Deck 1/4 Flashcards
VW and VWT
Define Virtual Water
amount of water used for producing (food) commodities
water/food
Purpose of Virtual water trade strategy
promotes water scarce regions to import water intensive crops and export crops w high water use values
trade of food between water scarce and water abundant regions
Water productivity
production per unit of water consumed
Number one consumer of water
agriculture
Crop water productivity types
physical, physical-economic, economic
crop water productivity (physical)
physical yield (ton/ha) per unit of water diverted or depleted
physical-economic CWP
value of crop per unit of water diverted or depleted
economic crop water productivity
value of crop per value of water diverted or depleted
field-level CWP improvement
change the literal field
- irrigation
- cultivation
- reclaiming of soil quality
- irrigation renovation
- training farmers
plant level improvement of cwp
change the plant itself
- increase harvest index
- improve drought tolerance
- improve salinity tolerance
regional level of cwp improvement
changing the crop pattern
which level of improvement of cwp is a virtual water strategy
the regional level
why was the term virtual water developed
to encourage the importation of food into water scarce countries so they can limit water use and meet food demands
water scarce regions typically MENA
it’s importing virtual water
how to increase water productivity
increase production per unit of water consumed
water saving
water footprint
water consumption in one region can impact other regions if export and import
imposed by VWT
which uses the most water for production?
corn, milk, cup of coffee, pair of jeans, beef, milk
beef, then jeans, milk, corn, coffee
mexico and india have _____ VW content of commodities than US and china
higher
use more water for same amount of food
VWContent of crops depends on
- crop/commodity type
- location of where it is produced
- time of when it is produced (climate, season, how much time it takes)
- management strategies in the production process
why does climate change VWC
favourable vs unfavourable climate conditions change the water requirements for crops
debates on VW concept
usefulness, feasibility of VW import to alleviate water scarcity
VWT literature covers
- water resource availability and food trade relations
- VW flow and water use efficiency in the food trade
- role of VW strategy in conflict mitigation and water scarcity management
Water resource and availability and food trade relations literature
not much supporting a relationship 2003, blue water still main/only consideration when gw is main source of food production
____1500 m3/capita/year means food import ____ with less water, ____ 1500 means changes in water availability ____ affect import
below, increases, above, do not
VW flow and use efficiency in the food trade literature
how much food is being traded, quantifying how much water is being saved with VWT
Blue water vs Green water
Blue water
- mobile
- possible substitutions
- many competitive uses
- requires conveyance facilities
- high cost
- significant impact on hydro system
blue water vs green water
green water
- immobile
- no substitutions
- few competitive uses
- doesn’t require conveyance facilities
- free
- insignificant impact on hydro system
blue water trade
water in rivers, lakes, reservoirs, ponds, aquifers
IRRIGATED AGRICULTURE typically uses blue water
green water trade
water stored in unsaturated soil and used by plants for evapotranspiration
SOURCE OF RAINFED AGRICULTURE AND ECOSYSTEM
opportunity costs and environmental impacts:
____ > ____
blue>green
which is more efficient for exporting countries
exporting green water is more efficient
in what way is exporting green water more efficient
in terms of physical water resources utilization
vast majority of crop production is based on ____ water
green
water challenges are ____ due to impacts and footprints of trade and consumption
local
VWC equation
1/CWP x production
ET/yield x production (m3/kg x kg = m3)
how much water will be saved in the global trade of cereal crops
400-600 km3 (~34%)
When food flows from the countries where the virtual water content is low to the countries where the virtual water content is high, it generates ____
global water saving
opposite leads to global overuse of water
VW saving at the global scale
if importing countries improve thier CWP (good thing), global water saving reduces and is not a meaningful indicator for efficiency
water scarcity and conflict mitigation in importing countries
- drive for self sufficiency despite decreasing water resources
- poverty unable to afford food imports at intl prices
- social problems with VWT (hiring farmers, policies, unemployment, immigration)
- unstable political relationships
conflict mitigation in exporting countries
- increased ag landuse
- increased soil and water pollution
- low food prices at intl market
major export barriers in production
tech, quality, cost of production, access to water
major export barriers in markets
info, transport conditions, market channels, trade regulations
the global VWT is predominantly ___ water
green
