Impacts of Changing Precipitation Events on Landscape Soil Erosion Estimates

Changing precipitation patterns associated with a changing climate result in altered rainfall erosivities that have direct impacts on soil erosion rates. Informed by observed climate change impacts on precipitation, three scenarios were run with the WEPP soil erosion model to assess changes in soil erosion estimates relative to the Daily Erosion Project (DEP) 2007-2020 baseline results over Iowa, USA. Unlike other studies which obtained results via statistical adjustment through a weather generator, these results were obtained via explicit adjustment of two-minute interval precipitation intensities. These scenarios found more than a 2% increase in average annual soil loss compared to the baseline for every 1% increase in precipitation intensity (Figure 1), a 0.7% increase in soil loss for every one day shift earlier in precipitation timing, and an 8% increase in soil loss for every additional 25 mm h-1 storm added during the spring season. Evidence suggests climate change impacts on precipitation characteristics affecting soil erosion must be considered a priority in planning conservation practices to maintain and/or improve soil health.