NASA data says it's worse than we thought.

Hey guys, Amy here for DNews.

A drought is a natural hazard that develops slowly over time as a climate or environment

changes.

Water levels drop in the lakes and rivers that we draw water from, forcing reliance

on underground stores called aquifers, sources of fresh water that farmers also rely heavily

on, particularly in times of drought.

So what exactly is an aquifer?

An aquifer is a saturated rock that water can easily move through.

Typically these rocks are permeable and porous, though non-porous rocks like granite can be

aquifers if they're fractured enough to hold water in the free spaces.

This is where well water comes from; wells are drilled into aquifers so the water inside

the rock can be pumped out.

If the well goes dry, you just have to dig deeper and lower the water table.

Water flows into and eventually drains from an aquifer in a cycle, so each has a natural

recharge and discharge zone or zones.

The recharge zones typically lie at higher altitudes so water can flow down, but they

can occur wherever it's natural for water to move.

The discharge zones typically occur in springs and low altitude wetlands.

The other benefit of this groundwater is that the rock acts as a natural filter that traps

sediment and other nasty particles like bacteria so the water that flows from the spring is

beautifully clean and clear.

But aquifers can become contaminated, typically by humans.

Contaminants can flow into an aquifer from a natural or manmade pathway that drains into

the waterlogged rock.

And as NASA's GRACE mission is showing, these underground water stores are drying

up.

The GRACE mission uses two satellites flying in tandem to very accurately measure variations

in the Earth's gravity field.

Changes to ocean currents do affect gravity measurements.

So do movements of glaciers.

And so does the movement of ground water, so these satellites can see that aquifers

are actually drying up because the gravity in these areas is changing.

And it's a global thing.

Using GRACE data of 37 aquifers over the course of 10 years, scientists see that groundwater

is being rapidly depleted in the Middle East, North Africa and Central Asia, and in the

United States.

The aquifer under California's Central Valley is being badly overused.

Even aquifers in sparsely populated and wet areas like the Amazon Basin and the Great

Plains are doing a little better thanks to rainfall that replenishes the water stores.

That less water is available globally is starting to affect political relations.

Border issues in some parts of the world are becoming increasingly complex as fights break

out about access to water under those borders.

To learn more about how low water levels in aquifers is affecting inter country relations,

check out this video from Test Tube News:

And there's a link in the description below!

So wherever you are, it's time to start saving water!

Turn the tap off while you brush your teeth!

Don't linger in the shower because you're bored!

What little things do you guys do to save a few ounces a day?

Let us know in the comments below or on Twitter @DNews.

And of course, for more DNews every single day of the week, don't forget to subscribe!