(12) geo: water resources (2)

how much water does subsurface water contain?

25% percent freshwater, more than lakes and rivers

zone of aeration = 

non-saturated rocks

zone of saturation =

saturated rock

what zones do wells access?

the zone of saturation

what is an aquifer?

loose and permeable layers that waters can move through

what is an aquiclude?

tight and impermeable layer that water can’t move through

what is an influent condition?

a stream losing water to the subsurface

what is an effluent condition?

a stream gaining water from the subsurface

the rate of removal is…

greater than the rate of recharge

what does (rate of removal > rate of recharge) mean?

groundwater is removed faster than it is replaced

local watering of the water table can cause….

shallow wells to dry, and negative effects on vegetation

what is saltwater intrusion?

saltwater intrudes the fresh groundwater and makes a well unstable

in a water budget balance, if input is > than removal…

there is a surplus

in a water budget balance, if removal is > input…

there is a deficit

what process removes water from the ground?

evaporation

what biological process moves water from plants?

transpiration

what is actual evapotranspiration?

measured evapotranspiration (satellites)

what is potential evapotranspiration?

a theoretical maximum amount of evapotranspiration possible if there was enough water

in a water budget, if precipitation > potential evapotranspiration…

there is a surplus!

in a water budget, if potential evapotranspiration > precipitation…

there is a deficit!

where is potential evapotranspiration the highest?

in places with high temps, high sunlight, and winds (arizona)

where is potential evapotranspiration the highest globally?

the subtropical oceans, little cloud cover and intense sunlight

what is the water budget like in iraq?

net deficit throughout the year (high sunlight and low rain)

what is the water budget like in tokyo?

net surplus throughout the year (high rain)

what is the water budget like in portugal?

surplus in winter, deficit in summer

what is the water budget like globally?

surplus with runoff in the tropics

deficit with high evap and low rain in subtropics

surplus in areas with cool midlads and tropical cyclones

in a water budget, what condition creates a deficit?

when potential evapotranspiration (PET) exceeds precipitation