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Along its contact with the Baltic Shield, the margin of the East European Platform reveals a well-developed, flooded terraced relief. The most striking and consistent set of escarpments at the contact of the Lower Palaeozoic calcareous and terrigenous rocks, known as the Baltic Klint (BK), extends from northwest of Russia to the Swedish island of Oland. Marine seismic reflection profiling in 1990–2004 revealed the central Baltic Sea Klint (BSK) section in detail and enabled comparison of its geology/geomorphology with a classical klint-section onshore, namely the North Estonian Klint (NEK). The conception of the BK onshore, which is based on the land-sea separating terraced relief in northern Estonia, is not fully applicable beneath the sea. Therefore, we consider that the BSK includes the entire terraced Cambrian outcrop. We suggest the term “Baltic Klint Complex” to include the well-terraced margin of the Ordovician limestone outcrop, which is weakly developed in Estonia. Because of a steady lithological framework of the bedrock layers across the southern slope of the Fennoscandian Shield, the central BSK in the western and the NEK in the eastern part of the Baltic Homocline have largely identical morphologies. The North Estonian Ordovician limestone plateau with the calcareous crest of the BK extends across the central Baltic Sea, whereas morphological changes/variations along the Klint base occur due to the east-westerly lithostratigraphic/thickness changes in the siliciclastic Cambrian sequence. The verge of the NEK, located some 30–50 m above sea level, starts to drop in altitude as its east-westerly course turns to northeast-southwest in western Estonia. Further westwards, the BK shifts gradually into southerly deepening (0.1–0.2°) layers as its crest drops to c. 150 m below sea level (b.s.l.) near Gotska Sandon. This course change is accompanied by a considerable decrease in thickness of the platform sedimentary cover, as below the central Baltic Sea the stratal sequence is 150–250 m thinner than in northern Estonia. This has facilitated a deviation of the terraced relief-forming Cenozoic rivers traversing east-westerly across the southern slope of the Fennoscandian Shield and forming different morphostructures in its eastern and western parts. Thus, a low-lying central Baltic Sea depression with well-developed asymmetrical cuesta valleys and terraces occur in the western half of the Baltic Homocline. In its eastern part, however, the only explicitly shaped cuesta valley along the shield-platform boundary forms a narrow east-westerly branch/gulf of the Baltic Sea (Gulf of Finland). The well-terraced southern margin of this gulf runs along the contact of the outcropping terrigenous and calcareous rocks, rises above the sea and forms a complex landform known as the NEK.

Characteristic landscapes (e.g., cuesta, cliff and overhang of caprock, or stepped terrain) formed by differential erosion can be found in areas composed of variable geology exhibiting different resistances to weathering. Parallel retreat of slopes, defined as recession of slopes without changes in their topography, is sometimes observed on slopes composed of multiple strata. However, the conditions needed for such parallel retreat have not yet been sufficiently clarified. In this study, we elucidated the conditions for parallel retreat of rock slopes composed of alternating layers using a geometric method. In addition, to evaluate whether various rock slopes fulfilled the conditions for parallel retreat, we analyzed topographic data obtained from periodic measurement of rock slopes in the Aka-kuzure landslide, central Japan. Our geometric analysis of the two-dimensional slopes indicates that dip angle, slope gradient, and erosion rate are the factors that determine parallel retreat conditions. However, dip angle does not significantly affect parallel retreat conditions in the case of steep back slopes (slope gradient > 40°). In contrast, dip angle is an important factor when we consider the parallel retreat conditions in dip slopes and gentler back slopes (slope gradient

This study identifies and analyzes a group of interrelated morphometric variables that contribute to the morphology of first-order basins in the Siwaliks and the adjacent part of the Lesser Himalaya in the Far West Nepal. First-order basins were identified and their various morphometric indices (21 variables) such as shape, area, pattern, roughness, height, gradient, angle, and distance were obtained from topographic maps (scale 1:25,000) and a digital elevation model using a geographic information system. The study also identifies the basin types based on morphometric properties and assesses their association with lithology, structure, and uplift rates. A principal component analysis identified seven major components that accounted for 78% of the total variance explained by the original 21 morphometric variables. Variables' loading reveals that the components are the expressions of slope, size, valley/depression, basin shape, relative massiveness, the convergence index, and basin asymmetry. Of these, slope and size components explain 48% of the total variance. The sets of variables represented by each major component for the entire study area were mostly common to all lithostratigraphic units. Some variables such as drainage density, junction angle, and the sediment transport index have associations with more than one group. This implies that complex geomorphic processes are involved in the development of basin morphology. Using the seven major components, five basin types were recognized by cluster analysis. The distributions of these basin types are similar in the Lower and Middle Siwaliks which have similar geological structures. The geometric relationship between the dip and the topography of a homoclinal structure significantly affects the proportion of basin types, as evidenced by the contrasting proportions between the cuesta and hogback and among dip, anti-dip and orthoclinal slopes. Correlation analysis also confirmed the effect of structure (dipping) on the morphometric variables, and indicated the influence of uplift rates on basin slope, stream slope, elevation range, mean elevation, valley angle, the shape index and the convergence index associated with the active thrust.

The vineyards of the Montagne de Reims are mostly planted on steep south-oriented cuesta fronts receiving a maximum of sun radiation. Due to the location of the vineyards on steep hillslopes, the viticultural activity is threatened by slope failures. This study attempts to better understand the spatial patterns of landslide susceptibility in the Champagne–Ardenne region by comparing a heuristic (qualitative) and a statistical (quantitative) model in a 1120 km² study area. The heuristic landslide susceptibility model was adopted from the Bureau de Recherches Geologiques et Minieres, the GEGEAA – Reims University and the Comite Interprofessionnel du Vin de Champagne. In this model, expert knowledge of the region was used to assign weights to all slope classes and lithologies present in the area, but the final susceptibility map was never evaluated with the location of mapped landslides. For the statistical landslide susceptibility assessment, logistic regression was applied to a dataset of 291 ‘old’ (Holocene) landslides. The robustness of the logistic regression model was evaluated and ROC curves were used for model calibration and validation. With regard to the variables assumed to be important environmental factors controlling landslides, the two models are in agreement. They both indicate that present and future landslides are mainly controlled by slope gradient and lithology. However, the comparison of the two landslide susceptibility maps through (1) an evaluation with the location of mapped ‘old’ landslides and through (2) a temporal validation with spatial data of ‘recent’ (1960–1999; n = 48) and ‘very recent’ (2000–2008; n = 46) landslides showed a better prediction capacity for the statistical model produced in this study compared to the heuristic model. In total, the statistically-derived landslide susceptibility map succeeded in correctly classifying 81.0% of the ‘old’ and 91.6% of the ‘recent’ and ‘very recent’ landslides. On the susceptibility map derived from the heuristic model, on the other hand, only 54.6% of the ‘old’ and 64.0% of the ‘recent’ and ‘very recent’ landslides were correctly classified as unstable. Hence, the landslide susceptibility map obtained from logistic regression is a better tool for regional landslide susceptibility analysis in the study area of the Montagne de Reims. The accurate classification of zones with very high and high susceptibility allows delineating zones where viticulturists should be informed and where implementation of precaution measures is needed to secure slope stability.

There are both internal and external controlling factors leading to slope instability and susceptibility to mass movement processes. This paper explores which external climatic variables of different temporal scales influence the occurrence of high-magnitude landslide events. The investigations were focused on the Wellenkalk-cuesta scarp in the Thuringia Basin (Thuringer Becken) in central Germany. The cuesta scarp is composed of a densely jointed limestone caprock (Wellenkalk), and impermeable mudstones and marls of the Upper Bunter Sandstone (Rot) in the lower part of the slope. Mass movements are a typical feature of the Wellenkalk-scarp. The entire scarp slope length (∼1000 km) has been systematically mapped and investigated in a comprehensive research project in order to provide reliable information on the spatial distribution and control of the mass movements. More than 20% of the scarp slope has been influenced by various types of Holocene mass movements with strong differences in spatial frequencies. Sixteen high-magnitude landslides (Sturzfliesungen) were identified by field inspection and mapping of slope geomorphology. Information on locations, morphometric characteristics, stratigraphic positions and rainfall-related attributes of the scarp slopes affected by the large landslides is presented. Mean annual rainfall amounts decrease from more than 800 mm in the western part of the basin to less than 550 mm in the east. Meteorological statistics on the spatial distribution of heavy rainfall intensities of different durations and return periods show that greatest precipitation intensities in short events (1 h) are reached at the western margin. Differences in rainfall intensities between the western and eastern parts decrease with increasing duration of the events. Where available, event-related meteorological information was collected. The spatial distribution of the landslides is most closely mirrored in the pattern of mean annual precipitation, though this variable is generally not thought to be a satisfactory or reliable climatic controlling factor. No landslides occur below a threshold value of ∼700 mm. The empirical data show that some general level of average perennial water input into the slope system seems to be of decisive importance for the occurrence of high-magnitude mass movements. Only when the precondition of a more general hydrological disposition is fulfilled, a direct triggering of high-magnitude mass movements by a short-time intensive rainfall period or event can become effective.

Problems in the analysis and interpretation of the interaction patterns of drainage basin characteristics are outlined. The canonical correlation technique is suggested as capable of simplifying and producing a high level of generalization of the complex interaction patterns. The technique is described and employed in structuring the relationships between the morphometric and topologic attributes of a sample of 36 monolithologic third-order drainage basins in the Udi-Awgu cuesta, southeastern Nigeria, and the factors controlling their development. The canonical solution identifies three significant patterns of association between basin planimetric properties and their causative and deterministic factors. The texture of dissection is strongly associated with soil and vegetation characteristics while the stream network size and the stream bifurcation ratio are closely related to the stage of basin development and basin relief respectively. Some general problems of the canonical correlation analysis are outlined.