Practical Manual - Malareo

Map Legend
You now have 2 layers loaded into your map legend. Capitals _Africa and Malaria_Cases_2008_WHO
Notice in the Map legend that each has a cross in a box to the left of the name of the layer. This
indicates that the layer is displayed.
You can make layers visible or non-visible by selecting the cross in
the tick box. Click on the cross next to Capitals_Africa and examine
the map view or canvas. Notice the layer is no longer visible. Play
with the layer visibility for both layers.
Layers can also be moved relative to one another. Using the mouse
left click and hold down the left mouse button on the Malaria cases
name in the legend. Keeping the left mouse button depressed drag the malaria layer upwards (A Small
icon appears with 2 arrows). Drag it up and above the capitals layer. Note what occurs. Most of the
capitals are no longer visible and are hidden under the countries. (You can still see a few present along
the coastline.)
This means that when displaying layers in QGIS you need to careful about the order you place your
layers in. The general rule of thumb is points above lines above polygons.
Move your layers back in order so that you can see them.
Go to the file menu and select save project as: Name your project as your Name e.g. Joe and save it in
the directory of your choice e.g. c:\temp\malereo\joe.qgs
Saving a project stores the layers and their properties in a file which enables you to open it again and
not have to reset all the properties. It does not however save any changes you have made to individual
layers. This you will have to do separately when editing
individual layers. And will be approached in a later
practical.
Map View
The Map view is the area where you view the visible
layers as listed in the Map legend. Here you can zoom in
and out, View the layers and view labels of points, lines
and areas. Any changes you make to the layer properties
are reflected in the map view.
Zooming
There are a number of tools which allow you to interact with your view effectively. The ones you will use
commonly are the Zoom tools. These are available both on the toolbar and in the View Menu.
QGIS for Malaria Page 7