Bar graph titled Average Precipitation at the Grand Canyon. Month is on the x axis and inches of Precipitation on the y axis in increments of 1. January is just above 3. February is above 3. March is halfway between 2 and 3. April is between 3 and 4, closer to 4. May is just above 1. June is just below 1. July is almost 2. August is almost 3. September is 2. October is about halfway between 1 and 2. November is halfway between 1 and 2. December is almost at 3, the same as August. The Colorado river flows through the Grand Canyon.

Which characteristic of the river is directly affected by the amount of precipitation in this area?

In which month would there be the most erosion where the river flows through?