Modélisation de l'eutrophisation en Loire - Modèle POLUPA

Modelling of eutrophication in the river Loire - the POLUPA model

Agence de bassin Loire, Bretagne

Abstract

Over the last ten years the Loire-Bretagne basin agency has been studying the invasion by phytoplanktonic eutrophication of the Loire and its tributaries, by means of a mathematical model called POLUPA which concerns 3 500 km of water ways broken down into 10 km stretches. It is made up of six sub-models: hydrological, water bound, transport, light, temperature and biological.

Five possible patterns for dephosphatization of waste have already shown that in order to be efficient increased dephosphatization is necessary in the upstream regions and secondly each region must be dephosphatized in as uniform a was as possible, which highlights the need to reduce phosphorus in washing powders. These patterns have also enabled an initial dephosphatization programme to be defined concerning urban waste. This programme is at present being carried out.