Thirty-one undisturbed samples were collected from depths of 1.5 to 3.0 m on clayey hill slopes in the Pliocene and Allochthonous geological formations of Tuscany and Abruzzi in central Italy. Thin sections were made from each of the samples and the micromorphological aspects described semi-quantitatively using both microscopic and image analyses. The results were compared with the three, broad hill slope profiles – straight, convex and concave. The study showed that hill slope evolution by both creeping and surface and subsurface runoff has changed the conditions within the clay fabric and that linear voids due to tension and shear processes have formed in the soil. The data suggest that clayey hill slope form evolves from convex to concave via a linear shape.

As sediment transport is mainly correlated with accelerated soil erosion, the study attempted to quantify the sediment transport by relying on qualitative classes of soil erosion risk. The classes were obtained by applying a modified RAIZAL model (MICROLEIS software package) to the most representative catchment basins of the Abruzzi area (Central Italy). They are characterized by eight homogeneous lithological groups (terrigenous and carbonatic units). Each lithological group is related to specific types of morphology, soil and land use. The estimates of total sediment transport obtained using the modified RAIZAL Codex were in good agreement with those measured or estimated by other methods, suggesting that the use of this Codex would be a valid alternative.

Profile development indices of Harden [Harden, J.W., 1982. A quantitative index of soil development from field: examples from a chronosequence in Central California. Geoderma 285, 1-98] and Ferrari and Magaldi [Ferrari, G., Magaldi, D., 1983. Significato ed applicazioni della paleopedologia nella stratigrafia del Quaternario. Bell. Mus. Civ. St. Nat. Verona 10, 315-340] have shown their utility for comparative dating of some paleosols during geomorphological and geological surveys. In Italy and other countries, pedostratigraphic methods have been commonly applied to soil profiles formed in continental formations. Unfortunately, buried and relict paleosols are very scarce or badly preserved in some areas of Italy due to past and recent tectonic activity and to strong human impact dating back to prehistoric times.In order to use relict paleosols for correct chronostratigraphic interpretation of relict paleosols and in order to correlate them with old landscape forms for the reconstruction of Quaternary sequences, a new micromorphological index (MISODI) for assessing soil development and degree of weathering was devised. The index was tested in the extensional tectonic basin of L'Aquila-Scoppito (Abruzzi, Central Italy) where some chronostratigraphic information is available.Results demonstrate that there is a good relationship between presumed relative age of paleosols and degree of weathering and pedogenesis in B and B/C horizons as assessed by this index. The index has the potential to be adapted for application to other paleosol types in other countries. (C) 2000 Elsevier Science B.V. All rights reserved.

The hillslope instability forecasting by a deterministic quantification of factors inducing the geomorphologic hazard is largely spread in recent scientific literature. The sum of conventional scorings attributed to each instability factor determines the overall instability hazard.A new method for assessing the hazard using the fuzzy mathematics was carried out and applied in a pilot area of Central Apennines (Italy) at 1:100,000 scale. A map with the mapping units arranged in 4 hazard classes which agree to present and past landslides occurrence was obtained. In order to evaluate the difference between the deterministic and fuzzy approaches, a smaller sub area was selected and tested by 7 operators from different technical and scientific expertise. Results suggested that the fuzzy method is more useful for its flexibility and skill in reducing the importance of errors and appears to be well related to the landscape variability.

Magaldi, D., Rissone, P. and Totani, G., 1994. Effects of simulated seismic acceleration on silty clay soil horizons: a submicroscopic, micromorphological and geotechnical approach. In: A.J. Ringrose-Voase and G.S. Humphreys (Editors), Soil Micromorphology: Studies in Management and Genesis. Proc. IX Int. Working Meeting on Soil Micromorphology, Townsville, Australia, July 1992. Developments in Soil Science 22, Elsevier, Amsterdam, pp. 719–728.