Tutorial: Visualise Flow Direction with Arrows

This tutorial will guide you through the steps of visualising the output of the SAGA flow direction algorithm as a mesh with arrows using the Crayfish plugin.

1. Introduction

The flow direction layer is a raster layer indicating the direction of the water flow. The directions are encoded into discrete values. Each software does that differently.

With a directional or circular ramp we can visualise the flow direction. Creating the colour ramp and interpreting the water flow is difficult. Therefore, here another, more intuitive visualisation method will be used. In this tutorial you'll learn how to visualise the SAGA flow direction layer with arrows indication the flow direction.

After this tutorial you'll be able to:

  • Convert the SAGA flow direction Raster layer to a mesh (GRIB format)
  • Style the flow direction mesh with arrows
  • Visualis the flow direction in the 3D view