1. Objectives of modeling and/or instrumentation of storm overflows

Instrumentation and modelling are two ways of understanding the actual operation or potential of a storm overflow weir. This knowledge is essential for various types of application, and primarily concerns purely hydraulic aspects characterized by flows and volumes. This first level of knowledge can be refined for certain applications, by supplementing it with information on the concentrations of various pollutants, giving access to flows (flow-masses) and masses of the pollutants concerned. This information is of particular interest for pollutants associated with particles, as their dynamics are complex and linked to hydraulic aspects. In this section, we detail the various types of application for which knowledge of pollutant flows is required, and offer an initial summary of the respective contributions of metrology and modelling. The specific objectives of each of these two approaches...