Water as all know is going to be a scarce commodity. Over the years
research is on to find out ways and means of saving water and making the
best from the vailable resources of water, be it permanent sources like
water bodies or the temporal one like rain. This weekend, please find
attached a small write-up on Water Footprint. It is a measure of usage of
water for surving of a community or that required for preparing something.
Though teh concept is not new but not very common. We can do our bit by
choosing items which require lesser water to prepare over others. For the
interested souls, one may refer www.waterfootprint.org.
Concept
The water footprint of an individual, community or business is defined as
the total volume of freshwater used to produce the goods and services
consumed by the individual or community or produced by the business. Water
use is measured in water volume consumed (evaporated) and/or polluted per
unit of time. A water footprint can be calculated for any well-defined
group of consumers (e.g., an individual, family, village, city, province,
state or nation) or producers (e.g., a public organization, private
enterprise or economic sector). The water footprint is a geographically
explicit indicator, not only showing volumes of water use and pollution,
but also the locations. However, the water footprint does not provide
information on how the embedded water negatively or positively affects
local water resources, ecosystems and livelihoods.
Components
A water footprint consists of three components: blue, green, and grey. The
blue water footprint is the volume of freshwater that evaporated from the
global blue water resources (surface water and ground water) to produce the
goods and services consumed by the individual or community. The green water
footprint is the volume of water evaporated from the global green water
resources (rainwater stored in the soil as soil moisture). The grey water
footprint is the volume of polluted water that associates with the
production of all goods and services for the individual or community. The
latter can be estimated as the volume of water that is required to dilute
pollutants to such an extent that the quality of the water remains at or
above agreed water quality standards.
Some facts and figures
a. The production of one kilogram of beef requires 15 thousand litres of
water (93% green, 4% blue, 3% grey water footprint). There is a huge
variation around this global average. The precise footprint of a piece of
beef depends on factors such as the type of production system and the
composition and origin of the feed of the cow.
b. The water footprint of a 150-gram soy burger produced in the Netherlands
is about 160 litres. A beef burger from the same country costs about 1000
litres.
c. The water footprint of Chinese consumption is about 1070 cubic meter per
year per capita. About 10% of the Chinese water footprint falls outside
China. In comparison to that, the figure reads 980 cubic meter.
d. Japan with a footprint of 1380 cubic meter per year per capita, has
about 77% of its total water footprint outside the borders of the country.
e. The water footprint of US citizens is 2840 cubic meter per year per
capita. About 20% of this water footprint is external. The largest external
water footprint of US consumption lies in the Yangtze river basin, China.
f. The global water footprint in the period 1996-2005 was 9087 Gm3/yr (74%
green, 11% blue, 15% grey). Agricultural production contributes 92% to this
total footprint.
g. Water scarcity affects over 2.7 billion people for at least one month
each year.
Why bothering about your water footprint?
Freshwater is a scarce resource; its annual availability is limited and
demand is growing. The water footprint of humanity has exceeded sustainable
levels at several places and is unequally distributed among people. There
are many spots in the world where serious water depletion or pollution
takes place: rivers running dry, dropping lake and groundwater levels and
endangered species because of contaminated water. The water footprint
refers to the volumes of water consumption and pollution that are ‘behind’
your daily consumption.
As I always say, brickbats and bouquets welcome
-Sukhi
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