In our engineering geological (EG) zoning, where we have a long tradition, we use scales 1:50 000 to 1:10 000 for zones of same genetic (lithofacial) complexes with subzones of similar lithology (and thickness of the Quaternary layers, i. e. similar subgrade for foundations), but if similar EG properties/behaviour should be expressed, scales are even bigger, 1:4 000 and more. Scales 1:250 000 are good only for zones of similat geological and geotectonical formations.

Thank you. I agree with you and my eperiences are similiar with yours. Despite it, there is some geological (Holocene) units in Brazilian territory whose present very similar landforms, in behaviour as weel as in morphogenesis processes and soil profile evolution and properties. So I'm asking for people with similar experiences all around the word. I know that this isn't a usual approach, so I'm searching for experiences.

I am curious, what Holocene forms could be seen in that scale, besides big alluvial planes. Maybe hughe proluvial fans/cones?

In fact are large colluvial deposits whose people belives had transportation mechanism similar with proluvial fans. In landform mapping they could be treated as land system, but due its homogeneous properties they show soil profile similarity. That is the reason I asked people about similar situations.