kinematics of the nicaraguan forearc from gps geodesy 1 campaign gps data from a network in the nicaraguan forearc show a strong component of arc parallel motion indicating northwest translation of a nearly rigid forearc sliver our measured mean velocity for forearc sites of 15 1 mm yr 1 agrees well with the arc parallel sliver motion predicted previously by demets 2001 derived from closure constraints on oblique convergence between the cocos and caribbean plates the lack of a northeasterly oriented arc normal component of motion in forearc velocities indicates that there are complexities involved beyond a simple interpretation of sliver motion being driven by oblique convergence the forearc is reasonably well fit by rigid rotation about an euler pole with a rms misfit of residual velocities of 4 9 2 6 mm yr 1 current motion of the forearc sliver relative to the stable caribbean plate yields predominantly boundary parallel nw motion with boundary normal extension in the northwestern region averaging 5m m yr 1 citation turner h l iii p lafemina a saballos g s mattioli p e jansma and t dixon 2007 kinematics of the nicaraguan forearc from gps geodesy geophys res lett 34 l02302 doi 10 1029 2006gl027586

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

composite transform convergent plate boundaries description and discussion abstract the leading edge of the overriding plate at an obliquely convergent boundary is commonly sliced by a system of strike slip faults this fault system is often structurally complex and may show correspondingly uneven strain effects with great vertical and translational shifts of the component blocks of the fault system the stress pattern and strain effects vary along the length of the system and change through time these margins are considered to be composite transform convergent ctc plate boundaries examples are given of structures formed along three ctc boundaries the aleutian ridge the solomon islands and the philippines the dynamism of the fault system along a ctc boundary can enhance vertical tectonism and basin formation this concept provides a framework for the evaluation of petroleum resources related to basin formation and mineral exploration related to igneous activity associated with transtensional processes

india and sunda plates motion and deformation along their boundary in myanmar determined by gps using a regional gps data set including 190 stations in asia from nepal to eastern indonesia and spanning 11 years we update the present day relative motion between the indian and sundaland plates and discuss the deformation taking place between them in myanmar revisiting measurements acquired on the main boundary thrust in nepal it appears that points in southern nepal exhibit negligible deformation with respect to mainland india including these points using a longer time span than previous studies and making an accurate geodetic mapping in the newest reference frame allows us to refine the present day indian motion our results confirm that the current motion of india is slower than predicted by the nuvel 1a model and in addition our india eurasia motion is significantly 5 mm yr slower than previous geodetic determinations this new indian motion combined with a refined determination of the sundaland motion gives way to a relative india sunda angular velocity of 20 2 n 26 1 e 0 370 myr in itrf2000 predicting a relative motion of 35 mm yr oriented n10 at the latitude of myanmar there the sagaing fault accommodates only 18 mm yr of right lateral strike slip only half of the shear component of motion we present two models addressing how and where the remaining deformation may occur a first model of distributed deformation implies convergence on the arakan subduction the northern continuation of the now famous sumatra andaman trench and wrench faulting in the arakan wedge the second model uses localized deformation where deformation observed west of the sagaing fault is entirely due to elastic loading on a faster and oblique arakan subduction 23 mm yr this latter model predicts that a major earthquake of mw 8 5 may occur every century on this segment of the subduction

sediment yield and erosion rate estimation in the mountain catchments of the camastra artificial reservoir southern italy a comparison between different empirical methods abstract the sedimentary budget assessment is an important topic for the scientific and social community because it is crucial to understand the dynamics of orogenic belts and cope with a number of practical problems such as soil conservation and sediment accumulation in reservoir sediment yield or denudation rate estimates in southern central italy are generally obtained either by applying simple empirical relationships based on the statistical regression between the geomorphic parameters of the drainage network and the suspended sediment yield measured at the drainage basins outlets or by using qualitative quantitative sediment delivery ratio or erosion models in this work we carry out a study of catchment dynamics and a sedimentary yield computation of several mountain catchments of the central western sector of the basilicata region southern italy which are located upstream of an artificial reservoir the sediment yield and erosion rate have been computed through both an indirect assessment of the suspended sediment yield based on the tu index mean annual suspension sediment yield and the application of the rusle and usped empirical methods the results obtained have been compared with the historical data of sediment accumulation measured in the artificial reservoir of the camastra dam where a detailed evaluation of the volumes of historical i e about 40 years sediment storage was collected the collected dataset represents a basic tool both for the investigation of the morpho dynamics of a typical mountain catchment of the mediterranean area and the evaluation of sediment budget related to fluvial and hillslope processes the 38 year long record of the sediment storage in the camastra artificial reservoir located at the outlet of the studied mountain catchments permits the validation of empirical relationships based on the geomorphic and climatic parameters of the drainage basin among the three different methods of sediment yield evaluation tu index rusle and usped the tu index showed the best prediction ability although usped erosion model also furnished a good estimation as also confirmed by other works the indirect estimation of sediment yield based on ciccacci s empirical relationships can represent a good proxy of short term denudation rates in the mediterranean areas with geological and geomorphological features similar to the study area but the use of empirical models with increasing complexity such as the usped erosion model can help to explore the spatial distribution of the sediment yield sectors of the drainage basin the erosion hot spots and the role of landslides in sediment mobilization and hillslope channel connectivity processes

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

tectonic drivers of the wrangell block insights on fore arc sliver processes from 3 d geodynamic models of alaska intracontinental shear zones can play a key role in understanding how plate convergence is manifested in the upper plate in regions of oblique subduction however the relative role of the driving forces from the subducting plate and the resisting force from within intracontinental shear zones is not well understood results from high resolution geographically referenced instantaneous 3d geodynamic models of flat slab subduction at the oblique convergent margin of alaska are presented these models investigate how viscosity and length of the denali fault intracontinental shear zone as well as coupling along the plate boundary interface modulate motion of the wrangell block forearc sliver and slip across the denali fault models with a weak denali fault 1017 pa s and strong plate coupling 1021 pa s were found to produce the fastest motions of the wrangell block 10 mm yr the 3d models predict along strike variation in offs et along the denali fault changing from dextral strike slip motion in the eastern segment to oblique convergence towards the fault apex models further show that the flat slab drives oblique motion of the wrangell block and contributes to 20 models with a short fault and 28 models with a long fault of the observed quaternary slip rates along the denali fault the 3d models provide insight into the general processes of forearc sliver mechanics and also offer a 3d framework for interpreting hazards in regions of flat slab subduction

displaced terranes in britain and ireland a meeting entitled displaced terranes in britain and ireland was held at burlington house on 2 november 1988 this was the third terranes meeting held in britain since the inception of international geological correlation project no 233 terranes in the circum atlantic palaeozoic orogens the others having been held at cardiff in 1986 and glasgow in 1987 igcp 233 grew out of igcp 27 the caledonide orogen many of the developments promoted by which are recorded within two special publications of the geological society harris et al 1979 harris fettes1988 over the last few years research on displaced terranes in the british caledonides has accelerated with new data now challenging what have become traditional applications of plate tectonic theory to the british caledonides the reports of work in progress on caledonian terranes and it was thought appropriate to take advantage of the rapid publication facilities afforded by the short papers scheme because of the four page limit on short papers much introductory material has had to be omitted so that we provide here an introduction to the concept of displaced terranes and its applications to british palaeozoic geology displaced terranes the essential value of the terrane concept lies in its recognition of the likelihood of large scale lateral fault movements occurring along active plate margins the concept of terrane tectonics is therefore no more than a fuller appreciation of the kinematic implications of plate tectonic theory the impact of this recognition upon our perception of geotectonic processes in general and the

modeling soil erosion and river sediment yield for an intermountain drainage basin of the central apennines italy abstract the overall aim of this research was to investigate the spatial patterns of the soil erosion risk we focused on accelerated soil erosion processes in an italian central apennine intermountain watershed using modeling techniques implemented in a gis environment our thorough literature review revealed a gap in research on soil erosion processes in such forested intermountain watersheds to gain a better understanding of the soil erosion processes in such landscapes we proposed an integrated modeling approach applying a rusle model and a turbidity unit index the model outcomes were validated through measurements of lake sediment deposition our findings indicate a potential high soil erosion risk with 1 33 m t 1 yr 1 of annual sediment yield corresponding to an area specific sediment yield of 32 35 t ha 1 yr 1 the turano drainage basin belongs to the italian basins with the highest sediment discharge the outcomes of the rusle model showed that despite the diverse forms of forests that cover about 62 of the drainage basin area sizable plots of the investigated area are prone to soil erosion the validation of the model outcomes revealed that the tu index model performed significantly better than the rusle model with regard to sediment yield prediction accordingly we found that even though rill and interrill processes reach very alarming values rusle they are not the dominant sediment source within the turano watershed other geomorphological processes contributing to the watershed sediment yield for instance megarill gully bank and channel erosion and re entrainment of landslide sediments were very active in the study area if both models are used in a combined approach the amount of river load tu index as well as the relative spatial distribution of rill and interrill erosion processes rusle can be described with sufficient precision

strain partitioning in transpression zones abstract transprcssional strain acting upon structurally anisotropic rocks can be partitioned into separate deformational domains of pure shear and simple shear this contrasts with homogeneous transpression in which both the pure shear and the simple shear strain components are uniformly distributed across the zone of deformation structural weaknesses capable of partially or fully accommodating one component of deformation include lithological contacts rheological heterogeneities and faults or shear zones situated within the deformation zone or lying along its boundaries partitioning of transprcssional strain can occur when stress is applied oblique to pre existing structural weaknesses or can occur during later stages of progressive strain when the early deformation of isotropic rocks imparts sufficient anisotropy to allow subsequent strain to be partitioned partitioning of transpressional strain into domains lying parallel to the deformation zone boundaries can be distinguished from fault stepped transpression in which strain is partitioned along the length of a segmented fault zone mesofracture analysis of rocks affected by mid devonian deformation on both sides of the highland boundary fault zone hbfz in central scotland shows that strain was not homogeneous the mesofracture data suggest that regional north south compression orientated oblique to the pre existing ne sw trending hbfz was partitioned into separate deformational domains the hbfz accommodated most of the simple shear component whilst the rocks flanking the zone were deformed predominantly by pure shear a contemporary example is the san andreas fault in central california where analyses of neo tectonic stresses show that the direction of principal compression is perpendicular to the fault zone many examples of the partitioning of transpressional strain have also been recognised at destructive plate margins where the direction of plate motion is oblique to the edge of the over riding plate

fore arc motion and cocos ridge collision in central america 1 we present the first regional surface velocity field for central america showing crustal response to interaction of the cocos and caribbean plates elastic half space models for interseismic strain accumulation on the dipping subduction plate boundary fit the gps data well and show strain accumulation offshore and beneath the nicoya and osa peninsulas in costa rica but not in nicaragua since large subduction zone earthquakes occur in nicaragua we suggest that interseismic locking in nicaragua and some other parts of central america occurs but is mainly shallow 20 km depth too far offshore to be detected by our on land gps measurements our data also show significant trench parallel motion for most of the region generally interpreted as due to oblique convergence and strong mechanical coupling between subducting and overriding plates however trench parallel motion is also observed in central costa rica where plate convergence is normal to the trench and in the nicaraguan fore arc where trench parallel motion is fast up to 9 mm a 1 but mechanical coupling is low a finite element model of collision as opposed to subduction involving the aseismic cocos ridge also fits the gps surface velocity field most significantly reproducing the pattern of trench parallel motion we infer that buoyant thickened cns 2 cocos ridge crust resists normal subduction and instead acts as an indenter to the caribbean plate driving crustal shortening in southern costa rica and contributing to trench parallel fore arc motion in costa rica and perhaps nicaragua as a type of tectonic escape

extensional basins in the tectonically bimodal central apennines fold thrust belt italy response to corner flow above a subducting slab in retrograde motion the apennines fold thrust belt has developed over the past 20 m y in response to southeastward retrograde migration of the adriatic trench in a region of ongoing subduction but little plate convergence the orogenic belt is characterized by a gently sloping southwestern flank in a state of regional extensional collapse and a steeply sloping northeastern flank in regional contraction in any given area in the central apennines the chronologies of thrusting and subsequent extension provide an estimate of the time required for attainment of high elevation 2 5 3 0 km the time between initial extension and eruption of local ultramafic lavas provides an estimate of the time required to collapse by regional crustal thinning these estimates suggest that the northeastern contractional flank of the range is rising at least twice as fast as the southwestern flank is collapsing we propose that the bimodal state of stress in the apennines is maintained by corner flow in the mantle wedge beneath the crest of the range

the southwest ryukyu arc is a migrating microplate forearc sliver abstract we propose a new interpretation for the tectonism of the southwest ryukyu arc based on inland stress field analyses and the interpretation of seismic reflection profiles the recent stress field in the southwest ryukyu arc is under tension the axial direction of which is parallel to the trench axis but an e w dextral slip shear zone is developing at its western extremity yonaguni and westwards to taiwan these features are closely related to the degree of the oblique subduction of the philippine sea plate and the strength of coupling between it and southwest ryukyu arc we regard the southwest ryukyu arc as a migrating microplate the neotectonics of the southwest ryukyu arc are attributed to the westward migration of the microplate which is bounded by the miyako depression to the east and by taiwan to the west the microplate obducting onto the eurasian plate at taiwan started to migrate westward at about 4 ma when the relative motion between two plates philippine sea and eurasian changed direction from s n to se nw in region

limit of strain partitioning in the himalaya marked by large earthquakes in western nepal great earthquakes in the himalaya are thought to occur mostly along the range front field mapping and radiocarbon dating reveal earthquake rupture on a previously unrecognized fault in the interior of the western himalaya which forms part of a key structural component of the mountain range implying that seismic risk evaluations should be revised

a new procedure for gridding elevation and stream line data with automatic removal of spurious pits abstract a morphological approach to the interpolation of regular grid digital elevation models dems from surface specific elevation data points and selected stream lines is described the approach has given rise to a computationally efficient interpolation procedure which couples the minimization of a terrain specific roughness penalty with an automatic drainage enforcement algorithm the drainage enforcement algorithm removes spurious sinks or pits yielding dems which may be used to advantage in hydrological process studies the drainage enforcement algorithm has also been found to significantly increase the accuracy of dems interpolated from sparse but well chosen surface specific elevation data moreover it facilitates the detection of errors in elevation data that would not be detected by more conventional statistical means and forms a sound physical basis for cartographic generalization

role of strike slip faulting in the tectonic evolution of the antarctic peninsula the antarctic peninsula mesozoic magmatic arc has had a long history of dextral strike slip deformation the deformation was initially associated with the development of a wide accretionary complex by the migration of fore arc slivers and the formation and inversion of a thick fore arc basin succession it also formed an important component within major shear zones in the arc and may have controlled the formation of sedimentary basins in the back arc region although some transcurrent motion within the fore arc region was related to a component of oblique subduction the main movement occurred during the breakup of gondwanaland and the formation of a major transtensional rift system a new reconstruction for this part of gondwanaland is presented taking this transcurrent motion into consideration

model simulations of tsunamis generated by the storegga slides abstract a mathematical model based on the hydrodynamic shallow water equations is developed for numerical simulation of water waves generated by the submarine storegga slides on the norwegian continental slope the equations are solved numerically by a finite difference technique computations of wave amplification effects reveal run up heights for the second storegga slide between 3 and 5 m in exposed areas along the eastern coast of greenland iceland and scotland and the western coast of norway the calculated run up heights agree remarkably well with possible tsunami wave heights deduced from geological evidences along the eastern coast of scotland the generated wave heights are strongly dependent on the acceleration of the slide the effects of shear stress at the interface between the water and the slide body has turned out to be important

terrane motion by strike slip faulting of forearc slivers forearc slivers bounded by a trench and an active strike slip fault occur in about 50 of modern subduction zones analysis of earthquake slip vectors indicates that modern sliver terranes typically migrate at rates of 1 2 cm yr tertiary transport of some forearc slivers by 1000 km or more is therefore expected as a consequence of normal subduction active arc parallel strike slip faulting occurs whenever interplate coupling is strong and convergence is somewhat oblique strike slip rate increases with greater convergence obliquity

assessment of land degradation susceptibility by scenario analysis a case study in southern tuscany italy abstract in the mediterranean area land degradation phenomena are becoming more and more important due to future climate change and increasing climate variability as highlighted in recent global assessment projects such as the millennium ecosystem assessment or the dialogue on water and climate thus there is consistent evidence that extreme events such as droughts and floods are more frequent than before on the other hand the mediterranean area is strongly influenced by human activities such as cultivation over hundreds of years however in the last decades the cultivation methods and techniques are subject to profound changes such as mechanization use of fertilizers and pesticides remodellation of entire hillslopes etc this particular situation leads to and aggravates the existing stress on land resources as a result land degradation and soil erosion phenomena are leading to decreasing soil productivity or the loss of fertile top soil and related water quality and quantity issues the centre for soil erosion studies cres in grosseto tuscany recently started a study to identify and monitor changes of land use in southern tuscany italy the aim of this study is to assess land degradation sensitivity by scenario analysis as a proxi for land degradation surface wash erosion processes such as rill and interill erosion processes are chosen these present day processes are identified by aerial photo interpretation and subsequently modelled with a simple rusle approach on a monthly basis in this study boundary conditions such as future precipitation were taken from the a2 future climate scenario published by the international panel on climate change ipcc special report on emission scenarios sres moreover current land use was identified from aerial photographs and future land use scenarios were developed considering ecological and socio economical issues for present day conditions of the test area subsequently the different climate and land use scenarios were analysed to study soil erosion susceptibility on the landscape scale the study shows that even with a decline in precipitation volume until 2070 in some months higher erosion rates occur due to higher rainfall erosivity furthermore land use changes play an important role for soil erosion susceptibility as shown the various scenarios can effectively reduce or enhance soil erosion

restoration of cenozoic deformation in asia and the size of greater india a long standing problem in the geological evolution of the india asia collision zone is how and where convergence between india and asia was accommodated since collision proposed collision ages vary from 65 to 35 ma although most data sets are consistent with collision being underway by 50 ma plate reconstructions show that since 50 ma 2400 3200 km west to east of india asia convergence occurred much more than the 450 900 km of documented himalayan shortening current models therefore suggest that most post 50 ma convergence was accommodated north of the indus yarlung suture zone we review kinematic data and construct an updated restoration of cenozoic asian deformation to test this assumption we show that geologic studies have documented 600 750 km of n s cenozoic shortening across and north of the tibetan plateau the pamir hindu kush region accommodated 1050 km of n s convergence geological evidence from tibet is inconsistent with models that propose 750 1250 km of eastward extrusion of indochina approximately 250 km of indochinese extrusion from 30 to 20 ma of indochina suggested by se asia reconstructions can be reconciled by dextral transpression in eastern tibet we use our reconstruction to calculate the required size of greater india as a function of collision age even with a 35 ma collision age the size of greater india is 2 3 times larger than himalayan shortening for a 50 ma collision the size of greater india from west to east is 1350 2600 km consistent with robust paleomagnetic data from upper cretaceous paleocene tethyan himalayan strata these estimates for the size of greater india far exceed documented shortening in the himalaya we conclude that most of greater india was consumed by subduction or underthrusting without leaving a geological record that has been recognized at the surface

assessment of soil erosion sensitivity and post timber harvesting erosion response in a mountain environment of central italy article i nfo this study aimed to assess the effects of forest management on the occurrence of accelerated soil erosion by water the study site is located in a mountainous area of the italian central apennines here forest harvesting is a widespread forestry activity and is mainly performed on the moderate to steep slopes of the highlands through modeling operations based on data on soil properties and direct monitoring of changes in the post forest harvestingsoilsurfacelevelatthehillslope scale we show thattheobserved site became pronetosoilero sion after human intervention indeed the measured mean soil erosion rate of 49 t ha 1 yr 1 for the harvested watershed is about 21 times higher than the rate measured in its neighboring undisturbed forested watershed 2 3 t ha 1 yr 1 the erosive response is greatly aggravated by exposing the just harvested forest with very limited herbaceous plant cover to the aggressive attack of the heaviest annual rainfall without adopting any conservation practices the erosivity of the storms during the first four months of field measurements was 1571 mj mm h 1 ha 1

climate scale modelling of suspended sediment load in an alpine catchment debris flow rio cordon northeastern italy abstract pulsing storms and prolonged rainfall can drive hydrological damaging events in mountain regions with soil erosion and debris flow in river catchments the paper presents a parsimonious model for estimating climate forcing on sediment loads in an alpine catchment rio cordon northeastern italian alps hydroclimatic forcing was interpreted by the novel clismssl climate scale modelling of suspended sediment load model to estimate annual sediment loads we used annual data on suspended solid loads monitored at an experimental station from 1987 to 2001 and on monthly precipitation data the quality of sediment load data was critically examined and one outlying year was identified and removed from further analyses this outlier revealed that our model underestimates exceptionally high sediment loads in years characterized by a severe flood event for all other years the clismssl performed well with a determination coefficient r2 equal to 0 67 and a mean absolute error mae of 129 mg y 1 the calibrated model for the period 1986 2010 was used to reconstruct sediment loads in the river catchment for historical times when detailed precipitation records are not available for the period 1810 2010 the model results indicate that the past centuries have been characterized by large interannual to interdecadal fluctuations in the conditions affecting sediment loads this paper argues that climate induced erosion processes in alpine areas and their impact on environment should be given more attention in discussions about climate driven strategies future work should focus on delineating the extents of these findings e g at other catchments of the european alpine belt as well as investigating the dynamics for the formation of sediment loads

modeling sediment yields in italian catchments abstract sediment yield observations derived from 40 long term sedimentation records in italian reservoirs were used to calibrate and validate the spatially distributed sediment delivery model watem sedem using the best data available at national scale the sediment yield data set includes records from semi natural catchments in northern italy as well as agricultural and semi natural basins in central and southern italy the average size of the catchments is 150 km2 with mean annual sediment yields ranging from 0 20 to 20 t ha 1 year 1 watem sedem estimates mean annual sediment fluxes to permanent river channels depending on the local transport capacity the sediment flux is detachment limited or transport limited the optimal transport capacity parameters for italian conditions were derived via automatic calibration procedures a global model calibration procedure taking into account all catchments in the dataset led to an overestimation of the sediment yield for the mountain catchments and an underestimation for the non mountain catchments sediment yield estimates are more reliable when calibration procedures are applied separately for mountain and non mountain catchments the model performance of watem sedem is rather poor in the mountain catchments r 0 25 which suggests that the model structure is too simplified to come to an adequate description of the sediment fluxes the model performance for the non mountain catchments which are more important from a management point of view is significantly better r 0 51 considering the fact that data layers with a 75 75 m resolution were used the results are encouraging the further development and application of spatially distributed sediment yield models at regional and national scale levels

assessing space time variations of denudation processes and related soil loss from 1955 to 2016 in southern italy calabria region studies on denudation processes and soil loss rates can provide insight into the landscape evolution climate change and human activities as well as on land degradation risk the aims of this study were to analyze the space time distribution of denudation processes and evaluate the soil loss changes occurred during the period 1955 2016 by using an approach integrating geomorphological geospatial and modeling analysis the study area is a representative stream catchment of the crati valley calabria southern italy which is affected by severe erosion processes the combined use of aerial photographs interpretation field survey geostatistics and gis processing has allowed to characterize the types of denudation processes and land use change in space and time revised universal soil loss equation implemented in gis environment was used to estimate the space time pattern of soil loss and the soil erosion rates for each investigated year the results showed that from 1955 to 2016 the study area was highly affected by denudation processes mainly related to landslides and water erosion slope wash erosion and gully erosion comparison of denudation processes maps showed that the total area affected by erosion processes has increased by about 31 and the distribution of geomorphic processes and their space time evolution resulted from the complex interrelation between geoenvironmental features and human activities the main land use changes concerned a decrease in areas covered by woodland scrubland and pasture and an increase in croplands and barren lands that favored erosion processes the most susceptible areas to soil loss in both years were mapped and the mean soil loss rates for the study area were 6 33 mg ha 1 y 1 in 1955 and 10 38 mg ha 1 y 1 in 2016 furthermore the soil loss in 2016 has increased by about 64 compared to 1955 finally the results showed that integrating multi temporal analysis of denudation processes land use changes and soil loss rates might provide significant information on landscape evolution which supports decision makers in defining soil management and conservation practices

soil erosion risk scenarios in the mediterranean environment using rusle and gis an application model for calabria southern italy abstract soil erosion by water wse has become a relevant issue at the mediterranean level in particular natural conditions and human impact have made the calabria southern italy particularly prone to intense wse the purpose of this investigation is to identify areas highly affected by wse in calabria by comparing the scenarios obtained by assuming control and preventive measures and actions as well as actual conditions generated by forest fires also in the presence of conditions of maximum rainfall erosion geographic information system techniques have been adopted to treat data of reasonable spatial resolution obtained at a regional scale for application to the rusle model this work is based on the comparison of such data with a basic scenario that has been defined by the present situation present scenario in this scenario i r has been assessed by means of an experimental relation adjusted to calabria on the basis of 5 min observations ii k has been drawn from the soil map of calabria including 160 soilscapes iii ls has been estimated according to the rusle2 model by using among other subfactors a 40 m square cell dtm iv c has been derived by processing the data inferred from the project corine land cover whose legend includes 35 different land uses on three levels and v p has been hypothesized as equal to 1 for the remaining three hypothesized scenarios the rusle factors have been adjusted according to experimental data and to data in the literature in particular forest areas subject to fire have been randomly generated as far as fire location extension structure and intensity are concerned the values obtained by the application of the rusle model have emphasized that land management by means of measures and actions for reducing wse causes a notable reduction of the erosive rate decreasing from 30 to 12 3 mg ha 1 y 1 on the other hand variations induced by hypothetical wildfires in forests on 10 of the regional territory bring wse over the whole region to values varying from 30 to 116 mg ha 1 y 1 this study can be offered to territorial planning authorities as an evaluation instrument as it highlights the merits and limitations of some territorial management actions in fact in calabria no observations exist concerning the implications of these actions