Chapter 3 Decision Support Model (IUWS-DSM) - Tubdok
Chapter 3 Decision Support Model (IUWS-DSM) - Tubdok
Chapter 3 Decision Support Model (IUWS-DSM) - Tubdok
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<strong>Chapter</strong> 3 · <strong>Decision</strong> <strong>Support</strong> <strong>Model</strong> (<strong>IUWS</strong>-<strong>DSM</strong>) 81<br />
Likewise, Figure 36 is an example showing the water usage of UD. Since the first option<br />
is almost the same as second one, it is skipped for simplifying the graph. The local sources<br />
(as loc.src.(UD)) are added into the third options because the reclaimed water anyway turns<br />
to the local water source through the indirect potable reuse. On the contrary, it is skipped in<br />
the fourth option of direct non-potable reuse in order to reduce the system complexity. As<br />
water reuse system can only be involved once, three options, i.e. directly reuse in WUU,<br />
indirect reuse in UD and direct reuse in UD, are mutually exclusive. In this example, the<br />
suface runoff utilisation is not considered in UD as it is utilised in CA.<br />
The graph already clearly shows different parts of water usage including demands, water<br />
source composition and discharged used water, as well as the relations in between. Thereby,<br />
the graph helps to make decision in the way of considering both water supply and used water<br />
management simultaneously.<br />
m 3 /d<br />
6000<br />
4000<br />
2000<br />
0<br />
-2000<br />
-4000<br />
WUU:<br />
ext.src.<br />
+rf.wa. +drct.<br />
reuse<br />
Water Usage of UD (as demonstration)<br />
+both WUU:<br />
ext.src.<br />
+rf.wa. WUU:<br />
ext.src.<br />
+rf.wa.<br />
UD: ext.src. (+loc.src.) UD: +indrct.reuse UD: +drct.reuse<br />
Scenario 1<br />
Figure 36: Water usage of UD (demonstration)<br />
drct.reuse (UD)<br />
indrct.reuse (UD)<br />
ext.src. (UD)<br />
loc.src. (UD)<br />
wa.demand (UD)<br />
used.wa.->disch.<br />
Up to CA, its water usage is the superimposition of its affiliated UDs and WUUs. In the<br />
same way, the required external source in UD is the water demand of CA (as wa.dmnd.(CA)<br />
in Figure 37. Meanwhile, for better revealing the relation between water demand and water<br />
sources, the water amounts of local sources of CA (as loc.src.(CA)) and surface runoff<br />
utilisation (as srfc.runoff(CA)) are presented in Figure 37. For representing the complicated<br />
situation, the local source of UD (as loc.src(UD)) is also involved and its covered water<br />
demand is correspondingly subtracted from CA. In actual projects, the situation is normally<br />
simpler than it in Figure 37.<br />
There are generally two situations in CA:<br />
1. combination of local source and indirect potable reuse; as CA: loc.src. + indrct.reuse<br />
2. combination of local source and external source. as CA: loc.src. + ext.src.<br />
Following the same rule, if water is indirect potable reused in CA, the reuse options in UD<br />
and WUU do not take place, whereby only two cases are in the first situation. If external<br />
sources (as ext.src.(CA)) is considered, all other options in UD and WUU can be involved