Badlands in marl lithologies: A field guide to soil dispersion, subsurface erosion and piping-origin gullies

摘要: Abstract Field scientists studying badland processes in Mediterranean and Semi-arid climates require assurances that the material which gullies are presented is not dispersive. A dispersive context means; first, infiltration rates may be radically changing very short periods due to swelling deflocculation of clays; second, surface crusts could result translocation sodium into subsurface positions; third, rills formed or at least exacerbated by shallow erosion; fourth, large with substantial up-channel headcuts, including so-called ‘bank gullies’, have because pipes collapsed; fifth, network connectivity evolution principally internal, being effected pipe capture integration; most importantly, bulk sediment moving around landscape lost from surface. This paper presents a decision-support tool assist effective diagnosis landscape's principal genetic process suite. The soil's behaviour response its geochemistry marls high exchangeable percentages (ESPs) outlined simple terms minimum use laboratory field chemical investigations. Using examples then set form indicators can used diagnose possibility dominating erosion. Surface crust character, ephemeral rills, tunnel settings explained classified. In final section, geomorphological implications piping gullied landscapes explored reference literature on connectivity.