Original Research Article
An updated isoerodent map of the conterminous United States

https://doi.org/10.1016/j.iswcr.2021.06.004Get rights and content
Under a Creative Commons license
open access

Abstract:

Maps of erosivity, which are also commonly referred to as isoerodent maps, have played a critical role in soil conservation efforts in the United States and around the world. Currently available erosivity maps for the United States are either outdated, conflict with erosivity benchmarking studies, or utilized less advanced spatial mapping methods. Furthermore, it is possible that the same underlying issues with US maps are impacting global maps as well. In this study, we used more than 3400 15-min, fixed-interval precipitation gauges to update the isoerodent map of the conterminous United States. Erosivity values were interpolated using universal kriging under several spatial model configurations and resolutions. The optimal spatial model was selected based on which result had the lowest sample variogram error. Rainfall, erosivity, and erosivity density maps were compared to existing products. Some average annual and annual erosivity results were compared to high-quality erosivity benchmarking publications. Erosivity values from both RUSLE2 and Panagos et al. (2017) were generally lower in the eastern United States and mixed in the western United States compared to our results. Topographic effects resulted in much greater erosivity differences in this study as compared to prior maps. Benchmark comparisons revealed that erosivity maps from this study and others were lower than the benchmark by 14% or more (up to 38%). These findings suggest current practices of storm omission and intensity dampening correction need to be revisited, especially in locations with relatively low-to-moderate rainfall erosivity such as the Midwest or Northeast United States, for example.

Keywords

Erosion index
Erosivity
United States
USLE
RUSLE2
Soil loss

Cited by (0)