 Hello, this is Hans van der Klaas Senior Lecturer at IHDF Institute for Water Education. In a previous video I've showed how to install the PCRuster tools for QGIS. In this video I'm going to explain more about the area operations. Area operations are also called zonal operations. These GIS operations they perform on classes. I'm going to show a few examples here. We're going to use the same layers as we imported in the last video. This is the layer with our classes, but it's more visible if I classify it and style it using the pelleted unique values. So now each class has a unique value and unique color. Now let's go to the scripts and to the PCRuster group there and there we find these area functions. And the first one that I'm going to show you is the area area tool, which basically calculates the surface area of each class. Let's call the output class area and make sure you choose dot map as the output format. And there it is. PCRuster doesn't store the projection, so you need to add the projection yourself. And we can use the identify tool to see the different areas of the clusters of pixels, which are the classes. I can also calculate the average value of a continuous raster within a class. So I choose again the raster with the classes and then the DTM, so I get the average elevation per class. An easy way to identify the results is to move the class layer to the top and then select the elevation per class layer. Here I don't bother about the projection, I use the identify tool. So for each class that has a unique color here I can sample the average elevation that we have calculated. Area diversity gives the amount of unique classes, unique cells within a class area. Area majority gives you the most occurring value. Area maximum gives you the maximum value in a class. Area minimum the minimum. Area normal gives a value sampled from a normal distribution. Here I choose the classes and I only define an output name and here I see the different sampled values from the normal distribution. Area total gives the sum of the values in each class.