Methodology and techniques for urban river rehabilitation

摘要

The rehabilitation of urban rivers is a complex process that requires the knowledge of the adequate hydraulic techniques, and its relations with other type of interventions and constraints in the urban area and in the drainage basin. The paper describes the fundamental steps in rehabilitation of urban rivers. For the definition of the site the three basic hydromorphological elements described in the Water Framework Directive (WFD) should be considered: the hydrological regime, the river continuity and the morphological conditions. An extension of the strategy to recover "natural" conditions is presented: the aim is not to obtain the original conditions but rather to establish hydrological and morphological conditions that support all river functions. If this process is not scientifically sounded, the probability of achieving long-term self-sustaining river system will be compromised, as new problems will appear in the future and additional interventions will be maintained in the "new" river.