Specifying the attributes of the digraph

The water supply at each "source" node of the network is the sum of the actual storage and the estimated net inflow of the corresponding reservoir.

The capacity uij of each arc is evaluated according to the following rules:

• if the arc corresponds to an aqueduct, uij is set equal to its real discharge capacity
• if the arc simulates the storing process in a reservoir, uij is set equal to its storage capacity
• if the arc simulates the transportation of desired magnitudes (e.g., target releases and consumptions), uij is set equal to the corresponding desired values
• if the capacity of an arc has no physical sense (e.g, case of spilling), it is assumed infinite

The unit cost cij of each arc is evaluated according to the following rules:

• if the arc corresponds to an aqueduct, cij is set equal to its real unit transportation cost
• virtual costs are assumed in order to penalize non-optimal transportations (e.g., spills) and, similarly, virtual negative costs are assumed in order to force the system to provide water for the satisfaction of its physical and operational constraints
• the definition of virtual costs is done automatically, according to a retrospective algorithm that takes into account the target priorities imposed by the use

ΝΑΜΑ Consulting Engineers and Planners S.A.

NTUA - Water Resources, Hdraulic & Maritime Engineering

Water Supply and Sewerage Company of Karditsa Municipality

AEPHORIKE of Dodecanesus Islands S.A.

Marathon Data Systems (MDS)