Flow map

The flow map shows the lines in the landscape where the water flows potentially concentrated after a rain shower, taking into account the topography and the watercourses present. A distinction is made between the flow map with single streamlines and the flow map with multiple streamlines. In the single-streamline flow map, the calculation algorithm directs all the flowing water that arrives in a pixel to the lowest surrounding pixel (Single Flow Direction). This creates concentrated, clearly defined drainage lines that represent the locations in the landscape with the most chance of drainage. When multiple streamlining is used, the calculation algorithm directs all the flowing water that arrives in a pixel proportionally to all lower surrounding pixels, with the lowest pixel receiving the most runoff and the least lower pixel receiving the least runoff (Multiple Flow Direction). This creates diffuse run-off lines that give a more realistic picture of run-off over a slope.