Expérience radar Rodin sur les départements du Val de Marne et de Seine Saint-Denis

The Rodin radar experiments in the Departments of Val de Marne and Seine Saint-Denis

¹ LCPC, Paris
² CERGRENE, Paris

Abstract

Automated operation of a sewerage system is based in particular on acquisition in real time of rain-gauge recordings required to evaluate direct water increments. In this context a digital picture meteorological radar gives a three-dimensional representation of the rain as a complement to the rain-gauge recordings. The current experiment intends to evaluate the merits involved. It is based on a measurement campaign carried out in Seine Saint-Denis and Val de Marne in conjunction with the National Meteorological Office. Synchronous radar data, rain-gauge (20 stations over 450 km2) and water-level recordings were collected for six rainfalls of different origins. They were utilized with allowances made for the objectives to be obtained which impose constraints on application of the radar data : random use at short intervals (10 to 20 min.). Initial, incomplete results relate to a frontal rain and convective cells. They show that primary laws cannot be adapted : Z = ARb . Application of a simple correction method has given encouraging results for frontal rain but has proved unsuitable for convective rain which requires use of a calibration where local factors are taken into account.