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In this short paper some examples of tafoni and similar features of cavernous weathering are described from Western Scotland and Southern Greece, including Crete and the Santorini group. All these forms belong to the younger Holocene. This age is indicated by young tectonic emergence from the sea, historical data, or the well known volcanic history of Santorini. Pre-Holocene tafoni are neither more widespread nor better developed than those of the last 2000 or 3000 years. Very different rocks are weathered into tafoni features: old and young sandstones and calcareous sandstones, pliocene conglomerates, eolianites, or lavas and holocene tephra. The tafoni are nearly in all cases strongly oriented towards the present sea front, and therefore salt weathering should be the most effective process.

Connectivity analysis has proved a very valuable approach in understanding runoff and sediment fluxes in catchments. Many analyses use Connectivity Indices to model the patterns, but various versions of the Index have been developed. This paper tests the effects of these variants of the Index as applied to an agricultural-terraced catchment in the semi-arid Mediterranean region where occurrence of connectivity is relatively well documented to validate the modelling. This paper compares three versions of the Connectivity Index that use vegetation/land use (C), topography (RI) and roughness (n) as the weighting factors. Two different slope algorithms are also tested. The weightings are derived from a UAV (drone) survey, with simultaneous ground field mapping. The UAV imagery is found to provide a good, high resolution basis for determining detailed topography and vegetation cover. The slope limit present in some modelling is found to be unsuitable in this landscape where steep terrace embankments that are vegetated in places, and also partially vegetated uplands, occur. Subsequent modelling removed the slope limit. The major patterns of flow produced are similar between the models and are largely related to the overall topography and major drainage lines but considerably modified by the terracing. The model outcomes differ in detail, with the C factor model, incorporating vegetation, coming nearer to the field situation. The main deficiency in all the indices is the weakness in modelling ponding and sedimentation created by the terraces, and therefore the disconnectivity in the landscape. Comparison with field data confirms the variable connectivity in rainstorms, the effects of features such as tracks, and the effect of management actions. Evidence from field mapping during the last two decades indicates that the models probably represent the maximum possible functional connectivity.

In this paper, we analyse the significance of alluvial substrates in shaping the morphodynamics of the bottom of a lowland river valley. The research focus was a 20-km reach of the Bug River valley, an example of a large river in the Polish Lowlands. There are no anthropogenic elements in the valley that can disturb the course of natural river processes. The Bug River channel has not been engineered in the section analysed. Eighty-one geological drillings performed in the channel allowed identification of 11 zones of sub-alluvial bedrock protrusions built up from erosion-resistant deposits. The determination of the valley bottom surface morphology was based on high-resolution multispectral satellite images in natural and near-infrared colours. Geological and geomorphological mapping of the valley bottom surface were also carried out. The obtained results showed that the key factors controlling the morphodynamics of this floodplain are protrusions of sub-alluvial bedrock. Under medium- and low-flow conditions, these are hidden under a layer of channel deposits. However, during high flows, the surface of the protrusions is exposed, affecting the pattern of flood flows and forcing them to enter the floodplain in certain, recurrent zones. The result of such phenomenon is the creation of characteristic sets of accumulative and erosive landforms. Thirteen types of such forms have been identified. The presence of sub-alluvial bedrock protrusions in this river channel has promoted formation and persistence of ice jams (confirmed by analysis of hydrograms from 1969 to 2018). The case presented in this paper shows that the certain arrangement of landforms indicate morphodynamic specificity of valley bottom whose alluvial substratum exerts an influence on flood flows. Since protrusions of alluvial substrate is associated with glacial genesis of the area cut by the Bug River, the described phenomenon may also occur in other postglacial areas.

Pumice, a component of pyroclastic soils, undergoes a grain crushing process, even at lower stress level, with the resulting decreasing in shear strength in such material. According to the content already discussed in Esposito et al. 2013, this paper is focused on the attempt to further correlate the in situ measures acquired on these kinds of soils, in particular about suction, humidity and saturation, to the mechanical behavior observed in laboratory. The data collected in situ during 19 months, to cover both dry and wet cycles, supported the evidence that the wetting and drying conditions of such soils, due to the analyzed meteoric precipitations, fulfilled the required conditions that may induce the phenomenon of grains crushing. Hence, we have further explored the connection of these kinds of phenomena introducing new elements of discussion such as the decay of the mechanical characteristics, in situ measurements of the hysteretic relation between the suction and the soil water content, investigation about the occurrence conditions of static liquefaction and more. The research was developed by selecting, as test case, a wide area around Naples and the Vesuvius (Italy), affected, in particular, by frequent landslide phenomena, due to the instability of the pyroclastic cover, such as the events occurred at Monte Faito, Nocera Inferiore, Coroglio and Monte di Procida Ridges. Evidence of a marked influence of the wetting-drying cycles on the pumice crushing and on the resulting structural collapse phenomena, was observed during laboratory tests. The issues and the related discussion addressed in this paper could be useful in order to identify the triggering phenomena of shallow collapses, fast landslides, flow liquefaction and more, where pyroclastic covers, similar to those coming from the selected areas, are located.

The stability evaluation of rainfall-induced landslides using a physical determination model supports disaster prevention, but it is mostly applied to the area with few landslides, and there is a lack of quantitative study on rainfall and landslide stability. This paper combined the Scoops3D model with the TRIGRS model (3D) to predict the shallow landslide spatiotemporal distribution and compared the simulation results with those of the TRIGRS model alone (1D), aiming to obtain more accurate assessment results. At the same time, the relationship between landslide stability and accumulative rainfall was quantitatively fitted to improve the real-time landslide prediction system. We applied the 1D and 3D models to the July 21, 2013 group-occurring landslide event (976 shallow landslides) in the Niangniangba basin, China. The required geotechnical parameters of both models were acquired by field and laboratory tests. We calculated the pressure head over time using the TRIGRS model based on practical rainfall data and predicted the shallow landslide stability using the Scoops3D model according to the resulting piezometric surface. We compared the landslide stability spatial distributions of the two models under initial and saturated conditions with the landslide catalogue. The success rate of landslides predicted by 3D model is 4.20% higher than 1D model. A composite index to quantitatively evaluate both models’ performances indicates over-prediction by the 1D model in the stable region, while the 3D model more effectively predicts shallow landslides with a smaller unstable region. The relationship between instability proportion and accumulative rainfall in the 1D and 3D model can be represented by y = 24.57 x 0.18 and y = 11.59 x 0.33 , respectively. The 3D model shows more conservative result, and the rainfall threshold analysis proposed in this paper can provide reference for the time of most landslides in the case of insufficient data, which is an important indicator for disaster early warning and prediction.

Floodplain deposits in the valley of the Moskva River contain a series of buried soils of the Holocene age, which can be an important source of paleoecological information. These soils were dated as follows: Soil 1 — 100 BP, Soil 2 — cal 1200 AD–500 BC, Soil 3 — 900–2700 BC, and Soil 4 — 3700–6000 BC. Archeological monuments associated with these soils belong to the Neolithic (Soil 4), Early Bronze Age (Soil 3), and Iron Age and Middle Ages (Soil 2). Buried soils have well developed profiles and diagnostic features. Dark-colored soils of the Atlantic period (Soil 4) in most cases can be attributed to Phaeozems. Pollen analysis shows that these soils were formed under forest-steppe communities. Buried soils of the Subatlantic period (Soil 2) are usually referred to as Luvisols. Unlike them, the soils of the Subboreal period (Soil 3) are traced in rare cases and have no clear diagnostic features allowing reconstruction of the paleoenvironment. These soils have a light-colored humus horizon, which does not allow them to be classified as Phaeozems. However, they do not have the Bt horizon characteristic of Luvisols. This paper describes the results of a new comprehensive study of the Moskva River floodplain near the Zvenigorod Biological Station (ZBS) of Moscow State University. The buried soils of the Atlantic and Subboreal periods were studied by palaeopedological and palynological methods. The findings confirmed previously obtained results and indicated that the buried Soil 3 at the ZBS site could be developed under mixed forests dominated by spruce. These results suggest that the landscapes of the lower levels of the valley changed dramatically between 5000 and 4500 cal BP. The forest-steppe communities were replaced by dense forests due to the early Subboreal climate change. The paper also examines the specifics of soil and pollen records of the landscape evolution. The anthropogenic influence on the floodplain landscapes is also considered.

In this paper we analyse the geomorphic response of a mountain river (Upper Cinca River, Central Southern Pyrenees) in relation to multi-scale disturbances during almost a century (i.e., 1927–2015). The integration of multiple geomorphic descriptors (i.e., morphology and topography) and disturbances (i.e., floods, land use changes, dams, embankments and gravel mining activities) allows better understanding of the cause-effect relations and their significance. The paper presents a novel methodology integrating the application of SfM-MVS algorithms to historical imagery to extract multitemporal channel topography and morphology; and the use of statistical tools to infer on the existence of significant trends and breakpoints in the temporal evolution of the geomorphic descriptors and disturbances. Results show that afforestation was the main land use change exhibited between 1957 and 2015, although mainly concentrated during 1977–2015. Annual runoff presented a general negative trend with a wet (1959–1983) and dry period (1983–2015). Extensive gravel mining occurred after flood events, together with channel engineering works such as the construction of embankments. These disturbances, together with the construction of three small dams in the headwaters, had a direct impact on lateral connectivity by confining and constraining channels and concentrating flows, resulting inchannel incision and stability. The evolution of the disturbances, process changes and geomorphic descriptors indicated that, during the last century, the river channel is in a transient state, in which the magnitude of the changes oscillate. The river is adjusting to the disequilibrium imposed by multi-scale disturbances acting at different temporal and spatial scales by means of two contrasting channel states. First, Channel State 1 (1927–1984) was characterised by having high geomorphic activity and channel incision. Conversely, Channel State 2 (1984–2015) was characterised, by having a low geomorphic activity, when channel constraining was the dominant process and incision was more localised and marginal. The results of the Upper Cinca may be relevant to infer in future fluvial metamorphosis associated with the effects of global change on water and sediment fluxes in mountain catchments, and to assist objective-based rehabilitation measures of rivers subjected to multi-scale disturbances.

In an experiment where one of the objectives was to evaluate the effects of slope gradient and rainfall intensity on splash detachment capacity, the authors measured material splashed into slots along the sides of an area eroding by rain-impacted flow. They concluded from their results that their finding was not consistent with previous reports which suggested that splash detachment capacity could be predicted by a power function of rainfall intensity and slope gradient. In rain-impacted flows, a number of transport mechanisms operate in the flow in addition to material transported by splash. Given that only particles that are transported by the transport by splash are considered in the work reported in this paper, the results presented do not give data on how rainfall characteristics and slope gradient influence detachment in raindrop driven erosion. Also, because the transport mechanisms that exist in rain-impacted flow are not 100% efficient, it is not possible to determine detachment by raindrops in rain-impacted flows from the measurement of sediments discharged by splash and surface water flows in experiments like those reported in this paper.

Badlands are highly erodible landscapes with sparse vegetation and rapid runoff responses. Badland surfaces experience high erosion rates that may have a direct and marked influence on river channel networks and catchment scale sediment budgets. Erosion rates from badlands have been widely estimated by discrete observations of topographic change measured by erosion pins or profile meters. Recent developments in survey instrumentation provide the opportunity to build high-resolution topographic models over multiple spatial scales at sub-centimeter accuracy. In this paper we demonstrate how reliable estimates of topographic variables and temporal change can be derived for badlands by repeat Terrestrial Laser Scanning (TLS) surveys undertaken at multiple temporal (event to annual) scales. A total of seven TLS-surveys were obtained in an experimental sub-humid badland located in the Central Pyrenees. Data analyses were conducted on two temporal scales: (a) five rainfall events and (b) three long term (spaced over an annual cycle) scales. Our results show a clear erosional pattern for most of the badland at the annual scale (i.e. annual net change at around − 6 cm yr − 1 ). Aspect, surface roughness and slope were significant predictors of topographic change, although the sign and magnitude of the change differed at the event scale. Net topographic change at the event scale varied from − 1.8 to 1.4 cm. Although these patterns could be also affected by swell-shrink processes, surface roughness was more important at controlling badland geomorphological processes at the event-scale than the annual scale. Our observations suggest that longer-term studies may underestimate the importance of surface roughness as a control on badland geomorphology. At the annual scale the effect of aspect in the sign of the topographic change was removed and slope becomes more important. Erosion proved to be dominant on slopes higher than 100%. Overall, the results indicate that coupling of appropriately-scaled spatial and temporal data is critical to understand topographic changes and their drivers on badlands. Although the approach outlined in this paper was only applied to a relatively small area, with careful survey design and application of new survey technology, it could readily be upscaled to cover entire badland systems. Such surveys would permit detailed analysis of controls of sedimentological connectivity across badlands and their influence on channel networks and catchment sediment budgets.

Based on quantitative simulations on the formation and evolution of aeolian dune fields, a semi-analytical equation describing the migration of aeolian sand dunes with respect to dune height, annual wind regime, frictional wind speed, and sand grain diameter is proposed in this paper through analyzing the migration speeds of aeolian sand dunes with different heights in a dune field. The migration speeds of aeolian sand dunes on Earth predicted by the equation is consistent with field observations, and it can be applied to describe the migration of underwater sand dunes and aeolian snow dunes on Earth, as well as that of aeolian sand dunes on other planets, for example Martian sand dunes. In addition, we can also obtain the annual wind regime and the frictional wind speed in dune fields by the A–W method proposed by this paper for given dune speed and sand diameter. It provides a new way to obtain the information of wind field in desert hinterland and on other planets.

The Mogi Guacu River rises in Bom Repouso (Minas Gerais State — Brazil) in the Mantiqueira Ridge, and flows into the Rio Pardo river at an elevation of 483 m in Pontal (Sao Paulo State — Brazil), after running a 530 km long course. Especially along the Lower Mogi Guacu Basin, the river morphology is extremely sinuous, characterized by intense processes of channel migration, avulsion, abandonment and reactivation of the channel, producing an extensive alluvial plain composed of a series of associated relief forms and sedimentary facies. Among these forms, point bar deposits by lateral accretion, abandoned meanders, paleo-channels and fluvial terraces are notable features. In this sense, the objective of this work was to investigate whether these features could be linked to environmental changes. To reach this goal, soil properties of a catena of the Jatai Ecological Station (Luiz Antonio — Sao Paulo State) were analyzed in four sectors: Slope, Terrace I, Terrace II and Alluvial Plain. The results from grain-size determination, geochemical and isotopic studies, dating, paleopalynology, coal fragments and micromorphology are presented in this paper. From these analyses, a paleo-environmental evolution divided in three stages is proposed for the area: 130,000 YBP (Upper Pleistocene), when the Mogi Guacu River base level was approximately 6 m above the present one; a drier second phase 10,250 years BP (Lower Holocene), when an organic horizon was formed inside of an abandoned meander (oxbow lake), and a third phase, 2096 YBP (Upper Holocene), of reactivation of a warm and humid climate that promoted the development of a two meters thick Typic Udifluvent in a sector where the Mogi Guacu River no more floods due to the incision of its thalweg, reaching more than six-meters depth in the last 130,000 years BP. Thus, this paper used a fluvial geomorphologic approach and its interplay with climate to understand how the landscape was shaped from Upper Pleistocene to Holocene, however, Neotectonics might have played a relevant role as well, not only in the Mogi Guacu River Basin, but also in the Parana Sedimentary Basin.

The scientific subjects addressed in the research into badlands since the publication of Bryan and Yair's book (Bryan, R.B. and Yair, A. (Editors), 1982 Badland geomorphology and piping. Geo Books, Norwich, 408 pp.) are briefly analysed. With a steadily increasing number of papers per year, attention to some aspects, such as runoff generation, piping and the role of lithology and soils, varied, whereas the percentage of studies on erosion rates increased steadily over time. Vegetation was not a subject of research in early papers, as most of the papers dealing with vegetation were rather descriptive and published in local or limited-diffusion media, which contrasts with the present situation when about 40% of papers published in international journals about badlands address some aspect of vegetation. However, the growth in the attention paid to vegetation and erosion rates was not linked to any increase in papers dealing with badland reclamation. Badlands are now seen as a group of systems with some common features but diverse dynamics, depending mainly on climatic and lithological drivers. More attention should be paid in the future to investigating the evolution of these landforms over time, mostly through modelling studies, whereas emerging technologies foster detailed analyses that were not possible formerly. Although some badland areas determine on- and off-site environmental issues, others are spots of landscape diversity that merit protection rather than reclamation.

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

Soil and vegetation are interacting factors controlling erosion. Soil degradation processes may affect the normal tree and shrub development and inversely, vegetation can modulate the velocity and intensity of soil development or denudation. A dendrogeomorphological approach can be used to study these interactions, allowing to obtain a date and estimate mean or specific erosion rates. This is especially useful in an unrecorded badlands and gullied environments,where the scarce vegetationmay be the only proxy available to quantify the different geomorphic processes which have occurred. This paper provides a fundamental review of the dendrogeomorphological methodology applied to erosion measurement in badlands. Focusing on the response of the vegetation to the geomorphic processes, this paper: (a) describes themethodology developed to estimate erosion rates with exposed roots; (b) shows newadvances through case studies; and finally, (c) discusses future lines of research to reduce methodological uncertainties and for making dendrogeomorphology more widely applicable.

This paper presents alternating periods of geo-ecological fragility and stability in a highly sensitive environmental setting: the desert-margin area of southern Peru (14.5° S). There, we have to state that fragility was dominantly triggered by climatic changes, which induced several oscillations of the desert margin. During the mid-Holocene, the study area received the Holocene maximum of precipitation, soil formation occurred and the desert retreated, as loess–paleosoil formation documents. In contrast, the Titicaca region further south-east experienced extreme drought at that time. This regional antagonism between humid and dry conditions was a result of meridional shifts in moisture transport across the Andes and occurred also during pre-Columbian times. Considering a coincidence between environmental and cultural changes, we state that success and decline of civilizations were dominated by hydrological oscillations, triggering fertility as well as a critical loss of natural resources. Fragile periods, i.e. periods of geomorphological activity, occurred contemporaneous with cultural transitions. In response to spatial changing resources cultural foci were shifted. So, the success of pre-Columbian civilizations was closely coupled to areas of geo-ecological favorability, which were directly controlled by distinct regional impacts of large-scale circulation mechanisms, including El Nino–Southern Oscillation (ENSO). This spatial view on non-uniform environmental and cultural changes has not been thoroughly considered before. Therefore, for the first time this paper offers geomorphological evidence for diachronous Andean (agri-)cultural development, which was geographically determined .

This paper examines the relations between rainfall, runoff and suspended sediment transport in the Isabena basin during a quasi-average hydrological year. The Isabena is a mesoscale river basin that drains a mountainous area comprising patches of highly erodible materials (badlands). The paper includes an analysis of the different hydrological and sedimentary responses of the catchment to a similar rainfall. Thirty-four floods were studied, with a very variable response observed. Runoff coefficients ranged from 0.32% to 33%. The sedimentary response was also highly variable, with maximum suspended sediment concentrations (SSC) oscillating between < 0.1 and 90 g l− 1 and flood sediment loads varying from 27 to 54,000 t per hydrological event. Most sediment load was concentrated in spring when competent floods occur frequently. Pearson correlation matrix and backward stepwise multiple regression indicate that the hydrological response of the catchment is strongly correlated with total precipitation, event duration, and rainfall of the previous days. Very low correlation was observed with rainfall intensity. The relation between rainfall and sediment transport followed the same trend. Sediment variables (e.g., total load and SSC) were significantly correlated with variables such as total rainfall and rainfall over the previous days, although the significance level was lower in comparison with the runoff related variables. There was again no correlation between sediment variables and rainfall intensity. On-going research in the area suggests that, apart from rainfall, factors such as sediment availability in the badlands and accumulation of sediment in the channels influences the river's sedimentary response. The non-linear hydrosedimentary response is reflected in the wide range of runoff coefficients and sediment loads that have been observed in response to similar amounts of precipitation.

Sedimentological connectivity within drainage systems may be controlled spatially by ‘pockets’ of intact valley fill, alluvial fans impinging laterally on mainstem rivers, floodouts impinging longitudinally on valley floors, and downstream resistant rock bands and their effect on valley width. Where local conditions favor prolonged inundation of the uppermost ~ 0.5 m of the sediment surface, these environments of deposition host wetlands that provide several ecosystem services to society. In this paper, we examine the long-term (millennia), large-scale mediation of connectivity by geological and geomorphological controls, highlighting the relationship between drainage disconnectivity and wetland origin, and appraise ongoing rehabilitation efforts in light of the long-term natural dynamic. The paper uses a wetland system in the KwaZulu-Natal Drakensberg Foothills, eastern South Africa, as a case study, focusing particular attention on part of the system in which cut-and-fill processes are evident, and proceeds, using observations from this and other similar wetland systems in the region, to discuss successive breaks in connectivity with increasing spatial scale and time. Implications for valley morphology are discussed, and channel incision is shown to play an important role in long-term valley and wetland morphodynamics in certain geomorphological settings, creating a diversity of geomorphological features and hydrological regimes. Thus, rehabilitation practitioners should focus on interventions that improve or stabilize desired functional outcomes, rather than on restoring or maintaining what is perceived to be ‘the natural dynamic’ in which erosion is absent.

The international symposium ‘HighLand2006’, held in Mekelle (Ethiopia), from 21 to 25 September 2006, was the second time that Ethiopia could host a major international scientific event on geomorphological processes. HighLand2006 created a forum for those conducting research on the impacts of environmental change on geomorphic processes and land degradation in East African highlands as well as in similar regions around the globe. Discussions of results and exchange of experiences during indoor sessions as well as excursions have resulted in this distinctive set of scientific papers. The two main questions addressed in this special issue, through case studies in tropical mountain areas on all continents are: 1. How have environmental changes impacted the type and intensity of geomorphic processes in tropical mountains since late Pleistocene times? The answer to this question is strongly linked to our knowledge on changes in climate, vegetation cover, human activities, hydrology, hillslope and fluvial processes for such environments. 2. Which factors control the intensity of land degradation, its on-site and off-site impacts in tropical mountains? This question addresses the role of natural and anthropogenic factors in the degradation of the vegetation cover and in controlling the intensity of hydrological processes, soil erosion, landsliding, reservoir sedimentation and flooding. In parallel with this special Catena issue, a number of selected papers on land degradation and its mitigation in tropical highlands are presented in a special issue of Soil & Tillage Research.

This paper reports on the development of a British database of 14C dated Holocene fluvial units over the last 15 years. Since its inception in 1989, the database has undergone substantial expansion, refinement and improvement together with considerable methodological development, so that today it serves as a powerful research tool for investigating the spatial and temporal dynamics of Holocene river development and flooding in Great Britain. The improved analytical method is here applied to the currently existing database by examining datasets of 14C dated fluvial units from river basins that lie within and beyond the limits of Late Devensian glaciation. This analysis indicates how the contrasted conditions in these two types of river environment have, to an extent, led to divergent records of flooding in response to Holocene climate and land-use change. However, even in the contrasting sedimentary records of upland glaciated, and lowland unglaciated river basins, six corresponding episodes of increased flood frequency are identified at c. 5730, c. 3540, c. 2730, c. 2280, c. 660 and c. 570 cal. BP. These represent widespread common responses from British river systems to large-scale changes in climate. The method of database construction and analysis outlined and demonstrated in this paper could be readily adopted in other parts of the world to improve our understanding of Holocene river behaviour at the continental- and global-scale.

Hummocky ground is a conspicuous feature of some cultivated pastures in the mountain forests of the Alps. In the German scientific literature, this pit and mound microrelief is termed “Buckelwiese” (literally: “hummocky meadow”) and is commonly interpreted as a fossil, Late Glacial relief of cryogenic origin. This paper suggests an alternative hypothesis, namely that relief formation was initiated by the uprooting of trees during storms. In the rootstock-pits, karst processes gradually amplified the initial relief. This alternative hypothesis is tested in a Buckelwiesen area of the Northern Limestone Alps, where pit-to-mound vertical relief amounts to 52 cm and mounds are 250–510 cm long and 170–270 cm wide, and the density of pits and mounds is 400 ha −1 . Field investigations included a ground survey using a tacheometer and the excavation of a trench to check the internal structure of one pit-mound couple. The trench was subsequently used to estimate solution rates in the subsurface material of pits and mounds. Based on the results of the field measurements and two radiocarbon dates from the test site, the paper concludes that in the study area a treethrow event occurred between 1120 and 1280 AD. Subsequently, the pits created by the uprooted trees were deepened by limestone solution at a rate of 77.2 mm/1000 years. The reconstructed formation history of the microrelief of the study area is consistent with a Holocene origin, with rates of limestone dissolution as measured in the field and with the morphometry of the features themselves.

A large number of studies have focused on water erosion in the southern Alps because of its intensity and the high erodability affecting numerous outcrops in this region. The aim of this paper is to determine the relations between natural and human factors on the one hand, geomorphologic behaviour of hillslopes and fluvio-torrential dynamics at two time scales (geological and historical) on the other hand. This paper specially focuses on the recent weakening of torrential activity and its linkage with reforestation and rural desertion on the watersheds. Another objective is to compare these results with a rich mainly French scientific production on this theme. Experimental data on: – current erosion measurements and the analysis of its processes on the one hand, – and geomorphologic background of river beds and slopes, are compared and analysed using archives and the present knowledge on historical climate. It has been shown that the overexploitation of watersheds leads to an increase in soil loss, in the number and intensity of floods in alpine valleys, as well as to an enhancement of sediment transport. However, climatic changes during the Holocene and during the past millennium have resulted in changes in morphological behaviour of the hillslopes upstream and of river beds downstream. Moreover, a strong sedimentary deficit can be observed over the last three or four decades in all the Alpine massifs. The consequences of this sediment deficit are firstly an entrenchment of river beds, which threatens bridges and embankments. This recent trend is probably due to the excessive extraction of material in gravel pits and the sedimentation in the numerous dams built between 1920 and 1980 in the entire alpine range. However, the entrenchment appeared recently on non-exploited rivers; therefore, the deficit is also due to the success of the natural and artificial reforestation and torrent correction since the end of 19th century.

The predicted rise in sea level due to global warming has given rise to much speculation as to the impact on erosion and accretion rates at the coast as well as increases in hazards to coastal users. This paper focuses on the spatial adjustments that coastal landforms will exhibit in response to changing energy gradients both normal to and parallel to the shore. These adjustments, in many cases, will take the form of the migration of landforms in order that they maintain their position within the coastal energy gradient. Prediction of the rates of such migration will be fundamental to the future management of the changing coastal environment. The paper discusses the impact of sea-level rise on the two basic coastal landform assemblages: those in estuaries and those on the open coast, and then goes on to examine the effect on ebb-tidal deltas that are located at the critical junction between estuaries and open coasts. In each case, the rates of landform migration under an accelerated sea-level rise are predicted and compared with existing rates using examples from the east coast of Britain. Assuming a sea-level rise of 6 mm/year, the paper predicts that estuaries will migrate landwards at rates of around 10 m/year, open-coast landforms can exhibit long-shore migration rates of 50 m/year, while ebb-tidal deltas may extend laterally along the shore at rates of 300 m/year. The implication for the management of such dynamic coastal systems, including such issues as coastal defence and conservation, are discussed.

In his 1990 paper (Catena, 17: 175–183), Jan de Ploey proposed a system whereby catchments are viewed as functional units in which geomorphic work results from the combined effects of water erosion and mass movements. His measure of erosional susceptibility of catchments, ES, introduced the gravitational potential in addition to the kinetic energy of the eroding agents. This modelling of the erosional susceptibility of catchments in terms of energy was being used to explore time-dependent variations of ES when Jan de Ploey died. Also at this time, he extended an invitation to the present authors to test and extend his model using our data base on the landslide-dominated catchments in the thick loess country of north-central China. This paper presents a series of new equations expressing variations in ES using a data base for over 200 landslides in the loess-covered mountainous terrain (relative relief up to 1500 m) of the Lanzhou region of eastern Gansu Province. These equations express the loss of potential energy of the landslide mass in relation to the relative relief and the pressure energy input in the form of rainfall. These indices of erosional susceptibility can be used to analyse the differences in response, from one catchment to another and through time, between the characteristics of vegetation cover including land use, hydrology, geomechanical behaviour, and mechanisms of movement on slopes. Using certain assumptions on percentage area of catchments affected by mass movement and long-term mean annual precipitation in the Lanzhou region, the Es equation suggests an estimate for non-clayey materials of about 10−4 m−2/s−2, which is a significantly higher susceptibility value than the mean worldwide value for non clayey materials obtained by De Ploey.

Subtropical laterites are partially found in the Argentinian province of Misiones, covering the Jurassic-Cretaceous Serra Geral flood basalts (known as Posadas Formation in Argentina). Two hypotheses have been proposed to explain the origin of these laterites. The autochthonous theory attributes the origin of these deposits to the chemical weathering of the underlying tholeiitic basalts. However, during the last decade, an allochthonous “tropical loess” model was proposed. Several mineralogical/geochemical characteristics of a lateritic profile (~2 m thick, 26°9′58″S–54°35′3″W) are analyzed in this paper in order to constrain the nature of weathering processes in this region and the provenance of the lateritic layer. The basaltic bedrock at the sampling site exhibits intergranular texture and is mainly composed of clinopyroxene, plagioclase and opaque minerals (likely titanomagnetite and ilmenite). Altered glass and apatite were also identified in lower proportions. The X-ray diffraction of the clay-size fraction shows prevailing kaolinite and hematite in the most altered samples, complemented by amorphous Fe-Al (hydr)oxides. Serra Geral basalts-normalized spidergrams and mass balance calculations confirmed almost complete losses of all major oxides (i.e., ~50 g of material was removed by weathering from each 100 g of the original basalt) and depletions of some trace elements (e.g., Sc, V, Sr, Cr, Ni, Rb and U) in the uppermost and intermediate layers of the lateritic profile, reflecting the weathering of feldspars, clinopyroxenes, volcanic glass and apatite. In contrast, some elements are enriched in the topmost and intermediate layers, due to intrinsic immobility during weathering (e.g., Zr, Hf, Ta, Th) or adsorption onto clays (e.g., Cs). Rare earth elements (REEs) are depleted in the top layers and enriched in the middle section of the profile. The preferential leaching of REEs from the uppermost levels during weathering and its accumulation in the middle section can be caused by a pH increase in this level, the decomposition of organic matter and the consequent precipitation of REEs which exhibit an affinity to form aqueous organic complexes, or the presence of Fe and Mn (hydr)oxides in the intermediate level. Weathering intensity was appraised by means of different alteration indices, which showed the extreme leaching endured by the basaltic bedrock. The index of lateritization (IOL), which ranges between 35 and 55, and the accompanying SAF ternary plot (SiO2-Al2O3-Fe2O3), indicate an increasing weathering trend towards the profiles' top, reflecting the modest loss of SiO2 (relative to Al2O3 and Fe2O3) during kaolinitization. The geochemical approach used to constrain the origin of the lateritic mantle that partially covers Misiones province, clearly relates the analyzed laterites to the underlying tholeiitic basalts, supporting the autochthonous origin theory.

In this paper we present new data on weathering and soil formation processes affecting alkaline pillow basalts on the summit of Mt. Cerviero (Calabria, southern Italy). We investigated two representative soil profiles using an integrated approach, including pedological, petrographic, mineralogical and geochemical investigations. We distinguished the main features inherited from the hydrothermal alteration of the pillow basalts in a submarine environment from the chemical weathering processes under meteoric conditions. Irregular geochemical patterns and chemical index of alteration values across the soil profiles indicate a lithological discontinuity between the bedrock and the upper soil horizons, as a response to soil rejuvenation, in turn controlled by erosive processes and an allochthonous pyroclastic input. The soil profiles display poor horizonation and an incipient to intermediate degree of weathering, in line with the clay mineralogy (chlorite or hydroxy-interlayered vermiculite, illite, kaolinite and varying mixed-layers). The degeneration microtextures of clay and iron-manganese coatings in one soil profile suggest their relict genesis, with an emplacement under warm-humid conditions during the last interglacial. A Late Pleistocene to Holocene age of soil development is supported by the trachytic composition of volcanic micropumices, correlated to explosive eruptions from the Campania Province or the Aeolian Islands, in both soil profiles. Geochemical indices obtained from selective extractions of pedogenetic Al, Fe and Si pools point to poor andic properties with humus-Al-complexes prevailing over short-range order minerals. Nonetheless, the latter are consistent with the presence of volcanic glass, an optically isotropic pedogenic matrix and the Andosol-like field features of the soil profiles, even if they developed in a non-volcanic area. This should lead to a partial reassessment of the volcanic versus non-volcanic origin of certain Andosols worldwide and claims a good field work as a basis for choosing the best-suited laboratory methods to fill the gap between ordinary lab and field results.

In this paper a recently theoretically deduced rill flow resistance equation, based on a power-velocity profile, was tested experimentally on plots of varying slopes and soil texture in which mobile bed rills are incised. Measurements of flow velocity, water depth, cross section area, wetted perimeter and bed slope conducted in rill reaches incised on experimental plots, having different slope values (9, 14, 22, 24 and 26%) and soil texture (clay fraction ranging from 42 to 73%), and literature data were used to calibrate the flow resistance equation. In particular, the relationship between the velocity profile parameter Γ, the channel slope, the flow Froude number and texture fractions was firstly calibrated using 147 rill reach data. Then this relationship was tested using 126 measurements carried out with soils having different texture (percentage of clay ranging from 9.6 to 73%) and slopes (6.9%–26%). The measurements allowed to establish that a) the Darcy-Weisbach friction factor can be accurately estimated using the proposed theoretical approach, and b) the data were supportive of the soil texture influence on rill velocity and flow resistance.

This paper demonstrates the applicability and usefulness of colourimetry as a fast and simple tool to assess the quality of limestones for cement and lime industry raw materials, a field where colourimetric measurements have not yet been applied. The results of the colourimetric analysis in a large sample set from the Mokra Quarry in the Moravian Karst (NE from Brno, Czech Republic) and comparisons with the results obtained by other methods are presented here. The studied samples belong to two lithologically different series of strata: the Macocha Formation and the Liseň Formation. Limestones of these formations differ in structure, the contents of their non-carbonate components and, therefore, in colour as well. The samples were prepared in four ways for the purposes of colourimetric measurements: i) unpolished bulk samples (fracture planes were measured), ii) polished sections, iii) powder in a plastic bag, and iv) uncovered powder. Each of these four ways led to different results, which were expressed using the CIE L*a*b* colour space. The L* (specific lightness) value gives an approximate estimate as to the amount of non-carbonate components. The specific lightness value can be used for assigning a sample to a lithostratigraphic member and, in many cases, possibly also to a correlation among members.

The coastline of the Pearl River Estuary (PRE) experienced significant changes due to the increasing demand for land. Previous studies have focused on coastline changes of the mainland in China; thus changes of island coastlines have not been well investigated. In this study, the coastlines of the continent and islands of the Pearl River Estuary from 1978 to 2018 were extracted and analyzed by integrating Canny edge detection and Otsu methods based on Landsat data, and the coastline was classified into six types including biological, sandy, muddy, estuarine, rocky, and artificial via visual interpretation. The coastline length, coastline change rate and change area were calculated and analyzed for the 40 years period. The precision test showed that the coastline extraction methods presented in this paper meet the accuracy standard. The coastline length of the Pearl River Estuary was found to have increased rapidly from 789 km in 1978 to 979 km in 2018. During the past four decades, a large proportion of natural coastline converted into artificial one (66% in 2018), while 577 km2 land increased in this area. The coastline of the western PRE demonstrates more rapid change rates than that of the eastern part, and more land reclamation has occurred in the western area. Between 1988 and 1997, the coastline length and area of reclamation experienced the most extensive changes. Both natural factors, including sediment transport, sea-level rise, wind, tide, as well as anthropogenic factors, such as land reclamation and dam construction, have impacted coastline variation of the Pearl River Estuary in the past four decades. In general, the western part of the study area showed more remarkable coastline change and experienced the enormous influence of land reclamation, dam construction and sediment transport, compared with the eastern part.

The paper presents records of lithofacial succession in the sediments of the Bagno Staw alkaline fen (Western Polesie Lowland, Eastern Poland), documenting the phase of rapid morphogenetic transformations during LG/H in the Lublin chalkland. Environmental conditions responsible for the morphogenesis and evolution of the site (from a shallow periglacial lake to an alkaline fen) were reconstructed. A detailed geological survey in combination with the analysis of Cladocera assemblages revealed the presence of numerous palaeodepressions under the plain covered today by the alkaline fen, which were initially small shallow lakes with a well-developed phytolittoral zone. Geochemical data and the analysis of stable O and C isotopes indicated that these lakes were supplied by ascending waters. Karstic phenomena under periglacial conditions, including subsidence at the bottom of biogenic accumulation basins, played an important role in the transformation of this site. These changes were largely determined by the chronology and dynamics of permafrost degradation.

Landslides are widespread natural phenomena that play an important role in landscape evolution and are responsible for several casualties and damages. Slope instability is linked to the combination of geological, geomorphological, and climatic factors with various triggering mechanisms; among these, seismic shaking can induce relevant changes in the landscape, leading to coseismic and post-seismic phenomena such as landslide events. The Abruzzo Region (Central Italy) is severely affected by Earthquake-Induced Landslides (EILs), linked to the geomorphological dynamics and the severe seismicity of the area. The distribution, mechanisms, and typology of landslides are strictly related to the different physiographic and geological-structural settings. This paper focuses on the realisation of an EILs susceptibility map, following a heuristic approach combined with a statistical analysis, integrated using GIS technology. This approach led to the identification of nine instability factors. These factors were analysed for the construction of thematic maps. Hence, each factor was assigned proper expert-based ranks and weights based on the critical evaluation of literature data as well as on available landslide inventories and combined in a preliminary map wherein high/low numerical values correspond to a high/low propensity of the slope to fail; furthermore, a statistical analysis of these values was performed to derive suitable susceptibility classes. Results presented herein highlight the robustness of the approach; remarkably, the applied methodology is suitable even in areas where a detailed landslide catalogue is lacking, when the same classification and weighting of available parameters is performed. The statistical analyses and the adoption of an absolute scale ranging from minimum to maximum potential values, finally, ensures the comparability of results among different study areas. Finally, this work represents a scientific and multidisciplinary tool for better defining situations that could lead to hazards (such as landslides) following an earthquake to develop sustainable territorial planning, emergency management, and loss-reduction measures.

Studies of the provenance of aeolian dunes are crucial for providing knowledge of landscape evolution and developing management strategies to control aeolian desertification. The lakeshore dune is a typical aeolian landform that is widely distributed around the world. However, there has been little work on the provenance and formation mechanism of lakeshore dunes. By comparing the elemental and grain-size compositions of lakeshore dunes and potential sources around Co Nag Lake, this paper combines sediment fingerprinting analysis and end-member modeling. The results identify the provenance of aeolian sands on the eastern bank of Co Nag Lake and draw the following conclusions. (1) The combined use of fingerprinting analysis and grain-size analysis can yield a comprehensive and reliable provenance assessment. (2) The lakeshore dunes on the eastern bank of the lake are primarily derived from lacustrine deposits and fluvial deposits on the eastern bank. The coupling of fluvial and aeolian systems promotes the development of eastern sandy land. (3) Sand-control projects in the Co Nag Lake region should be carried out according to the sources of aeolian sands. It is necessary to strengthen efforts to control lacustrine deposits and sands in gullies.

In the Cabo Basin, NE Brazil, conglomerates have given rise to soils with attributes that are rarely observed in humid tropical climates and remain relatively unknown within the scientific community. These soils have high levels of Al in the exchangeable phase, diminishing their agricultural and environmental potential in an underdeveloped region of great socioeconomic importance. This paper presents the mineralogy and genesis of soils derived from conglomerates on a slope in the Cabo Basin, with the aim of meeting the demand for studies on Al–rich soils. Three soils were classified, morphologically described and sampled for the accomplishment of chemical, physical and mineralogical analyses, including the main exchangeable cations content, mineralogy of the sand, silt and clay fraction, differentiation of the Fe and Al forms, mineral micromorphology and chemical composition of mineral species. In addition, chemical and physical attributes were used in multivariate analyses. The soil mineralogy is associated with the weathering evolution of three mineralogical zones identified in the Cr horizons. Pathways of alteration followed by feldspars and micas resulted in kaolinite, smectite and hydroxy–Al interlayered smectite formation (argilification). The susceptibility of the conglomerate to weathering, constant releases of Al from the structure of aluminous minerals, low contents of exchangeable bases and consequent low pH values (

Epikarst – the shallow, surficial part of a karstic massif – has a significant influence on the spatio-temporal variability of recharge and the hydrodynamic functioning of many karst aquifers. In the Mediterranean morphoclimatic zone, the average thickness of a well-developed epikarst is around ten metres, but the spatial patterns of its degree of development are very heterogeneous due to the complex interaction of a number of different factors such as lithology, fracturing, weathering, soil and vegetation. In addition, direct field observation is difficult because good outcropping conditions are restricted to particular locations, some areas are not accessible and the size of the study area is often too large for exhaustive field surveys. Satellite-based remote sensing, however, provides a complete coverage of an entire area with spectral resolutions that detect variability in features that can define image textures related to the development of the epikarst. This paper describes a quantitative methodology for epikarst mapping using satellite images and field data. The proposed method comprises an unsupervised classification to define the spectral signature of each of three epikarst development categories in a high-resolution satellite image followed by a supervised classification of the terrain into one of the three categories on a low spatial resolution scale. The training areas in the field are assigned to the three categories by a panel of experts using the Delphi method. Geophysical data are used for validation to overcome any bias that may be introduced by the panel. The proposed methodology has been applied to the Sierra de las Nieves karstic aquifer (Malaga, southern Spain). The outcome is a map of estimated epikarst development that is an approximation to reality and which can be improved as more experimental data become available.

Within Santa Margarita Ecological Reserve (SMER), southern California, an ~ 108 Ma diorite-gabbro pluton has weathered spheroidally resulting in the formation of concentric rindlets, i.e., a rindlet zone, around an unaltered ellipsoidal core of the parent rock. To our knowledge little is known about how spheroidal weathering is produced in Mediterranean climates like that characteristic of portions of the Peninsular Ranges. Hence, we undertook a detailed study aimed at determining the textural and chemical changes associated with the spheroidal weathering of the diorite-gabbro pluton. The parental spheroidally weathered corestone is characterized by a hypidomorphic-granular texture, and consists primarily of plagioclase, amphibole, and biotite, along with minor amounts of pyroxene and quartz. Within the corestone, sericite, and uncommonly, calcite and chlorite, replace plagioclase. The latter mineral also infrequently replaces portions of amphibole and biotite. Such alteration products are derived from sub-solidus deuteric alteration of the pluton. XRD clay mineral analysis of the 13 rindlets indicates the presence of mostly kaolinite and vermiculite, and a far lesser volume of green smectite. Thin section study of rindlet samples suggests that vermiculite is derived from the weathering of biotite, the most extensively altered mineral in the rindlet zone. Such alteration is paralleled by statistically significant losses of K mass across the rindlet zone. In addition, statistically significant losses of Ca and Na mass across the rindlet zone, likely reflect conversion of sericite to kaolinite. In contrast, the absence of statistically significant losses of Mg, Fe, and Mn over most of the rindlet zone, implies that fluids were mostly oxidizing, and that any Mg leached from amphibole was likely fixed within smectite, while leached Fe and Mn precipitated out as oxides or oxyhydroxides. Though calcite was present in the corestone, its absence in the rindlets indicates that fluids were sufficiently acidic to dissolve and remove it. Previous studies have shown that spheroidal weathering occurs when volume expansion produced by a positive ΔV of reaction builds up internal elastic strain energy in the rock. For example, this type of reaction occurs when iron oxidizes within biotite resulting in an expansion of d(001) from 10 A to 10.5 A, or when biotite is transformed into vermiculite leading to an expansion of d(001) from 10 A to 14 A. Data presented here suggest that the conversion of biotite to vermiculite, and the resulting positive ΔV produced the spheroidal fracturing of the corestone at SMER. Hence, these and other data discussed in this paper suggest that the weathering of biotite is the primary driving force in the formation of spheroidally weathered corestone in the Mediterranean climate of the Peninsular Ranges.

The present paper aims to investigate the geological and environmental parameters controlling the redness of sand at the megabarchans located nearby Khnifiss lagoon (SW of Morocco). Mineralogical investigation either by laboratory or remotely sensed data showed the abundance of a mixed composition of Quartz, Carbonates and mafic minerals with a dominance of Hematite Quartz coated grains. Also, grain size analysis revealed the heterogeneity of the megabarchans sand and the dominance of fine and well to very well sorted sand with a mean grains size of (0.2 mm). Mineralogical species were adequately distributed according to their size and density. We noted the dominance of iron bearing minerals including: Magnetite, Hematite, Ilmenite, Ulvospinel, and Pyroxenes, in the very fine fraction ( 63) μm knew a dominance of Hematite coated Quartz, Carbonates and Feldspars. These both fractions are carried by wind with almost the same threshold motion, which meant that the size could compensate the density. That explains their deposition in the same environment. The megabarchans migrated over the past 325 years with a rate of 2 m/year. Thus, grains may undergo many turnover cycles until they can be reactivated by wind. Climatic parameters such as precipitations with 164 mm/year, the frequent stormy events that bring a flash flooding, in addition to the high humidity and important fog and dew provide a source of moisture that make the megabarchans a moistened environment encouraging the iron oxidation. Thus, the abundance of a source of iron and a source of moisture, in addition to the stability of the megabarchans, and their water holding capacity remained the effective factors that led to the megabarchans redness.

In this paper the storage potential of soils within a heterogeneous structured hummocky young moraine region for organic carbon is discussed with respect to climate change and erosion. Erosion is discussed to be either a global terrestrial CO2 sink or a source. In hummocky young moraine regions of North East Germany water and tillage erosion are steadily changing factors since the beginning of arable landuse in ancient times. For such topographically complex landscapes the knowledge on soil organic carbon (SOC) dynamics and the limits of carbon storage are still limited. Our objective is to combine data collected during former soil erosion studies with recent findings on (i) soil property and (ii) estimated “optimal” SOC data to predict the SOC storage related to tillage and crop rotation, among others. Classified catenae were analysed for texture, SOC, CO3-C, nutrient contents, and depth of weathering. Optimal SOC contents were estimated on the fine sized particle content. Arable soil at convex slope positions of steep catenae show 4 time smaller SOC stocks as compared to respective forest soils and to arable soils at concave position. Our findings suggest changes in SOC stocks to be almost exclusively related to decomposable carbon pools. Comparison of estimated optimal with measured SOC contents in soils at such positions indicated that such soils could potentially store a surplus of 0.6 to 0.8 g kg− 1. SOC protection at convex positions is limited by soil texture, and frequent truncation of the respective soil profiles. Whereas truncation followed by downhill transfer may bury SOC at sedimentation/concave positions resulting in long-term SOC storage as far as decomposition is prevented by site conditions.

The unfavourable environmental conditions to Chernozem development in Central Europe has led to questions regarding their origin and age, and conditions necessary for Chernozem persistence in Central Europe under a humid climate. This paper deals with Chernozem transformation during the Holocene period in SW Poland in relation to land morphology. The study was based on a catenary approach, with additional remarks on parent material homogeneity and soil classification. Based on textural and geochemical indices, the homogeneity of aeolian material (loess) was proven in the main part of the catena, which confirmed that the differentiation of “dry” and “wet” chernozemic soil across the catena did not result from the variability of parent material. No differences in morphological or physicochemical characteristics of mollic horizons were identified between the well-drained and wet sections of the catena. The strong redoximorphic features (manifested as stagnic or gleyic properties) in the lowermost part of catena are, therefore, secondary features, i.e. developed after the mollic horizon development, presumably in late Holocene period. Chernozems with chernic horizon, weakly developed subsurface argic horizon and free of redoximorphic features prevail in the central, well-drained and not eroded section of the catena. It has been hypothesized that the loess soils in the uppermost, more inclined part of the catena have been truncated by erosion during the first agricultural period, then afforested and transformed into Luvisols, probably due to temporary abandonment of those sites less favourable for farming. The soils in the transitional zone received the colluvial addition of humus material from the eroded hill summit; however, the colour of the humus layer has a chroma too high for a chernic horizon that surprisingly shifted these soils to the Kastanozems group. This study showed that the direction of transformation of native Chernozems in the Holocene period was strongly related to their position in the landscape, which affected the erosion/accumulation intensity and water drainage conditions (soil moisture regime). As a final result of these transformations, a relief-related zonality of soils has developed with Stagnic/Gleyic Chernozems – Luvic Chernozems – colluvial “Kastanozems” – Haplic Luvisols, in the lower (moist), middle (well-drained), and upper colluvial/eroded sections of the undulating loess plain, respectively.

Badlands in Central Istria share a very frequent characteristic with other worldwide badland sites, the rapid erosion rate. Rock wall retreat measurement on such a relief is associated with all types of problems because a certain effort has to be put into the measurement equipment design. Spear vegetation and a few previous studies encouraged the testing of different photogrammetric technologies and data acquisition methods for the determination of the denudation rate in Istrian badlands. The main aim of this paper is the establishment of the most suitable methodological combination for the determination of the badland denudation rate, which is the gully rock wall retreat rate. The photogrammetric approach was tested by measuring and comparing the amount of denudation on the test site, which was established on a gully sidewall. The photogrammetric measurement was used twice within one year. The analysis of the photogrammetric technologies and data acquisition methods focused on the field and laboratory equipment and the accuracy and difference models obtained from the test site measurements. The analysis shows that the combination of digital photogrammetry and fully automatic matching data acquisition provides the most suitable measurement technique of the rock wall retreat in Central Istria badlands and other similar badlands.

Knowledge of pedodiversity is essential for the protection and management of soil resources. The analysis of regional pedodiversity is typically based on analysis units of different sizes. However, the effect of analysis unit size on regional pedodiversity studies remains unclear. In this paper, the effects of analysis unit size on the studies of spatial distribution characteristics of pedodiversity and its major driving factor in China were studied based on two levels of geomorphological regions. A combined method encompassing the moving window, soil richness, and Shannon index was used to analyze the spatial distribution pattern of pedodiversity in China. A geographical detector was used to determine a major driving factor of pedodiversity in each geomorphological region. The spatial distribution pattern of pedodiversity based on two levels of geomorphological regions both showed that pedodiversity was highest in southern China, followed by northern China, and lowest in the Qinghai-Tibet Plateau, which indicated that analysis unit sizes had little effect on the study on spatial distribution pattern of pedodiversity. The major driving factor analysis of pedodiversity based on first-order geomorphological regions showed that the major driving factor in China, except for the Qinghai-Tibet Plateau, was parent material. However, the results based on second-order geomorphological regions showed that the major driving factors of pedodiversity, except for the Qinghai-Tibet Plateau, were parent material and topography in hilly regions, topography in mountainous regions, and parent material in regions occupied by alluvial landforms, aeolian landforms, or karst landforms. The driving factor analysis of pedodiversity based on the two levels of geomorphological regions suggested that the effect of the analysis unit sizes on the major driving factor study was significant. The results of this study are an important supplement for pedodiversity studies.

Numerous artificial slopes emerged in the watersheds of the Chinese Loess Plateau (LP) after the Gully Land Consolidation project (GLCP) that cut slopes to create farmland in the gully, which had incurred instabilities over time and could potentially resulted in soil erosion and geological hazard. This paper explored the characteristics and prevention mechanisms of artificial slope instability after the GLCP with field investigation in a typical watershed and the Back Propagation Neural Network (BPNN) method. The results showed that: (1) 439 instabilities induced by infiltration and erosion were found in 79 artificial slopes. (2) The difference of soil moisture and failure mode resulted in the instability degree of shady slope and lower slope were significantly higher than that of sunny slope and upper slope. (3) Among the surface condition factors, slope instability volume was significantly influenced by gradient, soil compactness, height and soil shear strength. Platform instability volume had great connection with soil compactness and its shear strength. (4) A “Drain-Improve-Green-Reinforce (DIGR)” system was proposed as the prevention mechanism for artificial slope instability, which included drainage system, soil improvement, vegetation protection, and reinforcement engineering. Taken together, this research provides the scientific reference for a better understanding and prevention of artificial slope instability, which would contribute to ensuring GLCP effectiveness and ecological security in the LP.

Over recent decades, andic soils have been increasingly found in non-volcanic mountain ecosystems (NVME) in many parts of the world. In Italy, this type of soil has proved to be greatly affected by aeolian deposits and to be widely distributed geographically. However, there are still many open questions, especially regarding the genesis of these soils. This paper focuses on five representative pedons taken from NVME. Soil forming processes and relationships between soil and underlying bedrock were investigated by using an integrated approach including geochemical, magnetic, mineralogical, micromorphological and particle size distribution (PSD) analysis. The 5 pedons showed andic character and similar morphology and micromorphology (e.g. silt illuviation, pedorelicts), as well as large differences in terms of soil reaction and clay mineralogy. The analysis of the vertical distribution of C, Al and Fe extracted in pyrophosphate along with related geochemical indices (e.g. C p /Al p ) enabled us to indicate andosolization as the main process of soil formation and to exclude podzolization. With respect to the soil-bedrock relationship, 2 soils showed great similarity to the underlying bedrock along with a clear aeolian particle size distribution footprint, whereas, in the remaining 3 soils, there was a clear soil-bedrock discontinuity and an evident volcanic fingerprint. Some of the soil-bedrock differences related to the geographical settings and latitude.

Geomorphic processes driven by water are particularly active in mountain environments, especially under the current climate conditions. Erosion and dissolution processes shape meaningful landforms, in different kinds of deposits and rocks, and in some cases they are classified as geomorphosites. Such landforms, especially earth pyramids and rock pillars, are usually characterized by a high scientific value (e.g., representativeness, ecologic support role) and by additional values (e.g., cultural and aesthetic value) contributing to the local geoheritage. Mountain geomorphosites are growing in importance within scientific community and their morphological evolution can affect the global value of the site itself (e.g., integrity). In this paper, after a first review on the terminology used for classifying landforms modelled by water runoff and on their meaning within the mountain environment, the results of a detailed research performed at two sample sites, included in the Swiss National Inventory of Geosites, are presented. The two study sites are representative respectively of: i) water runoff on glacial deposits shaping earth pyramids (Pyramides d'Euseigne); ii) water dissolution on gypsum rocks, modelling articulate karst landscapes (Pyramides de gypse du Col de la Croix). For each site, landforms evolution was investigated and denudation rates were estimated by means of different methods: iconographic material analysis, quantitative geomorphology and dendrogeomorphology on exposed roots. Despite the long-term, average rates obtained by means of roots exposure for both water runoff on glacial deposits (e.g., 5.8 mm/y) and dissolution on gypsum rocks (5.6 mm/y) are comparable. Moreover, a strict relation between the activity degree of processes, the integrity of the site and the assignment of geomorphosites to a specific category (i.e., active, passive or evolving passive) emerged from the results.

In this paper, we report the findings from an experimental study on a parabolic cross-sectional sand bed channel with uniform fine sand under no seepage and downward seepage conditions. Through experiments, we observed that an alluvial channel, which remained at threshold condition of sediment movement during the no seepage experiment, started transporting sediments with the application of seepage in the downward direction. Shields stress of the threshold channel increased significantly from its critical value after the application of downward seepage, which led to the deformation of the cross-sectional shape and consequent development of the bedforms. The role of turbulence in the development of bedforms has also been analyzed. Measures of turbulent statistics show that the time-mean velocities and Reynolds stresses were increased significantly with the application of downward seepage. Under the action of seepage conditions, increase in the flux of streamwise turbulent kinetic energy in the streamwise direction was observed in the region close to the channel boundary. Also, quadrant analysis exhibited an increase in the contributions from all the bursting events and the thickness of the sweep-dominated zone in near-bed region after the application of downward seepage. A bedform tracking tool has been used to evaluate the variability in the geometry of bedforms. We have classified these developing bedforms as current ripples and linguoid ripples according to their evolution with time under the downward seepage condition. It has been further observed that the variation in Shields stress and corresponding bedform geometry reached an equilibrium state in the presence of downward seepage when the experiments were run over a longer period of time (24–31 h).

This paper reports from a survey of the occurrence of large avalanches in Żleb Żandarmerii. This couloir is known to be one of the most hazardous avalanche paths in the Tatra Mountains and has one of the longest histories of avalanche observation. This survey looked at the runout distance, return period, dynamics and geoecological implications of avalanches in the context of current climate change. The study took advantage of the longest record of meteorological data available in the Tatra Mountains, as well as archival avalanche observations, topographical maps, orthophotomaps and a high-resolution digital terrain model. Avalanche data were obtained using geomorphological and dendrogeomorphic methods and through modelling with the RAMMS numerical avalanche dynamics simulation software. The largest avalanches reach the foot of its counter slope. Their length, release volume, flow velocity and pressure can exceed respectively 1000 m, 80 000 m3, 45 m/s and 600 kPa. The results of our study suggest that current climate warming has been accompanied by thinning and shortening of the duration of snow cover, as well as by an upward expansion of the timberline (including in the large-avalanche runout zones) of up to 80 m since the mid-1920s. No distinct temporal trend was identified in the large avalanche return period since 1909, but their mass and intensity have declined. Forests and timberline expansion were found to have no influence on the extent of the avalanches in our study, while ground relief could determine both their downward extent and lateral expansion. Fil: Gadek, Bogdan. University of Silesi; Polonia Fil: Kaczka, Ryszard J.. University of Silesi; Polonia Fil: Raczkowska, Zofia. Polish Academy of Sciences. Institute of Geography and Spatial Organization; Polonia Fil: Rojan, Elzbieta. Uniwersytet Warszawski; Argentina Fil: Casteller, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Institute for Snow and Avalanche Research; Suiza Fil: Bebi, Peter. Institute for Snow and Avalanche Research; Suiza

This paper addresses the timing of accelerated soil erosion and landscape degradation in central Mexico. It shows data on erosion sequences in the Valley of Teotihuacan, an area where agricultural dates back to at least since 1100 BCE, and an ideal setting to test ideas on the effect of preconquest versus post-conquest anthropogenic impacts on the environment. The methods include stratigraphy, detailed description of soil profiles and soil micromorphology, along with analysis of pottery sherds and radiocarbon dating. A chronology of events for two catenas, focusing on periods of landscape stability and change, establish the sequence of erosion events from pre-Hispanic to modern times. Six erosion phases are recognized over the last 2000 years in Teotihuacan. Although results suggest that the most intense erosion occurred after Spanish conquest, in the 16th century, several erosion phases took place during pre-Hispanic times and also in the postcolonial period, including the 20th century. Probable causes for these impacts are related to settlement dynamics, population variability, and land use changes. Thus, it provides new information for the discussion on the timing and causes of erosion, sedimentation and landscape modification in the central Mexican Highlands during the late Holocene.