2.5 Water Loss of Flows and Systems
19
I−O = 0 → I d + I nd − (O d + O nd ) = 0 → I d − O d = O nd − I nd
WL d = I d −O d , 0 ≤ WL d ≤ I d , d = b,q,s
(2.4)
The subscript ‘d’ is a compact form of the desirables along two Pillars, i.e.,
beneficial (b), quality (q) and, consequently, useful flows (s). The subscript ‘np’
gives non-beneficial, non-quality and non-useful fractions, having in mind that, in
general, the desirable weights (W d ) of the inflow WPIs have influence on W nd of
the outflow WPIs. WL d , Eq. (2.4), is the undesirable of a WUS along ‘d’, and is
equal to desirable Inflow (I d ) minus desirable Outflow (O d ), or undesirable Outflow
minus undesirable Inflow for the entire system. For example, the quality WL (=
WL q = WL along the water quality Pillar) of an industry is the difference between
its quality Inflow (= I q ) and quality Outflow (O q ), or its Outflow pollution (= O nq )
minus its Inflow pollution (O nq ). The equalities put on the conditions of Eq. (2.4) are
very rare or rather non-existent. Additionally, flow WL is rarely used because it is
more common to employ the adjectives non-beneficial, polluted or non-useful. Let
us become clearer about the three differentials presented in Eq. (2.4):
• WL b (WL along the beneficial Pillar) is due to non-beneficial quantities excluding
water quality (W qX = 1). WL b is the total beneficial inflow into a WUS minus
total beneficial outflow from the same system. To calculate WL b , according to
Eq. (2.4) we need all the WPI quantities of water (three inflow plus four outflow
types) and their corresponding beneficial weight s (W bX ).
• WL q (WL along the quality Pillar) is due to pollution excluding water benefits
(W bX = 1). Water quality is a resource and pollution reduces its availability. WL q
is the total quality inflow into a WUS minus total quality outflow from the same
system. This kind of WL does not correspond to a real quantity of water but
rather an equivalent amount. One important question is whether WL q should be
considered as a cost to a WUS or as an uncompensated cost to downstream users.
• WL s (WL along the beneficial and quality Pillars, or along usefulness) is due
to non-useful water. It is the total useful inflow into a WUS minus total useful
outflow from the same system. It should be remembered that usefulness depends
on the degree of beneficial and quality attributes of various WPIs of a WUS.
Besides this fundamental understanding, Water Loss (sometimes called water
waste) has been used under other contexts, which raise questions, such as:
A. What is the relationship between WL and the least advantaged population?
B. What is the relationship between WL and the number of objectives of a WUS?
C. Does it integrate all the three Pillars of water management?
Globally the most important issue has to do with the use of water by the least
advantaged farmers and urban population. They divert water without permission for
their livelihood, which in reality is not a WL because nobody can declare that the use
of water by such members of our society is undesirable, so appropriately is counted
as part of the non-revenue water. This is one of the reasons that satisfying the water
19
I−O = 0 → I d + I nd − (O d + O nd ) = 0 → I d − O d = O nd − I nd
WL d = I d −O d , 0 ≤ WL d ≤ I d , d = b,q,s
(2.4)
The subscript ‘d’ is a compact form of the desirables along two Pillars, i.e.,
beneficial (b), quality (q) and, consequently, useful flows (s). The subscript ‘np’
gives non-beneficial, non-quality and non-useful fractions, having in mind that, in
general, the desirable weights (W d ) of the inflow WPIs have influence on W nd of
the outflow WPIs. WL d , Eq. (2.4), is the undesirable of a WUS along ‘d’, and is
equal to desirable Inflow (I d ) minus desirable Outflow (O d ), or undesirable Outflow
minus undesirable Inflow for the entire system. For example, the quality WL (=
WL q = WL along the water quality Pillar) of an industry is the difference between
its quality Inflow (= I q ) and quality Outflow (O q ), or its Outflow pollution (= O nq )
minus its Inflow pollution (O nq ). The equalities put on the conditions of Eq. (2.4) are
very rare or rather non-existent. Additionally, flow WL is rarely used because it is
more common to employ the adjectives non-beneficial, polluted or non-useful. Let
us become clearer about the three differentials presented in Eq. (2.4):
• WL b (WL along the beneficial Pillar) is due to non-beneficial quantities excluding
water quality (W qX = 1). WL b is the total beneficial inflow into a WUS minus
total beneficial outflow from the same system. To calculate WL b , according to
Eq. (2.4) we need all the WPI quantities of water (three inflow plus four outflow
types) and their corresponding beneficial weight s (W bX ).
• WL q (WL along the quality Pillar) is due to pollution excluding water benefits
(W bX = 1). Water quality is a resource and pollution reduces its availability. WL q
is the total quality inflow into a WUS minus total quality outflow from the same
system. This kind of WL does not correspond to a real quantity of water but
rather an equivalent amount. One important question is whether WL q should be
considered as a cost to a WUS or as an uncompensated cost to downstream users.
• WL s (WL along the beneficial and quality Pillars, or along usefulness) is due
to non-useful water. It is the total useful inflow into a WUS minus total useful
outflow from the same system. It should be remembered that usefulness depends
on the degree of beneficial and quality attributes of various WPIs of a WUS.
Besides this fundamental understanding, Water Loss (sometimes called water
waste) has been used under other contexts, which raise questions, such as:
A. What is the relationship between WL and the least advantaged population?
B. What is the relationship between WL and the number of objectives of a WUS?
C. Does it integrate all the three Pillars of water management?
Globally the most important issue has to do with the use of water by the least
advantaged farmers and urban population. They divert water without permission for
their livelihood, which in reality is not a WL because nobody can declare that the use
of water by such members of our society is undesirable, so appropriately is counted
as part of the non-revenue water. This is one of the reasons that satisfying the water