direct and indirect evaluation of denudation rates in central italy abstract this paper presents the main results of a series of geomorphological studies aimed to the quantitative direct and indirect evaluation of denudation processes in central italy these studies which started in some sample areas since long ago were further deepened and extended to a wider number of drainage basins representative of a variety of morphostructural conditions the complex cause effect relationships among factors influencing both the morphogenesis and the plano altimetric configurations of drainage basins resulted in a large variability in the values of the denudation index tu which ranged from 200 to 2500 t km2 year very high values tu 10 000 t km2 year were obtained for small catchments belonging to the wider basins of ombrone river and tevere river where fast morphological modifications occur due to the action of surface running waters and gravity in the drainage basins affected by the most powerful denudation processes direct measurements of denudation were performed several monitoring stations were equipped with iron stakes and disks to record the local modifications of the topographic surface with time whereas some of these stations have been working continuously since 1993 some others have been running only periodically direct measurements pertinent to periods longer than a decade indicated that mean annual values of denudation range between 1 and 2 5 cm year for slopes affected by sharp edged and or rounded edged badlands higher denudation rates 3 4 cm year were obtained for shorter observation periods still higher rates were recorded for short periods at the gully bottom or in coincidence with mass movements before bench marks were turned up or damaged denudation processes are likely to occur discontinuously they show a step like trend with time and are triggered by rainfall events distributed over a number of consecutive days though not greatly intense particularly their amount should overcome the threshold of 60 mm per 5 consecutive days below this threshold the surface runoff does not seem to reach the power necessary to induce significant modifications of the topographic surface in the study area

changes to the dispersive characteristics of soils along an evolutionary slope sequence in the vera badlands southeast spain implications for site stabilisation abstract in dispersive marls near vera badland gullies are eroding into a previously stable matorral covered landscape this relatively recent activity was probably triggered by minor climatic or land use change in this landscape calvo cases and harvey earth surface processes and landforms 21 1996 725 argued that new gully head slopes with differing aspect represent a sequence of progressive erosion using this interpretation as a basis slope surface materials were explored for evidence of material chemical stabilisation by sampling along profiles positioned centrally on those slopes the extent to which the inferred geomorphic sequence is paralleled by progressive changes in site geochemistry is considered crusts and subsoils differ significantly in terms of ph and sodium adsorption ratio sar but not calcium content the crust is thus distinctive but not calcic rather the ph differences suggest a process involving an organic agent probably algae slope position was an important discriminant taking sar alone differences between crusts and subsoils were not significant at the slope base but increased in significance with distance up the profile considering differences between the three profiles the middle profile had significantly higher sar values both in the crust and at depth than the other profiles whereas late slope subsoils and crusts taken alone are not dispersive sar the potential stabilisation of this type of badland soil and surface is finally considered whereas harvey harvey a m 1982 the role of piping in the development of badlands and gully systems in southeast spain in bryan r yair a eds badland geomorphology and piping geobooks norwich pp 317 335 argues that site morphology suggests that geomorphological instability increases through time the soil sequence suggests decreases in material dispersivity and consequently surface autostabilisation it is concluded that the concept of badland stabilisation needs further clarification

the causes of piping in a set of abandoned agricultural terraces in southeast spain this study aims to identify some of the factors contributing to the piping process in abandoned terraces in seven sites located in the murcia region southeast spain the local landscape has the appearance of badland geomorphology possessing deep valleys which until the 1970s were terraced and cultivated the terraces have now been abandoned to the piping process the research focuses on the relationship between the size and position of pipes and the physical and geochemistry properties of the local highly dispersive marl lithology and the extent to which the reworking of the materials for terrace cultivation has exacerbated piping erosion morphologically the terracing in the stream beds has resulted in a series of gentle benches separated by steeper risers with variable drop riser height a series of flat infiltration surfaces result and because the resculpting produces a reduced bulk density infill with enhanced throughflow infiltrating water is forced along steep hydraulic gradients to a low outfall at the base of the riser paralleling studies of land levelling and terrace abandonment in similar materials elsewhere piping in the study area is shown to be closely related to the physical and chemical characteristics of the materials its sodicity and dispersive character considerable differences in structure texture mineralogical composition and material s surface crust and subsoil geochemical properties emerged from site signature plots and these results suggest that agricultural processes affect the dispersive character of the crust materials presumably because agricultural activity increases the buffering effect of organic acids on the dispersed clay this is supported by the observation that on the one site that was levelled but not used for agriculture a stable organically distinct crust like the abandoned agricultural sites has not formed the changes to the material s aggregate stability and bulk density properties when terracing occurs is examined but insufficient evidence is available from the data collected to unpick the causes of aggregate stability changes in the study plots the way in which differences between crust and subsoil enhance infiltration is discussed and the role of the terrace drop in influencing hydraulic gradients and pipe development is illustrated a possible index to describe the relationship between evacuated material volumes and the controlling parameters discussed above is tested it is concluded that terracing which is intended as a conservation practice has in dispersive materials actually enhanced piping leading to the abandonment of farming

morphological analysis and erosion rate evaluation in badlands of radicofani area southern tuscany italy abstract since 1988 geomorphologic research based on field surveys and photo geological analysis has been conducted in southern tuscany italy in areas characterised by very rapid morphological evolution in the area outcrop pliocene marine claystones uplifted during the quaternary up to 750 m above sea level now undergoing intense erosion processes leading to considerable badlands formation morphodynamic analysis conduced by direct and indirect measurements in a sample area were taken in order to quantify the erosion rate in badland areas the torrente piantrafolla sample area was chosen as representative of the study area it was most recently monitored during the period nov 2000 feb 2004 at this time morphographic and morphometric analyses carried out in selected measurement stations located on slopes identified gravity as the main morphogenetic process responsible for slope shaping the calanchi badland areas are characterised by constant and rapid shrinking of their edges resulting from landslides which occur in autumn and winter as a consequence of intense rainstorms selected measurement stations indicate an erosion rate value range from 5 to 7 5 cm y the comparison between 1976 and 1994 digital elevation models dem obtained from photogrammetric restitution indicated a mean erosion rate of about 5 cm y in a nineteen year period this value considerably higher than the values measured in other italian basins indicate a very rapid evolution of the slopes due mainly to small earth flows inside calanchi badlands

space time variability of denudation rates at the catchment and hillslope scales on the tyrrhenian side of central italy studies on denudation rates can provide insight into the influence of climate change tectonics and human activities on landscape evolution research performed in central italy has shown considerable spatial variability of denudation rates in the major river basins these studies have focused mainly on the tyrrhenian side of the italian peninsula where plio pleistocene marine deposits filling nw se elongated sedimentary basins have been uplifted during the quaternary up to several hundreds of meters above present sea level small sub catchments developed on clays are affected by sharp and or rounded edged badlands i e calanchi and biancane representing denudation hot spots in the present day morphoclimatic framework in this paper we analyze the relationships between indirectly estimated denudation rates at the catchment scale and field monitoring data at the hillslope scale we attempt to better understand and quantify all hillslope processes that contribute to seasonal variability of denudation to help with predicting the net input from hot spots to the overall estimated sediment yield at the basin outlets at the hillslope scale we discuss in particular the variability of denudation rates at calanchi and biancane badlands as a function of their different morphoevolution

a typical calanchi landscape on the eastern apennine margin atri central italy geomorphological features and evolution abstract the surroundings of the town of atri abruzzo region central italy situated about 10 km from the adriatic shoreline can be considered as representative of most part of the italian seaward peninsular landscape the subject of this research the calanchi landscape often generally considered as badlands by non italian authors is in fact made up of many singular landforms each of which calanco corresponds to a more or less extended hydrographic unit the dynamics are mainly the result of the action of the particularly aggressive climatic factors such as the mediterranean rainfall regime on weak substrata clay silt and sand of the plio pleistocene marine cycles the morphogenetic activity is not only limited to channel erosion but it is also due to repeated superficial slides so that it should in fact be better to consider the calanco as the result of a combined erosion process sensu zachar d 1982 soil erosion elsevier amsterdam since the mechanism regulating this process remains unclear this work wants to offer a contribution to this research field multitemporal geomorphological analysis has helped us to distinguish the different areas in which the calanchi evolution has been more or less important in the past in such a way it has been possible to characterize the landscape evolution as a function of the parameters that influence soil loss especially in areas such as that of atri where calanchi like landforms are highly developed moreover this analysis coupled with the processing of 40 years rainfall data also taking into account the concurrent land use changes has clearly shown that the areas affected by calanchi erosion on the eastern apennine margin still tectonically active are progressively diminishing

micropiping processes and biancana evolution in southeast tuscany italy abstract biancane badlands consisting of small domes dissected by rills and micropipes with rough disordered microrehef can be found along the apennines in italy the dominant processes forming biancane differ from those of badlands formed on smectite rich mudrocks as micropipes associated with pseudokarstic enlargement of pores and cracks predominate and form the main routes for evacuation of eroded material biancana evolution is controlled by water infiltration into intact bedrock producing an erodible weathering rind which is more porous than intact rock this rind is easily removed by rill or micropipe flow and erosion is therefore weathering controlled depending on rind production by infiltrating water infiltration is initially slow and stepped due to slow water movement through very small capillary pores in intact rock alternating with rapid filling of macropores and cracks this occurs due to rapid matrix pore enlargement by dispersion and or dissolution the infiltration pattern is accurately reproduced by a model built on progressive development of weathering layers by moisture penetration model results are consistent with weathering rind depths and erosion observed in the field and show that a pipe network can be generated on newly exposed rock by the rainfall of one year propagation of the pipe network diverts a progressively larger proportion of runoff into micropipes expanding weathering rind production within the biancana as well as on the surface internal weathering and flow progressively dominate with few unweathered corestones and the biancana gradually collapses into a penultimate souffle like form

variations in soil dispersivity across a gully head displaying shallow sub surface pipes and the role of shallow pipes in rill initiation a small bifurcating gully head displaying shallow pipe development was surveyed to explore how far three dimensional patterns of geochemistry and sediment size can be related to hydraulic gradients in the local marl bedrock almeria se spain the crust sub crust and parent materials were sampled every 20 cm across a 2 m by 3 m grid and then analysed for dispersive and granulometric characteristics spatial patterns of sodium adsoption ratio sar for each layer were plotted separately in situ material at depths of 5 10 cm was only weakly dispersive and the thin 0 2 cm depth crust is also found to be mostly non dispersive paralleling ndings from other eld sites in almeria however the signature relating sar to electrical conductivity for each layer shows that in places the immediate sub crust layer 2 5 cm is highly dispersive the pattern is not random rather the sar of this sub crust layer follows inferred hydraulic gradients the dispersive hot spots being located in the most incised part of the small gully exacerbating the erodibility of that position patterns of sediment particle size and sorting do not correlate with inferred hydraulic gradients but surface material is slightly siltier than the sub crust clay fraction increased with depth and sar is shown to have a weak inverse relationship to particle size this association between sar and the increased clay fractions in the lower layers supports the inference that massive pipe enlargement in the messinian rich unit is suppressed by sub surface swelling since a reduction in in ltration capacity fc with depth can be inferred from these results in ltrating water must be de ected into the already vulnerable sub crust layer during rainfall events explaining the development of shallow pipe forms at preferential depths it is concluded that calcium replaces sodium in the crust during leaching leaving a calcic crust and a sub crust that is sodic and prone to subsequent pipe enlargement rill morphology in these materials also suggests that rills develop from these pipes when pipe roofs collapse i e rill discontinuity bridges steep headwalls and rills with excessively high depth to width ratios copyright 2004 john wiley sons ltd

tertiary extensional tectonics in tuscany northern apennines italy abstract two extensional events have been recognized in the tertiary evolution of tuscany the first event occurred in the period between the late oligocene and late tortonian and caused a stretching of 120 or greater the second event occurred between the late tortonian and quaternary periods and caused a stretching not greater than 10 the first event is characterized by the exhumation of middle crust rocks and therefore by the development of core complexes the most significant structures of the first event are low angle normal faults which characterize the upper plate of the core complexes and ductile shear zones which characterize the lower plate the low angle normal faults tend to die out in the late triassic evaporite level which constitutes the main detachment of the core complexes the main structures of the second extensional event are high angle normal faults which dissect all the previous tectonic features these faults border tectonic depressions which were the site of clastic sedimentation from late tortonian to quaternary time these normal faults may tend to flatten in a seismic lozenge shaped band explained as an active extensional shear zone which is located at the brittle ductile boundary a similar explanation is given for the detachment located in the late triassic evaporite level during the first extensional event while the first extensional event is in the framework of the northern apennine post collisional evolution the second extensional event because it affects an already stretched crust could be attributed to the southern tyrrhenian opening which began during late tortonian

early paleozoic magmatic history of central inner mongolia china implications for the tectonic evolution of the southeast central asian orogenic belt to provide insights into the early paleozoic tectonic evolution of the southern portion of the long lived central asian orogenic belt we have conducted major and trace element analyses and zircon u pb dating of granitoid samples from central inner mongolia our study area covers three pre mesozoic tectonic units from north to south the wenduermiao subduction accretionary complex the bainaimiao magmatic belt and the northern margin of the north china craton our new geochronological and geochemical data show the temporal and genetic relationships between the three tectonic units accordingly we suggest that the wenduermiao subduction accretionary complex developed in the middle cambrian late silurian 509 421 ma comprising of coeval oceanic crust arc magmatism and forearc deposits the bainaimiao continental arc was developed during the late cambrian to early silurian 501 437 ma which superposed on the basement with the affinity of the north china craton the back arc basin opened prior to early silurian and lasted to the late silurian which is slightly younger than bainaimiao island arc the wenduermiao ocean between the wenduermiao subduction accretionary complex and the bainaimiao continental arc existed in early paleozoic

morphology and development of selected badlands in southeast spain implications of climatic change four areas were selected to represent a range of processes characteristic of badland surfaces in southeast spain petrer and monnegre in alicante vera and tabernas in almeria at petrer rilling and swelling processes produce a deeply cracked surface drained by a finely textured network of shallow rills at monnegre piping and rilling are differentially developed on slopes ultimately controlled by basal incision at vera aspect controlled lichen and vegetation cover produce a sequence of badland development within which the relative importance of piping mass movement and rilling varies through the sequence at tabernas simple overland flow is the dominant process but aspect influences rill network density and badland evolution the factors controlling badland development can be grouped into those related to gross morphology to surface cover and runoff generation and to material properties these factors are effective over varying timescales implying that morphological response times differ among the selected badlands

the role of some site geochemical processes in the development and stabilisation of three badland sites in almeria southern spain samples of both surface and subsurface soils were collected on various surfaces in three badland areas of differing ages tabernas vera and mocatan in almeria province southern spain data were explored with the aim of identifying any diagnostic geochemical relationships between site ec ph sediment size and sar which might constitute typical signatures for site materials with some success data for the three sites are further used to explore the hypothesis that changes in site geochemistry through time are involved in badland stabilisation it was found that 1 the physico chemical properties of the three sites can be differentiated by the functional relationship between ec and sar and this may represent a useful tool in characterising sites where piping predominates 2 there is some equivocal evidence that sediment size distribution may play an additional role in site diagnosis and evolution and 3 surfaces appear to lose sodium over time the suggestion being that sodium is either progressively buffered by calcium during leaching or exchanges with hydrogen on the cation exchange sites under a vegetation cover since other research suggests that smectite can also relocate down the profile on some marl sites reducing hydraulic conductivity and suppressing pipes we argue that the surface at tabernas may be capable of long term autostabilisation in which piping intensity progressively reduces however this possibility really applies only to fine grained densely structured materials and evidence from the silty triassic rich unit in the mocatan basin suggests that without a high clay content piping may be expected to increase through time from this standpoint contemporary badland morphology at mocatan does not represent an early stage of the forms seen in vera and tabernas

the recurring cycles of biancana badlands erosion vegetation and human impact abstract the biancana badlands a typical element of the southern tuscany landscape were in expansion for centuries until bulldozers began erasing them for land reclamation purposes over the last 10 15 years some of the scattered remnants of biancanas have been placed under protection in order to preserve their biodiversity and their particular cultural and geomorphological landscapes rural abandonment and the lack of appropriate management practices have contributed to vegetation encroaching on biancana badland slopes causing a loss of elements of high ecological and cultural values as well as eroded spots the aim of this paper is to explore the direction and rate of change in land use of the biancana badland landscapes over the last 50 years evaluating the erosion vegetation dynamics and examining the processes involved in two biancana badlands lucciola bella and crete di camposodo crete di leonina which are sites of community importance first we analysed the landscape changes that occurred in the biancana areas from 1954 to 2005 comparing old and recent land use maps twinspan classification was applied on selected plots of a plant dataset to distinguish vegetation types and identify the indicator species of each different type we then evaluated soil erodibility on the eroded biancana surfaces regosols and well developed vertisols which represent the coexisting extremes of the soil situation within the biancana badlands we empirically assessed the effects of a few roots on saturated soil shear strength to introduce direct links between plants and soil processes our results showed a decrease in bare or scarcely vegetated spots of 0 9 ha y 1 if the encroachment continues to progress at this rate in 35 40 years from now all the biancana domes will be completely re vegetated encroachment on the most eroded biancanas was mainly ascribed to generalist ruderal species such as avena fatua and dactylis glomerata we showed that rills and subsurface micropipes are characterized by the same erosion processes meaning that they can be contrasted and eventually halted by the same means and we observed a clear positive trend that will substantially suppress rilling at very low plant cover no more than 20 badlands were previously kept alive by limited but nonetheless devastating grazing activities if this picture is correct then mimicking traditional badland grazing practices seems to be a necessary step towards saving the landscape and biodiversity that the protected areas were established to preserve

long and short term evolution of several mediterranean denudation hot spots the role of rainfall variations and human impact abstract severe slope denudation is one of the most important environmental problems in the mediterranean region in particular badlands are widespread in central italy as a result of extensive clayey outcrops current climatic conditions and rapid quaternary uplift human activity may significantly affect the development and evolution of these denudation hot spots especially through changes in land use this work is focused on a badland site that has developed over the last 30 years on a gently sloping area of cropland in central italy the site named bargiano underwent cropland abandonment in 1980 and was selected to evaluate the effects of external forcing such as human impact and rainfall variations on the development of water erosion processes the remnants of the 1980 cropland surface and the present eroded surface were sampled using differential global positioning system techniques to perform a volumetric estimation of the eroded material and to calculate the average erosion rate for fairly large time spans the dgps survey was coupled with a 2 year monitoring with erosion pins in the region which permitted comparisons between long and short term average erosion rates in addition the analysis of the rainfall series recorded at the orvieto pluviometric station allowed us to assess and evaluate the role of critical rainfall events on denudation intensity finally a further comparison of the measured and estimated erosion rates from the bargiano site with the data recorded at other long lasting monitoring stations that are set up in certain key areas of central italy the tevere river and ombrone river basins revealed that the bargiano experimental hillslope experienced considerably higher erosion rates than were noted at the other sites our investigations demonstrated that cropland abandonment caused an increase in the erosion rate relative to what happened in natural areas characterized by similar physiographic conditions this finding is consistent with previously reported results for other badlands found in the mediterranean area moreover the results obtained suggest that after the abandonment of its cropland the bargiano site evolved in a cyclical manner that was driven by intrinsic thresholds to a greater extent than it was affected by external climatic changes

the role of extensional tectonics at different crustal levels on granite ascent and emplacement an example from tuscany italy abstract the role of regional extension on the rise and emplacement of granites in the crust is still debated pluton ascent and emplacement widely occurred in tuscany italy since late miocene during the post orogenic collapse of the inner apennines and are presently occurring in the geothermal areas of amiata and larderello tuscany offers a preferred test site to study the role of regional extension on pluton ascent and emplacement at different crustal levels ductile extension enhanced the segregation and ascent of granitic melts in the lower crust controlling pluton emplacement in correspondence with the brittle ductile transition in the brittle crust magma ascent occurred through subvertical faults and fractures compatible with the regional extension direction pluton emplacement mainly occurred by means of roof lifting the case of tuscany suggests that the extensional structures enhance melt segregation and ascent in the ductile crust but are not efficient alone to provide a pathway for the ascent of granitic magmas in the brittle extending crust the estimated magmatic strain rates due to pluton emplacement in the geothermal areas are much larger than the regional tectonic strain rates this suggests that regional tectonics did not control magma emplacement in the brittle crust and explains why nontectonic processes roof lifting accommodated the space required for pluton emplacement

dynamic evolution of badlands in the roglio basin tuscany italy abstract the roglio basin in the relatively arid central tuscany italy is characterised by the presence of 191 badlands that have developed on pliocene fine grained blue clays a morphometric analysis on the badlands has highlighted that these landforms formation and distribution are primarily related to the steepness of the hill flanks which favour runoff and gravitational processes along with favourable aspects typically the southern ones that experience a stronger solar induced daily thermal variation a detailed physico chemical analysis of the clayey material involved has also been carried out with the specific aim of testing whether this plays a role in the various stages of activity shown by the roglio basin badlands the results indicate that there are no significant differences in the physico chemical properties of an active vs an inactive dormant badland observation and field data however indicate that the dynamic of the roglio basin badlands is strongly controlled by the occurrence of earth flows and the velocity of sediment removal at the bottom of the badlands these two processes variously combined at different intensity in relationship to many local factors are likely to be the main responsible for the different stages of activity shown by the roglio basin badlands

late quaternary geomorphological evolution and erosion rates in the clayey peri adriatic belt central italy abstract this study analyses the geomorphological evolution during the last 20 000 years in two areas representative of the peri adriatic belt of central italy mt ascensione in the high hilly sector 600 1100 m a s l and the atri district in the hilly coastal sector up to ca 500 m a s l in both areas the lithostructural setting is characterized by an east verging monocline mainly composed of clayey formations the two areas are compared in relation to their morpho chronological aspects and geomorphological dynamics the results suggest two fundamental evolutionary phases 1 about 20 000 yr bp sedimentation occurred along the main valleys when the middle to upper portions of slopes were covered by colluvial deposits and 2 at the beginning of the holocene the climatic improvement triggered erosion along rivers producing deep and narrow valleys estimated denudation rates during the last 20 000 yr are 7 8 mm yr 1 for the mt ascensione area and 2 4 3 0 mm yr 1 for the atri district reflecting frequent landslides and fluvial erosion the rates are consistent with the data available in literature denudation rates double if we assume most of the erosion process took place after the beginning of the holocenic warming phase

a functional entity approach to predict soil erosion processes in a small plio pleistocene mediterranean catchment in northern chianti italy abstract in this paper we evaluate different methods to predict soil erosion processes we derived different layers of predictor variables for the study area in the northern chianti italy describing the soil lithologic complex land use and topographic characteristics for a subcatchment of the orme river we mapped erosion processes by interpreting aerial photographs and field observations these were classified as erosional response units eru i e spatial areas of homogeneous erosion processes the eru were used as the response variable in the soil erosion modelling process we applied two models i bootstrap aggregation random forest rf and ii stochastic gradient boosting treenet tn to predict the potential spatial distribution of erosion processes for the entire orme river catchment the models are statistically evaluated using training data and a set of performance parameters such as the area under the receiver operating characteristic curve auc cohen s kappa and pseudo r2 variable importance and response curves provide further insight into controlling factors of erosion both models provided good performance in terms of classification and calibration however tn outperformed rf similar classes such as active and inactive landslides can be discriminated and well interpreted by considering response curves and relative variable importance the spatial distribution of the predicted erosion susceptibilities generally follows topographic constraints and is similar for both models hence the model based delineation of eru on the basis of soil and terrain information is a valuable tool in geomorphology it provides insights into factors controlling erosion processes and may allow the extrapolation and prediction of erosion processes in unsurveyed areas

slope channel coupling between pipes gullies and tributary channels in the mocatan catchment badlands southeast spain the dispersive nature of the highly sodic silts of the triassic rich unit of the gochar formation plays a fundamental role in the erosion of the mocatan catchment badlands in almeria where a rejuvenating pipe and incised channel network is rapidly evacuating slope materials referring to concepts of medium and long term landscape evolution and incorporating contemporary thoughts on the role of connectivity in system evolution from the geomorphological literature this paper attempts to develop a conceptual model of the way geologic topographic material property and ecological factors combine to explain the complex geomorphological evolution of the site an electronic distance measurement edm survey was undertaken using a leica tc3100 to produce a detailed topographic map this database was supplemented by geomorphological geological and ecological data derived from ground survey and remote sensing and further morphometric analysis undertaken preferred orientations of channel segments and the topographic distribution of pipe roof collapse features and outfalls in relation to known stratigraphic controls suggests that once coupled to the slope base channel pipe networks develop in a systematic sequential way a wave of incision moving up the main channel reconnects channels with slopes and the resulting increased hydraulic gradients on sideslopes encourage extensive deep pipe development for the first time in these materials once major pipe development is possible three dimensional pipe networks enlarge and then collapse to form an extensive partially coupled steep sided gully network from this perspective the coupling of the pipe to a rejuvenating channel is a significant intrinsic threshold event and the main reason that badlands have developed locally in these dispersive materials it is concluded that erosion in this landscape will only be suppressed after a considerable period of slope base stability which could allow a gradual loss of sodium from the surface by leaching or organic exchanges both theoretical and management implications are explored

the influence of physico chemical material properties on erosion processes in the badlands of basilicata southern italy piping tunnelling appears to be one of the more significant methods of erosion in the badlands in the plio pleistocene marine sourced clays of the basilicata area in southern italy a detailed field investigation of the pedological textural mineralogical and geochemical properties of the clay rich terrains widely outcropping in two selected badland field sites the fossa bradanica area and the bacino di sant arcangelo was undertaken to further elucidate process variability across the complex site paralleling findings from other piped badlands certain physico chemical properties of the clays were found to influence the different erosional processes in fundamental ways the very dispersive nature of the materials enhances pipe enlargement so that subsurface flow rapidly becomes the dominant process causing pipe enlargement by a process of positive feedback the paper speculates on the progressive role of surface and subsurface processes in the genesis of all evolutional badland forms calanchi calanchi mammellonari and biancane in an early stage the calanchi mammellonari are produced as slope mounds become increasingly separated by a dense network of small inclined pipes in the intermediate part of the slopes a site which is presumed to favour elevated subsurface flow when the overburden collapses many cones are isolated in these portions of the slope a second stage follows in which overland flow dominates with the water canalizing into small gullies generated by the collapsed crust at the base of many slopes this same mechanism produces biancane as residual cones because of the structural weakness of piped materials mass movements cannot be ruled out in a few locations landsliding may be involved especially in the formation of calanchi mammellonari in this case the intersection of the vertical pipes with the impermeable substratum focuses subsurface flow and collapse of the surface along this failure plane subsequent remodelling occurs by surface processes since the catchment volume for large pipes no longer exists this interpretation differs from that of others who have argued that in other locations the biancane formation is linked to the development of large vertical pipes along tectonic joints

preliminary study of the erosion mechanisms in a biancana badland tuscany italy abstract italian badlands are present along the appennini mountains with an annual precipitation which ranges from 400 to 1200 mm the genesis of these badlands has often been studied whereas current processes and erosion rates have only rarely been examined and measured this paper describes a preliminary study on a badland developed in temperate mediterranean climate and located in sw tuscany italy the selected site is characterized by biancane dome shaped features a few meters in height generally having a vegetated nne aspect and severely eroded ssw slope with a sub horizontal basal pediment field rainfall and runoff experiments were carried out field results were substantiated by data collected in specially devised laboratory tests it was concluded that near surface pipes which develop at the point of contact between a surficial layer of weathered and severely fractured regolith and the less fractured and weathered regolith underneath are the main drainage channels while rills play a secondary role soil detachment is largely due to mechanical and chemical slaking of the regolith during infiltration the role of runoff is almost solely transport in particular it was found that the runoff detachment rate is limited by the rate at which the water front penetrates into the regolith

origin of biancane and calanchi in east aliano southern italy abstract areas underlain by plio pleistocene marine mudstone in south italy are severely affected by denudation processes and have been transformed into badlands with two well defined types of landform biancane and calanchi in this paper factors that contributed to the development of the aliano badlands and particularly to the geneses of biancane and calanchi have been studied based on aerospace data field observations on geomorphic processes and geological structure laboratory measurements of soil and bedrock samples and morphometric analysis several maps and spatial data were prepared to describe factors which are thought to be related with landform formations such as lineament distribution elevation slope and pipe distribution morphometric characteristics of biancane and calanchi steepness and slope length dominant active processes and the dip orientation of beddings joints and fault planes were investigated and 71 samples of soils and bedrock were taken to characterise their properties the results of the analyses of the soil bedrock samples show no significant differences in their properties between biancane and calanchi field observations do not support the idea that biancane are the final product of calanchi development but support the hypothesis that biancane and calanchi are formed under different terrain conditions related to structural patterns and denudation processes of highly erodible materials the origin of biancane is associated with highly dissected surfaces along a reticular system of small joints in contrast calanchi are formed on steep wall like slopes along larger lineaments where the rate of incision into the slopes surpasses the denudation of the densely vegetated back slope

mineralogical and grain size composition of clays developing calanchi and biancane erosional landforms abstract clayey terrains outcropping in many parts of italy are frequently affected by accelerated erosion processes producing landforms known as calanchi and biancane the calanchi are intensely dissected landscapes presenting rill and gully landforms and a dense dendritic drainage network the biancane are landforms characterized by bare cones and hummocks separated by flatter areas of surface wash deposits the factors controlling the development of these two landforms are still poorly understood this study was undertaken to identify the material properties of calanchi and biancane the data suggest a biancane tend to develop in very fine sediments such as silty clays with a very high clay content 65 70 b calanchi tend to occur in relatively coarser sediments such as clayey silts and sandy clayey silts having a notable sand fraction 6 18 c both biancane and calanchi may develop in intermediate textures such as silty clays and clayey silts made up of approximately equal quantities of silt and clay d no strong trend in clay mineralogy can be correlated with the landforms the swelling phyllosilicate contents are roughly equivalent in the parent materials of biancane and calanchi e pore water chemistry seems to play a very important role in the development of these landforms the biancane have high concentrations of sodium relative to other cations essentially calcium and magnesium in pore water all the analysed calanchi pore waters have low concentrations of sodium relative to divalent cations

factors controlling the erosion rates in a semi arid zone bardenas reales ne spain abstract bardenas reales is an erosive depression 415 km 2 in area located in the central western part of the ebro depression tertiary sediments crop out in the margin of the basin whereas quaternary sediments holocene in age occur only in its centre these holocene sediments clays and silts are the result of the erosion and weathering of the tertiary clays and are made up of 3 different stratigraphic units erosion is clearly the dominant process in the centre of the depression generating gullies up to 10 km in long and 8 m deep in order to analyse and quantify the erosion rates of the studied area erosion was measured on two soil erosion plots with volumetric and instrumental techniques that have been supplied for the last 12 years the results show that the estimated erosion rates depend extrinsically on the used method and intrinsically on the time of the year in which they are measured the most accurate values are those obtained by means of collector devices the values obtained by the microtopographic profile gauge are overestimated while the results of the measurement with erosion pins are clearly lower the study area is located in a semi arid environment with two pluviometric maximums in spring and autumn associated with convective storms in summer and winter rainfall is related to atlantic cyclonal fronts soil loss is significant during the pluviometric maximums when rainfall quantity and intensity are higher during cyclonal periods in contrast water erosion is null or scarce and soil loss is related to mudflows in addition the erosion rates of each holocene unit are different the c2 holocene unit has undergone greater erosion because of its physico chemical properties all the stratigraphic units have similar characteristics regarding tertiary materials since 1993 the average erosion rate measured by the collector device on the tertiary materials is 32 mg ha 1 year 1 and 77 mg ha 1 year 1 in the holocene

hydrochemistry of the saline groundwaters of the lower mersey basin permo triassic sandstone aquifer uk saline groundwater occurs at depth in the triassic sandstones of the northern end of the cheshire basin in northwest england major and minor ion data suggest that the origin of the salinity is dissolution of evaporite deposits the salinity probably developed in an interval following the tertiary inversion of the basin which would have allowed faulted contact between the sandstones and the overlying evaporite sequence of the mercia mudstone group isotope evidence suggests the saline waters to have been considerably diluted by presumably dispersive mixing with a meteoric water recharged under cool and therefore quaternary climatic conditions comparison with other uk permo triassic basin brines suggests the merseyside waters are not unusual except in terms of the importance of exchange reactions and dilution by quaternary recharge waters these factors are due to the shallow maximum burial depth of the aquifer and the preservation of smectites and also to the geometry of the aquifer and its low permeability faults in the light of the water chemistry data it is suggested in a slight modification of the proposal of naylor et al q geol soc lond 146 685 699 1988 that the cheshire basin mineralization resulted from mixing of the relatively oxidized so4 rich evaporite brines with the reduced so4 poor metal rich barich coal measures brines which were expelled through faults from the coal measures during basin inversion some degree of oxyhydroxide stripping of the sandstones by the coal measures brines would have enhanced metal concentrations the water resulting from the mixing of brines would have been far from equilibrium and the barite and sulphide precipitation followed along the faults

badlands denudation hot spots the role of parent material properties on geomorphic processes in 20 years monitored sites of southern tuscany italy abstract some monitoring stations have been recording for 20 years the geomorphic processes acting on calanchi and biancane badlands located in the tyrrhenian side of central italy field monitoring was aimed at studying the dynamics of surface processes such as sheet rill and gully erosion shallow landsliding piping and tunneling considering their space time variability as a consequence of both natural factors and human pressure this paper shows the results of grain size geochemical and mineralogical composition of parent materials from upper orcia valley sites southern tuscany to further elucidate the role of their properties on processes acting on both bare and vegetated surfaces parent materials properties are discussed with respect to the initiation and development of different badlands processes in particular clay dispersivity at different depths in the sample sites is examined as a well known controlling factor of accelerated erosion thus providing some interesting clues for understanding the spatial variability of denudation rates in the considered badlands sites

erosion processes in calanchi in the upper orcia valley southern tuscany italy based on multitemporal high resolution terrestrial lidar and uav surveys a 125 000 m2 calanchi badland in the province of siena tuscany was monitored with an unmanned aerial vehicle uav and terrestrial laser scanning over the period of one year tls terrestrial laser scanning was carried out on two sample slopes whereas the image acquisition of the uav covered the entire catchment in combination with ground control points the uav images were used to create orthophotos and 3d point clouds using the structure from motion sfm software photoscan the tls surface models indicate seasonal differences in erosion and deposition the surface change measured with sfm showed nearly 6 700 m3 of net material loss resulting from 8 700 m3 erosion and 2 000 m3 deposition these values reveal a mean annual surface lowering of 5 3 cm for the catchment additionally several geomorphological processes such as rill erosion slope wash and translational slides could be detected in the one year monitoring period a comparison of tls and sfm results showed differences in the calculated volumes of mobilised material these discrepancies resulted from shadowing effects and low point densities of the tls point clouds

dendrochronological and geomorphological investigations to assess water erosion and mass wasting processes in the apennines of southern tuscany italy abstract the tyrrhenian side of the central apennines is located in a lively geological context in which uplift denudation dynamics played a key role in landscape evolution intense water erosion and gravitational processes led to the development of spectacular badlands on the widespread clayey hillslopes the crete d arbia badlands as part of the crete senesi of southern tuscany represent one of the most beautiful examples of these landforms developed on pliocene clays on the other hand these rapidly evolving landforms endanger the artistic heritage of the area as with the monte oliveto maggiore abbey that was constructed on the top of a badland hillslope and confers additional value to the landscape in the perspective of monitoring and reconstructing some significant phases of the relief evolution of this area an integrated approach has been used which is based on dendrogeomorphology and geomorphological monitoring techniques in particular the correspondence between the data from dendrogeomorphological indicators and the measured denudation rates on badland hillslopes was tested the sampling for dendrogeomorphological analysis has been performed in two stages on 45 trees of the pinus pinea l species on hillslopes affected by soil creep and shallow landslides in order to identify annual ring growth anomalies compression wood and roots exposure trees local behaviour is not homogeneous but some common trends have been detected on the basis of the anomaly index and compression wood since 1993 several monitoring stations at badland denudation hot spots have been equipped with erosion pins quantitative data from monitoring stations compared to pluviometric series indicated critical phases of denudation that were supported by dendrochronological data the integrated approach between dendrogeomorphology and geomorphological monitoring techniques allowed calibration of both tools in order to extend the analysis in the period preceding the field measurements this kind of approach capable of implementation in many contexts could be particularly helpful in order to forecast the relief evolutionary trend