environmental
agriculture
animal
arid
climate
conditions
crisis
demand
depletion
desert
desertification
deterioration
dry
environment
extinction
foreground
fresh
geographic
global
groundwater
impact
impacts
industrial
irreversible
irrigated
lack
location
negative
pollution
problems
region
resources
risk
salinization
scarcity
severe
sixth
skull
surface
warming
water
waterless