Second Graders Model Erosion in Our Own Backyard

Here’s a scenario for you: a hurricane is predicted to make landfall soon. You have two minutes to protect your sand structure from damaging winds and water. What do you do?

Second graders ran with this time-sensitive motivation during an outdoor science lesson on Lowell’s back playground. The class gathered in the large sand pits to simulate different erosion experiments. They could use coarse sand or finer, compacted sand to build mountain-like structures. Next, they blew at the sand to see how wind erodes or poured water over it to see the effect. They noticed that flatter shapes withstood erosion better than tall spindles. Eventually, they supplemented structures with leaves they found in the sand, and teacher Becca provided them with strips of burlap. After a lot of hands-on tweaks, many students found that these added materials changed the flow of water or protected the sand underneath.

“Here comes Hurricane Becca!” she warned a small group of students. Together they scrambled to flatten their structure and cover it with leaves and burlap, drawing on their earlier observations. In the commotion, other friends gathered around. Hurricane Becca showed no mercy as the remaining water poured over the structure. When “the storm” had passed, they all checked the damage. Becca pointed out where the burlap had kept sand in place and dry, and where water had carved away jagged pieces that would continue to erode further with time. The class will think through where they might find eroded areas like this in nature and what kind of solutions—a la burlap and leaves—might help to prevent damage from extreme weather.