large scale responses of complex shaped coastlines to local shoreline stabilization and climate change 1 when modeling the large scale km evolution of coastline morphology the influence of natural forces is not the only consideration ongoing direct human manipulations can substantially drive geomorphic change in this paper we couple a human component to a numerical model of large scale coastline evolution incorporating beach nourishment periodically placing sand on the beach also called beach replenishment or beach fill beach nourishment is the most prevalent means humans employ to alter the natural shoreline system in our case study the carolina coastline beach nourishment can cause shorelines adjacent to those that are nourished to shift both seaward and landward when we further consider how changes to storm behaviors could change wave climates the magnitude of morphological change induced by beach nourishment can rival that expected from sea level rise and affect the coast as far as tens of kilometers away from the nourishment site in some instances nonlocal processes governing large scale cuspate cape coastline evolution may transmit the human morphological signal over surprisingly large hundreds of kilometer distances

placer mining along the fraser river british columbia the geomorphic impact we investigate the geomorphic impact of nineteenth century placer mining along the fraser river british columbia by estimating the volume and grain size distribution of excavated sediment evaluating the transport potential for the sediment in the river and discussing the relation between placer waste sediment and observed morphodynamics of the fraser river channel volume by area regression relations applied to 456 mapped mines estimate the total volume of material excavated to be 58 10 6 m 3 bulk volume sampling of mine scarp and mine lag sediments indicates that the discharged tailings consisted of 54 sand and finer material and 46 gravel and small cobbles modern observation and historical narratives indicate that the channel of the fraser between quesnel and laidlaw has been generally stable following placer mining application of a sediment transport function indicates that the river is capable of moving annually an amount of sediment comparable to the maximum loading from placer mining by applying established relations between channel scale and sediment virtual velocity we estimate the rate of downstream movement of the placer waste slug to be between 1 and 6 km yr 1 the predicted rates of sediment migration indicate that peak delivery of placer waste to the lower river below laidlaw likely occurred early in the twentieth century this predicted behavior agrees well with observed aggradation on the lower river the result emphasizes the importance of historical legacy in the appraisal of recent geomorphological processes and shows that widespread small scale disturbance has affected the fraser river with the effect concentrated where the gradient of the river is reduced

review of erosion dynamics along the major n s climatic gradient in chile and perspectives abstract chile is an elongated country running in a north south direction for more than 30 along a subduction zone its climate is progressively wetter and colder from north to south this particular geography has been used positively by a growing number of studies to better understand the relationships between erosion processes and climate land use slope tectonics volcanism etc here we review the erosion rates factors and dynamics over millennial to daily periods reported in the literature in addition 21 new catchment mean erosion rates suspended sediment and 10be are provided and previous suspended sediment derived erosion rates are updated a total of 485 local and catchment mean erosion rates are reported erosion rates vary between some of the smallest values on earth 10 5 mm a to moderate values 0 5 mm a compared to other active ranges this review highlights strong limitations concerning the quantification of local erosion factors because of uncertainties in sampling point location slope and rainfall data for the mean erosion rates e for the millennial and decennial catchments a model of the form e s 1 s 0 6 2 r with 0 3 0 8 accounts for 40 to 70 of the erosion variance confirming a primary role of slope s compared to precipitation rate r over this time scale over the long term this review points to the long 5 to 10 ma response time of rivers to surface uplift in north central arid chile over millennia data provide evidence for the progressive contribution of extreme erosion events to millennial averages for drier climates as well as the link between glacier erosion and glacier sliding velocity in this period of time a discrepancy exists between the long term offshore sedimentological record and continental decennial or millennial erosion data for which no single explanation appears still little information is available concerning the magnitude of variation of millennial erosion rates over centuries data show the variable role of groundwater in the dynamics of suspended load and document a decrease in erosion over hundreds of years probably associated with historical harvesting

post disturbance sediment recovery implications for watershed resilience abstract sediment recovery following disturbances is a measure of the time required to attain pre disturbance sediment fluxes insight into the controls on recovery processes and pathways builds understanding of geomorphic resilience we assess post disturbance sediment recovery in three small 1 5 100 km2 largely unaltered watersheds within the northern colorado rocky mountains affected by wildfires floods and debris flows disturbance regimes span 102 floods debris flows to 103 years wildfires for all case studies event sediment recovery followed a nonlinear pattern initial high sediment flux during single precipitation events or high annual snowmelt runoff followed by decreasing sediment fluxes over time disturbance interactions were evaluated after a high severity fire within the south fork cache la poudre basin was followed by an extreme flood one year post fire this compound disturbance hastened suspended sediment recovery to pre fire concentrations 3 years after the fire wildfires over the last 1900 ybp in the south fork basin indicate fire recurrence intervals of 600 years debris flows within the upper colorado river basin over the last two centuries have shifted the baseline of sediment recovery caused by anthropogenic activities that increased debris flow frequency an extreme flood on north st vrain creek with an impounding reservoir resulted in extreme sedimentation that led to a physical state change we introduce an index of resilience as sediment recovery disturbance recurrence interval providing a relative comparison between sites sediment recovery and channel form resilience may be inversely related because of high or low physical complexity in streams we propose management guidelines to enhance geomorphic resilience by promoting natural processes that maintain physical complexity finally sediment connectivity within watersheds is an additional factor to consider when establishing restoration treatment priorities

stratigraphy of the anthropocene the anthropocene an informal term used to signal the impact of collective human activity on biological physical and chemical processes on the earth system is assessed using stratigraphic criteria it is complex in time space and process and may be considered in terms of the scale relative timing duration and novelty of its various phenomena the lithostratigraphic signal includes both direct components such as urban constructions and man made deposits and indirect ones such as sediment flux changes already widespread these are producing a significant event layer locally with considerable long term preservation potential chemostratigraphic signals include new organic compounds but are likely to be dominated by the effects of co2 release particularly via acidification in the marine realm and man made radionuclides the sequence stratigraphic signal is negligible to date but may become geologically significant over centennial millennial time scales the rapidly growing biostratigraphic signal includes geologically novel aspects the scale of globally transferred species and geologically will have permanent effects

delta growth and river valleys the influence of climate and sea level changes on the south adriatic shelf mediterranean sea abstract incised valleys across continental margins represent the response of fluvial systems to changes in their equilibrium dynamics mainly driven by base level fall forced by glacial eustatic cycles the manfredonia incised valley formed during the last glacial sea level lowstand when most of the southern adriatic shelf was sub aerially exposed but the outer shelf remained under water the pronounced upstream deepening of the valley is ascribed to river incision of the mis5e highstand coastal prism and related subaqueous clinoform under the influence of mis5 4 sea level fluctuations while the downstream shallowing and narrowing mainly reflects the impact of increased rates of sea level fall at the mis3 2 transition on a flatter mid outer shelf until 15 ka bp the valley fed an asymmetric delta confined to the mid outer shelf testifying that continental and deep marine systems remained disconnected during the lowstand sea level rise reached the inner shelf during the early holocene drowning the valley and leading to the formation of a sheltered embayment confined toward the land at this time part of the incision remained underfilled with a marked bathymetric expression this mini basin was rapidly filled by sandy bayhead deltas prograding from both the northern and southern sides of the valley in this environment protected by marine reworking and where sediment dispersal was less effective the accommodation space was reduced and autogenic processes forced the formation of multiple and coalescing delta lobes bayhead delta progradations occurred in few centuries between 8 and 7 2 ka cal bp confirming the recent hypothesis that in this area the valley was filled during the formation of sapropel s1 this proximal valley fill representing the very shallow water equivalent of the cm thick sapropel layers accumulated offshore in the deeper southern adriatic basin is of key importance in following the signature of the sapropel in a facies tract ideally from the shoreline to the abyss

detecting climatic signals in an anthropogenically disturbed catchment the late holocene record from the petit lac d annecy french alps historical and documentary records from the petit lac d annecy indicate that human activities have been the dominant geomorphic process shaping the catchment during the late holocene with deforestation agriculture and artificial drainage profoundly affecting both the pace and spatial distribution of soil erosion the impact of past climatic change on the evolution of the catchment is less certain because of the lack of long term climate records for the site previous attempts to use the sediment record from the lake to investigate the role past climate change may have played were hampered by the difficulty in isolating and disentangling the climatic signal preserved within the archive because of overprinting of human activity this is a common problem in regions with a long history of human activity in the landscape in this study we use a range of novel statistical techniques including cross correlation and cross spectral analysis to assess the relative importance of climate in driving landscape dynamics the statistical analysis is carried out on an updated high resolution palaeo environmental data set from the petit lac d annecy the results of the statistical analysis indicate that regional climate phenomena such as the atlantic multidecadal oscillation are partly responsible for landscape dynamics at petit lac d annecy throughout the late holocene we find that the petit lac d annecy catchment typically requires decades or longer to respond to changes in precipitation reflecting the stochastic nature of river sediment storage and transport the use of a 4 yr integrated lake core record effectively attenuates the signal shredding effect of shorter term internally generated sediment transport processes nonetheless the lake record of climatically induced geormorphic process responses is weak compared with the pervasive impact of human activities

historical changes in terrestrially derived organic carbon inputs to louisiana continental margin sediments over the past 150 years 1 major rivers and associated deltaic environments provide the dominant pathway for the input of terrestrial derived organic carbon in sediments toct to the ocean natural watershed processes and land use changes are important in dictating the amount and character of carbon being buried on continental margins seven core sites were occupied on the louisiana continental margin aboard the r v pelican in july 2003 along two major sediment transport pathways south and west of the mississippi river mouth lignin profiles in these age dated cores 210pb geochronology indicate artificial reservoir retention as a primary control on organic carbon quantity and quality reaching the margin post 1950 whereas pre 1950 sediments may reflect soil erosion due to land clearing and farming practices lignin 8 concentrations range 0 2 to 1 7 also indicate that toct delivery rates decay processes have probably remained relatively consistent from proximal to distal stations along transects the down core profile at the canyon station seems to be temporally linked and connected to inner shelf deposition suggestive of rapid cross shelf transport sources of terrestrially derived organic carbon were reflective of mixed angiosperms over the last 150 years in cores west and south of the mississippi river delta the lignin phenol vegetation index lpvi range 130 0 to 510 proved to be a sensitive indicator of source changes in these sediments and eliminated some of the variability compared to c v range 0 01 to 0 4 and s v range 0 9 to 2 1 ratios stochastic events such as hurricanes and large river floods have a measurable albeit ephemeral effect on the shelf toct record burial of toct on the river dominated louisiana continental margin is largely driven by anthropogenic land use alterations in the last 150 years land use changes in the mississippi river basin and river damming have likely affected carbon cycling and toct burial on the louisiana continental margin over a large spatial extent as observed by similar trends in cores from across and along the margin

can an anthropocene series be defined and recognized we consider the anthropocene as a physical chronostratigraphic unit across terrestrial and marine sedimentary facies from both a present and a far future perspective provisionally using an approximately 1950 ce base that approximates with the great acceleration worldwide sedimentary incorporation of a bomb derived radionuclides and light nitrogen isotopes linked to the growth in fertilizer use and other markers more or less effective recognition of such a unit today with annual decadal resolution is facies dependent and variably compromised by the disturbance of stratigraphic superposition that commonly occurs at geologically brief temporal scales and that particularly affects soils deep marine deposits and the pre 1950 parts of current urban areas the anthropocene thus more than any other geological time unit is locally affected by such blurring of its chronostratigraphic boundary with holocene strata nevertheless clearly separable representatives of an anthropocene series may be found in lakes land ice certain river delta systems in the widespread dredged parts of shallow marine systems on continental shelves and slopes and in those parts of deep water systems where human rafted debris is common from a far future perspective the boundary is likely to appear geologically instantaneous and stratigraphically significant

limited carbon contents of centuries old soils forming in legacy sediment abstract accelerated erosion from european agriculture overwhelmed transport capacities of relatively low gradient piedmont watersheds and triggered widespread and massive sediment deposition on floodplains referred to as legacy sediments while erosion driven soil loss on the southern piedmont landscape has been widely studied the resultant legacy sediments deposited on hillslopes floodplains and in channels appear remarkably understudied in the interim between deposition and future remobilization legacy sediments are undergoing soil formation in ways that impact carbon stocks nutrient retention and a number of other soil sediment functions here we use a pedological framework to understand the dynamics of these legacy sediments by constraining the time since deposition and redevelopment of vegetation and the soil profile in this study we characterized the properties of legacy sediment and buried pre legacy sediment alluvium established the timing of legacy sediment deposition and its volume in a 600 ha watershed and analyzed the impact of accelerated sedimentation on floodplain soil carbon soc storage we found alluvial legacy sediment in the 6 km2 holcombe s branch watershed to range in thickness from 0 35 to 1 25 m averaging 1 01 m in depth n 20 cv 19 radiocarbon 14c dates from buried wood indicate that accelerated deposition began by the mid 1800s during the next century deposition rates increased and peaked at levels up to 40 higher than contemporary sedimentation rates by the mid 1900s accelerated deposition rates had slowed significantly as indicated by surficial distributions of 1960s fall out 137cs in sediments upstream floodplains are today less frequently flooded and function as abandoned floodplains or terraces in contrast downstream sites remain active floodplains and zones of deposition a century of pedogenesis has formed acidic well drained entisols characterized by incipient redeveloping a horizons over coarse textured c horizons buried pre legacy sediment alluvium have well developed redox features are lower in hue and chroma than legacy sediments and occasionally have moderate to strong aggregate structure a century old mixed pine hardwood forest has diminished subsoil carbon stocks and created a shallow vertical distribution of soc stocks that total 95 mg c ha 1 cv 25 in the upper 2 m legacy sediments have nearly doubled alluvial sediment in the catchment and account for 55 of soil carbon stock coarse texture and porous legacy sediment soils limit accumulation of mineral associated soil carbon a horizon morphology was preserved in buried a horizons underlying legacy sediment yet these horizons did not account for significant soc stocks at depth depth profiles of active light fraction organic carbon revealed differences in soc preservation between upstream and downstream sites the hydrogeomorphic change responsible for this difference from abandoned legacy sediment terraces upstream to active sedimentation on floodplains downstream will continue to impact soil sediment dynamics and functioning time since last deposition and revegetation are dominant forces in soc dynamics while gradients in soil moisture may be creating subtle longitudinal patterns in soc preservation at depth

palaeozoic accretionary and convergent tectonics of the southern altaids implications for the growth of central asia the southern altaids present a unidirectional section from mongolia to china through an accretionary orogen that youngs progressively from neoproterozoic in the north to permian in the south the orogen formed by forearc accretion of island arcs accretionary wedges ophiolites and precambrian microcontinents this regularity was upset by early growth within the ocean of arcs that later collided at the accreting continental margin by imbrication of old ophiolites with young arcs and by himalayan style thrust nappe tectonics when an arc collided into a microcontinent lateral growth of the southern altaids represents a massive addition of juvenile material to the palaeozoic crust

metrics for quantifying anthropogenic impacts on geomorphology road networks this work tests the capability of a recently published topographic index the slope local length of auto correlation sllac to portrait and delineate anthropogenic geomorphologies the patterns of the anthropogenic pressure are defined considering the road network density and the urban complexity index uci first the research investigates the changes in the sllac in two derived parameters average sllac and the sllac surface peak curvature spc per km2 connected to the increasing of the anthropogenic structures next natural and anthropogenic landscapes are clustered and classified the results show that there is a direct correlation between the road network density and the uci and the mean sllac per km2 however the spc is inversely correlated with the anthropogenic pressure network density and urban complexity this shows that the surface morphology slope of regions presenting anthropogenic structures tends to be well organized low spc and in general self similar at a long distance higher average sllac the results of the clustering approach show that the procedure can correctly depict anthropogenic landscapes having a road network density greater than about 3 km km2 also in areas covered by vegetation this latter result is promising for the use of such a procedure in regions that cannot be seen directly from orthophotos or satellite images the proposed method can actively capture the alteration produced by road networks on surface morphology identifying different signatures of urban development exploration and densification networks that are responsible for increasing the local density of the network and expanding the network into new areas respectively the effects of this alteration on surface processes could be significant for future research creating new questions about differences due to human or landscape forcing on earth surface processes copyright 2015 john wiley sons ltd

on the history of humans as geomorphic agents the human population has been increasing exponentially simultaneously as digging sticks and antlers have given way to wooden plows iron spades steam shovels and today s huge excavators our ability and motivation to modify the landscape by moving earth in construction and mining activities have also increased dramatically as a consequence we have now become arguably the premier geomorphic agent sculpting the landscape and the rate at which we are moving earth is increasing exponentially as hunter gatherer cultures were replaced by agrarian societies to feed this expanding population erosion from agricultural fields also until recently increased steadily this constitutes an unintended additional human impact on the landscape

floodplain occupation and landscape modification in early rome abstract the site of rome in central italy provided many opportunities for the development of a city access to natural resources defensible terrain a ford in the tiber river among others in addition to these advantages the environment and landscape also presented numerous challenges to early inhabitants this ecological dichotomy is especially observable in the forum boarium a region situated in the tiber s floodplain at the base of the capitoline and palatine hills by the archaic period 7th 6th centuries bce this vital gateway for trade and communication was operating as a river port equipped with a harbor temple periodic flooding of the tiber river however consistently jeopardized these commercial and cult pursuits in the forum boarium as a result this region became the focus of early endeavors at landscape modification which helped to protect and facilitate the growth of urban infrastructure in the floodplain in order to explore geoarchaeological conditions in the floodplain a multi disciplinary research project was undertaken in the forum boarium between 2013 and 2015 this paper presents preliminary results from this recent investigation including evidence on the natural topography of the river valley floods and sedimentation as well as building techniques in a flood prone region in archaic and early republican rome it is argued that in response to varied and prolonged environmental stress landscape modification and continuous management became important prerequisites to rome s urbanization process in this way ecological pressures directly influenced the development of the city s built landscape this research not only represents a significant step towards a paleoenvironmental reconstruction of early rome but also demonstrates the advantages of coring survey in urban areas where access to deeply buried archaeological and geological stratigraphy is restricted

anthrobiogeochemical platinum palladium and rhodium cycles of earth emerging environmental contamination abstract anthrobiogeochemical cycles have been a subject of scientific research for many decades as they are important for identifying possible sources sinks and pathways of an element in the environment in this study we quantified global cycles for the platinum group elements pge platinum pt palladium pd and rhodium rh we quantified the stocks of pt pd and rh in earth s various reservoirs such as the core mantle consolidated crust biomass seawater unconsolidated sediments and atmosphere as well as coal and petroleum deposits we further quantified their fluxes both natural and anthropogenic between each reservoir by identifying the flows across the hydrosphere geosphere biosphere atmosphere and anthroposphere including from mining activities fossil fuel and biomass burning construction activities soil erosion human contributions to net primary productivity riverine transport aeolian dust movement primary production volcanic eruption sea salt spray crustal subduction crust formation at mid ocean ridges pge recovery from recycling processes and cosmic dust inputs at the earth s surface stocks of pges were quantified by multiplying the mass of the reservoir by the average pt pd and rh concentration in the reservoir whereas pt pd and rh fluxes were calculated by multiplying the rate of mass movement across the reservoirs with the pt pd and rh concentrations of the material uncertainties were explicitly incorporated in stock and flow estimations through monte carlo simulations our calculations reveal that the total surficial anthropogenic pt pd and rh mobilizations were greater than their corresponding natural surficial mobilizations we show that crustal subduction and crustal formation is the most important natural flow and contributes 21 42 of total pge mobilization when earth s surficial processes are considered soil erosion is the dominant flow for rh and pt mobilization comprising 33 and 13 respectively of the total mobilization on earth s surface whereas npp dominates the natural pd mobilization on the other hand mining activities fossil fuel burning and automobile emissions are the most important anthropogenic flows therefore our qualitative and quantitative assessment indicates that mining activities contribute almost 60 80 of the total anthropogenic flow on earth and crustal subduction and production dominates the total global pge cycle

human and natural impacts on fluvial and karst depressions of the maya lowlands abstract this paper begins to differentiate the major drivers and chronology of erosion and aggradation in the fluvial and fluviokarst landscapes of the southern and central maya lowlands we synthesize past research on erosion and aggradation and add new data from water soils radiocarbon dating and archaeology to study the quantity timing and causes of aggradation in regional landscape depressions geomorphic findings come from many excavations across a landscape gradient from upland valleys karst sinks and fans into the coastal plain floodplains and depressions findings from water chemistry show that sources in the uplands have low quantities of dissolved ions but water in the coastal plains has high amounts of dissolved ions often nearly saturated in calcium and sulfate we found significant geomorphic complexity in the general trends in upland karst sinks in a few instances sediments preserve late pleistocene paleosols buried 2 3 m though many more have distinct middle to late holocene paleosols buried 1 2 m after c 2300 bp maya early to late preclassic from 2300 1100 bp late preclassic to classic periods the landscape aggraded from five main mechanisms river flooding climatic instability accelerated erosion ancient maya landscape manipulation and gypsum precipitation from a rise in a water table nearly saturated in calcium and sulfate ions evidence exists for two or three high magnitude floods possibly driven by hurricanes moreover lake core and geophysical studies from the peten lakes region have shown high rates of deposition of silicate clays maya clays starting and peaking during the maya preclassic and continuing to be high through the late classic the main driver on upland karst depressions the peten lakes upland valleys and fans was accelerated soil erosion but water table rise probably driven by sea level rise was the main driver on the wetlands of the coastal plain because the aggraded sediments here are dominantly composed of gypsum precipitated from the groundwater this latter mechanism represents a little recognized mechanism of aggradation over a large region these large scale environmental changes occurred during periods of intensive ancient maya land use and climatic instability both of which may have contributed to erosion by increasing runoff despite these geomorphic changes ancient maya farmers adapted in several key cases

anthropogenic landforms and sediments from dredging and disposing sand along the apalachicola river and its floodplain abstract the apalachicola river which begins at the confluence of the chattahoochee and flint rivers near the georgia florida state line has multiple human impacts water inputs declined due to upstream irrigation and urbanization in georgia sediment trapped by numerous small to large dams including construction of jim woodruff dam in 1954 near the apalachicola chattahoochee flint acf confluence has increased degradation shortly thereafter the river was modified for a navigation project with 29 6 10 6 m 3 dredged between 1957 and 2002 from the apalachicola alone this study investigates how historic dredging coincides with the modern morphology of the channel and how historic dredging disposal and other activities have modified the floodplain landforms and sediments this analysis of the navigation impacts in the middle apalachicola river river miles 40 to 65 ties spatial and temporal variations of dredging field derived bathymetry historic maps patterns of floodplain disposal of dredge spoil from lidar imagery and modern point bar channel change of the apalachicola river floodplain mounds of coarse material built from out of bank disposal constitute 800 000 m 3 in the study area approximately 7 7 10 6 m 3 of sediment was dredged within the study reach roughly 11 of the volume dredged remains on the floodplain sand bars were disposal sites thus their increased area of 263 is partly tied to this practice thus the legacy of dredging affects the modern sedimentology and morphology of the floodplain and channel findings show that a failed navigation project could have been pre empted with better geomorphic geologic and hydrologic study and suggest that vegetative restoration of point bars would help in narrowing and stabilizing this dynamic system

influence of holocene stratigraphic architecture on ground surface settlements a case study from the city of pisa tuscany italy abstract the holocene stratigraphic architecture of modern coastal and deltaic plains has peculiar characteristics that may influence ground surface settlements in the pisa urban area the inhomogeneous spatial distribution of geotechnically weak layers typically formed during the mid late holocene highstand coastal progradation is inferred to be responsible for urban ground settlement and building damage as evidenced by the tilt of several surface structures among which the famous leaning tower of pisa is the most prominent on the basis of integrated stratigraphic sedimentological and geotechnical data from a wide georeferenced database three facies associations with high deformability potential units 1 3 are identified in the uppermost 30 m as opposed to depositional facies units 4 5 with higher geotechnical strength whereas unit 1 represents a thick laterally extensive lagoonal clay deposit the overlying highly deformable units units 2 3 show more discontinuous spatial distribution controlled by the holocene paleohydrographic evolution of the arno coastal plain unit 2 dated between the neolithic and the etruscan age ca 5000 2000 yr bp is composed of swamp clays and silty clays recording lagoon infilling due to arno delta progradation units 3 and 4 which consist of wet levee deposits and stiff floodplain clays respectively formed during the subsequent phases of alluvial plain construction started around the roman age from ca 2000 yr bp whereas units 3 and 4 are recorded within the uppermost 5 m fluvial and distributary channel sands unit 5 cut the underlying deltaic alluvial succession at various stratigraphic levels down to unit 1 the spatial distribution of these units gives rise to three locally juxtaposed stratigraphic motifs in pisa underground reflecting different potential risks for settlement under building loads we show how lateral changes in stratigraphic architecture account for the irregular spatial distribution of geotechnically weak layers that are responsible for building damage and ground settlement

land2sea database of river drainage basin sizes annual water discharges and suspended sediment fluxes 1 the land2sea database contains data on the sizes of 1519 exorheic river drainage basins 79 of the exorheic land area annual suspended sediment fluxes 593 rivers 63 of the exorheic land area and water discharges 1272 rivers 76 of the exorheic land area that have been compiled from a variety of sources the database extends earlier compilations such as gems glori the river basins are grouped into 19 large scale drainage regions to investigate the regional variability in freshwater and sediment fluxes to various ocean basins the annual suspended sediment flux to the coastal ocean 18 5 109 tons is dominated by east asia 6 1 109 tons arabia india and southeast asia 4 3 109 tons and eastern south america 2 4 109 tons small topical islands of oceania support the highest annual sediment fluxes per drainage area 9650 t km 2 a 1 annual freshwater discharge to the coastal ocean 38 857 km3 is dominated by runoff from eastern south america 11 199 km3 east asia 7114 km3 and arabia india and southeast asia 4384 km3 the empirical data agree well with results from global models art and bqart that have been trained on a subset of the data compiled here

using meteoric 10be to track fluvial sand through the waipaoa river basin new zealand we use meteoric 10 be measured in 24 fluvial sand samples collected along the mainstem and from prominent tributaries within the tectonically active waipaoa river basin new zealand to identify sediment sources and monitor the mixing of sediment as it travels from headwater basins to the sea deforestation for agriculture beginning in the early 1900s resulted in severe but nonuniformly distributed erosion tributaries in the northern headwaters where large amphitheater gullies that continually feed prodigious amounts of deeply sourced sediment to the mainstem are prevalent yield exceptionally low concentrations of meteoric 10 be 1 5 10 6 atoms g 1 in the more stable eastern and western tributaries concentrations of meteoric 10 be are nearly an order of magnitude greater 14 10 6 atoms g 1 meteoric 10 be concentrations in samples collected along the mainstem above and below tributary confluences steadily and regularly increase downstream r 2 0 92 as large amounts of low concentration gully derived sediments are augmented with higher concentration sediment from more stable tributaries providing strong evidence that meteoric 10 be concentrations reflect sediment sourcing in this fluvial network a two component mixing model indicates that the gullied northern region of the waipaoa basin produces sediment at a rate 20 times that of the eastern and western regions these results suggest that meteoric 10 be in contrast to the widely applied in situ technique that is limited by the availability and distribution of quartz is an effective tool for the rapid assessment of sediment dynamics and movement within a wide range of fluvial networks

sensitivity of west and central european river systems to environmental changes during the holocene a review abstract sediment deposition in floodplains is an essential part of the sediment dynamics of a catchment these sediment dynamics can vary largely on a holocene time scale under the influence of driving forces such as land use and climatic variations in this paper we review the holocene floodplain sediment deposition history of rivers in west and central europe with special attention to the influence of climate and land use variability during the early holocene preboreal to atlantic period most floodplains were rather stable with limited floodplain aggradation after this initial phase of relative stability sedimentation rates increase during the middle and late holocene with often the most important deposition phase during the last 1000 to 2000 a the start of the increase in sedimentation varies spatially with an earlier start in the west france germany then in the east poland belarus ukraine while there are also local differences between regions which are settled early e g loess regions compared to later settled regions the sedimentation history of most floodplains can be linked to the local land use history while influence of climatic variations on floodplain aggradation is often reported to be of minor importance processes related to bedload are often reported to be more influenced by climatic events relationships between the driving forces and the sediment history are mainly based on synchronicity and there is seldom proof for a direct causal relationship future research should focus on a system based approach integrating the floodplain deposition in the entire sediment dynamics which includes also erosion colluvial deposition and export main research questions that need further attention include integration of system based concepts like landscape connectivity and buffering effects and also the assessment of the individual contribution of land use changes and climatologic variations on the sediment dynamics detailed sediment budget studies combined with modeling studies can make an important contribution to the understanding of floodplain sediment dynamics

proposal to add anthrostratigraphic and technostratigraphic units to the stratigraphic code for classification of anthropogenic holocene deposits anthropogenic surficial deposits are formed from holocene and older deposits that have been so modified by human activity that their original form is unrecognizable because their characteristics are fundamentally different from those of natural origin the creation of special stratigraphic categories seems justified two new material categories are proposed for the stratigraphic classification of anthropogenic deposits an anthrostratigraphic unit asu is defined as a stratiform or irregularly shaped body of anthropogenic origin in the sedimentary record distinguished and delineated on the basis of lithologic characteristics and or bounding disconformities an anthropogenic origin is indicated if the deposit 1 lies beneath an anthropogenic landform 2 contains artifacts 3 shows evidence of artificial mixing or other human disturbance and or 4 was imported from offsite and is allochthonous the basic asu is the anthrostratum defined as a mostly stratiform body of artificially mixed earth rock

reach scale channel sensitivity to multiple human activities and natural events lower santa clara river california usa abstract understanding the cumulative impact of natural and human influences on the sensitivity of channel morphodynamics a relative measure between the drivers for change and the magnitude of channel response requires an approach that accommodates spatial and temporal variability in the suite of primary stressors multiple historical data sources were assembled to provide a reach scale analysis of the lower santa clara river lscr in ventura county california usa sediment supply is naturally high due to tectonic activity earthquake generated landslides wildfires and high magnitude flow events during el nino years somewhat typically for the region the catchment has been subject to four reasonably distinct land use and resource management combinations since european american settlement when combined with analysis of channel morphological response quantifiable since ca 1930 reach scale and temporal differences in channel sensitivity become apparent downstream reaches have incised on average 2 4 m and become narrower by almost 50 with changes focused in a period of highly sensitive response after about 1950 followed by forced insensitivity caused by structural flood embankments and a significant grade control structure in contrast the middle reaches have been responsive but are morphologically resilient and the upstream reaches show a mildly sensitive aggradational trend superimposing the natural and human drivers for change reveals that large scale stressors related to ranching and irrigation have been replaced over time by a suite of stressors operating at multiple spatial scales lower reaches have been sensitive primarily to local scale impacts urban growth flood control and aggregate mining whereas upstream catchment scale influences still prevail including flow regulation and climate driven sediment supply factors these factors illustrate the complexity inherent to cumulative impact assessment in fluvial systems provide evidence for a distinct anthropocene fluvial response and underpin the enormity of the challenge faced in trying to sustainably manage and restore rivers

ecogeomorphic feedbacks in regrowth of travertine step pool morphology after dam decommissioning fossil creek arizona abstract the linkages between fluvial geomorphology and aquatic ecosystems are commonly conceptualized as a one way causal chain in which geomorphic processes create the physical template for ecological dynamics in streams with a travertine step pool morphology however biotic processes strongly influence the formation and growth of travertine dams creating the potential for numerous feedbacks here we take advantage of the decommissioning of a hydroelectric project on fossil creek arizona where restoration of caco 3 rich baseflow has triggered rapid regrowth of travertine dams to explore the interactions between biotic and abiotic factors in travertine morphodynamics we consider three conceptual frameworks where biotic factors independently modulate the rate of physical and chemical processes that produce travertine dams combine with abiotic factors in a set of feedback loops and work in opposition to abiotic processes such that the travertine step pool morphology reflects a dynamic balance between dominantly biotic constructive processes and dominantly abiotic destructive processes we consider separately three phases of an idealized life cycle of travertine dams dam formation growth and destruction by erosive floods dam formation is catalyzed by abiotic factors e g channel constrictions and bedrock steps and biotic factors e g woody debris and emergent vegetation from measurements of changes over time in travertine thickness on a bedrock step we find evidence for a positive feedback between flow hydraulics and travertine accrual measurements of organic content in travertine samples from this step show that algal growth contributes substantially to travertine accumulation and suggest that growth is most rapid during seasonal algal blooms to document vertical growth of travertine dams we embedded 252 magnets into nascent travertine dams along a 10 km stretch of river growth rates are calculated from changes over time in the magnetic field intensity at the dam surface at each magnet we record a range of hydraulic and travertine composition variables to characterize the dominant mechanism of growth abiotic precipitation algal growth trapping of organic material or in situ plant growth we find 1 rapid growth of travertine dams following flow restoration averaging more than 2 cm year 2 growth rates decline downstream consistent with loss of dissolved constituents because of upstream travertine deposition but also parallel to a decline in organic content in dam surface material and a downstream shift in dominant biotic mechanism 3 biotic mechanisms are associated with faster growth rates and 4 correlations between hydraulic attributes and growth rates are more consistent with biotic than abiotic controls we conclude that the strong influence of living organisms on rates of travertine growth coupled with the beneficial effects of travertine on ecosystem dynamics demonstrate a positive feedback between biology and geomorphology during our two year study period erosive flood flows occurred causing widespread removal of travertine the temporal distribution of travertine growth and erosion over the study period is consistent with a bimodal magnitude frequency relation in which growth dominates except when large infrequent storms occur this model may be useful in other systems where biology exerts strong controls on geomorphic processes

the landscape reynolds number and other dimensionless measures of earth surface processes abstract an analogy between turbulent fluid systems and landscape drainage systems parker g haff p k murray a b 2001 eos transactions of the american geophysical union 82 pp f564 is suggested by the observation that transport in both systems can be approximated by diffusion with size proportional effective diffusivities with a cross over at small scales to fickian diffusion the landscape reynolds number of a typical fluvial landscape is estimated to be of order re l 10 6 to 10 9 these large values reflecting the relative efficiency of fluvial transport compared to creep re l is the ratio of the large scale effective diffusivity of rivers to the small scale diffusivity of creep processes on hillslopes the spatial dependence of the effective diffusivity produces rivers with logarithmic long profiles similar to the profiles of many rivers in nature and analogous to the logarithmic dependence of mean fluid velocity on distance from a wall in turbulent flow the landscape example suggests how other generalized reynolds numbers can be constructed as ratios of large scale to small scale diffusivities to measure the efficiencies of complex processes that affect the surface as an example the global airline transportation network is estimated to have an efficacy relative to that of direct human mechanisms for transport of similar goods and materials of about 10 8 as measured by a corresponding technology reynolds number the appearance of such large dimensionless numbers pertaining to the consequences of human invention and design reflects the emergence of the technosphere as an increasingly efficient overlay on the historical domain of biology and surficial geology

stratigraphic expressions of the holocene anthropocene transition revealed in sediments from remote lakes stratigraphic boundaries are ideally defined by distinct lithological geochemical and palaeobiological signatures to which a chronological framework can be applied we present a range of observations that illustrate how the holocene anthropocene transition meets these criteria in its expression in sediments from remote arctic and alpine lakes removed from direct catchment scale anthropogenic influences in glaciated lake basins the retreat of glaciers commonly leads to lithological successions from proglacial clastic sedimentation to non glacial organic deposition sediments from the majority of lakes record marked depletions in the nitrogen stable isotopic composition of sediment organic matter reflecting anthropogenic influences on the global nitrogen cycle in all cases siliceous microfossil assemblages diatoms and chrysophytes change markedly and directionally with regional nuances these stratigraphic fingerprints begin to appear in the sediment record after ad 1850 but accelerate in pulses between ad 1950 and 1970 and again after ad 1980 our review indicates that recent environmental changes associated with humankind s dominance of key global biogeochemical cycles are sufficiently pervasive to be imprinted on the sediment record of remote lakes moreover these changes are of sufficient magnitude to conclude that the holocene has effectively ended and that the concept of anthropocene more aptly describes current planetary dynamics the synthesis of these observations pertains directly to ongoing discussions concerning the eventual formalization of a new stratigraphic boundary

rivers in the anthropocene the u s perspective abstract during the past 50 yr the number and variety of papers written by u s fluvial geomorphologists that examine human alterations of rivers has accelerated substantially from an initial focus primarily on how human induced changes in land cover influence sediment yield and river dynamics the literature has expanded to emphasize the effects of flow regulation channel engineering removal of large wood and beavers and changing climate these multiple human influences are now widely recognized to have resulted in global scale cumulative effects including significantly altered fluxes of water sediment nitrogen and carbon and complete transformation of river networks across much of the planet one outgrowth of this recognition is the increasing involvement of geomorphologists in diverse forms of river restoration a form of river management that thus far has largely been dominated by engineers acknowledging the ubiquity of human alteration of rivers implies that i investigators cannot assume that even the most remote and seemingly pristine river segment has not been affected at least indirectly by people ii the use of reference conditions requires careful consideration with respect to what reference sites indicate about past conditions as well as their relevance for the future iii detailed geomorphic understanding of the nature and timing of past human alterations of rivers is likely to be critical to effective restoration and iv each scientist must decide how to engage within the context of research and advocacy with the issues of ecosystem degradation and loss of river form and function

hillslopes rivers plows and trucks mass transport on earth s surface by natural and technological processes the surface of the earth is being transformed by a new force in the form of technological systems and processes that move significant quantities of mass large distances because movement of mass is perhaps the most basic geomorphic process and because the continuing rise of technology appears to characterize a new epoch in earth evolution the anthropocene it is of interest to compare technological and natural mass transport mechanisms a purely dynamical mass action metric representing the product of mass displaced distance moved and mean speed of displacement is used to compare the transport effectiveness of selected systems systems with large mass action tend to be advective and systems with small mass action diffusive local environments are conditioned by mass action through the introduction of transport corridors such as roads and rivers which put constraints on mass transport by embedded diffusive systems advection also subjects local environments to externally determined time scales such as the times for delivery of unit mass of water or sediment to a river mouth and supports the emergence of associated dynamical processes there for example those of human activity or delta construction that are too rapid to be sustained by diffusion most of the world s mass action is generated by the motion of fluids of global or continental extent as in atmospheric circulation or river flow technological mass action exceeds that of all land based geomorphic systems except rivers technological systems with large mass action tend to be comprised of discrete self powered units e g trucks discretization of transported mass reflects the different locomotion strategy required for transport of solids on land compared with the transport requirements of spatially extensive fluids in nature the principle of maximum entropy production may provide a framework for understanding the emergence of advective technological mass transport systems copyright 2010 john wiley sons ltd

anthropogenic hillslope terraces and swidden agriculture in jiuzhaigou national park northern sichuan china abstract small irregular terraces on hillslopes or terracettes are common landscape features throughout west central china despite their prevalence there is limited understanding of the nature of these topographic features the processes that form them and the role humans played in their formation we used an interdisciplinary approach to investigate the geology ecology and cultural history of terracette development within jiuzhaigou national park sichuan province china terracettes occur on south facing 20 slopes at 2500 m elevation which appears to coincide with places people historically preferred to build villages ethnographic interviews suggest that traditional swidden agricultural cycles removed tree roots causing the loess sediments to lose cohesion slump and the terrace risers to retreat uphill over time this evidence is supported by landslide debris at terracette faces archaeological analysis of terracette sites reveal remains of rammed spread soil structures bones stone tools and ceramics dating from at least 2200 years before present within a distinct paleosol layer radiocarbon and optically stimulated luminescence dating of terracette sediments ranged in age from between 1500 and 2000 14 c yr bp and between 16 and 0 30 ka respectively these multiple lines of evidence indicate a long history of human habitation within jiuzhaigou national park and taken together suggest strong links between terracette formation and human landuse interactions

rates and spatial variations of soil erosion in europe a study based on erosion plot data an extensive database of short to medium term erosion rates as measured on erosion plots in europe under natural rainfall was compiled from the literature statistical analysis confirmed the dominant influence of land use and cover on soil erosion rates sheet and rill erosion rates are highest on bare soil vineyards show the second highest soil losses followed by other arable lands spring crops orchards and winter crops a land with a permanent vegetation cover shrubs grassland and forest is characterised by soil losses which are generally more than an order of magnitude lower than those on arable land disturbance of permanent vegetation by fire leads to momentarily higher erosion rates but rates are still lower than those measured on arable land we also noticed important regional differences in erosion rates erosion rates are generally much lower in the mediterranean as compared to other areas in europe this is mainly attributed to the high soil stoniness in the mediterranean measured erosion rates on arable and bare land were related to topography slope steepness and length and soil texture while this was not the case for plots with a permanent land cover we attribute this to a fundamental difference in runoff generation and sediment transfer according to land cover types on the basis of these results we calculated mean sheet and rill erosion rates for the european area covered by the corine database estimated rill and interrill erosion rates are ca 1 2 t ha 1 year for the whole corine area and ca 3 6 t ha 1 year 1 for arable land these estimates are much lower than some earlier estimates which were based on the erroneous extrapolation of small datasets high erosion rates occur in areas dominated by vineyards the hilly loess areas in west and central europe and the agricultural areas located in the piedmont areas of the major european mountain ranges c 2010 elsevier b v all rights reserved

historical changes in channel network extent and channel planform in an intensively managed landscape natural versus human induced effects abstract humans have become major geomorphological agents effecting substantial change in the characteristics of earth s physical landscapes the agricultural midwest of the united states is a region marked by pronounced human influence at the landscape scale humans undoubtedly have strongly influenced critical zone processes including fluvial processes in intensively managed agricultural landscapes yet the exact nature of human alteration of these processes is unknown this study documents historical changes in the extent of the stream channel network and in channel planform within the upper sangamon river basin an intensively managed agricultural watershed in illinois results indicate that the modern channel network is nearly three times more extensive than the channel network in the 1820s most change in drainage density has occurred in headwater portions of the basin where numerous drainage ditches have been added to the network to drain flat uplands no detectable change in channel position is evident between 1940 and 2012 along about 60 of the total length of the sangamon river and its major tributaries nearly 30 of the total length exhibits change related to meander dynamics cutoffs and lateral migration whereas about 8 has changed as a result of channelization channelized sections typically remain straight for decades following human modification supporting the notion that humans produce long lasting catastrophic change in channel planform in this region the findings confirm that humans are effective agents of morphological change in fluvial systems in this intensively managed watershed documenting human induced versus natural changes in fluvial systems is important for evaluating how other critical zone processes in intensively managed landscapes have been affected by these changes human induced changes in channel extent and planform most likely have altered this landscape from one dominated by biogeochemical transformations and storage of water and sediment prior to agricultural development into one now characterized by enhanced fluxes of water sediment and nutrients

the binghamton geomorphology symposium bgs 50 years of enhancing geomorphology abstract the binghamton geomorphology symposium bgs celebrated its golden anniversary in 2019 fifty years have passed since donald r coates and marie e morisawa organized a symposium to bring geomorphologists together in a single venue as faculty members at the state university of new york they foresaw that such an event was needed to enhance the science from this small university and city in central new york ny a geomorphology event blossomed into an international event that influences geomorphic thought theory and has shaped the direction of the discipline this introductory paper sets the stage for the volume from the 50th binghamton geomorphology symposium by providing an historical perspective of the beginning growth and impact that this symposium has had and continues to have on the science of geomorphology given that a variety of topics have been covered over the years the organizers of the 50th bgs elected to have presenters address the status of the profession and to provide their perspectives on future advancements this introduction provides a brief synopsis of the presentations delivered at the 50th bgs symposium and concludes with a tribute to the two founders of the bgs donald r coates and marie e morisawa

effects of grain size mineralogy and acid extractable grain coatings on the distribution of the fallout radionuclides 7 be 10 be 137 cs and 210 pb in river sediment abstract grain size dependencies in fallout radionuclide activity have been attributed to either increase in specific surface area in finer grain sizes or differing mineralogical abundances in different grain sizes here we consider a third possibility that the concentration and composition of grain coatings where fallout radionuclides reside controls their activity in fluvial sediment we evaluated these three possible explanations in two experiments 1 we examined the effect of sediment grain size mineralogy and composition of the acid extractable materials on the distribution of 7be 10be 137cs and unsupported 210pb in detrital sediment samples collected from rivers in china and the united states and 2 we periodically monitored 7be 137cs and 210pb retention in samples of known composition exposed to natural fallout in ohio usa for 294 days acid extractable materials made up predominately of fe mn al and ca from secondary minerals and grain coatings produced during pedogenesis are positively related to the abundance of fallout radionuclides in our sediment samples grain size dependency of fallout radionuclide concentrations was significant in detrital sediment samples but not in samples exposed to fallout under controlled conditions mineralogy had a large effect on 7be and 210pb retention in samples exposed to fallout suggesting that sieving sediments to a single grain size or using specific surface area based correction terms may not completely control for preferential distribution of these nuclides we conclude that time dependent geochemical pedogenic and sedimentary processes together result in the observed differences in nuclide distribution between different grain sizes and substrate compositions these findings likely explain variability of measured nuclide activities in river networks that exceeds the variability introduced by analytical techniques as well as spatial and temporal differences in erosion rates and processes in short we suggest that presence and amount of pedogenic grain coatings is more important than either specific surface area or surface charge in setting the distribution of fallout radionuclides

the geomorphology of the anthropocene emergence status and implications the anthropocene is proposed as a new interval of geological time in which human influence on earth and its geological record dominates over natural processes a major challenge in demarcating the anthropocene is that the balance between human influenced and natural processes varies over spatial and temporal scales owing to the inherent variability of both human activities as associated with culture and modes of development and natural drivers e g tectonic activity and sea level variation against this backdrop we consider how geomorphology might contribute towards the anthropocene debate focussing on human impact on aeolian fluvial cryospheric and coastal process domains and how evidence of this impact is preserved in landforms and sedimentary records we also consider the evidence for an explicitly anthropogenic geomorphology that includes artificial slopes and other human created landforms this provides the basis for discussing the theoretical and practical contributions that geomorphology can make to defining an anthropocene stratigraphy it is clear that the relevance of the anthropocene concept varies considerably amongst different branches of geomorphology depending on the history of human actions in different process domains for example evidence of human dominance is more widespread in fluvial and coastal records than in aeolian and cryospheric records so geomorphologically the anthropocene would inevitably comprise a highly diachronous lower boundary even to identify this lower boundary research would need to focus on the disambiguation of human effects on geomorphological and sedimentological signatures this would require robust data derived from a combination of modelling and new empirical work rather than an arbitrary war of possible boundaries associated with convenient but disputed golden spikes rather than being drawn into stratigraphical debates the primary concern of geomorphology should be with the investigation of processes and landform development so providing the underpinning science for the study of this time of critical geological transition

an evolving research agenda for human coastal systems within the broad discourses of environmental change sustainability science and anthropogenic earth surface systems a focused body of work involves the coupled economic and physical dynamics of developed shorelines rapid rates of change in coastal environments from wetlands and deltas to inlets and dune systems help researchers recognize observe and investigate coupling in natural non human morphodynamics and biomorphodynamics this same intrinsic quality of fast paced change also makes developed coastal zones exemplars of observable coupling between physical processes and human activities in many coastal communities beach erosion is a natural hazard with economic costs that coastal management counters through a variety of mitigation strategies including beach replenishment groynes revetments and seawalls as cycles of erosion and mitigation iterate coastline change and economically driven interventions become mutually linked emergent dynamics of two way economic physical coupling is a recent research discovery having established a strong theoretical basis research into coupled human coastal systems has passed its early proof of concept phase this paper frames three major challenges that need resolving in order to advance theoretical and empirical treatments of human coastal systems 1 codifying salient individual and social behaviors of decision making in ways that capture societal actions across a range of scales thus engaging economics social science and policy disciplines 2 quantifying anthropogenic effects on alongshore and cross shore sediment pathways and long term landscape evolution in coastal zones through time including direct measurement of cumulative changes to sediment cells resulting from coastal development and management practices e g construction of buildings and artificial dunes bulldozer removal of overwash after major storms and 3 reciprocal knowledge and data exchange between researchers in coastal morphodynamics and practitioners of coastal management future research into human coastal systems can benefit from decades of interdisciplinary work on the complex dynamics of common pool resources from computational efficiency and new techniques in numerical modeling and from the growing catalog of high resolution geospatial data for natural and developed coastlines around the world

partitioning the quaternary abstract we review the historical purposes and procedures for stratigraphical division and naming within the quaternary and summarize the current requirements for formal partitioning through the international commission on stratigraphy ics a raft of new data and evidence has impacted traditional approaches quasi continuous records from ocean sediments and ice cores new numerical dating techniques and alternative macro models such as those provided through sequence stratigraphy and earth system science the practical usefulness of division remains but there is now greater appreciation of complex quaternary detail and the modelling of time continua the latter also extending into the future there are problems both of commission what is done but could be done better and of omission what gets left out in partitioning the quaternary these include the challenge set by the use of unconformities as stage boundaries how to deal with multiphase records in ocean and terrestrial sediments what happened at the early mid middle pleistocene transition dealing with trends that cross phase boundaries and the current controversial focus on how to subdivide the holocene and formally define an anthropocene

a geoarchaeological perspective on the challenges and trajectories of mississippi delta communities recent geochronology of the mississippi delta of coastal louisiana usa provides a high resolution record of land growth that facilitates the study of ancient settlement patterns in relation to delta evolution we use stratigraphy and optically stimulated luminescence osl dating to show that two late holocene earthen mounds were constructed several hundred years after the land emerged from open water this multi century pause allowed natural processes of overbank and crevasse splay deposition to elevate the land surface reduce flood risk and foster desirable environmental conditions prior to human occupation these results are applied to obtain new age constraints for a large number of at risk or lost archaeological sites with little to no absolute chronology we use our findings to comment on prehistoric contemporary and future human landscape interactions in the mississippi delta and other deltaic environments

automatic geomorphic feature extraction from lidar in flat and engineered landscapes 1 high resolution topographic data derived from light detection and ranging lidar technology enables detailed geomorphic observations to be made on spatially extensive areas in a way that was previously not possible availability of this data provides new opportunities to study the spatial organization of landscapes and channel network features increase the accuracy of environmental transport models and inform decisions for targeting conservation practices however with the opportunity of increased resolution topographic data come formidable challenges in terms of automatic geomorphic feature extraction analysis and interpretation low relief landscapes are particularly challenging because topographic gradients are low and in many places both the landscape and the channel network have been heavily modified by humans this is especially true for agricultural landscapes which dominate the midwestern united states the goal of this work is to address several issues related to feature extraction in flat lands by using geonet a recently developed method based on nonlinear multiscale filtering and geodesic optimization for automatic extraction of geomorphic features channel heads and channel networks from high resolution topographic data here we test the ability of geonet to extract channel networks in flat and human impacted landscapes using 3 m lidar data for the le sueur river basin a 2880 km 2 subbasin of the minnesota river basin we propose a curvature analysis to differentiate between channels and manmade structures that are not part of the river network such as roads and bridges we document that laplacian curvature more effectively distinguishes channels in flat human impacted landscapes compared with geometric curvature in addition we develop a method for performing automated channel morphometric analysis including extraction of cross sections detection of bank locations and identification of geomorphic bankfull water surface elevation using the slope plotted along each channel floodplain cross section we demonstrate the ability to identify and measure the height of river banks and bluffs finally we present an example that demonstrates how extracting such features automatically is important for modeling channel evolution water and sediment transport and channel floodplain sediment exchange

morpho dynamic evolution patterns of subcarpathian prahova river romania abstract the prahova river romania at the southern carpathian mountains was affected by a number of measureable changes in its planform pattern and longitudinal profile over the past 200 years the mountain river has been incising into bedrocks narrowing its valley abandoning its lateral channels and straightening its path while crossing the subcarpathian study section the purpose of this study is to analyze using gis the relationship between short term less than 200 years lateral and vertical morphological adjustments observed over the 18 km length subcarpathian prahova river and specific long term evolutionary patterns more than 200 years human disturbances and hydrodynamic characteristics during high intensity flood periods are assessed in the context of existing neotectonics and lithology controls on channel and valley morphology surveyed cross section profiles were used to construct the geometry of a 1d hydraulic model simulations were performed using the hec ras software usace under steady flow conditions for flow values between bankfull and the peak discharge value of typical flood events with a return period of 20 and 50 years three main areas with high values of computed shear stresses and velocities and corresponding low values of width to depth ratio w d were identified these areas were found to match the observed erosion areas where the river has incised into bedrock and eroded its banks other potentially aggradation areas of low shear stress values and high w d were confirmed by field observations the evolutional patterns of prahova river channel are tectonic structurally determined developed and maintained during the quaternary mainly by the principles of river morphodynamics the evolution over shorter timescale bears the mark of the man induced impact changes in sediment and hydrologic regimes in a long term perspective the overall channel evolution of this river is expected to be strongly influenced by human activity

increase of human over natural erosion rates in tropical highlands constrained by cosmogenic nuclides we quantify the difference between the human caused sediment yield and the natural rates of soil production and bedrock erosion in a now largely deforested tropical highland the present day rate of soil loss in the upper mahaweli catchment sri lanka is calculated by using suspended river load fluxes these data provide spatially averaged sediment yields of 130 2100 t km 2 yr 1 local rates of soil loss from agricultural plots on hillslopes are as high as 7000 t km 2 yr 1 by comparison natural rates of sediment generation as determined by measuring cosmogenic 1 0 be in quartz from sediments and soils are only 13 30 t km 2 yr 1 the natural rates presented here provide a benchmark against which recent erosion rates determined by various sediment gauging techniques can be referenced in the sri lankan highlands these results suggest that soil is now being lost 10 100 times faster from agriculturally utilized areas than it is being produced

coupled economic coastline modeling with suckers and free riders 1 shoreline erosion is a natural trend along most sandy coastlines humans often respond to shoreline erosion with beach nourishment to maintain coastal property values locally extending the shoreline through nourishment alters alongshore sediment transport and changes shoreline dynamics in adjacent coastal regions if left unmanaged sandy coastlines can have spatially complex or simple patterns of erosion due to the relationship of large scale morphology and the local wave climate using a numerical model that simulates spatially decentralized and locally optimal nourishment decisions characteristic of much of u s east coast beach management we find that human erosion intervention does not simply reflect the alongshore erosion pattern spatial interactions generate feedbacks in economic and physical variables that lead to widespread emergence of free riders and suckers with subsequent inequality in the alongshore distribution of property value along cuspate coastlines such as those found along the u s southeast coast these long term property value differences span an order of magnitude results imply that spatially decentralized management of nourishment can lead to property values that are divorced from spatial erosion signals this management approach is unlikely to be optimal

the impact of humans on continental erosion and sedimentation rock uplift and erosional denudation of orogenic belts have long been the most impor tant geologic processes that serve to shape continental surfaces but the rate of geomor phic change resulting from these natural phe nomena has now been outstripped by human activities associated with agriculture con struction and mining although humans are now the most important geomorphic agent on the planet s surface natural and anthro pogenic processes serve to modify quite dif ferent parts of earth s landscape in order to better understand the impact of humans on continental erosion we have examined both long term and short term data on rates of sediment transfer in response to glacio fl u vial and anthropogenic processes phanerozoic rates of subaerial denuda tion inferred from preserved volumes of sedimentary rock require a mean conti nental erosion rate on the order of 16 m per million years m m y resulting in the accumulation of 5 gigatons of sediment per year gt yr erosion irregularly increased over the 542 m y span of phanerozoic time to a pliocene value of 53 m m y 16 gt yr current estimates of large river sediment loads are similar to this late neogene value and require net denudation of ice free land surfaces at a rate of 62 m m y 21 gt yr consideration of the variation in large river sediment loads and the geomorphology of respective river basin catchments suggests that natural erosion is primarily confi ned to drainage headwaters 83 of the global river sediment fl ux is derived from the high est 10 of earth s surface subaerial erosion as a result of human activity primarily through agricultural practices has resulted in a sharp increase in net rates of continental denudation although less well constrained than estimates based on surviving rock volumes or current river loads available data suggest that present farmland denudation is proceeding at a rate of 600 m m y 75 gt yr and is largely confi ned to the lower elevations of earth s land surface primarily along passive continental margins 83 of cropland erosion occurs over the lower 65 of earth s surface the conspicuous disparity between natu ral sediment fl uxes suggested by data on rock volumes and river loads 21 gt yr and anthropogenic fl uxes inferred from measured and modeled cropland soil losses 75 gt yr is readily resolved by data on thicknesses and ages of alluvial sediment that has been deposited immediately downslope from erod ing croplands over the history of human agriculture accumulation of postsettlement alluvium on higher order tributary channels and fl oodplains mean rate 12 600 m m y is the most important geomorphic process in terms of the erosion and deposition of sedi ment that is currently shaping the landscape of earth it far exceeds even the impact of pleistocene continental glaciers or the cur rent impact of alpine erosion by glacial and or fl uvial processes conversely available data suggest that since 1961 global cropland area has increased by 11 while the global population has approximately doubled the net effect of both changes is that per capita cropland area has decreased by 44 over this same time interval 1 per year this is 25 times the rate of soil area loss antici pated from human denudation of cropland surfaces in a context of per capita food pro duction soil loss through cropland erosion is largely insignifi cant when compared to the impact of population growth

human topographic signatures and derived geomorphic processes across landscapes abstract the earth s surface morphology in an abiotic context is a consequence of major forcings such as tectonic uplift erosion sediment transport and climate recently however it has become essential for the geomorphological community to also take into account biota as a geomorphological agent that has a role in shaping the landscape even if at a different scale and magnitude from that of geology although the modern literature is flourishing on the impacts of vegetation on geomorphic processes the study of anthropogenic pressures on geomorphology is still in its early stages topography emerges as a result of natural driving forces but some human activities such as mining agricultural practices and the construction of road networks directly or indirectly move large quantities of soil which leave clear topographic signatures embedded on the earth s morphology these signatures can cause drastic changes to the geomorphological organization of the landscape with direct consequences on earth surface processes this review provides an overview of the recent literature on the role of humans as a geological agent in shaping the morphology of the landscape we explore different contexts that are significantly characterized by anthropogenic topographic signatures landscapes affected by mining activities road networks and agricultural practices we underline the main characteristics of those landscapes and the implications of human impacts on earth surface processes the final section considers future challenges wherein we explore recent novelties and trials in the concept of anthropogenic geomorphology herein we focus on the role of high resolution topographic and remote sensing technologies the reconstruction or identification of artificial or anthropogenic topographies provides a mechanism for quantifying anthropogenic changes to landscape systems this study may allow an improved understanding and targeted mitigation of the processes driving geomorphic changes during anthropogenic development and help guide future research directions for development based watershed studies human society is deeply affecting the environment with consequences on the landscape therefore establishing improved management measures that consider the earth s rapidly changing systems is fundamental

quantifying anthropogenic modification of the shallow geosphere in central london uk abstract the veneer of artificial anthropogenic deposits present beneath contemporary cities is commonly markedly heterogeneous particularly in cities such as london with a history of two millennia of development to what extent can the analysis of borehole data historical land use maps and digital terrain models provide adequate assessment of such heterogeneity two adjacent london boroughs city of london and tower hamlets are selected because of their contrasting historical development and current land use statistical comparison of the variations in deposit thickness is related to the natural holocene topography underlying geological deposits non anthropogenic deposits and heights of overlying buildings estimates of the volume 67 million m3 and mass 100 million tonnes of the deposits and additional volume 359 million m3 and mass 25 million tonnes of buildings provides indication of additional loading that may cause local compaction or regional subsidence a concern during a time of rising global sea level extrapolated across greater london the mass of anthropogenic deposits is estimated at 6 billion tonnes assessment of the compositional variations within the artificial deposits provides an approximation of accumulation rates post world war ii a potential event horizon coincident with the early 1940s blitz could not be demonstrated as an extensive marker but distinct lithological compositions for post world war ii strata are broadly coincident with the globally resolved signals marking the start of the anthropocene epoch

restoring dense vegetation can slow mountain erosion to near natural benchmark levels tropical mountain areas may undergo rapid land degradation as demographic growth and intensified agriculture cause more people to migrate to fragile ecosystems to assess the extent of the resulting damage an erosion rate benchmark against which changes in erosion can be evaluated is required benchmarks reflecting natural erosion rates are usually not provided by conventional sediment fluxes which are often biased due to modern land use change and also miss large episodic events within the measuring period to overcome this we combined three independent assessment tools in the southern ecuadorian andes an area that is severely affected by soil erosion first denudation rates from cosmogenic nuclides in river sediment average over time periods of 1 100 k y and establish a natural benchmark of only 150 100 t km 2 yr 1 second we find that land use practices have increased modern sediment yields as derived from reservoir sedimentation rates which average over periods of 10 100 yr to as much as 15 10 3 t km 2 yr 1 third our land cover analysis has shown us that vegetation cover exerts first order control over present day erosion rates at the catchment scale areas with high vegetation density erode at rates that are characteristically similar to those of the natural benchmark regardless of whether the type of vegetation is native or anthropogenic therefore our data suggest that even in steep mountain environments sediment fluxes can slow to near their natural benchmark levels with suitable revegetation programs a set of techniques is now in place to evaluate the effectiveness of erosion mitigation strategies

quantitative analysis of climate versus human impact on sediment yield since the lateglacial the sarlieve palaeolake catchment france minimum rates of solid ssy and dissolved dsy sediment yield sy were evaluated in t km2 per yr from sediments stored in the sarlieve palaeolake french massif central for seven phases of the lateglacial and holocene up to the seventeenth century the catchment 29 km2 mainly formed of limestones and marls is located in an area rich in archaeological sites in the massif central the respective impacts of human activities and climate on sy were compared by quantification of human settlements through archaeological survey and palynological data during the lateglacial and early holocene up to about 7500 yr cal bp variations in ssy and dsy rates were mainly related to climate change with higher rates during colder periods younger dryas and preboreal and lower rates during warmer periods bolling allerod and boreal however cf1 tephra fallout induced a sharp increase in sy during the allerod during the middle and late holocene after 7500 yr cal bp ssy and dsy greatly increased by factors of 6 5 and 2 8 respectively particularly during the final neolithic at about 5300 yr cal bp when the climate became cooler and more humid after this date at least 75 of the ssy increase and more than 90 of the dsy increase resulted from human activities but ssy rates showed little variation during protohistoric and historic times up to the seventeenth century ssy and dsy rates and dsy ssy ratio indicate that catchment soils began to form during the lateglacial and preboreal thickened considerably during the boreal and atlantic finally thinning rejuvenation mainly as the result of human induced erosion during the sub boreal and sub atlantic increased mechanical erosion during the late holocene also induced an increase in chemical erosion

impacts of land use change on patterns of sediment flux in weraamaia catchment new zealand forest clearance between the 1890s and the early 1920s subsequent scrub growth and commencement of an afforestation program in 1979 modified the pattern and rate of sediment delivery to valley floors via shallow landslides and gully complexes in a steep headwater catchment 4 8 km2 in new zealand analysis of the historical record air photograph interpretation and field survey indicates that both erosion types occurred across the catchment in the 1938 storm aggrading channel beds and widening the active channel zone in contrast a 1 in 100 year event in 1988 cyclone bola induced numerous shallow landslides but erosion of gully complexes was largely restricted to subcatchments that retained pasture and the geomorphic impact of this event on channels was small the changing volume and calibre of materials delivered to the valley floor and the distribution of gully complexes altered patterns and rates of channel adjustment after the events and the resulting sediment flux development of gully complexes maintained coupling processes with channels for periods up to 102 years forming wide channels in downstream reaches upstream downstream connectivity along the trunk stream was altered by the formation of a large debris fan at the confluence with a tributary subjected to gully complex erosion in contrast slopes subjected to shallow landslides became decoupled from channels within 10 years accelerating channel degradation and narrowing effective conveyance of a large volume of fine grained materials promoted immediate aggradation of gentle gradient channels downstream as gully complex areas stabilized following an increase in forest and scrub cover channel courses became significant sediment sources although shallow landslide activity will continue to induce intermittent aggradation in the future it is inferred that average sediment yield will continue to diminish to levels approaching those experienced prior to clearcutting and the pattern of sediment flux will recover by 2030

influence of anthropogenic land use change on hillslope erosion in the waipaoa river basin new zealand european settlement of the poverty bay region resulted in deforestation and conversion of 90 of the landscape to pastureland the resulting loss of vegetation triggered a rapid increase in hillslope erosion as widespread landslide complexes and gully systems developed on weak lithologic units in the waipaoa basin to quantify the rate and volume of historic hillslope degradation we used a 1956 2010 sequence of aerial photographs for a 16 km2 catchment to map temporal changes in the spatial extent of active landslides then we created a turf index based on the extent and style of pastoral ground disruption which correlates with downslope velocity based on the movement of trees and other features we assigned average velocities to the turf classes as follows 1 minimal disrupted ground 0 6 m yr 2 a mix of disrupted ground and intact blocks 3 4 m yr and 3 no intact blocks or vegetation 6 m yr we then calculated the average annual sediment flux using these turf derived velocities the width of the landslide channel intersection and an average toe depth of 4 4 1 3 m mean standard deviation sd from 37 field measurements the resulting catchment averaged erosion rates are mean sd 29 9 12 9 mm yr 1956 28 8 13 7 mm yr 1969 13 4 4 9 mm yr 1979 17 0 6 2 mm yr 1988 and 9 9 3 6 mm yr 2010 compared with long term post 18 ka erosion rates 1 6 mm yr and the long term uplift rate 1 mm yr for this site the 50 year anthropogenically driven rate is an order of magnitude larger 20 mm yr previously we measured an increase in erosion over the past 3 4 kyr 2 2 mm yr and here we demonstrate this increase could be primarily due to human land use change showing that a century of rapid erosion superimposed on the background geologic rate can profoundly skew the interpretation of erosion rates copyright 2016 john wiley sons ltd

quantifying sediment transport across an undisturbed prairie landscape using cesium 137 and high resolution topography soil erosion is a global environmental problem and anthropogenic fallout radionuclides offer a promising tool for describing and quantifying soil redistribution on decadal time scales to date applications of radioactive fallout to trace upland sediment transport have been developed primarily on lands disturbed by agriculture grazing and logging here we use 137cs to characterize and quantify soil erosion at the konza prairie long term ecological research lter site an undisturbed grassland in northeastern kansas we report on the small scale 10 m and landscape scale 10 to 1000 m distribution of fallout 137cs and show significant variability in the concentrations and amounts of 137cs in soils at our site 137cs soil concentrations and amounts typically vary by 10 to 30 on small scales which most likely represents the spatial heterogeneity of the depositional processes landscape scale variability of soil 137cs was significantly higher than small scale variability most notably soils collected on convex divergent landforms had 137cs inventories of 2500 to 3000 bq m 2 which is consistent with the expected atmospheric inputs to the study area during the 1950s and 1960s concave landforms however had statistically lower inventories of 1800 to 2300 bq m 2 the distribution of 137cs on this undisturbed landscape contrasts significantly with distributions observed across disturbed sites which generally have accumulations of radioactive fallout in valley bottoms because the upslope contributing area at each sampling point had a significant negative correlation with the soil inventory of 137cs we suggest that overland flow in convergent areas dominates soil erosion at konza on time scales of decades very few points on our landscape had 137cs inventories significantly above that which would be predicted from direct deposition of 137cs on the soil surface we conclude therefore that there is little net sediment storage on this undisturbed landscape

contrasting mountain and piedmont dynamics of sediment discharge associated with groundwater storage variation in the biobio river supply and transport of sediment in catchments involve processes with fundamental consequences for river management land use and the prediction of climate driven sediment fluxes in the present study we addressed spatial variability in the water routes through the surface and subsurface of a catchment and the suspended sediment discharge qs over a mountain piedmont system we analyzed daily suspended sediment concentration cs and water discharge q measurements at stations located in different topographic settings mountain and piedmont in the biobio river basin southern central andes 37 39 s in steep catchments the q versus qs relationship has a marked seasonal hysteresis in the piedmont qs is proportional to q with no seasonal hysteresis the contrast in the hysteresis pattern between catchments with different topographies is explained by differences in the routing of rainfall derived water in the piedmont most of the rainfall is converted into surface runoff because the water table is near the surface in the mountains groundwater storage results in large seasonal variations in the proportion of q that flows at the surface and transports sediment from the hillslopes producing hysteresis by separating the total q into two components direct discharge qd and base flow qb we observed the response of qs to the fraction of water that quickly leaves the catchment after a rainfall event qd similar results between the mountain and piedmont and the absence of hysteresis simplify the behavior of qs into a linear relationship with qd over the entire catchment and lead us to propose that sediment mobilization to the river along the biobio catchment is primarily controlled by overland flow our findings highlight the importance of an adequate hydrological model for understanding the erosion and transport processes of a catchment and which can be applied to other natural and modeled mountain piedmont systems

dynamics of coupled human landscape systems a preliminary dynamical analysis of landscapes and humans as hierarchical complex systems suggests that strong coupling between the two that spreads to become regionally or globally pervasive should be focused at multi year to decadal time scales at these scales landscape dynamics is dominated by water sediment and biological routing mediated by fluvial oceanic atmospheric processes and human dynamics is dominated by simplifying profit maximizing market forces and political action based on projection of economic effect also at these scales landscapes impact humans through patterns of natural disasters and trends such as sea level rise humans impact landscapes by the effect of economic activity and changes meant to mitigate natural disasters and longer term trends based on this analysis human landscape coupled systems can be modeled using heterogeneous agents employing prediction models to determine actions to represent the nonlinear behavior of economic and political systems and rule based routing algorithms to represent landscape processes a cellular model for the development of new orleans illustrates this approach with routing algorithms for river and hurricane storm surge determining flood extent five markets home labor hotel tourism and port services connecting seven types of economic agents home buyers laborers home developers hotel owners employers hotel developers tourists port services developer and port services owners employers building of levees or a river spillway by political agents and damage to homes hotels or port services within cells determined by the passage or depth of flood waters the model reproduces historical aspects of new orleans economic development and levee construction and the filtering of frequent small scale floods at the expense of large disasters

middle to late holocene environmental evolution of the pisa coastal plain tuscany italy and early human settlements a cross disciplinary sedimentological geochemical micropalaeontological and archaeological examination of 12 continuous cores up to 20 m long integrated with stratigraphical geomorphological and historical investigations allows for reliable delineation of the middle late holocene environmental evolution in the pisa old town area with special emphasis on the etruscan age transition depositional facies were identified through integration of sedimentological and micropalaeontological benthic foraminifers ostracods phytoclasts and palynomorphs data while sediment dispersal patterns were reconstructed on the basis of geochemical analyses facies architecture was chronologically constrained by combined archaeological and radiocarbon dating the turnaround from early holocene transgressive conditions to the ensuing middle late holocene phase of sea level highstand is witnessed by a prominent shallowing upward succession of lagoonal paludal and then poorly drained floodplain deposits supplied by two river systems arno and serchio this regressive trend reflecting coastal progradation under nearly stable sea level conditions was interrupted by widespread swamp development close to the iron etruscan age transition the expansion of vast low lying paludal areas across the alluvial plain was mostly induced by the intricate short term evolution of the meandering arno and serchio river systems these changes in the fluvial network which occurred during a period of variable climate conditions strongly influenced the early etruscan culture 7th 5th century bc in terms of human settlement and society behaviour conversely a strong impact of human frequentation on depositional environments is observed at the transition to the roman age from the 1st century bc onwards when the wetlands were drained and the modern alluvial plain started to form the palaeoenvironmental reconstruction fits in with the original geographical descriptions mentioned in strabo s chronicles and provides chronologically constrained data of fluvial evolution from the pisa old town area

changes in the channel bed level of the eastern carpathian rivers climatic vs human control over the last 50 years article i nfo this paper is focused on the changes over the past 50 years in the channel beds of seven major rivers that are part of the siret drainage basin located in eastern romania each river has been subjected to various degrees of human intervention assessed based on the morphological quality index mqi two rivers siret and bistrita have undergone complex human interventions on 40 and 60 respectively of their channel lengths two rivers suceava and moldova are 30 artificial and the remaining three rivers trotus putna and buz u have a good or moderate mqi the changes occurring in channel beds and data on water discharge qw and sediment load qs w ere assessed simultaneously for the last 50 years the bedload was indirectly evaluated as ranging between 5 and 15 of the total sediment load it was determined that incision was prevalent among the processes acting on the channel bed sections under investigation representing 62 of the altered area and changing bed level by between 0 25 and 2 70 m with aggradation accounting for the remaining 38 causing changes ranging from 0 15 to 1 25 m the magnitude of the processes incision or aggradation for sections with an mqi b 0 3 was four times higher than for sections with a moderate or good mqi 0 3 the pattern of change in the channel bed processes between 1960 and 2010 for all river categories was as follows a low rate of incision from 1960 to 1979 followed by a higher rate of incision from 1980 to 1989 and finally a tendency of recovery toward the river s initial state characterised by a decrease in the incision rate or slight aggradation after 1990 the variable that exhibited the strongest response to climate conditions was water discharge qw whereas the sediment load qs was highly responsive to both climatic signals and anthropogenic factors the sediment load has been instrumental in the adjustments of the channel beds by maintaining a balance between the two controlling factors nature and man

holocene river and slope activity in the visoko basin bosnia herzegovina climate and land use effects alluvial and colluvial deposits were investigated at prehistoric tells close to the bosna river the chronology is based on ten radiocarbon ages five optically stimulated luminescence ages and on the archaeological record fluvial activity of the bosna river is indicated by overbank fines ca 5000 1000 bc 500 bc until today and a phase of lateral displacement of the river bed with subsequent channel fills ca 2000 500 bc early holocene fluvial activity was probably triggered by climatic variability but might have promoted the expansion of neolithic societies into the visoko basin mid to late holocene river activity occurred under increased climatic aridity but coincided with the expansion of prehistoric settlements to a wider area of the river basin on hard rocks in the adjacent mountainous areas the destruction of the thin soil cover in the mountains is discussed as a probable trigger for enduring subsequent river activity this is also indicated by a change in the geochemical signature of the alluvial sediments the proposed mechanism might explain the mid to late holocene river history in other regions the potential of geochemical analyses and diachronous high resolution archaeological records to make inferences regarding sediment sources and geomorphological processes is demonstrated copyright 2013 john wiley sons ltd