One or more of Luna Leopold’s publications mentioned the climate reversal effects of having more erosion during drought periods than during wet years, a result in the difference in vegetative cover density was one of the reasons. Some soils can develop hydrophobic conditions. I have seen instances in a wetland soil, during extended dry period, where after a heavy rain event, the water remained perched, with dry soil conditions below. This was not expected. I have wondered if heavy rains on dry soils could seal the surface, creating something like an air lock in subsurface, preventing deep infiltration and encouraging runoff. The term Sahelian paradox you describe sounds similar, and will look into. In a presentation, I was fortunate enough to hear Luna Leopold describe why there are instances when dry conditions such as in portions of SW USA signal more erosion, which as you indicate, seems to be a paradox. He suggested the difference being the lacking vegetative cover and density, especially during drought periods that seem to happen on about a 20 year cycle. I attached his paper in one of my recent responses, and will try to attach again when I get to my computer and files.

Thanks a lot William for this very instructive report of study result, moreover in US territory, where I wouldnt have expected such a "tropical like" soil behaviour.

I wait for the paper, and will search google in the meanwhile

I will also try to a soils research paper that discussed piedmont agriculture soils whose macropores were sealed by fine soil particles and hydraulic conductivity reduced during SC heavy tropical storms. This old paper was one of my references in early gully work.

I am not a member to have digital access to this from the internet, perhaps you do.

Hoover, Marvin D. (1949). Hydrological Characteristics of South Carolina Piedmont Forest Soils. Proceedings of the Soil Science Society. pp 353-358.

https://dl.sciencesocieties.org/publications/sssaj/pdfs/14/C/SS01400C0353

Attached two papers of Luna Leopold

Thanks a lot William

I have downloaded them. They offer a very nice historical perspective.

Including the coolling of the 40's...