Debris Cones Research Articles

Theoretical concepts about alluvial fans and debris cones: case studies of an Alluvial Fan in São Desidério (Bahia, Brazil) and a Debris Cone at Mount Somma, near the Vesuvius Volcano (Naples, Italy)

Analyzing the last 24 years of the Brazilian Journal of Geomorphology and the National Symposiums of Geomorphology (SINAGEO), it is evident that there is a lack of studies on alluvial fans in Brazil and in Portuguese literature. The situation is even more unclear concerning debris cones. This paper aims to provide a concise and comprehensive bibliographic review of alluvial fans and debris cones in Portuguese and to the Brazilian geomorphological science. These features are crucial for understanding and studying the relationship between form and process, paleoenvironmental reconstruction, sensitivity to climate variations, risks associated with mass movements on slopes, and more effective territorial planning by human actions. Additionally, the paper seeks to clarify the main theoretical and conceptual distinctions between alluvial fans and debris cones, proposing a new classification based on two particularly illustrative case studies. Do alluvial fans and debris cones represent the same or different depositional forms in the landscape? To this end, the methodology includes a detailed theoretical and conceptual review of the topic, a survey of relevant data about the subject in the main means of the Brazilian geomorphological community dissemination, a proposal of a new classification to differentiate these forms, and the mapping, characterization, comparison and analysis of two specific study areas: an Alluvial Fan identified in São Desidério (Bahia, Brazil) and a Debris Cone identified in Mount Somma, the ancient crater of the current Vesuvius Volcano (Naples, Italy).

Campanula bergomensis (Campanulaceae), a new species from Bergamo Prealps (Northern Italy)

A new species of Campanula (Campanulaceae), C. bergomensis sp. nov., is described from the Bergamo Prealps (Orobic Prealps, Lombardy, Northern Italy), based on both morphological and molecular evidence. The new species was considered in the past as an isolated population of C. cespitosa, which presents an eastern Alpine distribution. C. bergomensis is morphologically well distinguishable from C. cespitosa on the number of flowers in the racemose inflorescence, the corolla shape, and the whitish-yellow pollen surface with many spinulae. Genetically, the presence of an insertion of 81-bp in the trnL-F sequences is very characteristic. Further studies are needed to better define the phylogenetic relationship among the three closely related species, C. bergomensis, C. cespitosa and C. cochleariifolia. C. bergomensis inhabits dolomitic debris cones at low elevations. The species is range-restricted and is severely threatened by human activities. Therefore, it is urgent to adopt protection and conservation measures for the new species.

Brief communication: An ice-debris avalanche in the Nupchu Valley, Kanchenjunga Conservation Area, eastern Nepal

Abstract. Beginning in December 2020, a series of small to medium, torrent-like pulses commenced upon a historic debris cone located within the Nupchu Valley, Kanchenjunga Conservation Area (KCA), Nepal. Sometime between 16 and 21 August 2022 a comparatively large ice-debris avalanche event occurred, covering an area of 0.6 km2 with a total estimated volume of order 106 m3. The area of the debris cone left by the August 2022 event increased the historic debris cone area by 0.2 km2 (total area 0.6 km2). Although no human or livestock deaths occurred, the increase in torrent-like pulses of debris upon this historic debris cone since 2020 exemplifies a style of mass movement that may become increasingly common as air temperatures rise in the region. Although the magnitude of this event was small compared to events like the 2021 Chamoli avalanche, the widespread distribution and frequency of comparable events present a substantial, and potentially increasing, hazard across High Mountain Asia.

Can topographic features of debris cones (SW Spitsbergen) be geoindicators of environmental changes?

Can topographic features of debris cones (SW Spitsbergen) be geoindicators of environmental changes?

Deposition areas: An effective solution for the reduction of the sediment volume transported by stony debris flows on the high‐sloping reach of channels incising fans and debris cones

SummaryThe main approach to managing the volume of sediment transported by stony debris flows routing along channels is through retention basins and open check dams, usually built in the lower reach just upstream of inhabited areas where slopes are gentler. In some cases, these measures are not sufficient to retain all the volume of sediment transported by debris flows. Works for trapping the sediments should also be placed in the upper reach of debris‐flow channels. In this area, where the channel bed is characterized by very high slopes and vertical variability over time, constructing and maintaining transversal embankments for sediment retention is difficult. In addition, they could also be susceptible to failure, potentially increasing the magnitude of the phenomenon instead of mitigating it. On the other hand, other types of works, such as solid‐body check dams or net barriers, have a decreasing efficiency over time in reducing the volume of sediment transported by debris flows. An alternative solution could be a retention basin open on the downstream side, that is, without the ending transversal embankment or berm. Therefore, it can be designated as a deposition area because the retention effect of the downstream embankment is missing, and sediment deposition only occurs due to the flatness of the basin. For sizing purposes, here, we derive two relationships between the deposition area and the volume of the deposit. These two relationships are derived from a physically based geometrical approach and empirical approach, respectively. After analyzing the morphology of the depositional processes that occurred in an existing deposition area during debris‐flow events, we test the validity of the two relationships. Overall, these can be used independently or in combination for designing a deposition area. At last, we introduce the necessary geomorphological conditions for the construction of the deposition area and guidance for its placement.

Avalanche Hazards Around Kedarnath Temple, Mandakini River Valley, Uttarakhand – A Case Study

Abstract The Shri Kedarnath town is located in the western extremity of the Central Himalaya (30°44'6.7" N; 79°04'1"E) in the Mandakini River valley. This has a total catchment area of ~67 km2 (up to Rambara), out of which 23% area is covered by glaciers. In September 2022, avalanches were observed repeatedly in the mountains to the north of Kedarnath town. Based on aerial survey and ground observations of the area around Kedarnath, we found that the avalanches initiated ~6 km (Aerial distance) uphill of the Kedarnath Temple from the peaks of the Mahalaya Parvat (5970 m asl) of the Companion Glacier adjacent to the Chorabari Glacier. The Companion Glacier does not have a well-defined accumulation zone but receives accumulation mostly from the avalanches. The run-out and deposition zones of the avalanches are located ~5 km uphill of the Kedarnath Temple. The avalanche activity thus poses no threat to the Kedarnath Temple and township. In addition, fifteen avalanche sites (A1-A15) have been identified based on slope morphology, grass clearing, the presence of snow drifts, and debris cones in the area. We observed that the Temple of Shri Kedarnath Complex is located at a reasonably safe place as far as avalanche hazards are concerned.

Glacio-Geomorphological Investigation and Deglaciation pattern of Nehnar valley, North Western Himalayas

Glacial landforms are pieces of evidence to comprehend the glaciological past and paleoclimatic conditions in the region. In paleo-glacial reconstructions, a critical geomorphological context is provided for determining glacial chronologies. The study provides a detailed geomorphological mapping and investigation of the Nehnar valley, NW Himalayas, Jammu and Kashmir, India. To map the glaciogeomorphological features, the study uses LISS-IV (5.8 m resolution) and Google Earth Pro (1 m resolution) images as well as morphological sketches and GPS data collected during field visits. The Advanced Spaceborne Thermal Emission and Reflection Radiometer Digital Elevation Model (ASTER-DEM, 30m resolution) has also been used to enhance the morphological and elevation characterization of glacial features. A host of glacial features like lateral and terminal moraines, serrate, debris cones, moulins and outwash plains are among several others mapped in the study region. Using dating techniques, the spatial data on glacial landform features in the area can be used to guide the reconstruction of paleo-glaciological setups. This fills in some of the gaps in our knowledge about glaciation in the Kashmir Himalaya during the Pleistocene.

Large-Scale Debris Cover Glacier Mapping Using Multisource Object-Based Image Analysis Approach

Large-scale debris cover glacier mapping can be efficiently conducted from high spatial resolution (HSR) remote sensing imagery using object-based image analysis (OBIA), which works on a group of pixels. This paper presents the spectral and spatial capabilities of OBIA to classify multiple glacier cover classes using a multisource approach by integrating multispectral, thermal, and slope information into one workflow. The novel contributions of this study are effective mapping of small yet important geomorphological features, classification of shadow regions without manual corrections, discrimination of snow/ice, ice-mixed debris, and supraglacial debris without using shortwave infrared bands, and an adaptation of an area-weighted error matrix specifically built for assessing OBIA’s accuracy. The large-scale glacier cover map is produced with a high overall accuracy of ≈94% (area-weighted error matrix). The proposed OBIA approach also proved to be effective in mapping minor geomorphological features such as small glacial lakes, exposed ice faces, debris cones, rills, and crevasses with individual class accuracies in the range of 96.9–100%. We confirm the portability of our proposed approach by comparing the results with reference glacier inventories and applying it to different sensor data and study areas.

Sedimentation pattern of kame terraces and its implication to climatic events in the Gangotri glacier region since 25 Ka BP, Garhwal Himalaya, India

• The sedimentation in the Kame terraces has taken place under low energy stagnant water conditions in a lacustrine environment . • The Kame terraces were evolved under glacial-fluvial at the base and lacustrine environment at the top. • The study demonstrates climate change since 25 Ka BP. • The study confirms the major climatic signatures such as Last Glacial Maximum , Older Dryas , Bølling-Allerød, Younger Dryas , Indus Valley Civilization Collapse, Medieval Warm Period and Little Ice Age. Gangotri glacier, located in the Uttarkashi district, is one of the longest valley glaciers of the Garhwal Himalaya. It exhibits lateral moraines, recessional moraines, outwash plains, kame terraces, and debris cones. Kame terraces are significant landforms that preserve the climatic records and geological history in their deposits. The sedimentary and mineral magnetic analysis on 165 cm thick trenched sections sampled at 2.5 cm interval of the kame terraces together with the AMS (Accelerator Mass Spectrometer) age indicate its response to the major climatic events in this region and sedimentation history of the kame terraces. The granulometric analysis describes that the mean grain size of these sediments varies from coarse to fine sand, which are poorly sorted with an excess of finer sediments. This indicates, low to moderate energy over a longer duration with fluctuation of the depositional environment. The mineral magnetic analysis reflects unimodal detrital modes governed by the energy conditions from meltwaters that are in turn controlled by the climatic conditions from warmer to colder episodes. Therefore, the sedimentation in the kame terraces has taken place under the low energy lacustrine environment during warmer climates. The kame terraces sedimentation therefore has recorded the major climatic events, such as Last Glacial Maximum (LGM) 21–19.5 Ka BP, Older Dryas (OD) 16.5–14.5 Ka BP, Bølling-Allerød (BA) 14.5–13.5 Ka BP, Younger Dryas (YD) 13.5–12 Ka BP, Indus Valley Civilization Collapse (IVCC) 5.0–3.0 Ka BP, Medieval Warm Period (MWP) 1.25–0.7 Ka BP and Little Ice Age (LIA) 0.7–0.2 Ka BP.

Space Target Classification Improvement by Generating Micro-Doppler Signatures Considering Incident Angle.

Classifying space targets from debris is critical for radar resource management as well as rapid response during the mid-course phase of space target flight. Due to advances in deep learning techniques, various approaches have been studied to classify space targets by using micro-Doppler signatures. Previous studies have only used micro-Doppler signatures such as spectrogram and cadence velocity diagram (CVD), but in this paper, we propose a method to generate micro-Doppler signatures taking into account the relative incident angle that a radar can obtain during the target tracking process. The AlexNet and ResNet-18 networks, which are representative convolutional neural network architectures, are transfer-learned using two types of datasets constructed using the proposed and conventional signatures to classify six classes of space targets and a debris–cone, rounded cone, cone with empennages, cylinder, curved plate, and square plate. Among the proposed signatures, the spectrogram had lower classification accuracy than the conventional spectrogram, but the classification accuracy increased from 88.97% to 92.11% for CVD. Furthermore, when recalculated not with six classes but simply with only two classes of precessing space targets and tumbling debris, the proposed spectrogram and CVD show the classification accuracy of over 99.82% for both AlexNet and ResNet-18. Specially, for two classes, CVD provided results with higher accuracy than the spectrogram.

PRZ index for identifying potential areas of recharge in alluvial aquifers and for land use planning

An index to identify potential recharge zones (PRZs) in alluvial aquifers was developed to protect these zones during land use planning. The PRZ index was designed as an additive index through the selection of five characterization indicators. The variables were then operationalized and categorized to generate a conceptual model of the physical-geological system. The PRZ index places recharge zones into four classes according to their potential. This index was applied to the Bolo River hydrogeological area (Valle del Cauca, Colombia), and the following proportions were identified for each PRZ category with a total area greater than 426 km2: very high: 23%, high: 30%; moderate: 40% and low: 7%. The areas with a very high recharge potential were found in the upper portion of the debris cones; their potential was predominantly due to the presence of sand and gravel unconfined aquifers and to aquifer outcrop layers at depths of less than 2.5 m. These PRZs were validated with piezometry, and the hydraulic gradient for 71% of the area was greater than 1%. These areas should be declared protected areas.

Radiocarbon dating of a composite multi-period debris cone stratigraphy in the Lochan na Lairige, Ben Lawers

An early stage in formation of a composite debris cone in the glacial trough of the Lochan na Lairige, on Ben Lawers, is 14 C dated to 6398–6225 cal years BP. A large proportion of the debris cone comprises a structureless gravel with boulders, possibly deposited in a single event. Blanket peat formed on the debris cone surface at 3820–3496 cal years BP. Sediment slurries are recorded across the peat after this time, at c . 3950– c . 3100, c . 2000 and c . 1400 cal years BP, and at c . 1200– c . 1100 cal years BP. They were much less significant events. They can be related to periods of higher effective precipitation in the region.

Quantification of Gravitational Mass Wasting and Controls on Submarine Scarp Morphology Along the Roseau Fault, Lesser Antilles

AbstractDue to challenges involved in mapping the seafloor at high‐resolution (e.g., <2 m), data are lacking to understand processes that control the evolution of submarine normal fault scarps, which cover large parts of the global seafloor. Here, we use data from autonomous deep‐sea vehicles to quantify local erosion and deposition associated with a pronounced tectonic surface scarp formed by slip on the submarine Roseau normal fault (Lesser Antilles). We use high‐resolution video imagery, photomosaics, and high‐resolution bathymetric data (0.1–10 m/pixel) to identify active erosional features on the scarp including channels, steep gullies, small scarps, and debris cones. We compare volumes of erosion and deposition and find that under certain depositional conditions, debris cones effectively record the erosion signal of mass wasting from the footwall with a ratio of hanging wall deposition to footwall erosion of 0.80. We use eroded volumes to estimate earthquake‐induced landslide erosion rates for the Roseau fault of 14–46 m Myr−1. Assuming mass wasting of the Roseau fault scarp is mostly coseismic, the erosion rates for the Roseau fault imply that submarine earthquake induced mass‐wasting can occur at similar rates to various terrestrial lithological and tectonic settings. We present a process‐based model of submarine scarp degradation via retrogressive erosion in basement lithology where scarps have a gravitational stability threshold height of 20–40 m and a long‐term average slope of 30°–40°. More generally, the results presented here may be applicable to develop models of submarine landscape evolution based on degradation of normal fault scarps on the seafloor.

Assessing the effect of lithological setting, block characteristics and slope topography on the runout length of rockfalls in the Alps and on the island of La Réunion

Abstract. In four study areas within different lithological settings and rockfall activity, lidar data were applied for a morphometric analysis of block sizes, block shapes and talus cone characteristics. This information was used to investigate the dependencies between block size, block shape and lithology on the one hand and runout distances on the other hand. In our study, we were able to show that lithology seems to have an influence on block size and shape and that gravitational sorting did not occur on all of the studied debris cones but that other parameters apparently control the runout length of boulders. Such a parameter seems to be the block shape, as it plays the role of a moderating parameter in two of the four study sites, while we could not confirm this for our other study sites. We also investigated the influence of terrain parameters such as slope inclination, profile curvature and roughness. The derived roughness values show a clear difference between the four study sites and seem to be a good proxy for block size distribution on the talus cones and thus could be used in further studies to analyse a larger sample of block size distribution on talus cones with different lithologies.

Geomorphological impact, hydraulics and watershed- lake connectivity during extreme floods in mountain areas: The 1959 Vega de Tera dam failure, NW Spain

Dam-failure floods typically involve greater peak discharge than the largest meteorological flood at a basin. Determining the geomorphic effectiveness of extreme flooding caused by a breach mechanism provides insight into the role of flood scale on the resulting processes and landforms. Here, we present a geomorphological and hydraulic analysis of the 1959 Vega de Tera (NW Spain) dam-break flood, a worldwide notable dam-failure incident that released a flow of 7.8 106 m3 that caused the death of 144 people at Ribadelago before reaching Lake Sanabria (9 km down valley). This watershed-lake connection provides a comprehensive analysis of an extreme sediment delivery event in the context of a millennial long lake depositional record. One-dimensional unsteady flow computation shows a peak flow hydrograph attenuating from 13,000 m3 s−1 to 5150 m3 s−1, that reached a maximum flow depth of 34 m and velocity of 30 ms−1. Spatial variation of erosional and depositional landforms are related with local flow hydraulics: i) in steep sectors flow regime was supercritical (shear value up to 11,200 Pa) and produced up to 30 m deep bedrock channel erosion; ii) at the boundary of steep and flatten sectors, transition to subcritical regime generated large plunge pools (up to 6000 m2 and 15.2 m in depth); iii) in low-gradient sectors low shear stress gave rise to depositional landforms, namely gravel bars with dam boulders up to 3 m long, and a debris cone with coarse gravel and expansion sand bars. The depositional landforms amount for a total volume of ca 2.11 · 106 m3 in the Tera valley (37% in the gorge and 63% in the floodplain). The dense, energetic sediment-laden flow reached Lake Sanabria forming a debris cone close to the mouth and caused an underwater hyperpycnal current, depositing a ~10 cm-thick sandy-silt layer all over the two distal subbasins. The estimated volume of the deposited fine sediments in the lake ranges between 200,000 and 368,000 m3. The lake record shows that this was the largest flood in the basin during the Holocene. Previous to the dam break, the sediment connectivity between the Sanabria watershed and the lake was limited because of the “staircase” topography and the presence of small glacial depressions filled with sediments since deglaciation. Even during the flood, the great majority of the sediments were deposited along the flood pathway, and only a small percentage (10–20%) reached the lake. Although the hydraulics of the Tera River were not changed after the flood, the newly formed pools in the watershed could diminish the connectivity between the river and the lake in the future, as some new sedimentation areas (pools) were generated acting as natural dams and thus decreasing sediment input to the lake.

Results of works carried out via electrical exploration method for searching groundwater sources suitable for drinking and household use in the debris cone of Turyanchay river

The paper deals with the exploration works conducted via electrical exploration method for searching groundwater sources suitable for drinking and household use in the debris cone area of Turyanchay river. As a results of carried out studies, the areas with groundwater sources suitable for drinking and household use are marked, lithological content and depth of water horizons specified as well. With the aim of estimation of fresh groundwater reserves in the debris cone area of Turyanchay river suitable for drinking, ρf and geological-geophysical sections have been developed due to the geophysical surveys executed via vertical electrical sounding (VES) methods. To specify the lithology of the rocks and reveal formations with reservoir properties, logging operations have been carried out. The thickness of clay formations comprising the sections increases from the north-west to the south-east; alongside with this due to the alternations of gravel sediments with clay rocks the specific electrical resistence of the rocks decreases. As a result of exploration of water sources suitable for drinking in the debris cone of Turyanchay river, the water content of the rocks in mentioned area has been studied to the depth of 285 m, the prospective zones of fresh and less mineralized groundwater marked, initial reserves estimated and prospective zones for accurate surveys specified as well.

Deep to shallow-marine sedimentology and impact of volcanism within the Middle Triassic Palaeo-Tethyan Semantan Basin, Singapore

The Middle Triassic Pulau Ayer Chawan Formation is a predominantly deep-marine, occasionally shallow-marine sedimentary succession, deposited in the Singapore sector of the Palaeo-Tethyan Semantan Basin. The formation provides an important record of the dynamic interplay between a siliciclastic sedimentary system and the products of an adjacent active volcanic arc. It is characterised by six sub-environments, including: deep-marine turbidite fan, deep-marine background sedimentation, subaqueous debris cone, shallow-marine, volcanically-sourced turbidite fan, and hyaloclastite mound or ridge. Turbidite fan deposits preserve the input of both siliciclastic and volcaniclastic sediments from the shelf, transported into the deep-marine environment by a suite of subaqueous sediment gravity flow processes, including: turbidity currents; mixed flow types (hybrid event beds); concentrated and hyper concentrated sediment gravity flows, and debris flows. Thick heterolithic successions of debrites were likely sourced through regular collapse of an unstable shelf. The presence of hybrid event beds, encountered within the deep-marine turbidite fans, supports a slope that was out-of-grade, and may have been actively retreating towards the hinterland. Together, these factors suggest regional-scale uplift of the eastern margins of the Semantan Basin during Triassic times, most likely facilitated through volcanic activity in the adjacent Palaeo-Tethys Sukhothai Arc. Evidence for contemporaneous, arc-related magmatism includes ubiquitous volcaniclastic sedimentary rocks within formation, including pyroclastic density current deposits and perhaps more-strikingly through the hyaloclastites of the Nanyang Member. The hyaloclastites formed through quenching of magmas delivered into the deep-marine setting from a series of sub-sea vents or mounds.

Glacial conditioning and paraglacial sediment reworking in Glen Croe (the Rest and be Thankful), western Scotland

Glen Croe, located near the western edge of the Loch Lomond and Trossachs National Park, is a well-known landslide hazard site in Scotland. Debris flows have repeatedly closed the A83 Rest and be Thankful road that passes through the valley, and considerable investment has been directed towards hazard risk reduction. However, little research has focused on the former glaciation and paraglacial response that have played an important role in governing current landscape processes at the site. This paper addresses the knowledge gap by investigating the glacial processes that have shaped and conditioned Glen Croe, and pathways that have characterised subsequent paraglacial sediment transfer. The large-scale valley form results from watershed breaching and interaction between glacier erosion and paraglacial rock slope failures. The distribution of thick glacigenic sediment is conditioned by deposition at former lateral ice margins, which was influenced by topography. Sediment reworking has resulted in accumulation of debris cones and alluvial fans in the upper part of the catchment, and growth of a delta at the outlet. Spatial connectivity mapping supports an interpretation whereby upper Glen Croe is poorly connected to the valley outlet, influencing sediment storage. In contrast, slopes in the lower part of Glen Croe are well connected. Sediment distribution in Glen Croe fits within the context of glaciated valley and paraglacial landsystems, allowing an understanding of sources and transport pathways. In upland infrastructure corridors this type of information is potentially helpful for understanding how landscapes might be affected by renewed sediment reworking under altered threshold conditions.

Spatial distribution and livelihood effects of debris cones at the western Afar Rift Valley margin, northern Ethiopia

ABSTRACT The objective of the study on which the article is based was to investigate the distribution, characteristics and livelihood effects of debris cones in the Aba’ala and Raya grabens in Ethiopia. The characteristics of the debris cones and their upper catchment areas were obtained from Google Earth Pro and Landsat images. Questionnaires were used to understand the livelihood effects of the debris cones. In addition, transect studies, interviews and observations were used to supplement the data. The data were analysed using descriptive statistics, a regression model and coupled criteria. The results showed that the debris cones differed in their physical characteristics and distribution, and their volumes were larger in the Raya graben than in the Aba’ala graben. The average flow lengths of the upper catchments was the major predictor of debris cone volume. The expansion of debris cones devastated farmlands, resulting in crop yield loss. Moreover, deposited debris damaged dwellings and pasture, and led to smallholder farmers’ displacement. However, the cones remained attractive for settlement and spate irrigation. The authors conclude that despite the benefits of debris cones, catchment rehabilitation measures should be implemented in the upper catchments to reduce the expansion of debris cones in the studied grabens.

THE MODERN MORPHODYNAMICS IN THE QUARRIES OF LVIV AND ITS SUBURBS

The seven big quarries have been explored in and around Lviv. All quarries are sandy and most of them are inactive now. There are 3 quarries located directly in the city: two – within the Znesinnia Regional Landscape Park (western and eastern) and Kryvchytskyi. The four quarries are located in the southeastern outskirt of Lviv within the Davydivskyi Chain near the villages of Davydiv (3 quarries) and Vynnychky. The processes of water erosion (sheet, rill and gully erosion), suffosion, falls, scree formation processes, slides, physical and chemical weathering are widespread in the explored quarries. The specific azonal processes such as aeolian processes (deflation and accumulation of sandy material) and formation of takyrs are also common. The most common are water erosion processes (sheet, rill and gully erosion). They are present in almost all quarries (except of Western Znesinskyi and Kryvchytskyi Quarries). These processes occur in the lower parts of quarry benches and on the slopes of dumps. They are represented by small and medium-sized erosive pre-rills and rills (width 5–30 cm, depth up to 45 cm), small gullies (depth up to 2.2 m), debris cones, deluvial cones. The sheet, rill and gully erosions mainly occur together. The suffosion processes develop in the sandy-loam deposits with low density (the Davydivskyi Quarry № 2, the Vynnychkivskyi Quarry). The result of these processes is the formation of suffosion sinkholes (35–60 cm in diameter) and suffosion “wells”. The processes of rockfalls are locally widespread on steep denudation benches of quarries, where beds of limestone or sandstone are cropped out (the Davydivskyi Quarry № 1, № 3). The scree formation processes are also common in gravitational processes and mainly occur in sandy deposits and are represented by scree cones. Slides occur rarely having small main bodies and are located on the quarry walls and dump slopes. A special type of processes in the studied quarries is the formation of takyrs, which occurs in closed watered areas of the pit floors. After the takyrs dry up, the so-called "desert papyrus" is created. Key words: modern morphodynamics, quarry, water erosion processes, falls, scree formation processes, Lviv.