My name is Molly Maupin and Im a hydrologist with the US Geological Survey in
the water mission area.
And I am the national water use science team lead.
And over the years we've used satellite imagery to help us to get a cross
the landscape picture of water use and what the satellite data can help us with
is showing how much water is evapotranspired from the landscape and in the west thats
a really big component of water use because as you know its dry and a
lot of water gets evaporated.
So that changes across the country and the Landsat data is really good about giving
us a complete picture across the landscape.
My name is Gabriel Senay I work for USGS EROS.
My title is a Research Physical Scientist.
The main goal in the water census is how water is used.
So its usually at the county scale.
For each county they want to know how much water is used for agriculture how
much water is used for thermoelectric plants which is required for cooling purposes and how
much water is used for industrial.
How much water is for domestic.
So really splitting of water use in to measure the water into its major uses.
For us to be able to take the Landsat product which is showing the evapotranspiration
or the consumptive use of water across the landscape.
In order for us to take that and put it into the context of our
water use compellations we focus on irrigation.
So we need to discretize out those irrigated lands.
We can monitor using satellite data the rainfall variability and how evapotranspiration is happening.
Which means how much crop is grown in irrigation fields or in rain fed systems.
And that can be transferred into alerts. Security alerts.
Because ET is strongly linearly correlated to food production.
The more plants transpire more likely more grain is being produced.
So ET can be used for drought monitoring purposes but also indirectly we can monitor
how much water is being withdrawn from the ground water.
It's a computer model.
It stands for Simplified Surface Energy Balance and the OP is operational.
It started out as a simplified surface energy balance model and we operationalized it.
Which means we simplified the modeling parameters procedures so we can apply it globally.
Gabriel is a leader in his field.
Theres a large body of literature that is showing his algorithm and others.
Because his is easy to understand.
It is giving us the type of information we need at a resolution and over
a time series that is helping us a lot.
So I think his work has been extremely valuable.
Knowing how much water is being used because of demand and supply were going to match it.
Do we have enough water to meet this demand So knowing the water use will
help us well maybe the water used in this component is becoming lower so water
will be available on other uses.
So it will help you design or do we need to transfer water from one
basin to another.
So it will help you understand to design a system that will meet the demand.
So thats a major advantage just knowing the trends as well.
So when you do it over the years given water use is going up or
going down because of the population movement and cities growing.
Maybe water is moving from agriculture to domestic water use.
The main question is do we have enough water for the people and also not
only for people for the ecosystem.
Thanks to the Landsat missions and EROS these very valuable remote sensed satellite images are
available and they have a lot of value in the fact that theyre regularly measured
over the same geographic places on earth so you can get this stream of pictures
that help us to show whats changing on the landscape and often that change in
the landscape can be reflected or is part of the driving force in changes in water use.