Chapter 3 Decision Support Model (IUWS-DSM) - Tubdok

10 New Conception and Decision Support Model for IUWS
so that the optimised water infrastructure system (WIS) is obtained, which fully satisfies the
optimised water usage.
Especially, the term Used Water is used to substitute for wastewater in this report
because the wastewater is not the waste anymore since it is used again. Meanwhile, sewage
is used to indicate the conventional municipal wastewater.
Water Cycle in Modern Cities
distribution
system
raw water
treatment
water
sources
rain-
water
Legend:
advanced
treatment
rainwater
treatment
storm drain
industrial
& special
end-users
social &
commercial
end-users
communal
& ecological
end-users
water
resources
used water
treatment
conventional water flows possible water pathways
2.1.2 Composition of water system
Figure 4: Water cycle in modern cities
water
sources
back to
nature
collection
system
used water
treatment
Consequently, several subsystems are constituted in the urban water system, i.e. water
usage, water sources, desired water (see § 2.1.4.1 for definition), used water, and rainwater
subsystems. Figure 5 depicts the interrelationships among the subsystems. The solid arrow
lines represent the conventional water flow routine, where the dashed arrow lines show the
possible water pathways in cities. The popular concepts of urban water systems are
therewith involved, such as water reuse, and utilisation of rainwater. As independent but also
related subsystems, each one can have their own system options and at the same time
influences the related subsystems.
In order to introduce the new conception for the IUWS, in the following sections the
structure of IUWS is established in the first, and then the essential components are defined.
Afterwards, the subsystems are constructed. In the end, all elements are integrated together,
whereby the IUWS is built up.