3.1 Five FIWs (Foundational Ideas About WUS)
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the WUS, evaporation during taking a shower, and water consumed to produce meat
and food.
The definition of the word ‘consume’ in dictionaries (such as Oxford and
Cambridge) includes eating and drinking as clear examples of consumption.
However, this is not correct when applied to water use. Let us present a candy
example taken from these dictionaries. A candy totally disappears after eating it and
cannot be reused, i.e., it is completely consumed. However, drinking a litre of water,
a fraction of it leaves our bodies as urine and becomes available in the same day and
can be reused (treated or not), meaning that the one litre was partially consumed.
Conversely, the fraction of the outflow that the same WUS has the possibility to reuse
within its time interval is called non-consumptive water. The word ‘possibility’ in the
previous statement is important because in many cases reuse is not only dependent
on the existence of water, but also on cultural acceptance, financial resources, and
management expertise.
Generally, the total outflow from a WUS has two states, viz.: unavailable and
available, which are labelled as consumptive and non-consumptive, respectively. It
is of interest to know that such a binary state of water is rare, and other resources
do not exhibit this characteristic, or its occurrence is negligible. For example, fuel,
electricity and food are only consumed (single state), which justifies the logic of
utilizing the word ‘consumer’. Filling the tank of a car with say 10 litres of fuel and
driving it until the tank is empty, all the 10 litres get consumed and there remains no
fuel for reuse by the same car within the time interval (say one day). However, after
taking a shower, most of the water can be reused (treated or not), meaning that only
some of the water was consumed (e.g., evaporated).
Besides this crucial quantity aspect of consumption, we can also consider two
states for the other two Pillars, i.e., water quality and benefits. For example, if a
return flow is polluted to the extent that cannot be reused by the same WUS within
a period of time, then it should be accounted as unrecoverable, which by definition
is a kind of consumption that should influence water management and planning.
FIW2b) Water consumption is a crucial factor of water scarcity.
There are various reasons for water scarcity, such as mismanagement, lack of infrastructures, and physical shortage. One of the overall objectives of the current theory is
to substantially reduce the first reason. The second one is mostly because of economic
issues, which with the first reason are influenced by corruption. The third one is due
to the absence of water resources, which, in general, means low precipitation or
its improper pattern. As explained above, water consumption decreases water availability for a WUS, hence is one of the real contributors to the appearance of water
scarcity. Indeed, places that have or are approaching water scarcity should decrease
their water consumption. However, the real question is the amount of reduction due
to various trade-offs among the three Pillars. Furthermore, in dealing with water
(scarcity) the crucial need of nature must be considered particularly under temperature increases, which have a tendency to increase water consumption and consequently scarcity. This is most critical for downstream as a water body approaches
27
the WUS, evaporation during taking a shower, and water consumed to produce meat
and food.
The definition of the word ‘consume’ in dictionaries (such as Oxford and
Cambridge) includes eating and drinking as clear examples of consumption.
However, this is not correct when applied to water use. Let us present a candy
example taken from these dictionaries. A candy totally disappears after eating it and
cannot be reused, i.e., it is completely consumed. However, drinking a litre of water,
a fraction of it leaves our bodies as urine and becomes available in the same day and
can be reused (treated or not), meaning that the one litre was partially consumed.
Conversely, the fraction of the outflow that the same WUS has the possibility to reuse
within its time interval is called non-consumptive water. The word ‘possibility’ in the
previous statement is important because in many cases reuse is not only dependent
on the existence of water, but also on cultural acceptance, financial resources, and
management expertise.
Generally, the total outflow from a WUS has two states, viz.: unavailable and
available, which are labelled as consumptive and non-consumptive, respectively. It
is of interest to know that such a binary state of water is rare, and other resources
do not exhibit this characteristic, or its occurrence is negligible. For example, fuel,
electricity and food are only consumed (single state), which justifies the logic of
utilizing the word ‘consumer’. Filling the tank of a car with say 10 litres of fuel and
driving it until the tank is empty, all the 10 litres get consumed and there remains no
fuel for reuse by the same car within the time interval (say one day). However, after
taking a shower, most of the water can be reused (treated or not), meaning that only
some of the water was consumed (e.g., evaporated).
Besides this crucial quantity aspect of consumption, we can also consider two
states for the other two Pillars, i.e., water quality and benefits. For example, if a
return flow is polluted to the extent that cannot be reused by the same WUS within
a period of time, then it should be accounted as unrecoverable, which by definition
is a kind of consumption that should influence water management and planning.
FIW2b) Water consumption is a crucial factor of water scarcity.
There are various reasons for water scarcity, such as mismanagement, lack of infrastructures, and physical shortage. One of the overall objectives of the current theory is
to substantially reduce the first reason. The second one is mostly because of economic
issues, which with the first reason are influenced by corruption. The third one is due
to the absence of water resources, which, in general, means low precipitation or
its improper pattern. As explained above, water consumption decreases water availability for a WUS, hence is one of the real contributors to the appearance of water
scarcity. Indeed, places that have or are approaching water scarcity should decrease
their water consumption. However, the real question is the amount of reduction due
to various trade-offs among the three Pillars. Furthermore, in dealing with water
(scarcity) the crucial need of nature must be considered particularly under temperature increases, which have a tendency to increase water consumption and consequently scarcity. This is most critical for downstream as a water body approaches