Integrated Water Management.

In this paper, an overview on the development and application of state of the art integrated water modelling tools to study water pollution, either from urban or agricultural origin, from source to final destination, and also of the research carried out at IST in the framework of integrated water management is described. The modelling tools are used for computing the urban load in a sub-catchment of Lisbon metropolitan area for assessing the trophic levels of Tagus estuary and its relation with urban and agricultural loads. The strategy for modelling development at IST is also described, showing that modelling can be an important contribution for the integration of water management. Results have shown that modelling of the functioning of wastewater treatment plants is a mechanism for managing the urban wastewater loads and that the trophic level in the Tagus estuary is controlled by light penetration and not by nutrients. As a consequence, a reduction of the nutrient loads from urban origin or a 50% of the agricultural nutrient load would have no benefits in terms of trophic activity. [ABSTRACT FROM AUTHOR]