Colorado’s flood of 2013 caused centuries’ worth of erosion
DOI: 10.1063/PT.5.028773
Ars Technica : Starting on 9 September 2013, Colorado’s Front Range experienced a year’s worth of rainfall in just five days. The flooding caused extensive damage to Boulder and other cities. Less conspicuous was the loss of top soil and other ground cover that occurred in unpopulated parts of the region. Now, thanks to the use of lidar, researchers from the University of Colorado Boulder have quantified that loss. Comparing lidar images before and after the flood, the researchers identified 120 new grooves formed by landslides. In total, about 21 000 m3 of sediment was washed away. Given that the average erosion rate is 30–60 millimeters per millennium, the five-day flood caused as much erosion as would normally occur in 150 to 2200 years.
