Friday, December 12, 2014

Erosion models

In fourth grade, students are currently working on:

4-ESS2-1.Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation.
Examples of variables to test include angle of slope in the downhill movement of water and volume of water flow

Students used wallpaper troughs and sand to create model riverbeds. These allowed students to measure the rates of erosion by water. The models were given a consistent slope on one side and the variable that was changed was the amount of time water was allowed to flow through the riverbed. 

The first step was to create a riverbed in the sand.

A toothpick was placed on the edge of the meander of the river.

Water was poured through the riverbed with a modified watering can to regulate the flow. 

This picture shows the amount of sand that eroded as a result of the water flow. The toothpick stayed in place to represent where the meander had been.

 Students used a centimeter ruler to measure how much of the sediment had eroded from the meander. 

The erosion data was recorded in tables for later use: sharing results among groups, graphing of data and engineering mitigation methods.