Tutorial: Spatial Analysis of Accessibility of Wells using Map Algebra

4. Condition 2: No Industry, Mine, or Landfill within 300 Meters from Wells

4.2. Create Zones of 300 Meters Around Industry, Mine, and Landfill

With the Boolean map with True for industry, mine, and landfill we can calculate the distance to these pixels. Because the Proximity (Raster Distance) tool does not allow us to assign values for pixels larger than a threshold, we have to calculate all distances and then use the Raster Calculator to calculate a Boolean map with True for pixels further than 300 meters from industry, mine, and landfill.

1. Open the Proximity (Raster Distance) tool.

2. Make sure that Industry is the Input layer. Keep all other settings as default. Name the Output proximity map inddist.tif.

proximity industry dialog

3. Check the result.

The inddist layer is a continuous raster, with real values representing distances.

4. Make a legend that is appropriate for this raster type using Singleband pseudocolor as render type. Use intuitive colors (e.g. a ramp from red to green).

5. Use the Raster Calculator to calculate inddist@1 >= 300. Call the output layer ind300m.tif.

This again results in a Boolean layer.

6. Style the ind300m layer.

ind300m result