10
2 Terminology
ET
PP
OS
RF
VA
RP
NR
WUS
VD
VU
river
Fig. 2.1 Typical schematic of a WUS (Water Use System) with fixed WPTs (Water Path Types)
Table 2.1 Fixed water path types (WPTs) of a water use system (WUS)
WPT
Description
ET
Evapotranspiration
NR
Non-Reusable
OS
Water from Other Sources
PP
Total Precipitation
RF
Return Flow (return to the main source)
RP
Potential Return (does not return to the main source)
VA
Abstracted/Applied water from the main source
VD
Volume of water Downstream after RF in the main source
VU
Volume of water Upstream before abstraction in the main source
must have the same units for the same time interval, e.g., millimetre or cubic meter
per year.
Let us make Table 2.1 a bit clearer:
• Main source usually supplies the most amount of water to a WUS. For example,
the above schematic has a river as a main source of water. In many parts of the
world, ground water is the main source of water.
• ET: a consumptive water, which means outflow that cannot be reused by the same
WUS during a time interval (see Sect. 2.4).
• NR: non-ET consumptive water, such as bottled water leaving a WUS.
• OS: any other flow into a WUS, besides the main source (VA) and precipitation
(PP). For example, if there are two sources of water for a WUS and the main
source is a river, then any extra inflow say from groundwater is OS.
• VU and VD give the influence of the WUS on the main source and hence the
basin.
• Considering V1 for the inflow section and V2 for the outflow section, they are:
– V1 = Volume of water at Sect. 2.1 which is set as VA or VU
– V2 = Volume of water at Sect. 2.2 which is set as RF or VD