Part 1: Water

Part 1: Water• Water is stored in “reservoirs”

– Oceans– Lakes– Rivers– Atmosphere– biosphere

Oceans

Cover 71% of Earth’s surface

SEA SEA LAND LAND+ 336 Runoff from land+ 398 Precipitation

over sea+ 434 Evaporation

+ 434 Evaporation– 398 Precipitation + 436 Excess to land

via precipitation

+ 107 Precipitation– 371 Evaporation

+ 436 Runoff toocean

+ 107 Precipitation– 336 Runoff to ocean

+ 471 Evaporation

Evaporation434

Precipitation398

Runoff 36 Groundwater

table Groundwaterflow

Infiltration

Surfacerunoff

Precipitation107

Evaporation71

Porosity:

The percentage of the volume of a rock occupied by

open space between grains

Permeability:

The capacity of a rock to allow fluids to flow through it

Subsurface Distribution of Water

Ogallala Aquifer

Sand and gravel from 6 Ma-2 Ma

Provides about 6 billion cubic meters water/year from 170,000 wells

Irrigates 5.1 million acres of land and has water for > 1 million people

Recharge area is local.

Will go dry in early 21st century

Ogallala Aquifer

Central Plains

Minimal rainfall

“Dustbowl” in the 30’s

Central pivot irrigation

Extraction is 100 times greater than recharge rate.

Las Cruces Water Use• Where does our water come from?• Where does the water go after use?

– Domestic– Agriculture

Las Cruces Water Use• All water comes from groundwater• In 10?-15 years: surface water (Rio Grande)• Treatment = $$$• Farms vs. homes

Las Cruces Water Use• Your water bill:

– 1st 5000 gallons per month are cheap– Each interval of 10,000 gallons get more expensive

• El Paso/Juarez have a more critical problem

• There are no limits on development (YET)

TUCSON WATER:

CENTRAL ARIZONA PROJECT

Mineral content is 325 ppm, will rise to 650 ppm by 2020.

Treatment plant? Will reduce to 450 ppm

Cost: $340 million

OR just pipe it into your home and see what happens

Las Cruces WATER:

Low levels of arsenic

Uranium concentrations: Maximum contaminant level: 30 ppbHighest detected levels: 132 ppb

“Exposure may result in toxic effects to the kidney.”“Some increase risk of cancer”

EROSION BY GROUNDWATER

Permeablevolcanic rock

Impermeablevolcanic rock

Faultzone

Risinghot water

Magma

Zone of intense heat

Geyser

HotspringsSinking

cold water

Water soaks into the soil and filters down.

As the water approaches the magma, it heats up and becomes less dense.

Hot springs occur where heated groundwater isdischarged at the surface.

Steam and boiling water are released under pressure, resulting in intermittent eruptions.