end of the DSM.

The detail of the DSM is superb - the track of the old railway line (removed in the 1960s) can be traced from where it crosses the side road in the east of the DSM, just south of the river, and, staying south of the river, sweeps around and eventually heads SW into Drimoleague which was a major railway junction on this line. Another line, almost on an EW orientation, lies north of the railway line, and cuts straight up across the hillslope. Is this an artefact of the survey mosaic, or a feature on the ground?

Of particular note in this area are;

  1. At the western end of the DSM the river can be seen to make a loop to the south and then back north again, before heading SW into Drimoleague (on the mid Western edge of the map). The river clearly loops around what appears to be a landslip. Interestingly, the townland boundary follows the river in this loop. The line of the railway actually crosses the river here. This raises the questions - is this an ancient landslip? Is the townland boundary an indication that the rivers course was disrupted by the slipped hillside before townlands were established? So does the townland boundary infer an age for the feature? Further observations as to townland boundaries and landscape features may be seen here;
  2. The gravel pit mentioned in the IQUA Field Trip Report, and referred to above, can be seen at the eastern end of the DSM;
  3. The various mounds of sediment - presumably of glacial sediment - in the valley bottom. These will be investigated as the project progresses.

How this map was made

The map has been generated, using a program called QGIS2Web, from an Open Source GIS called QGIS. This software is constantly being improved and, like all open source products, is highly efficient and free. The layers have all originated from data made freely available to the public domain. There are some inconsistencies in the map, arising partly through the different sources the data came from not being in alignment either with accuracy, completeness or definition.

Read more about how these maps are made and where the data comes from.

Click here to centre the map in the screen

Click here to centre the map in the screen