Amélioration des résultats d'une campagne de mesures par la modélisation en vue de l'autosurveillance

Improvement of the results of a measurement campaign by numerical modelling allowing self-monitoring

¹ Laboratoire des Systèmes Hydrauliques Urbains, Ecole Nationale du Génie de l'Eau et de l'Environnement de Strasbourg, 1 quai Koch, BP 1039, 67070 Strasbourg
² Laboratoire des Systèmes Hydrauliques Urbains Ecole Nationale du Génie de l'Eau et de l'Environnement de Strasbourg 1 Quai Koch, BP 1039, 67070 Strasbourg

Auteurs de correspondance : guillaume.henrion@agriculture.gouv.fr pjd@engees.u-strasbg.fr

Abstract

The city of Sélestat (East of France - Alsace) wished to improve its knowledge of the operation of its sewing system and to evaluate the impact of the discharges to the environment. The goal was first, to obtain the data allowing to dimension works for retaining the pollution and then, to fulfill the obligations as regards to self-monitoring of the sewing system. Because of peculiar configurations, the installation of sensors and probes is problematic in Sélestat and does not allow to directly ensure the self-monitoring and the control of the discharges. This is why measurements were carried out in 1999. This was followed by the creation and validation of a numerical model of the sewing system, operating on the software "CANOE". The results are of sufficiently good quality to allow in the second time a better choice of the most favourable places to take correct measurements, as well as a more judicious judgement of the data obtained. In the majority of the cases of the outfalls that year in Sélestat, and taking into account the difficulties related to the measurement of flow in the specific configurations of the sewing system, the model should allow, with few complementary measure, and even none, to answer the needs for the self-monitoring with an reasonable margin of error.