Base Of Cliff Research Articles

Cross‐shore decay of cliff top ground motions driven by local ocean swell and infragravity waves

Ground motions at the frequencies (between 0.01 and 0.1 Hz) of ocean infragravity and swell waves were observed on a cross‐shore transect extending landward from the edge of a southern California coastal cliff. Cliff top ground motions are coherent and in phase with water level fluctuations at the cliff base. Vertical ground motions at infragravity and single frequencies decay rapidly with inland distance from the cliff edge (e‐folding scale is about 12 m), and at the edge decrease by several orders of magnitude between high tide when waves reach the cliff base, and low tide when the waterline is about 50 m from the cliff base. The observed cross‐shore decay scales are qualitatively consistent with gravitational loading and attraction of water waves at tidally modulated distances from the cliff base. At approximately constant distance from the waterline, ground motions vary roughly linearly with nearshore swell wave energy. In contrast to these locally forced ground motions, double frequency band (0.1–0.2 Hz) cliff top vertical ground motions are remotely generated with spatially uniform magnitudes approximately equal to those observed 14 km inland. Near the cliff edge, ground tilt dominates the observed large (relative to vertical) cross‐shore acceleration at infragravity frequencies, contributes significantly to cross‐shore acceleration at swell frequencies, and is a small fraction of cross‐shore acceleration at higher frequencies.

Deriving mechanisms and thresholds for cliff retreat in soft-rock cliffs under changing climates: Rapidly retreating cliffs of the Suffolk coast, UK

Understanding changing thresholds and mechanisms for retreat in soft rock cliffs is important under changing climates. This can be achieved through combining detailed field observation, long-term process and morphological monitoring and numerical modelling. The cliffs of the Suffolk coast, southern North Sea have exhibited long-term (1883–2010) recession rates of 3.5ma−1, rising to 4.7ma−1 in the period 1993–2010. Annual to biannual ground survey data, and the application of GIS techniques to digitised records of changing shoreline position from historic maps and aerial photography, reveal considerable decadal-scale variations in cliff recession, within which are nested inter-annual fluctuations in rates of retreat. Archival datasets on significant periods of onshore winds and their interaction with high water levels (including the incidence of storm surges) and rainstorm events are used to determine thresholds for cliff base erosion and its propagation upwards through the cliff profile. In addition, the ‘GEO-Slope’ dynamic coupled hydrology-stability model is used to establish thresholds for cliff face failures driven by variations in rainfall inputs. Retreat mechanisms are complex, governed by cliff geology, both as a primary control on suction loss and through its interaction with basal marine conditions. The study allows a general model of cliff retreat for soft rock cliffs to be put forward, whereby a resistant basal platform is overlain by more erodible, weakly and moderately cemented sands and gravels. In this model, the varying balance between marine and terrestrial forcing factors are reflected in low (<4ma−1), intermediate (4–7ma−1) and high (>7ma−1) modes of cliff retreat.

Using Cosmogenic 10Be Dating to Unravel the Antiquity of a Rocky Shore Platform on the West Coast of Korea

Abstract CHOI, K.H.; SEONG, Y.B.; JUNG, P.M., and LEE, S.Y., 2012. Using cosmogenic 10Be dating to unravel the antiquity of a rocky shore platform on the west coast of Korea. Shore platforms commonly occur at the base of coastal cliffs on rocky shores. It is generally accepted that they form by the retreat of such cliffs through wave action and weathering processes. Although a handful of previous studies have sought to directly constrain the rate of shore platform development over annual–decadal scales, there remains little consensus on the rate of their long-term (>millennial) evolution, as a result of the complex nature of shielding processes that operate in parallel with variable sea levels. Some platforms show contemporary features; however, the possibility that some features were inherited from the last interglacial or earlier stages always exists. The occurrence of wide shore platforms in resistant rocks is often regarded as evidence of such inheritance because the short stillstands of the Holocene ...

Coastal cliff ground motions from local ocean swell and infragravity waves in southern California

[1] Ground motions atop a southern California, USA coastal cliff are compared with water level fluctuations observed at the cliff base, and with ground motions observed 10 km inland. At high tide, cliff top ground motions in three frequency bands were generated locally by ocean waves at the cliff base: (1) high-frequency (>0.3 Hz) “shaking” caused by waves impacting the cliff, and (2) gravitational loading-induced “swaying” at the frequency of the incident sea swell waves (0.05–0.1 Hz), and (3) slow “swaying” at infragravity frequencies (0.006–0.05 Hz). At high tide, at infragravity and incident sea swell wave frequencies, cliff top vertical ground displacement and cliff base water level fluctuations are coherent and oscillate in phase (with occasional deviation at sea swell frequencies), and spectral levels at the cliff top are much higher than at the inland seismometer. In contrast, at “double frequencies” (0.1–0.3 Hz) spectral levels of vertical motions are nearly identical inland and at the cliff top, consistent with a common (distant or spatially distributed) source. At low tide, when ocean waves did not reach the cliff base, power levels of vertical ground motions at the cliff top decreased to inland levels at incident wave frequencies and higher, and only infragravity-band motions were noticeably forced by local ocean waves.

Effects of Long-Term Trampling on the Above-Ground Forest Vegetation and Soil Seed Bank at the Base of Limestone Cliffs

Exposed limestone cliffs in central Europe harbor a highly divers flora with many rare and endangered species. During the past few decades, there has been increasing recreational use of these cliffs, which has caused local environmental disturbances. Successful restoration strategies hinge on identifying critical limitations. We examined the composition of aboveground forest vegetation and density and species composition of seeds in the soil seed bank at the base of four limestone cliffs in mixed deciduous forests that are intensively disturbed by human trampling and at four undisturbed cliffs in the Jura Mountains in northwestern Switzerland. We found that long-term human trampling reduced total aboveground vegetation cover at the base of cliffs and caused a significant shift in the plant-species composition. Compared with undisturbed cliffs, total seed density was lower in disturbed cliffs. Human trampling also altered the species composition of seeds in the soil seed bank. Seeds of unintentionally introduced, stress-tolerant, and ruderal species dominated the soil seed bank at the base of disturbed cliffs. Our findings indicate that a restoration of degraded cliff bases from the existing soil seed bank would result in a substantial change of the original unique plant composition. Active seed transfer, or seed flux from adjacent undisturbed forest areas, is essential for restoration success.

Numerical and physical modelling of coastal cliff retreat processes between La Hève and Antifer capes, Normandy (NW France)

The study area is located along the French eastern Channel coastline, in Upper Normandy, between the La Hève and Antifer capes. The sedimentary series dip North-Eastward by 0.7° and comprise clay layers (Kimmeridgian and Albian clays) located at varying vertical elevation along the cliff (about 90 m high). This coastal cliff section is undergoing slow gravitational deformation, assumed to take place along the clay layers. Using numerical and experimental models, we investigated the role of clay layers, acting as potential detachment layers, on the development of gravitational instabilities. In order to properly design our models, we characterized the rock mechanical parameters using triaxial shear tests on in-situ samples dated from Kimmeridgian to Cenomanian. We ran a series of numerical simulations using a finite-element code applied to 2-D cliff cross section having varying lithological and mechanical layering. Under the sole effect of gravity forces, the plastic strains are mainly localised along the two clay layers, and the predicted displacements evidence a seaward sliding of the cliff. We further investigated gravitational deformation in the cliff using experimental models subjected to high pore-fluid pressure using by injecting compressed air at the base of the model. The presence of fluid overpressure can trigger spontaneous dismemberment of a cliff that would otherwise remain stable. The region of the model located near the initial cliff spread seaward, which generated a set of normal faults that propagated landward and create a frontal toe bulge. We modelled a more complex initial geometry closer that observed in the field by simulating the northward progressive deepening of a potential décollement (the Gault clay). In the segment of the model where the potential décollement layer lay above or at the cliff's base, the absence of frontal buttress allowed for a large part of the cliff to slide seaward. The compressional toe of the deformed wedge progressively grew, thus acting as a buttress preventing further sliding. Removal of this toe by erosion lead to renewed gliding. Going northward, the vertical position of the potential décollement layer deepened, below the base of the cliff. There, the chalky shore platform acts as a buttress and the cliff deformation and seaward translation stops. Results lead us to hypothesize that cliff retreat would be faster where the potential décollement layer is located higher in the cliff along the southern segment. Therefore, the overall cliff trend would progressively rotate counterclockwise with ongoing deformation and erosion. This modelling works illustrates why the coastline trend changes drastically between the north (N60E) and the south segment (N25E). This progressive coastline re-orientation through time is confirmed by the fan-shape morphology of the bathymetry offshore the southern segment whereas the northern one presents a slight and regular slope.

Rockfall-induced impact force causing a debris flow on a volcanoclastic soil slope: a case study in southern Italy

Abstract. On 10 January 2003, a rockfall of approximately 10 m3 affected a cliff some 25 m high located along the northern slopes of Mt. St. Angelo (Nocera Inferiore, province of Salerno) in the southern Italian region of Campania. The impact of boulders on the lower sector of the slope, along which detrital-pyroclastic soils outcrop, triggered a small channelled debris flow of about 500 m3. Fortunately, no damage nor victims resulted from the landslide. Several marks of the impacts were observed at the cliff toe and outside the collapsed area, and the volumes of some fallen boulders were subsequently measured. By means of in-situ surveys, it was possible to reconstruct the cliff's geo-structural layout in detail. A rockfall back-analysis was subsequently performed along seven critical profiles of the entire slope (surface area of about 4000 m2). The results of this numerical modelling using the lumped-mass method were then used to map the kinetic iso-energy curves. In the triggering area of the debris flow, for a falling boulder of 1 m3, the mean kinetic energy was estimated at 120 kJ, this value being equivalent to an impact force, on an inclined surface, of some 800 kN. After landing, due to the locally high slope gradient (about 45°), and low angle of trajectory at impact (about 23°), some boulders slid down the slope as far as the endpoints. The maximum depth of penetration into the ground by a sliding block was estimated at about 16 cm. Very likely, owing to the high impact force of boulders on the saturated soil slope outcropping at the cliff base, the debris flow was triggered under undrained loading conditions. Initial failure was characterized by a translational slide involving a limited, almost elliptical area where the pyroclastic cover shows greater thickness in comparison with the surrounding areas.

Stability of an undercut sea-cliff along a Cilento coastal stretch (Campania, Southern Italy)

This paper deals with a finite element stability analysis performed on a sea-cliff affected by a deep notch. The cliff is about 200 m long with height ranging between 8 and 19 m. The notch at the cliff base is about 1 m above sea level, nearly stretching along the entire cliff toe. Detailed geo-structural and geo-mechanical surveys were performed in situ, and rock samples were tested in laboratory. The relevant physical and mechanical properties were used for determining rock mass strength parameters. A finite element approach was implemented using a two-dimensional elasto-plastic finite-element stress analysis program. The stability analysis shows that the notch causes increasing shear strains spreading from the notch end towards the top cliff. Decreasing strength reduction factors affect the cliff as the notch reaches increased depth into the rock mass, and when its depth is about 2 m the analysis results do not converge. At this stage, an uninterrupted shear plane develops along which a roughly prismatic rock block can slide and then topple.

Comparison of Airborne and Terrestrial Lidar Estimates of Seacliff Erosion in Southern California

Seacliff changes evaluated using both terrestrial and airborne lidar are compared along a 400 m length of coast in Del Mar, California. The many large slides occurring during the rainy, six-month study period (September 2004 to April 2005) were captured by both systems, and the alongshore variation of cliff face volume changes estimated with the airborne and terrestrial systems are strongly correlated (r 2 = 0.95). How- ever, relatively small changes in the cliff face are reliably detected only with the more accurate terrestrial lidar, and the total eroded volume estimated with the terrestrial system was 30 percent larger than the corresponding airborne estimate. Although relatively small cliff changes are not detected, the airborne system can rapidly survey long cliff lengths and provides coverage on the cliff top and beach at the cliff base.

Habitat heterogeneity, disturbance, and productivity work in concert to regulate biodiversity in deep submarine canyons

Habitat heterogeneity is a major structuring agent of ecological assemblages promoting beta diversity and ultimately contributing to overall higher global diversity. The exact processes by which heterogeneity increases diversity are scale dependent and encompass variation in other well-known processes, e.g., productivity, disturbance, and temperature. Thus, habitat heterogeneity likely triggers multiple and cascading diversity effects through ecological assemblages. Submarine canyons, a pervasive feature of the world's oceans, likely increase habitat heterogeneity at multiple spatial scales similar to their terrestrial analogues. However, our understanding of how processes regulating diversity, and the potential for cascading effects within these important topographic features, remains incomplete. Utilizing remote-operated vehicles (ROVs) for coring and video transects, we quantified faunal turnover in the deep-sea benthos at a rarely examined scale (1 m-1 km). Macrofaunal community structure, megafaunal density, carbon flux, and sediment characteristics were analyzed for the soft-bottom benthos at the base of cliff faces in Monterey Canyon (northeast Pacific Ocean) at three depths. We documented a remarkable degree of faunal turnover and changes in overall community structure at scales < 100 m, and often < 10 m, related to geographic features of a canyon complex. Ultimately, our findings indicated that multiple linked processes related to habitat heterogeneity, ecosystem engineering, and bottom-up dynamics are important to deep-sea biodiversity.

Beach Volume on an Eroding Sand–Gravel Coast Determined Using Ground Penetrating Radar

Abstract Mixed sand and gravel beaches form a wedge of protective sediment at the base of eroding cliffs. In profile these beaches are typically steep with a prominent storm berm. If the volume of beach sediment is insufficient, storms strip beach sediments seaward, exposing the cliff toe to wave attack. The beach volume is thus crucial to the protection of sea cliffs. In this article we describe a method of calculating alongshore variation in the volume of mixed sand and gravel beaches using ground penetrating radar (GPR). Eighteen sites were studied along 50 km of the east coast of South Island, New Zealand. The method was underpinned by an ability to map the boundary between beach sediments and underlying Pleistocene alluvial-fan sediments. This was achieved by studying the radar facies, particularly landward-dipping overwash deposits and seaward-dipping beach erosion surfaces. The method was ground-truthed in three ways: (1) a stream provided a clean section through one site that was imaged by radar; ...

Comparison of short-term seacliff retreat measurement methods in Del Mar, California

Seacliff retreat has been variously characterized as the recession rate of the cliff top, of the cliff base, and as the bulk recession rate based on volumetric changes of the entire cliff face. Here, these measures of retreat are compared using nine semi-annual airborne LiDAR (Light Detection And Ranging) surveys of southern California seacliffs. Changes in the cliff base location (where the steeply sloping cliff face intersects the beach) include cliff retreat owing to basal erosion, but also reflect changes in beach sand level and basal talus deposits. Averaged over the 2.5 km alongshore study span, the cliff base actually prograded seaward about 12 cm during the 4-year study. Cliff top change was dominated by few, relatively large (several meters) localized retreats. Cliff face changes, that include failures and deposits anywhere on the cliff profile, had a relatively small mean magnitude compared to cliff top changes and were more widely distributed alongshore. However, the similar alongshore averaged, cumulative cliff top and net bulk cliff face end-point retreat (14 and 19 cm, respectively) suggest that mean cumulative cliff top retreat can potentially be a viable surrogate for mean net cumulative cliff-wide erosion (and vice versa) over relatively short time periods. Cliff face erosion occurred repeatedly at some locations, confirming the presence of seacliff erosion hot-spots during the study period.

Combining scales in habitat models to improve conservation planning in an endangered vulture

Predictive modelling of species’ distributions has been successfully applied in conservation ecology, but effective conservation requires predictive and accurate models. The combination of different scales to build habitat models might improve their predictive ability and hence their usefulness for conservation, but this approach has rarely been evaluated. We developed habitat-occupancy models combining scales from nest-site to landscape for a key population at the northwestern edge of the distribution of the globally endangered Egyptian vulture ( Neophron percnopterus). We used generalised linear models (GLM) and an information-theoretic approach to identify the best combination of scales and resolutions for explaining occurrence. Those models that combined nest-site and landscape scales improved the predictive ability compared with the scale-specific ones. The best combined model had a very high predictive ability when used against an independent dataset (92% correct classifications). Egyptian vultures preferred to nest in caves with vegetation at the entrance that were situated at the base of long cliffs, provided that these cliffs are embedded within low-lying, heterogeneous areas with little topographic irregularity and with little human disturbance. The density of sheep around the nest positively influenced Egyptian vulture presence. Conservation of the studied population should focus on minimising human disturbance and on promoting sustainable development through conservation of traditional pastoralism. Our findings highlight the importance of developing region-specific multiscale models in order to design effective conservation strategies. The approach described here may be applied similarly in other populations and species.

‘The Killer Point’: Contemporary Reconfigurations of The Gap as a Crime Scene

In November 2008, Gordon Wood was found guilty of the murder of his girlfriend, model Caroline Byrne, over a decade after her body was found at the base of an ocean cliff in Eastern Sydney, New South Wales, known as The Gap -- a place that, even while bearing the reputation of a ‘notorious suicide spot’, has been widely promoted as a popular tourist attraction. This article explores the mainstream media’s reporting and regulation of meaning in relation to the crime and the dichotomous tensions and competing (re)interpretations of The Gap this has produced throughout the investigation into Caroline Byrne’s death. More generally, this article seeks to understand the ways in which legacies of violence, death and suffering are often embodied in and by the spaces and places where these acts take place and how we might begin to explain our own and the media’s frenetic fascination with and ambivalence towards these sites, using a critical discourse that moves beyond the lexicon of legal discourse. In doing so, this article explores the limitations of language; questioning whether available and relevant critical cultural vocabularies are able to adequately capture and communicate the sometimes unsettling complexities and intricacies of embodied places and spaces that ultimately challenge (and complicate) the conventions of crime scene (re)presentation as a result of their multiple other histories.

Anthropogenic modifications in the erosional rhythm of a coastal cliff. Rocha do Gronho (western coast of Portugal)

The beach-cliff system “Rocha do Gronho” is a stretch of the west coast of Portugal that marks the southern limit of a coastal lagoon – The Obidos lagoon. The cliff is cut in sedimentary material and the elongated beach is generally narrow being almost submerged by the spring tides. Existing documents show that, in almost all of the second half of the twentieth century, there has been a state of equilibrium of the beach-cliff system because the abundance of sediments proceeding from the lagoon and carried south by the longshore current (predominantly N-S) provided a covering of the cliff base that protect it from the assailing force of the waves. The cliff face evolved mainly by small magnitude rockfall events. Between 1958 and 1995, a rate of retreat of 0.15m (±0.02m) year−1 was recorded. Afterwards, the frequency and the magnitude of the occurrences of mass movements had changed. Five events leading to a 33.6m retreat of the cliff top have been recorded. The type of movement, the affected length of the top of the cliff, the maximum retreat, the lost area of the top of the cliff and the volume of material displaced were estimated for each event. The identification of the processes involved as well as the evaluation of the potential triggering factors allowed an assessment of the influence of human intervention in the lagoon (changing the main draining paths and consequently the patterns of sediment transport) in the modifications of the “Rocha do Gronho” evolution.

Topographic controls on the distribution of tree islands in the high Andes of south‐western Ecuador

AbstractAim To evaluate the hypothesis that geomorphometric parameters of upper montane Andean environments have an important influence on the regional fire ecology and consequently play a role in the spatial distribution of ‘remnant’ tree islands dominated by Polylepis.Location A glacial landscape located between 3600 and 4400 m elevation in Cajas National Park, south‐western Ecuador.Methods The eigenvalue ratio method was used to evaluate the regional geomorphometric parameters of a 30‐m digital elevation model for Cajas National Park. The landscape character was evaluated by quantifying the topographic roughness, organization, and gradient. This information was used to determine the spatial correlations between terrain characteristics and the distribution of tree islands in the region.Results We demonstrate a strong spatial correlation between areas of high topographic roughness and gradient, and the locations of the major tree islands. We find that there is a distinctive relationship between the topographic roughness and organization in the vicinity of the tree islands (e.g. increased upslope roughness and decreased topographic grain strength) that substantiates the notion that the tree islands are located in relatively inaccessible topography.Main conclusions In the northern and central Andes, the location of Polylepis‐dominated ‘forest islands’ has been shown to be a function of climate, terrain characteristics, and anthropogenic disturbances. Although the relative importance of various ecological factors has been debated, it remains clear that fires have exerted a strong influence on these ecosystems. Other authors have noted that tree islands are more likely to occur at the base of cliffs, above moist areas, and in other areas where fires do not burn frequently. Our results corroborate these observations, and demonstrate that the occurrence of Polylepis patches is strongly correlated with specific combinations of terrain features. Although we do not discount the importance of other factors in determining the spatial position and areal extent of these forests, we demonstrate strong support for fire‐related hypotheses.

Noteworthy Collections: North Carolina

Jeffersonia diphylla (L.) Pers. (BERBERIDACEAE)—Madison County: approximately 25 plants consisting of 9 to 21 leaves per plant observed at the transition zone of mature hemlock / mixed mesophytic forest and base of a mesic mafic cliff and ledges, on northfacing slopes, private property draining into the Ivy River at 530 m (1,750 ft.) elevation. Lat/ Long: N 35u46910.810, W 082u38928.670. Kevin Caldwell s.n. and Josh Kelly, 13 April 2007 (WCUH). Significance. The population represents Madison County’s first known record and the second extant site of three total reported sites in North Carolina. It occurs at the southeastern periphery of its range at this site and it represents the northern and eastern-most population in North Carolina. Regionally, it is more common in the limestone country in Tennessee southwest into Alabama. An extant population in Jackson County, estimated at between 500 and 1,000 plants, was reported by Pittillo (1992). The first and historical population reported by Radford, Ahles, and Bell (1968) for Jackson County has not been relocated.

Effect of Cliff Shape on Internal Stresses and Rock Slope Stability

Abstract The failure of coastal rock cliffs is attributed to a variety of factors such as weathering, wave action, ground water level, and rock and joint parameters. The wave-induced undercutting of the vertical cliff face is hereby assumed to play a critical role. Very little attention has, however, been paid to the gravity-induced stresses within the cliff face. A numerical analysis of the stress distribution in idealised rock cliffs of varying slopes (50–90°) and in various stages of undercutting has been conducted. Investigated parameters included slope angle, cliff height, influence of a cliff base cavity, front face loading, and cliff surcharge loading. The analysis showed that stresses in the cliff face geometry immediately after a failure were insignificant. With the steepening of the cliff, stresses increased to reach very high values for a vertical cliff face. Additional undercutting of the cliff resulted only in a slight increase of those stress magnitudes. The steepened rock cliff can result i...

Relict rock glaciers and protalus lobes in the British Isles: implications for Late Pleistocene mountain geomorphology and palaeoclimate

AbstractMany relict rock glaciers and protalus lobes have been described in mountainous areas of the British Isles. This paper reviews their distribution, chronology, supposed origin and development, and places the research within current investigations and knowledge. Rock glaciers and protalus lobes are located in a number of different topographic locations and settings. They developed at the base of steep cliffs following the catastrophic failure of rock faces, at the base of scree slopes following the gradual accumulation of rock debris and in association with glaciers. Protalus lobes probably developed in response to the permafrost creep of talus material while rock glaciers formed through the deformation and sliding of large bodies of buried ice. Rock glaciers probably developed, or were last active, during the Younger Dryas, although the possibility exists that some of these landforms are Dimlington Stadial in age. The development of protalus lobes during the Younger Dryas suggests that precipitation levels were low and permafrost was widespread during this time. The lack of rock glaciers (sensu stricto) in the British Isles compared with other mountain areas is believed to be a consequence of the rock type and relative scarcity of weathered debris for their formation rather than a lack of suitable sites or appropriate environmental conditions. Copyright © 2007 John Wiley &amp; Sons, Ltd.

Band-e-Amir Lakes and Dragon Valley (Bamiyan): myths and seismicity in Afghanistan

Abstract Located SW of the Hindu Kush range, the Band-e-Amir lakes and other continental bioherms around Bamiyan are famous for their ordering into terraces and their great variety of colours. Numerous legends, the earliest likely dating to the establishment of the Zoroastrian religion, refer to the topography, ecology, and colours of the lakes and seismic activity of the area. The lakes have been formed by the chemical and biologically-induced build-up of semicircular or successive linear travertine dams. The discovery of a highly truncated karstic network located at an elevation of around 4000 m. along the base of Maastrichtian carbonate cliffs surrounding the lakes, may explain the presence of this carbonate sedimentation which has fluctuated with time and was responsible for legendary floods. Localized at the eastern end of the Herat strike-slip fault, the timing and duration of the build-ups and lakes are under the influence of intense seismic activity, partially due to the seismic activity of the nearby Hindu Kush, in relation to the northern drift of the Afghan Gondwanian block towards the Eurasiatic plate. These bioherms and lakes occur in an area of high risk; a zone of floods, freezing temperatures, earthquakes and rock avalanches caused by the high altitude and location in the Himalayan alpine belt. These natural features have affected local populations beginning with the movement into the area of more or less sedentary people, apparently coming from the Bactrian province. Such a fragile biological and sedimentological environment should be maintained by organized governmental assistance, with a primary goal of protecting the local inhabitants, but also preserving this exceptional environment for others to enjoy.