4.4 Coursework assignment – visual impact assessment
This final learning object provides you with an opportunity to use the techniques learned into the preceding units. This work is assessed and forms part of the coursework assignment for ‘GIS for Environmental Management’.
Scenario
A new cell phone mast is being constructed on a hillside on the Isle of Wight. As an environmental consultant, you are charged with identifying the potential visual impacts of the radio mast using GIS software. You are particularly concerned with the visual impact upon visitors and local residents, such as those driving along roads, visiting public amenities, or in built-up areas.
In this activity, you will assess the visual impact of the proposed development.
Note that whilst most of the GIS data used in this exercise are real, those relating to the proposed radio mast are entirely fictitious.
Data
You have been provided with the location of the proposed cell phone mast, which is planned to be 30 metres tall (available in this zip). You may wish to supplement this with further data downloaded from the internet, as indicated by the resources below.
Activity
Assessing the visual impact of a development
For this stage of the planning process, you are required to assess the likely visual impact on the landscape of the proposed cell phone mast. Write a brief (2,000 words maximum) description of its likely visual impact (e.g. upon buildings, roads and other areas likely to be used by visitors to the area), supporting your description with map illustrations and graphics as necessary. Briefly describe the GIS approach that you have used and what you consider to be its limitations.
References (Essential reading for this learning object indicated by *)
The data for this assignment are largely sourced from several public domain web sites. Further details of the data sets used, together with relevant meta-data, can be accessed from these web sites.
We recommend that you visit the Ordnance Survey OpenData site and download VectorMap District data for the proposed site. Note that you should download data for grid square SZ and you will probably find it easier to download the VectorMap data in vector rather than raster format (both are provided on this site): https://www.ordnancesurvey.co.uk/opendatadownload/products.html
You will also need some elevation data. Possible sources include the OS Terrain 50 product, available through the Ordnance Survey OpenData site above. Note that it is probably easier to download the DTM product (which is in raster grid format) than the contours product, which is vector and which will require subsequent interpolation. For higher spatial resolution elevation, you could also try:
The coastal channel observatory data portal, available via http://www.channelcoast.org/
If you do use data from this site, we recommend that you restrict your analysis to a much smaller area, given that the size of the data files involved.
If you are based in the UK, you could also try the Digimap project, which includes access to Ordnance Survey Terrain 5 data (unfortunately, if you are outside the UK, you are not covered by the data licence for this product): http://digimap.edina.ac.uk/. After logging in, click on ‘Ordnance Survey’, then ‘data download’, and on the left-hand panel, click on ‘land and height data’. You should then be able to choose the ‘OS terrain 5 DTM’ product from here, ‘draw rectangle’ to select your area, then ‘add to basket’ to download. If you are using ArcGIS Desktop, the .asc file you receive via a confirmation email can be read directly by ArcMap or you can use ‘conversion tools / raster / ascii to raster’ in the ArcToolBox to import it. It can also be read directly by ArcGIS Pro.