Representation of the Drainage Network in Urban and Peri-urban Areas Using a 2D Polygonal Mesh Composed of Pseudo-convex Elements

Abstract

This chapter presents a module implemented in QGIS, belonging to the GEO-PUMMA toolbox. This plugin allows a triangulation of surface elements with a vectorial format, and thus the segmentation of a mesh composed of heterogeneous polygons. This module allows the generation of vectorial meshes for the representation of urban and peri-urban landscapes with a high resolution, whereas classical tools do not provide a realistic solution for the determination of drainage networks in complex landscapes, highly modified by the human activity, with in particular road networks and sewer networks. The chapter describes the basic concepts needed to understand the generation of an irregular mesh in Hydrological Response Units (HRUs). It also presents the implementation of the TriangleQGIS and its installation in Windows, as well as the options to use it and the final result on the mesh of the Mercier catchment, a subcatchment of the Yzeron catchment, located in the suburbs of Lyon, France.