4. Weighted Overlay Analysis

4.3. Land Cover

The Land Cover map is going to be a bit weird to Reclassify. It uses values to determine the land cover type. We can see it on the map with the labels (Tree cover, Cropland, etc.), but the Reclassify tool doesn’t understand that.

We can’t use the label naming of the LandCover map in the Reclassify, we need to use the values. In the Layer Styling panel, we can see the values that correspond to the labeling. In the table, you can see a nice overview for your convenience:

Value

Label

10

Tree cover

20

Shrubland

30

Grassland

40

Cropland

50

Built-up

60

Bare/sparce vegetation

70

Snow and ice

80

Permanent water bodies

90

Herbaceous wetland

95

Mangroves

100

Moss and lichen

 

Note: Yes, there is a weird outlier with the 95 value.

1. Open the Reclassify by table tool again and make sure the Land Cover layer is selected.

2. In the table, fill in the values down below:

Minimum

Maximum

Value

10

10

8

20

20

10

30

30

6

40

40

6

50

50

0

60

60

4

70

70

0

80

80

0

90

90

2

95

95

1

100

100

0

 

Note: The 0 score means that this land cover type cannot burn, like Water, or we don’t take it into the calculation, like Built-up area (we use the Buildings layer for this purpose).

We use the same value for the minimum and maximum amount, as that is how the ESA World Cover data is provided. QGIS doesn’t let us use just 1 value, so this is how we have to fill it in.

3. Under Advanced Parameters, set Range boundaries to min <= value <= max. This will make the weird min/max values work correctly.

TIP: Look closely at the way the "<" and ">" are pointing, this does matter.

4. Save the Permanent layer as LandCover_Reclassified and Run the tool.

Now we have the reclassified LandCover layer. You can look around on the map and see the different scores with Identify Features.

Don’t forget to save your project.