**3.1 Models implementation**

56 Current Issues of Water Management

The main window displays a list box with the available simulations results. It also provides an area with indication of possible simulations available for storage (if the user has permission to store simulations) and an area with additional information about the selected river and simulation data. After selecting the river to be analysed, a plan view of the river is displayed with graphical features that represents river reaches, nodes and hydraulic

Fig. 13. Plan view for selection of river features in the analysis system

summary of these variables over the simulation period.

discussed.

**3. Water quality simulations at the River Cávado Basin** 

The plan view, also allows visualization of aerial photos, location names and the river name that are used as auxiliary information for easily locate the conceptual elements of the model (nodes, reaches and hydraulic structures). Based on these elements it is possible to automatically generate a report with results of the selected simulation. The report consists of: (i) general information about the simulation and information about the number of model nodes; (ii) reaches or hydraulic structures; (iii) plant and profile location of the selected element; (iv) representation of the profile view at the initial time; (v) intermediate instant and at the final instant of the simulation; (vi) table of results for the active element; (vii) graph of results for all variables associated with the selected element; (viii) and a statistical

General procedure for setting up models is briefly presented. In order to illustrate the potentialities of the developed technological platform hydrodynamics and water quality simulations results are presented. Some particular problems of the presented river basin are

structures (Figure 13).

Models implementation followed a comprehensive procedure that includes four main phases: (i) monitoring data analysis; (ii) identification of key parameters including internal processes parameters or open boundary conditions variables; (iii) model calibration base on monitored data; and (iv) scenarios definition and simulations execution.

All available monitored data was included in the system databases witch facilitate the identification of the relevant hydraulic structures to be included in the model as well as the relevant waste water discharges. The segmentation of the model was defined considering the important influence of the upstream reservoirs in the river flows and the intense occupation (industrial, agriculture and urban areas) of the basin in the downstream areas.

In the calibration procedure a hybrid approach was followed: several parameters were established according to proposed values in the literature (Thomann and Mueller, 1987, Chapra, 1997), from previously developed works about river Cávado water quality (Vieira et al, 1998) and/or based on available field data.
