advances in fourier transform infrared spectroscopy of natural glasses from sample preparation to data analysis fourier transform infrared spectroscopy ftir is an analytical technique utilized to measure the concentrations of h and c species in volcanic glasses water and co2 are the most abundant volatile species in volcanic systems water is present in magmas in higher concentrations than co2 and is also more soluble at lower pressures and therefore it is the dominant volatile forming bubbles during volcanic eruptions dissolved water affects both phase equilibria and melt physical properties such as density and viscosity therefore water is important for understanding magmatic processes additionally quantitative measurements of different volatile species using ftir can be achieved at high spatial resolution recent developments in analytical equipment such as synchrotron light sources and the development of focal plane array fpa detectors allow higher resolution measurements and the acquisition of concentration maps these new capabilities are being used to characterize spatial gradients or lack thereof around bubbles and other textural features which in turn lead to new insights into the behavior of volcanic feeder systems here practical insights about sample preparation and analysis of the distribution and speciation of volatiles in volcanic glasses using ftir spectroscopy are discussed new advances in the field of ftir analysis produce reliable data at high spatial resolution that can be used to produce datasets on the distribution dissolution and diffusion of volatiles in volcanic materials

use of airborne lidar and historical aerial photos for characterising the history of braided river floodplain morphology and vegetation responses this paper combines synoptic airborne lidar data with historical aerial photos to reconstruct floodplain formation and relate this with vegetation patch characteristics on three different alpine braided rivers in france displaying a gradient of geomorphic activity bouinenc drome bes lidar data were processed to extract understory topography and vegetation properties once combined with sequential aerial photographs for the dating of floodplain formation they were used to establish the timing of channel incision associated with active channel narrowing it has thus been possible not only to reconstruct the main incision periods following the end of the little ice age but also to show the geomorphic effect of floods on active channel widening which was clearly modulated by sediment supply conditions well developed floodplains with a predominance of mature vegetation units are associated with long term narrowing and incision trajectories whereas rivers maintaining a wide active channel over time show equi diversity of floodplain vegetation units the presence of shrub patches seems to be a good indicator of incision periods a discriminant analysis using lidar derived topographic and vegetation properties of floodplain patches as well as their age provided a validation of the expert based mapping of physiognomic vegetation units shrubland sparse pioneer dense pioneer and post pioneer units this approach also provides insights into identification and interpretation of misclassifications and open new perspectives for exploring landscape ecological trajectories and their controlling factors

morphological changes and human impact in the entella river floodplain northern italy from the 17th century abstract in this article the morphological changes undergone by the entella river northern italy over the last four centuries has been investigated the historical analysis has allowed reconstruction of fluvial evolution and shoreline dynamics and demonstrated their relationship to human disturbance over a very long period compared to most previous studies in italy and europe a set of 12 historical and current maps and aerial photos ranging from the 17th century to the present were entered into a geographic information system gis in order to calculate four morphological parameters i e channel length width sinuosity and centreline shifting and the distance of the shoreline modification of the entella river over the 360 years period 1656 2016 include i a reduction in channel length by 128 m 3 ii a mean narrowing of 56 m 46 iii a decrease in total sinuosity from 1 10 to 1 05 with a variation in river pattern from sinuous to straight iv a total shifting of the centreline of 30 m this evolutionary trend is consistent with most of the previous studies on italian and european rivers conversely the total channel shortening and the recent phase of substantial morphological stability with a slight increase in channel width and length seems to be in contrast with the results of other studies we correlated the channel planform changes and the regression of the shoreline at least until the latter 20th century to the reduction in sediment supply produced by the morphological modifications due to human intervention at the beginning of the 19th century and later from the 1950s to the end of the 20th century channelization channel diversion land use changes and coastal defences accounted for this supply change to the entella river and its floodplain furthermore our findings reveal that human disturbance has contributed to increased flood risk in the plain through the progressive reduction in width of the riverbed and the increasing urbanization along its riverbanks at the same time channelization seems to have a negative effect not only on the morphological evolution of the river but also in terms of prevention and flood risk reduction within the floodplain

estimation and propagation of error in measurements of river channel movement from aerial imagery rates of river channel migration or widening are only valid if it can be demonstrated that the amount of change in the measured parameters exceeds the measurement errors however it is still uncommon to see estimates of errors presented alongside rates of river channel change measured from aerial photography here detailed methods are presented for the estimation of errors in quantifying channel migration rates that can be easily applied to gis based analysis of planform change in addition the impact of relaxing assumptions regarding error independence between image dates and systematic registration errors is presented and discussed copyright 2005 john wiley sons ltd

estimation of error in bankfull width comparisons from temporally sequenced raw and corrected aerial photographs this study investigates the propagation of error through image to image comparison of 285 river bankfull width measurements of the afon trannon mid wales bankfull width is quantified from both aerial photographs analysed as rectified images in erdas imagine orthomax and raw images in paintshop pro a method for the robust estimation of bankfull width measurement error through temporal sequences of scanned aerial photographs is presented and the improvement in accuracy achieved using rectified imagery is quantified results from this study are placed in the context of previously published rates of bankfull width change from a wide range of river scales and the bankfull change rates for robust medium term analysis using approximately 1 10 000 historical aerial photography are identified

channel morphology changes and their relationship to valley bottom geology and human interventions a case study from the vistula valley in warsaw poland the aim of the study was to determine the role of the geological setting of channel zone in the morphological variability of a river reach situated between engineered and seminatural channel sections investigations were carried out in the vistula river channel in warsaw the study included the drilling of 60 geological boreholes in the river channel and the registering of sedimentary structures of modern river channel sediments the morphology of the channel was defined based on a series of bathymetric measurements of different river levels to identify the reasons for the variation in the channel bed morphology numerical modelling of river flow was performed calculations were made using the fluent cfd computational fluid dynamics model the stabilization of bottom erosion along the engineered reach of the river was found to be associated with a shallow depth to the top of the basement of modern alluvial sediments composed of erosion resistant glacial deposits the suballuvial basement in this part of the river channel also serves as a local base level in relation to the river reach upstream

channel forms recovery in an ephemeral river after gravel mining palancia river eastern spain abstract during the 1970s the palancia river was intensively affected by gravel mining instream this activity completely destroyed the fluvial forms devastating the original wandering pattern at the end of the 1980s gravel mining ceased and the river started a process of recovery only altered by several clearing operations the aim of this work is to describe these processes of change analyzing the river s morphosedimentary conditions through a gis analysis of aerial photographs previous to simultaneous with and subsequent to the intense gravel mining activity results explain the current difficulties of some ephemeral rivers to recover their original forms because of the sediment and water deficit conditions the critical role of channel incision and inappropriate actions of river clearing and channelization for flood prevention

spatial disaggregation and aggregation procedures for characterizing fluvial features at the network scale application to the rhone basin france network scale heterogeneity in fluvial forms and processes has been analyzed for decades through the field based characterization of a reduced number of sites spatially continuous data sets are increasingly available at a national scale e g digital elevation models or aerial orthophotographs and open up new possibilities to investigate spatial structures in stream networks the paper introduces a gis methodological framework to support and automate the large scale characterization of the fluvial system based on spatial disaggregation and aggregation procedures the spatial disaggregation consists in the longitudinal discretisation of geographical objects into relatively high resolution spatial units to characterize fluvial features continuously along stream networks because rivers are heterogeneous and hierarchically organized the spatial aggregation aims to delineate statistically pattern or process based spatial units to answer questions at appropriate scales the paper develops the gis implementation of the disaggregation and aggregation procedures for characterizing stream networks in a geomorphic perspective we illustrate the approach on the rhone network focusing on the characterization of three geographical objects commonly used in classification schemes the streamline the valley bottom and the active channel the latter on a limited area the spatial aggregation is automated using the threshold test of pettitt 1979 to detect change points in univariate data series and delineate homogeneous spatial units throughout the stream network we provide three simple application examples to illustrate the potentialities of the spatial aggregation to investigate spatial heterogeneity in stream networks finally insights limitations and future challenging issues emerging from the application of the methodological framework are discussed

recent channel adjustments in alluvial rivers of tuscany central italy drastic channel adjustments have affected the main alluvial rivers of tuscany central italy during the 20th century bed level adjustments were identified both by comparing available topographic longitudinal profiles of different years and through field observations changes in channel width were investigated by comparing available aerial photographs 1954 and 1993 98 bed incision represents the dominant type of vertical adjustment and is generalized along all the fluvial systems investigated the arno river system is the most affected by bed level lowering up to 9 m whereas lower incision generally less than 2 m is observed along the rivers of the southern part of the region human disturbances appear to be the dominant factors of adjustments the main phase of vertical change occurred during the period 1945 80 in concomitance with the phase of maximum sediment mining activity at the regional scale the second dominant type of adjustment that involved most of the rivers in the region consists of a narrowing of the active channel based on measurements of channel width conducted on aerial photographs 38 of the reaches analysed experienced a narrowing greater than 50 of the initial channel width the largest values of channel narrowing were observed along initially braided or sinuous with alternate bars morphologies in the southern portion of the region a regional scheme of channel adjustments is derived based on initial channel morphology and on the amounts of incision and narrowing different styles of channel adjustments are described rivers that were originally sinuous with alternate bars to braided generally became adjusted by a moderate incision and a moderate to intense narrowing in contrast sinuous meandering channels mainly adjusted vertically with a minor amount of narrowing copyright 2003 john wiley sons ltd

relation between eurasian snow cover snow depth and the indian summer monsoon an observational study abstract satellite derived snow cover data for 22 yr and snow depth data for 9 yr over eurasia have been analyzed to reexamine the possible relation of snow with the indian summer monsoon in contrast to the previous studies that use snow cover averaged over all of eurasia as a single number the frequency of occurrence of snow at each grid point over eurasia is correlated with the indian summer monsoon rainfall thus specific geographical regions over eurasia that are responsible for the well known inverse relationship between eurasian snow cover and indian monsoon rainfall are delineated it is found somewhat surprisingly that western eurasia is the only geographical region for which a significant inverse correlation exists between winter snow cover and subsequent summer monsoon rainfall however composites for high and low snow cover over eurasia show spatially homogeneous large scale patterns of snow cover and surface temperature anomalies winters of high and low snow cover for eurasia are found t

morphological changes of the floodplain reach of the taro river northern italy in the last two centuries summary the quantitative analysis of the planform changes of the unconfined reach of the taro river in the italian northern apennines has allowed the channel evolution in the last 200 years to be outlined nine sets of maps and orthophotos ranging from 1828 to 2011 have been used to evaluate the medium term changes in channel morphology along the entire time interval as well as the short term changes in the most recent decade starting from the digitized channel limits and bars a number of shell scripts based on gis commands has been used for fast and automatic calculation of the main morphological parameters channel length width braiding sinuosity centerline shifting and for the drawing of graphs showing in detail their continuous variations along the entire study reach the analysis of the differences in parameters on subsequent dates has revealed that at least until the end of the 20th century continuous reduction in channel width up to a total of 75 and braiding 43 as well as continuous increase in channel length 13 and sinuosity 29 took place this is in agreement with most of the previous studies on other rivers both in italy and abroad in contrast with the results of other studies the most recent evolutionary trend of the taro river shows substantial morphological stability with possible slight narrowing the identification of the variations along the channel facilitated by the analysis of the parameter curves and supported by the historical documentation reveals that these variations can be substantially attributed to human activities in particular the continuous narrowing is largely due to the recurrent subtraction of riverbed areas to be used for agricultural and industrial purposes as well as to the construction of 10 bridges with the relevant bank protections the intense mining between 1950s and 1980s seems to have caused a sharp incision and partial narrowing only the morphological changes due to the reduction in the flow regime which seem to emerge from the sporadic and discontinuous hydrological data are expected to be negligible and in any case are immaterial when compared with the remarkable changes due to human activities

channel adjustments in a mediterranean river over the last 150 years in the context of anthropic and natural controls abstract evolutionary trajectories and related control factors of the fortore river southern italy are analyzed over a 150 year period as to assess channel modifications a multitemporal gis analysis of topographic maps and aerial photographs together with topographic and geomorphological field surveys were performed attention was focused on the impact caused by human disturbance above all the presence of the occhito dam at only 40 km upstream of the fortore mouth central adriatic coast results show that channel adjustments occurred in three distinct phases and were primarily driven by human disturbance that diversely affected reaches located upstream and downstream of the dam from the last decades of the nineteenth century to the 1950s phase 1 channel widening prevailed along upstream reaches whilst narrowing along downstream reaches major channel adjustments occurred from the 1950s until the end of the 1990s phase 2 especially channel narrowing of up to 81 in upstream reaches and 98 in downstream reaches narrowing was accompanied by channel bed lowering of 1 to 5 m and by pattern changes in prevalence from multithread to largely prevailing single thread channel configurations in channel mining channel works and hydraulic interventions are considered key driving factors of observed channel adjustments the closure of the occhito dam in 1966 had significant and permanent effects on downstream reaches through overall discharge regulation and permanent sediment trapping as also proved by the progressive retreat of the fortore river mouth area from 2000 to 2015 phase 3 a substantial trend inversion was observed with overall channel widening and partial aggradation of upstream reaches and total stabilization of downstream reaches as highlighted by an integrated multitemporal analysis of recent channel changes and flood events the latter have played an important role in channel recovery of upstream reaches comparison between the fortore river and other rivers in southern italy has allowed us to ascertain that the reconstructed evolutionary trajectories are quite similar and that control factors are essentially the same in particular it confirms the role of major hydraulic structures as to the amount of channel adjustments of downstream reaches and the ensuing scarce to nil potential to channel recovery of regulated reaches

assessment of channel changes in a mediterranean ephemeral stream since the early twentieth century the rambla de cervera eastern spain abstract an analysis of morphological changes during the last six decades is presented for a 16 5 km reach of the rambla de cervera a mediterranean ephemeral stream located in eastern spain channel changes were analysed through a range of techniques specifically the analysis of aerial photographs with geographical information systems gis and comparison of topographic surveys the gravel channel underwent a general decline over the study period losing width 68 5 and surface area 45 7 caused by the development of established islands frequently attached to the floodplain these morphological changes exhibit an interesting temporal variability with a maximum decrease of the gravel channel in the period 1946 1956 and another narrowing stage between 1977 and 1991 two periods 1956 1977 and 1991 2006 also had mixed performance in addition incision processes occurred along the entire study reach at an average depth of 3 5 m natural and human induced factors producing contradictory effects are considered responsible for changes in the rambla de cervera

continental depositional systems of the quaternary of the po plain northern italy abstract the po plain is a molasse foredeep bounded by two mountain chains apennines and alps apenninic thrusting is still active whereas the alpine one ended by early pliocene times the continental deposits form a veneer at the surface and form the topset of a prograding complex the po river divides the plain into two sectors with different sedimentary facies and body geometries to the south the alluvial fan and plain deposits are small embedded in clays and show elongate shapes to the north sedimentary bodies are laterally extensive tabular and with minor amounts of fine grained sediments this difference could be due to a different climatic conditions during quaternary ice ages on the two sides of the basin b different structural settings in the two sectors of the basin that produce a higher subsidence rate to the south c different lithologies in the source areas i e alps and apennines

assessment of morphological changes induced by flow and flood pulses in a gravel bed braided river the tagliamento river italy large gravel bed braided rivers show a highly dynamic evolution where even moderate flow pulses can produce significant morphological adjustment an estimation of network variations is needed by river authorities as well as by ecologists for better managing river ecosystems however few field investigations have been performed to measure the effect of unsteady discharges in braided rivers in this paper we report on the morphological changes induced by six different floods in a 1 km long reach of the tagliamento river italy topographic surveys were performed after each significant flood and an automatic digital camera continuously monitored the planimetric configuration repeated measurements of cross section profiles allowed the quantification of the transported sediments volume and in particular provided a basis to estimate the percentage of the floodplain subject to morphological evolution data analysis showed a good relationship between peak flow level active width and mean bed level changes similarly lateral channel shifting is likely to increase for larger floods monitoring of a range of discharges up to bankfull conditions revealed a fundamental difference between flow pulses events on the average occurring one or more times per year and flood pulses with a return period larger than two years the morphological evolution in the former case is mainly limited to a few active branches and is locally driven by bank erosion at the bend apex on the other hand larger floods induce a complete reworking of the network configuration where bifurcations and confluences play a crucial role single morphological units like branches nodes bars are no longer recognizable after this type of event braided rivers are therefore characterized by the occurrence of two different spatial and temporal scales that force the ecosystem dynamics

fluvialcorridor a new arcgis toolbox package for multiscale riverscape exploration abstract both for scientists and river basin managers development of automated geographic information system gis tools is essential today to characterize riverscapes and explore biogeomorphologic processes over large channel networks since the 1990s gis toolboxes and add in programs have been used to characterize catchments however there is currently no equivalent to a planimetric and longitudinal characterization of fluvial corridor networks at multiple scales this paper describes fluvialcorridor a new gis toolbox this package allows the user i to extract a large set of riverscape features such as the main components of fluvial corridors from dem and vector layers e g stream network or valley bottom and ii to aggregate spatial features into homogeneous segments and metrics characterizing each of them the methodological frameworks involved have been previously described by alber and piegay 2011 leviandier et al 2012 and bertrand et al 2013 and this contribution focuses on the gis tools allowing the user to automatically operate them a case study on the drome river france is provided to illustrate the potential of the package both for geomorphologic understanding and target management actions fluvialcorridor has been developed for arcgis with the related native python library named arcpy and tested on arcgis 10 0 and 10 1 obviously each component of the package can be used separately however it also provides a complete workflow for fluvial corridor characterization even as the toolbox is continually under development and revision case study database fluvialcorridor package and guidelines are available online at http umrevs isig fr

channel adjustments and vegetation cover dynamics in a large gravel bed river over the last 200 years article i nfo the timing and extent of the morphological changes that occurred in the last 200 years in a large gravel bed river the piave river eastern italian alps that was heavily impacted by human activities training structures hydropower schemes and gravel mining have been analyzed by historical maps aerial photos repeated topographic measurements and geomorphological surveys results show that the channel underwent a strong narrowing during the twentieth century but with a faster pace during the 1970s 1990s and with an associated shift from a dominant braided pattern to a wandering morphology bed incision up to 2 m mostly from gravel mining has been documented for this period large areas of the former active channel were colonized by riparian forests both as islands and as marginal woodlands the ceasing of gravel extraction in the late 1990s seems to have determined a reversal in the evolutionary trend with evidence of vegetation erosion channel widening even though a significant aggradation phase is not present we conclude that alteration of sediment regime has played a major role on the long term channel evolution however only relevant flood events rin10 15 years appear to determine substantial island erosion and therefore the proportion of island vs channel area fluctuates depending on flood history

accuracy assessment of georectified aerial photographs implications for measuring lateral channel movement in a gis aerial photographs are commonly used to measure planform river channel change we investigated the sources and implications of georectification error in the measurement of lateral channel movement by testing how the number 6 30 and type human versus natural landscape features of ground control points gcps and the order of the transformation polynomial first second and third order affected the spatial accuracy of a typical georectified aerial photograph error was assessed using the root mean square error rmse of the gcps as well as error in 31 independent test points the rmse and the mean and median values of test point errors were relatively insensitive to the number of gcps above eight but the upper range of test point errors showed marked improvement i e the number of extreme errors was reduced as more gcps were used for georectification using more gcps thus improved overall georectification accuracy but this improvement was not indicated by the rmse suggesting that independent test points located in key areas of interest should be used in addition to rsme to evaluate georectification error the order of the transformation polynomial also influenced test point accuracy the second order polynomial function yielded the best result for the terrain of the study area gcp type exerted a less consistent influence on test point accuracy suggesting that although hard edged points e g roof corners are favored as gcps some soft edged points e g trees may be used without adding significant error based upon these results we believe that aerial photos of a floodplain landscape similar to that of our study can be consistently georectified to an accuracy of approximately f5 m with 10 chance of greater error the implications of georectification error for measuring lateral channel movement are demonstrated with a multiple buffer analysis which documents the inverse relationship between the size of the buffers applied to two channel centerlines and the magnitude of change detected between them this study demonstrates the importance of using an independent test point analysis in addition to the rsme to evaluate and treat locational error in channel change studies d 2005 published by elsevier b v

river channel planform change software for historical analysis abstract er mapper an image processing system was used to manipulate scanned maps plans and aerial photographs to enable detailed analysis of historical river channel planform change the er mapper package offers the opportunity to spatially reference each item of planform data into the same scale and co ordinate space as a base map using a warping algorithm and operator selected ground control points once all the data are in the same co ordinate space and at the same scale a given point can be returned to over time and a number of indices can be easily calculated to examine past channel behaviour here lateral shift channel width sinuosity and area of sedimentation within the reach were used as the maps and aerial photographs themselves are used the errors associated with digitising vectors are avoided and a more flexible approach towards analysis and the identification of important indices can be adopted at the outset results obtained for the cleekhimin burn a site in southern scotland are briefly presented and discussed and the advantages of the package and the limitations of the historical database are also outlined

channel planform geometry and slopes from freely available high spatial resolution imagery and dem fusion implications for channel width scalings erosion proxies and fluvial signatures in tectonically active landscapes article i nfo the rapid expansion of high spatial resolution optical sensors and imagery over the last decade presents ex ceptional opportunities for quantifying visible attributes of geomorphic systems in this study we detail a simple robust methodology changeom to extract continuous channel width and centerline datasets for single thread channels using freely available high spatial resolution imagery currently available in google earth and bing maps comparisons with a global dataset of field and lidar derived channel widths indicate minimal errors associated with the imagery and changeom methodology b1 overall while examples from the goriganga river indian himalaya and the yakima river wa usa emphasize the benefit of em pirical width values over established channel width scalings in deciphering fluvial responses to complex landscape forcings in tectonically active regions additionally accurate centerline delineation from the changeom methodology provides improved sinuosity measurements and when fused with coarse resolution digital elevation models dems removes along profile shortening and coincident increases in reach scale channel slope lastly comparisons of aster gdem v2 srtm v4 1 and lidar channel profiles extracted in moderate to high relief regions demonstrate the inferiority of the aster gdem for channel slope calcula tions despite the apparent spatial resolution advantages 9 the methodology presented here will facili tate new discoveries in the fluvial environment that have historically been difficult due to access and imagery resolution issues and provide greater perspective on channel signatures and responses to a host of landscape forcings especially in tectonically active bedrock and lower order drainage systems

evolutionary trajectory of channel morphology and controlling factors in a large gravel bed river abstract interpretation of channel changes is not always straightforward since it requires a detailed reconstruction of the evolutionary trajectory of channel morphology a quantitative analysis of controlling factors and finally identification of links between evolutionary trajectories and controlling factors the aim of this paper is to explain channel adjustments and controlling factors in the tagliamento river a large gravel bed river in northeastern italy traditional methods for studying historical channel changes i e use of aerial photos topographic data were employed but numerical modelling turned out to be very useful for the quantification of bedload transport and for supporting interpretation of past changes and likely future channel evolution river channel underwent three main phases of adjustment over the last 200 years the first two phases from the end of the nineteenth century to the early 1990s were characterized by narrowing channel width decreased from 1250 to 540 m and incision about 1 m and the third phase from the 1990s to present day by widening from 540 to 600 m and slight aggradation about 0 2 m combining evolutionary trajectories of channel morphology and analysis of controlling factors we argue that the long term channel evolution of the tagliamento river was driven mainly by human intervention at the reach scale i e sediment mining and channelization changes in sediment supply in the catchment area had no or minor effects in the study reach the most recent changes i e widening and slight aggradation are explained as a response to past disturbances that have produced a remarkable change of channel geometry and an increase of unit stream power in the reach magnitude and frequency of formative discharges are a key driving factor of the intensity of recent changes while this was not the case during the previous phases of adjustment

evolutionary trajectory of channel planforms in the middle garonne river toulouse sw france over a 130 year period contribution of mixed multiple factor analysis mfamix the purpose of this study is to propose a methodological essay for defining evolutionary trajectories of channel planforms and to examine the channel change in the middle garonne river southwest france over a 130 year period the study focuses on a reach of 90 km situated downstream from the city of toulouse a set of four historical maps 1868 1940s 1970s and 2000s is used to build a geomorphometric diachronic database data processing through mixed multiple factor analysis mfamix and hierarchical cluster analysis hca allows distinction between four homogeneous zones within the study reach depending on their evolutionary trajectories channel behavior in the upstream and median zones evolved as of the beginning of the study period narrowing of the fluvial area colonization by vegetation and removal of alluvial bars likely owing to punctual anthropogenic actions the downstream zone is characterized by stabilization of the channel and alluvial bar removal over the second half of the twentieth century coinciding with the campaign undertaken by french local authorities between 1960 and 1984 to protect river banks the role of accepted manuscript climate transition between the little ice age lia and the onset of the global warming period gw is also discussed results generally are consistent with the chronology established for most european rivers