There was more erosion in the Colorado Rockies scenario where there was steady rain compared to the scenario in the same area where there was only a drizzle. There is more erosion because the steady rain increased the volume of the river more than the drizzle did. Because there was more water added to the river, the river flowed faster. The faster a river flows, the more sediments it transports or erodes.
The Erosion in the Colorado Rookies Scenario that record a ready rain were more than the other scenario in the same area with just a drizzle. The Erosion is much in the Colorado Rockies Scenario that record a steady rain because the volume of the rivers has goes up compare to that of the Scenario with just a drizzle. As a result of the increased in the amount of the rivers bank that is flowing, the river flows more faster which helps in the transportation of the sediments or Erodes.