2.1 Water Use System (WUS)
11
A few points worth mentioning at this stage:
• In general, a WUS is a construct, meaning that it does not correspond to a specific
geographic scale and all its water users. For example, a basin may be considered
as a WUS however, we may be only interested to look at the urban water users,
even though there are various other types of water users within that basin.
• If the WUS goes beyond one institution or government (i.e., transboundary WUS),
they should develop an agreement for considering the WUS as a single system
for (comprehensive) analysis.
• It should be noted that a flow in a specific time interval, such as a month or a year,
is volume and in this book they have been used interchangeably unless stated
otherwise. Indeed, for any given application, the time interval for all the WPTs
must be the same making flow and volume equivalent.
• One crucial feature of such a fixed WUS structure is to bring transparency into
the foundation of the water management process.
• For a particular case, each WPT has greater than or equal to zero Water Path
Instances (WPIs). For example, in an industrial application, we may decide that
there is no ET, hence, zero WPI for the type ET, and a city water supply has more
than one WPI for its RP, such as, leakage, green zone irrigation, hydrants, etc.
• This book clearly differentiates between flows (WPIs) and systems (WUSs) and
integrates them for comprehensive, transparent and reasonable water management. This difference is significant and plays an important role in the following
chapters.
Finally, a note on calculating ET by the famous Penman-Monteith equation
(ASCE-EWRI 2005; FAO 1998). It utilizes various climate variables including mean
air temperature based on its minimum and maximum (highly significant variables in
a warming world). For an analysis of the domains of the mean temperature, please
refer to the open access paper by Hai et al. (2018). For a complete analysis of the
eight-dimensional domain (or space) of the Penman-Monteith equation, please refer
to Haie et al. (2019). My personal webpage at Haie (2020) has a version of this
paper with a frequently asked questions file that explains in more details some of the
concepts associated with the domain analysis performed in this paper. Let me clarify
the notion of the behaviour of the domain of an equation, which is different from
sensitivity analysis common in many studies. For this, let us see a simple example
by considering y = x
2
+ 1, which is symmetric along the y-axis, without real zeros,
nonlinear, etc. These characterize the behaviour of the domain of y and are of great
value to those interested in such an equation. Of course expanding from two to eight
dimensions has its difficulties.
11
A few points worth mentioning at this stage:
• In general, a WUS is a construct, meaning that it does not correspond to a specific
geographic scale and all its water users. For example, a basin may be considered
as a WUS however, we may be only interested to look at the urban water users,
even though there are various other types of water users within that basin.
• If the WUS goes beyond one institution or government (i.e., transboundary WUS),
they should develop an agreement for considering the WUS as a single system
for (comprehensive) analysis.
• It should be noted that a flow in a specific time interval, such as a month or a year,
is volume and in this book they have been used interchangeably unless stated
otherwise. Indeed, for any given application, the time interval for all the WPTs
must be the same making flow and volume equivalent.
• One crucial feature of such a fixed WUS structure is to bring transparency into
the foundation of the water management process.
• For a particular case, each WPT has greater than or equal to zero Water Path
Instances (WPIs). For example, in an industrial application, we may decide that
there is no ET, hence, zero WPI for the type ET, and a city water supply has more
than one WPI for its RP, such as, leakage, green zone irrigation, hydrants, etc.
• This book clearly differentiates between flows (WPIs) and systems (WUSs) and
integrates them for comprehensive, transparent and reasonable water management. This difference is significant and plays an important role in the following
chapters.
Finally, a note on calculating ET by the famous Penman-Monteith equation
(ASCE-EWRI 2005; FAO 1998). It utilizes various climate variables including mean
air temperature based on its minimum and maximum (highly significant variables in
a warming world). For an analysis of the domains of the mean temperature, please
refer to the open access paper by Hai et al. (2018). For a complete analysis of the
eight-dimensional domain (or space) of the Penman-Monteith equation, please refer
to Haie et al. (2019). My personal webpage at Haie (2020) has a version of this
paper with a frequently asked questions file that explains in more details some of the
concepts associated with the domain analysis performed in this paper. Let me clarify
the notion of the behaviour of the domain of an equation, which is different from
sensitivity analysis common in many studies. For this, let us see a simple example
by considering y = x
2
+ 1, which is symmetric along the y-axis, without real zeros,
nonlinear, etc. These characterize the behaviour of the domain of y and are of great
value to those interested in such an equation. Of course expanding from two to eight
dimensions has its difficulties.