Erosion
What is erosion? Erosion is the process by which weathered rock is picked up and moved. For example, flowing rivers pick up sand and pebbles from the riverbanks and river bottoms.Another example is a flood which transports great amounts of rocks and soil.
The Grand Canyon was formed by weathering and erosion working together for more than two million years.
Today, the Colorado River continues to cut its way through the Grand Canyon.
Human activity has increased the rate of erosion in many areas. This happens through farming ,ranching , cutting down forests, and the building of roads and cities. Human activity has caused about one million acres of top soil to erode each year. For example landslides, wind, and , glaciers cause erosion.