Maps, Graphs, and Data

May 2018 Soil Moisture for Continental USA

The amount of water contained in the top few centimeters of soil is small on a global scale, but it is critical for agriculture analysts trying to monitor crop productions and other human health influencers. Create as many sentences using the sentence starters by looking at the map.

The Soil Moisture Active Passive mission (SMAP) was launched in 2015 as the first NASA satellite dedicated to measuring the water content of soils. The satellite uses a radiometer to measure soil moisture in the top 5 centimeters of the ground. It is a small amount of water on a global scale, but it is critical for farmers trying to figure out when, where, and what to plant.

Thanks to tools developed by researchers at NASA’s Goddard Space Flight Center, SMAP soil moisture data is now being used by the U.S. Department of Agriculture (USDA) Foreign Agricultural Service, which monitors global croplands and makes crop forecasts. Variations in global agricultural productivity have tremendous economic, social, and humanitarian consequences.

Soil Moisture USA

Since 2015, SMAP has helped map the amount of water contained in soils worldwide across months and seasons. Now those data are being applied on regional and local scales. The map above, based on SMAP data, shows soil moisture anomalies—how much the moisture content was above or below the norm—in the United States in mid-May 2018. The second map depicts anomalies and how they changed in southern Africa from 2016 to 2017.

Soil Moisture Anomaly Africa

Mini Lesson

Student Worksheet

Step 1: “I see...” 

Have students spend 2 minutes coming up with as many things they see on this map. They can work in pairs to discuss everything that they observe. Push them to think a little longer.  Their statements should start with, “I see…”

Some general questions you can ask your students to get them thinking are:

  • What is the scale of the map?

  • What is represented within this map?

  • What is the range of the data?

  • Where are the extreme values located?

Example of observations:

  • I see the color brown represents drier soil while the color teal represents more moist soil.

  • I see Arkansas and Louisiana are two states experiencing extreme dryness in their soil.

  • I see DC experienced a rainstorm that added soil moisture.

Step 2: “I think...”

Have students generate as many thoughts as possible on what this map makes them think.


  • I think soil moisture changes as seasons change so this is the soil moisture for the end of spring.

  • I think this information is vital for farmers.

  • I think there was likely a weather system that moved across from South Dakota to Pennsylvania.

  • I think another storm system went up the East Coast dropping precipitation.

Step 3: “I Wonder..”

The last step is to have students generate questions that this map leaves them thinking. Have them create a final group of sentences that begin with, “I wonder…”


I wonder what the soil moisture is during the summer months?

  • I wonder if Arkansas is in a drought?

  • I wonder, within what range of values can crops grow healthy?


  • Color projector or printed images

  • Copies of student activity sheets