Guide to using QGIS. QGIS is a free and open source Geographical Information System programme which can be downloaded at

Transcription

1 Guide to using QGIS QGIS is a free and open source Geographical Information System programme which can be downloaded at It is a great programme for displaying data which can be collected through primary or secondary data collection. I was asked to produce a How to use QGIS Guide for the use of school students and teachers. This is an UNOFFICIAL guide and no copyright is intended. Contents: Page 2 5: How to display a base map Page 5 15: How to enter and display data points Page 16 20: How to enter and display data in polygons If you have any questions or would like a hard copy of this guide you can contact the author by ing: fieldworktutor@gmail.com

2 P a g e 2 Inserting a base map Firstly you need to find and insert a map to work from. To do this: Click on plugins and then click on Manage and Install Plugins

3 P a g e 3 Search for openlayers Install the OpenLayers Plugin

4 P a g e 4 Once the plugin has been installed go to the Web tab go down to OpenLayers Plugin and then pick your base map. For this demonstration we have chosen to use the OpenStreetMap

5 P a g e 5 Once you have picked the area you would like to display data on then there are a number of different things you can do.

6 P a g e 6 Inserting data points First click on the V with a yellow * and the New Vector Layer box will appear. This will allow you to create a vector layer into which you will be able to enter data.

7 P a g e 7 Firstly you need to choose what measurements you would like to take. For this example we will measure EQA, Traffic Count, and Pedestrian Count. We want dots on the map so I have chosen Point for the type. Then enter the first measurement into the Name box, and then choose whether you want to enter Text or Numbers as our scores will be whole numbers i.e. 6 people I have chosen the Whole Number setting from the drop down menu. Once you have done this click Add to attributes list

8 P a g e 8 Once you click add the Attribute list it should end up in the box Click OK and then save the shape file. We ve called ours Glasgow Points

9 P a g e 9 Once it is saved to add data to the map: FIRST Click on the pencil in the corner Then click on the 3 green dots with the yellow *

10 P a g e 10 Then you can click on the map and a box should appear with your attributes table. This is how you start to enter geo-located data. You can then enter the value into the box i.e. EQA scores, Pedestrian Counts etc. Click OK and then you can keep adding points to the map.

11 P a g e 11 The points should then show up on the map as red dots. You can change the style, size, and colour of these dots by: Right clicking on the Glasgow Points and then going to Properties

12 P a g e 12 This is the properties box. You can change the Size Transparency Look Once you are happy with how they look you can start exploring how to display different data.

13 P a g e 13 Right click on Glasgow Points and then select Open Attribute Table The box with your data should them open up.

14 P a g e 14 Let s say we only want to display data points with pedestrian counts of over 100. FIRST Click on the E button and then click on Fields and Values

15 P a g e 15 Click: on Pedestrian Then type > (greater than) 100 You can also search for things like: Click: Select and the points with over 100 will then be shown in yellow. Traffic over 100 and EQA under 50 to see if two variables are linked More equations can be found online. If

16 P a g e 16 Polygons This time click on the V* for vector layer Then select Polygon Add attributes like before, for this example we are going to be doing a tree survey throughout different parts of the map.

17 P a g e 17 Click OK Then save the shape file. For this example we ve saved it as Tree Survey

18 P a g e 18 To add a polygon click on the yellow pencil Then click on the add feature button

19 P a g e 19 Start clicking and then RIGHT CLICK when you have finished your shape. The attributes box should pop up and you can then input your numbers.

20 P a g e 20 Click on the yellow pencil again to save your layer and then you can start displaying data much like with the points. In the table click on the E to start searching for data This will pop up Right click on Tree Survey and then click Attribute Table Click on Fields and Values and then click on Birch Then type Birch >12 and then click Select All the areas with more than 12 Birch trees will now be highlighted yellow.

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