Search

We developed a multi-source, integrated remote sensing approach to characterize the geomorphological features of the alluvial and coastal lowlands around the ancient Abdera (coastal Thrace, Gr.). By combining multi-temporal composites of satellite imagery, DEM-derived products, orthophotography, and different cartographic resources, more than 1000 linear km of ancient landforms have been identified and mapped. When crossed with archaeological and historical data, our results allowed to propose a reconstruction of the palaeogeographic evolution and geomorphological dynamics in the eastern lobe of the Nestos Delta, the Kosynthos plain, Lake Vistonida and the Porto Lagos coast since the Antiquity. Our results suggest that the delta developed mainly between Hellenistic times and the Late Antiquity, when it had reached a shape similar to the current. Most of the large palaeochannels visible in the delta seem to be Nestos' short-lived avulsions occurring in late Byzantine and Ottoman periods. Eastwards progradation of the Kosynthos plain, especially during Byzantine and Ottoman periods and accelerating in the 20th c. due to river channelization, was the main cause of the silting and a significant size reduction of Lake Vistonida since the Antiquity. Lake Lafra was also partially silted in late Byzantine and Ottoman times, likely due to the sedimentary discharge of the Kosynthos after a change in its course. By contrast, other lagoons and wetlands in the coast of Porto Lagos seem relatively stable in the last millennia with only minor silting and coastline progradation. Further geomorphological and geoarchaeological research in the area will allow to draw more precisely long-term interaction of past societies with environmental dynamics and resulting landscape change. [ABSTRACT FROM AUTHOR]

Unguja Ukuu, located on the Zanzibar Archipelago, eastern Africa, was an active Indian Ocean trading settlement from the mid-first millennium until the early second millennium AD. As part of recent archaeological excavations aimed at understanding the site's transregional trade networks, geoarchaeological analyses were undertaken to document the geomorphic context of the ancient settlement. Here, we outline the results of these field and laboratory studies to discuss patterns of anthropogenic sediment deposition. Unguja Ukuu's deep coastal stratigraphy appears to record progradation of an inhabited back-reef shore from the mid-seventh to the nineth centuries AD, perhaps in the wake of an earlier middle to late Holocene marine transgression. Excavations on the back-beach show that deposits associated with the ancient settlement include interlayered middens, paleofloors, and backshore sands and, in later phases, a peri-urban dump with dark-earth-type anthrosols developed on these deposits. Coastal progradation appears to have been driven in part by the accumulation of anthropogenic detritus and compaction of ancient surfaces. We hypothesize how the inherited, submerged relic Late Pleistocene geomorphology of the intertidal zone and later Holocene sediment supply from the hinterland may have supported the emergence of Unguja Ukuu as a trading locale, and possibly contributed to its decline in the early second millennium AD. [ABSTRACT FROM AUTHOR]

Cultural Geomorphology attempts to find the relationships between cultural elements and geomorphological features of a region. Such studies have proven invaluable to understanding the interactions between culture and geomorphology and have formed an important part of the epistemology of nature-society studies. Using concepts of Cultural Geomorphology, the current study argues for the need to develop a Cultural Geomorphology of hazards. The study shows that such a work will be invaluable in preserving the knowledge of cultural heritage sites that are at risk of being permanently lost because of the changing landscape brought about by natural hazards or climate change related events. [ABSTRACT FROM AUTHOR]

This study focuses on photographic analysis of Enchanted Rock, a granite dome in central Texas; fourteen photo pairs compare contrasting views after—thirty-six to forty-six years, and assess changes in geomorphology, sediments, and vegetation on miniature landforms, especially erosional depressions—gnammas and vernal pools. Several distinct landscape changes occurred during the study period, but these affected sites unevenly. Vegetation displayed noticeable differences in plant density and species, particularly a pronounced increase of Opuntia cacti and woody shrubs on several depressions; these changes, however, are not considered permanent, and are interpreted as representing periodic fluctuations due to climatic oscillations such as recurrent drought. Among geomorphic features, a rock pedestal and a tafoni panel—displaying friable, crumbling, material—are seemingly being rapidly obliterated by weathering; their low compressive strength (Schmidt hammer) R values support this idea. In contrast, a large, isolated, boulder near the dome base did not—as anticipated—display any obvious changes. Large stones and gravelly sediments, accumulated on vernal pools, or deposited along rill channels between depressions, showed the most conspicuous alterations. The observed changes are arranged along a presumed developmental sequence portraying subsequent geomorphic stages during pool development, which occur as detached stones gradually weather and eventually disintegrate; both coarse and fine sediments are transported downslope during intense, infrequent rainfall events. Pools, gnammas, rills, sediments, and vegetation function on Enchanted Rock as interconnected geographical units and components of an elaborate drainage network, steadily affecting each other over space and time. [ABSTRACT FROM AUTHOR]

December 2023 marks the 20th anniversary of the first issue of the Journal of Geophysical Research: Earth Surface. The past 20 years have brought rapid growth in the field of Earth‐surface processes, changes in AGU's structure and objectives, and new practices across the scientific publishing landscape. In recent years our mission has evolved to focus increasingly on science for the benefit of society and the global environment. The growth and diversification of the international Earth‐surface scientific community has enriched the science immeasurably, and we continue to reach out to scientists in parts of the globe that have remained under‐represented in the scientific literature. JGR Earth Surface strives to provide peer review that is rigorous, constructive, efficient, and with an increasing emphasis on also being civil and free of bias. As preferences and practices for publishing science change, the journal explores new opportunities, including publishing rigorous, insightful case studies and leading cross‐journal Special Collections. The Editorial Board thanks AGU for 20 years of support and the Earth‐surface scientific community for their continued dedication to moving our field forward. Key Points: JGR Earth Surface editors look back on the first 20 years of this journalOur field, AGU, and the publishing landscape continue to change, and the journal adapts to continue distributing rigorous, impactful scienceThe journal reaches out to scientists in parts of the globe that have remained understudied, to achieve an improved geographical coverage in the future [ABSTRACT FROM AUTHOR]

The Arctic is experiencing rapid climate change, and the effect on hydrologic processes and resulting geomorphic changes to hillslopes and channels is unclear because we lack quantitative models and theory for rapid changes resulting from thawing permafrost. The presence of permafrost modulates water flow and the stability of soil‐mantled slopes, implying that there should be a signature of permafrost processes, including warming‐driven disturbance, in channel network extent. To inform understanding of hillslope‐channel dynamics under changing climates, we examined soil‐mantled hillslopes within a ∼300 km2 area of the Seward Peninsula, western Alaska, where discontinuous permafrost is particularly susceptible to thaw and rapid landscape change. In this study, we pair high‐resolution topographic and satellite data to multi‐annual observations of InSAR‐derived surface displacement over a 5‐year period to quantify spatial variations in topographic change across an upland landscape. We find that neither the basin slope nor the presence of knickzones controls the magnitude of recent surface displacements within the study basin, as may be expected under conceptual models of temperate hillslope evolution. Rather, the highest displacement magnitudes tended to occur at the broad hillslope‐channel transition zone. In this study area, this zone is occupied by water tracks, which are zero‐order ecogeomorphic features that concentrate surface and subsurface flow paths. Our results suggest that water tracks, which appear to occupy hillslope positions between saturation and incision thresholds, are vulnerable to warming‐induced subsidence and incision. We hypothesize that gullying within water tracks will outpace infilling by hillslope processes, resulting in the growth of the channel network under future warming. Plain Language Summary: Climate and ecology can shape hillslopes and the extent of river networks by controlling how much water is available for erosion. These forces also control whether water can erode soil if it is strengthened by ice or roots. The permeability and stability of permafrost hillslopes change with seasonal and long‐term warming due to frozen ground's impermeability and resistance to erosion. This link between temperature and erosion in permafrost landscapes is thus more direct than most geomorphic models developed at lower latitudes presume. We related the locations of satellite topographic change to the geomorphic processes that dominate that part of the landscape based on the shape of the hillslopes and valleys. This allows us to determine whether the pattern of disturbance across the landscape is related to geomorphic variables such as slope or climate‐modulated variables such as soil saturation. Topographic change primarily occurs in saturated areas at the tips of the river network. At these locations, features called "water tracks" form the transition between hillslopes and river valleys. Changes in climate and vegetation in permafrost landscapes are potentially driving water tracks to transition into true channels, expanding the channel network. Key Points: Seasonal and long‐term permafrost thaw change hillslope hydrology and erodibilitySatellites observe surface displacements concentrated at the transition between hillslopes and channelsA conceptual model is proposed for hillslope‐channel transitions in permafrost landscapes mediated by water tracks [ABSTRACT FROM AUTHOR]

Extricating histories of uplift and erosion from landscapes is crucial for many branches of the Earth sciences. An objective way to calculate such histories is to identify calibrated models that minimize misfit between observations (e.g., topography) and predictions (e.g., synthetic landscapes). In the presence of natural or computational noise, widely used Euclidean measures of similarity can have complicated objective functions, obscuring the search for optimal models. Instead, we introduce the Wasserstein distance as a means to measure misfit between observed and theoretical landscapes. Our results come in two parts. First, we show that this approach can generate much smoother objective functions than Euclidean measures, simplifying the search for optimal models. Second, we show how locations and amplitudes of uplift can be accurately recovered from synthetic landscapes even when seeded with different noisy initial conditions. We suggest that this approach holds promise for inverting real landscapes for their histories. Plain Language Summary: The shapes of Earth's landscapes tell us about how they were formed by processes like tectonic uplift and erosion. Mathematical models are used to predict how landscapes change over time due to these processes. However, identifying models that produce theoretical landscapes that resemble reality can be challenging. One way to do so is by comparing model predictions to actual landscapes we observe. To make this comparison, we need a way to measure how similar or different predicted and observed landscapes are. One common approach is to compare heights of land from both cases. However, this method can struggle because a small shift in the position of a theoretical valley, say, can dramatically change the outcome of a comparison. In this paper, we introduce an alternative approach that uses a metric called the Wasserstein distance from the field of "Optimal Transport." The Wasserstein distance is a measure of how different two probability distributions are from each other by considering how much "work" is needed to transform one distribution into the other. We show that this metric is effective for finding models to understand how landscapes were shaped by uplift over time. Key Points: The use of the Wasserstein distance for identifying optimal landscape evolution models is demonstratedThis approach can produce simple objective functions, simplifying the search for models that minimize data misfitAccurate amplitudes and locations of uplift can be retrieved from synthetic landscapes generated using different initial conditions [ABSTRACT FROM AUTHOR]

The outward growth of many orogens occurs through pulsed migration of the strain front. During Cenozoic shortening of the central Andes, the strain front abruptly migrated ∼400 km eastward across the Altiplano, isolating the plateau interior from major deformation. In contrast to the traditional critical wedge model that focuses on shallow crust deformation, our lithosphere‐scale numerical models show the ductile lower crust plays a key role in the dynamics of the orogen. As the orogen grows upward, the lower crust flows outward and causes stepwise expansion of the orogen through landward‐migrating deformation. The step length of the strain‐front migration increases with decreasing lower crustal strength. Topographically, a weaker crust promotes the formation of a smooth plateau and underthrusting of stronger foreland lithosphere. Our results indicate that the seemly unrelated physiography, deep‐lithosphere structure, and plateau‐wide strain migration in the Altiplano may all be the result of a weak lower crust. Plain Language Summary: The formation of large mountain belts is typically considered using the analogy of the growth of a wedge of snow or soil in front of a bulldozer, and it is expected that the mountain belt widens continually. However, observations show that many mountain belts expand laterally in abrupt pulses, where shortening is punctuated by periods during which the deformation front rapidly migrates inland by 100's of kilometers. This includes the Tibetan plateau in Asia, central Andes in South America, and Sevier orogen in North America. Here, we show that mountain belt growth significantly modified when the lower crust is weak. In this case, initially localized crustal shortening causes the lower crust to flow outward from the elevated mountain to the adjacent low‐elevation region. The subsurface flow redistributes crustal mass and changes the mountain landscape. Crustal flow causes compressional stresses associated with mountain growth to expand into the continental interior, leading to the formation of a new deformation front several hundred kilometers inland. This causes the mountain belt to widen in a stepwise fashion and creates a smooth, high plateau interior. In contrast, if the crust is stronger, pulses of deformation are shorter, resulting in more rugged and steep topography. Key Points: Lower crustal strength strongly affects the kinematics of the retroarc orogenic strain frontWeak lower crust (≤1020 Pa s) promotes the formation of new strain loci several hundred kilometers landward from the original strain frontA weak lower crust in the Altiplano (central Andes) can explain the ∼400 km eastward jump in deformation in the Eocene [ABSTRACT FROM AUTHOR]

Glaciers in the Tibetan Plateau are melting at an unprecedented recently rate in the context of global warming. Time-sequenced landform mapping for the Hailuogou Glacier, a partly debris)covered glacier in the southeastern Tibetan Plateau, shows the detailed evolution of glacier changes as the ice recedes. This study presents four maps of the Hailuogou Glacier tongue, a partly debris-covered glacier in the southeastern Tibetan Plateau, documenting the spatial evolution of glaciological, hydrological, and geomorphological features from 2018 to 2021. Structure from Motion with Multiview Stereo software was applied to images captured by from uncrewed aerial vehicles were used to produce digital surface models and orthophoto mosaics. These datasets were used, and then to identify and map the features based on pre-defined mapping criteria. From 2018 to 2021, the glacier underwent continuous recession, with the terminus retreating, intense crevassing in the lower part of the ablation zone, and continuous expansion of the terminal disintegration area. The recent evolution of the glacier implies that the gradual disintegration of the lower glacier tongue is likely to be exacerbated over the next decades by the continuous climate warming. [ABSTRACT FROM AUTHOR]

High tide floods (HTFs) are minor, shallow flooding events whose frequency has increased due to relative sea‐level rise (SLR) and secular changes in tides. Here we isolate and examine the role of historical landscape change (geomorphology, land cover) and SLR on tides and HTF frequency in an urbanized lagoonal estuary: Jamaica Bay, New York. The approach involves data archeology, historical (1870s) map digitization, as well as numerical modeling of the bay. Numerical simulations indicate that a century of landscape alterations (e.g., inlet deepening and widening, channel deepening, and wetland reclamation) increased the mean tidal range at the head of the bay by about 20%. The observed historical shift from the attenuation to amplification of semidiurnal tides is primarily associated with reduced tidal damping at the inlet and increased tidal reflection. The 18% decrease in surface area exerts a minor influence. A 1‐year (2020) water level simulation is used to evaluate the effects of both SLR and altered morphology on the annual number of HTFs. Results show that of 15 "minor flood" events in 2020, only one would have occurred without SLR and two without landscape changes since the 1870s. Spectral and transfer function analyses of water level reveal frequency‐dependent fingerprints of landscape change, with a significant decrease in damping for high‐frequency surges and tides (6–18 hr time scale). By contrast, SLR produced only minor effects on frequency‐dependent amplification. Nonetheless, the geomorphic influence on the dynamical response significantly increases the vulnerability of the system to SLR, particularly high‐tide flooding. Plain Language Summary: High tide floods (HTFs) are shallow coastal flooding events that typically occur near the time of predicted high tide. Here we isolate and examine how sea‐level rise (SLR) and historical landscape changes related to urban development have altered tides and increased flooding frequency in Jamaica Bay, New York City. Using water level observations and digitized maps from the 1870s, we create a computer‐based model to study how HTF frequency has changed from the 1870s to now. Model results indicate that dredging and wetland landfill increased tidal ranges in the bay by nearly 20%. We then use a model simulation of 2020 to evaluate the effects of both SLR and the changed landscape on the annual number of HTF events. Results show that of 15 minor flood events in 2020, only one would have occurred without SLR and two would have occurred without landscape changes since the 1870s. A better understanding of how specific landscape changes have affected tides and caused increases in coastal flooding can help mitigation efforts and provide more rationale for restoration and nature‐based solutions. Key Points: Landscape change since the 1870s (e.g., dredging, land filling) increased tidal range by 20% in Jamaica Bay, New York CityThese landscape changes reduced inlet choking and increased tidal reflection, resulting in a frequency‐dependent amplification of tidesOf 15 minor floods in 2020, there would have been only two without landscape change and one without sea level rise since the 1870s [ABSTRACT FROM AUTHOR]

Drylands represent more than 41% of the global land surface and are at degradation risk due to land use and climate change. Developing strategies to mitigate degradation and restore drylands in the face of these threats requires an understanding of how drylands are shaped by not only soils and climate, but also geology and geomorphology. However, few studies have completed such a comprehensive analysis that relates spatial variation in plant communities to all aspects of the geologic–geomorphic–edaphic–plant–climate system. The focus of this study is the Colorado Plateau, a high‐elevation dryland in the southwestern United States, which is particularly sensitive to future change due to climate vulnerability and increasing land‐use pressure. Here, we examined 135 long‐term vegetation‐monitoring sites in three national parks and characterized connections between geology, geomorphology, soils, climate, and dryland plant communities. To first understand the geologic and geomorphic influences on soil formation and characteristics, we explore associations between soil pedons, bedrock geology, and geomorphology. Then, we characterize principal axes of variation in plant communities and ascertain controls and linkages between components of the edaphic–geomorphic system and plant community ordinations. Geologic and geomorphic substrate exerted controls on important properties of the soil profile, particularly depth, water‐holding capacity, rockiness, salinity, and fine sands. Ordination identified five distinct plant communities and three primary axes of variation, representing gradients of woody‐ to herbaceous‐dominated communities (Axis 1), saline scrublands to C3 grasslands (Axis 2), and annual to perennial communities (Axis 3). Geology, geomorphology, and soil explained a large proportion of variation in Axis 1 (74%), while climate variables largely explained Axis 2 (68%), and Axis 3 was not well explained by the random forest models. The variables identified as most influential to each axis were, respectively: (1) soil depth; (2) aridity, lithology, and soil salinity; and (3) temperature and precipitation. We posit that Axis 3 represents a land degradation gradient due to historic grazing, likely exacerbated by dry conditions. Results provide a novel framework that links the geologic and geomorphic evolution of landscapes, with the distribution of soils and plant communities that can guide ecosystem management, exemplifying an approach applicable to drylands globally. [ABSTRACT FROM AUTHOR]

Today, climate change is affecting virtually all terrestrial and nearshore settings. This commentary discusses the challenges of measuring climate‐driven physical landscape responses to modern global warming: short and incomplete data records, land use and seismicity masking climatic effects, biases in data availability and resolution, and signal attenuation in sedimentary systems. We identify opportunities to learn from historical and paleo data, select especially sensitive study sites, and report null results to better characterize the extent and nuances of climate‐change effects. We then discuss efforts to improve attribution practices, which will lead to better predictive capabilities. We encourage the Earth‐science community to prioritize scientific research on climate‐driven physical landscape changes so that societies will be better prepared to manage the effects on health and safety, infrastructure, water–food–energy security, economics, and ecosystems that follow from climate‐driven physical landscape change. Plain Language Summary: Modern global warming will ultimately affect physical landscape processes virtually everywhere on Earth, and some of those effects are evident already. This commentary describes the challenges to measuring climate‐driven physical landscape responses to global warming: short and incomplete data records, land use and earthquakes masking climatic effects, biases in data availability and resolution, and climate signals becoming harder to read at the downstream end of a landscape. We discuss ways to collect more informative data in key locations to better understand climate‐change impacts, while also diligently reporting where impacts are not evident. Forming a more complete picture in these ways will mean societies are better prepared to predict and manage impacts on human health and safety, infrastructure, water–food–energy security, economics, and ecosystems that are linked to climate‐driven physical landscape change. Key Points: Modern anthropogenic climate change affects a vast range of geomorphic settingsWe identify challenges of measuring physical landscape response to modern climate change and opportunities to improve studiesBetter understanding physical landscape impacts will prepare societies to manage hazards and economic effects of climate change [ABSTRACT FROM AUTHOR]

The compounding societal and environmental crises of the Anthropocene necessitate a more holistic, critical and systems understanding of our relationship to and with the earth surface. We are now aware that every landscape is touched by man, a mosaic of recorded artifacts of historical human activity. These effects emerge from distinct perspectives that require global, local, and complex frameworks of inquiry. In order to address the braided realities of this age, geomorphologists need to embrace diverse ways of knowing, most especially indigenous, local and place‐based knowledges of landscapes and our role in shaping them. We need to examine how a singular, objective standpoint in the scientific process privileges determinism over other ways of seeing and being. In this commentary, I argue that the discipline of geomorphology as it is commonly practiced in the Global North is ill‐suited to address the crises of the Anthropocene. In order to reorient the discipline towards a more ethical and societally‐relevant role, we need to seek and integrate place‐based, local and situated perspectives into the scientific work of understanding the landscapes we are working in, particularly as so many of the communities most impacted by these changing landscapes are the least involved in guiding our scientific efforts and outcomes. [ABSTRACT FROM AUTHOR]

Climate change is causing drastic landscape changes in the Arctic, but how these changes modify stream biogeochemistry is not clear yet. We examined how catchment properties influence stream nitrogen (N) and dissolved organic carbon concentrations (DOC) in a high‐Arctic environment. We sampled two contrasting headwater streams (10–15 stations over 4.8 and 6.8 km, respectively) in Northeast Greenland (74°N). We characterized the geomorphology (i.e., bedrock, solifluction and alluvial types) and the vegetation (i.e., barren, fell field, grassland and tundra types) cover of each subcatchment area draining into each sampling station and collected water samples for hydrochemistry characterization. The two sampled streams differed in geomorphology and vegetation cover in the catchment. Aucellaelv catchment was mostly covered by a 'bedrock' geomorphology (71%) and 'fellfield' vegetation (51%), whereas Kæerelv was mostly covered by 'alluvial' geomorphology (65%) and 'grassland' and 'tundra' vegetation (42% and 41% respectively). Hydrochemistry also differed between the two study streams, with higher concentrations of inorganic N forms in Aucellaelv and lower DOC concentrations, compared to Kærelv. The results from the linear mixed model selection showed that vegetation and geomorphology had contrasting effects on stream hydrochemistry. Subcatchments with higher solifluction sheets and limited vegetation had higher nitrate concentrations but lower DOC concentrations. Interestingly, we also found high variability on the production and removal of nitrate across subcatchments. These results indicate landscape controls to nutrient and organic matter exports via flow paths, soil organic matter stocks and nutrient retention via terrestrial vegetation. Moreover, the results suggest that climate change induced alterations to vegetation cover and soil physical disturbance in high‐Arctic catchments will affect stream hydrochemistry, with potential effects in stream productivity, trophic relations as well as change of solute export to downstream coastal areas. [ABSTRACT FROM AUTHOR]

Assessing rivers' and hillslopes' sensitivity to external forcing is paramount to understand landscape evolution, in particular as a response to Quaternary climate changes. River networks are usually considered to be the main conveyors of environmental signals, such as changes in precipitation, temperature, or baselevel. Yet because hillslopes provide the source of sediment for river networks, their response to environmental change also modulates landscape dynamics. In order to characterize such behavior, we analyze the response times of a transport‐limited hillslope. We use simple numerical models of denudation to study hillslope responses to oscillatory forcing and understand their filtering effects on environmental signals. Modifications in the frequency of climate oscillation, such as the change that occurred at the Mid‐Pleistocene Transition, can significantly modulate hillslope sediment‐flux response. We infer a wide range of hillslope responses, ranging from negligible change over the full range of climate‐forcing frequencies, to a significant filtering of long‐period signals. Plain Language Summary: Landscapes are constituted of hillslopes and rivers where different types of erosion and sediment transport processes take place. Due to their large extent, river networks are an important driver of global landscape response to climatic or tectonic changes. Hillslopes have smaller dimensions but are also where most sediment production occurs and for that reason it is important to have a good understanding of how they respond to perturbations. We use simple numerical models of hillslope evolution to study the influence of oscillating changes of either the efficiency of sediment transport across the hillslope or the rate of channel downcutting at its base. Our results indicates that the period of oscillations for these perturbations controls the amplitude of the sediment flux response out of the hillslope, and provide a framework to understand how this landscape component reacts to climatic cycles such as the glacial/inter‐glacial oscillations of the Quaternary. For example, a major change occurred 800 ka ago with a shift in climate oscillation from 40 to 100 ka period. Our models suggest that in some landscapes this change in period alone could have induced a significant decrease in the amplitude of hillslope sediment flux response. Key Points: A complex hillslope dynamics is associated with the linear to nonlinear sediment flux transitionHillslopes filtering potential of external signals is highly contrasted depending on the type of forcingChanges in the climatic signal frequency at the Mid‐Pleistocene Transition could induce a significant shift in hillslope erosional response [ABSTRACT FROM AUTHOR]

Geomorphological changes have had numerous environmental impacts on landscape features, natural resources, landform stability, and ecosystem services on Bhasan Char Island in the Northern Bay of Bengal, Bangladesh. Therefore, the present study examines the morphological change of the island and its impacts on landscape features, landform stability, and coastal mangrove forest resources since its evolution. Optical satellite images from Landsat (TM and OLI) spanning from 2003 to 2023 have been used to assess geomorphological parameters using the bio-physical indices NDWI and MNDWI. A hybrid classification method involving unsupervised classification, supervised machine learning, and post-classification refinement was employed to precisely delineate landscape features and evaluate ecosystem services. Indeed, to evaluate forest cover health dynamics, the leaf area index (LAI) was estimated using the Google Earth Engine (GEE) cloud platform. The study results reveal that the geomorphology of the island was changed by fluvial and marine processes and responses, whereas only 3% of the landscape ages older than 19 years. Results also disclosed that built-up area construction for Rohingya nations drastically lost ∼ 7% of mangrove plantations over the last 8 years, from 2015 to 2023. The current research delivers crucial management strategies regarding further structural development by evading unplanned construction, hastening reforestation, and evolving the green belt along the existing embankment. The study findings will help policymakers, environmental managers, coastal and marine resource planners, ecologists, and geomorphologists take an eco-friendly sustainable development plan and conserve the coastal island and its landscape resources from the risk of fluvial and marine processes. [Display omitted] [ABSTRACT FROM AUTHOR]

To settle in a given area, man has to deal with the surrounding environment and the geomorphological processes that shaped it. Landscape defines the available resources and landscape changes are related to tectonics, hydrography and variations in climate and biota. To cope with environmental limitations, man developed efficient techniques and capabilities to survive, making the best use of natural resources. The Fars arc (southern Iran) is known for being the cradle of some of the earliest civilizations in Iran. It comprehends the southeastern sector of the Zagros Mountains, a Cenozoic orogen formed after the collision between Arabia and central Iran. The landscape is dominated by a series of folding structures which isolate internal basins. This configuration, together with arid climate conditions, limited biological resources, and the occurrence of natural disasters such as earthquakes, floods, landslides, water salinity, biological/climatic changes and droughts, all dictated the development and pattern of human settlements. This paper aims to give a broad overview on the deep influence exerted by geomorphological processes, such as tectonics, earthquakes, landslides, sea level fluctuations, and climate changes, on the emergence and development of human settlements in the Fars arc which, with its long-lasting and documented civilization history, represents an ideal test site to study the interaction between nature and man. [ABSTRACT FROM AUTHOR]

This paper presents an in-depth study and analysis of the spatial distribution of urban landscapes in Jiangnan cities under the influence of geomorphology and extracts the characteristics to explore the construction mechanism from the perspective of spatial functionality based on the analysis of the process and content of landscape construction. The construction of cities and ponds originated from political influence, environmental constraints, and architectural techniques; the landscape pattern of the combined shape and complementary potential originated from the creation of various types of gardens in various dynasties; the complementary planning of landscape, the traffic creation of the plain and water network, and the production factors of agriculture and sanitation influenced the construction of the countryside landscape; the traditional view of feng shui, poetry and painting, the eight scenes of the city and countryside, and other humanistic intentions influenced the overall situation of the town and the landscape. This paper extracts and analyzes the spatial distribution characteristics of Jiangnan city landscape from several perspectives, and the results can clearly show the distribution of landscape features under the influence of geomorphology and can give the best layout suggestions. From the perspective of spatial variability, the main features of traditional landscape construction in Jiangnan are analyzed through three levels: the characteristics of the process of humanized landscapes evolving into natural landscapes, the comparative analysis of similarities and differences in the construction of cities and towns, and the characteristics of the system of regional landscape construction. Finally, the changes in the landscape pattern of the region under the influence of globalization are analyzed through the changing characteristics of landscape architecture. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Human Sciences (19922876) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Uncertainties about landscape evolution under cold, nonglacial conditions raise a question fundamental to periglacial geomorphology: what and where are periglacial landscapes? To answer this, with an emphasis on lowland periglacial areas, the present study distinguishes between characteristic and polygenetic periglacial landscapes, and considers how complete is the footprint of periglaciation? Using a conceptual framework of landscape sensitivity and change, the study applies four geological criteria (periglacial persistence, extraglacial regions, ice‐rich substrates, and aggradation of sediment and permafrost) through the last 3.5 million years of the late Cenozoic to identify permafrost regions in the Northern Hemisphere. In limited areas of unglaciated permafrost regions are characteristic periglacial landscapes whose morphology has been adjusted essentially to present (i.e., Holocene interglacial) process conditions, namely thermokarst landscapes, and mixed periglacial–alluvial and periglacial–deltaic landscapes. More widespread in past and present permafrost regions are polygenetic periglacial landscapes, which inherit ancient landsurfaces on which periglacial landforms are superimposed to varying degrees, presently or previously. Such landscapes comprise relict accumulation plains and aprons, frost‐susceptible and nonfrost‐susceptible terrains, cryopediments, and glacial–periglacial landscapes. Periglaciation can produce topographic fingerprints at mesospatial scales (103–105 m): (1) relict accumulation plains and aprons form where long‐term sedimentation buried landsurfaces; and (2) plateaux with convexo–concave hillslopes and inset with valleys, formed by bedrock brecciation, mass wasting, and stream incision in frost‐susceptible terrain. [ABSTRACT FROM AUTHOR]

Human activity along the Amalfi coastline in Italy has been tied to the sea for millennia – for sustenance, migration, trade, warfare, and leisure. As a result, this region has an equally rich and extensive maritime cultural landscape composed of tangible and intangible elements. In 2016, a multi-disciplinary project began efforts to model and to understand changes within this landscape, and this essay presents the preliminary results of our first three seasons of work. Some efforts, such as the documentation of maritime cultural heritage in local museums, archival work, and geomorphological research proceeded smoothly. Unexpectedly, however, little material from the pre-modern era was found under water, adding questions to this study that future work in the Marine Protected Area west of Positano may answer. [ABSTRACT FROM AUTHOR]

Mountain area is an important geographical unit of land, and its ecology is sensitive and fragile. Over the past few decades, human activities have caused dramatic changes in land use in mountainous areas, which caused changes in landscape patterns and impacts on the ecological environment. It is unknown how the mechanism of land use affects the landscape pattern at different scales. The Hantai District, a typical human settlement in the mountain area in Shaanxi, China, was chosen as the study area. Based on the remote sensing images, the mathematical models and landscape indexes were adopted to evaluate the impact of land use change from 1998 to 2017 on the landscape pattern at different scales, and its main driving forces were analyzed. The results showed that the urbanized land expanded largest from 15.39% to 24.30%, and cultivated land experienced the largest decline from 43.54% to 35.35%. Changes in land use have made the patch morphology of most land types developed from a natural random to a sawtooth shape, and its spatial pattern evolved from a ruleset to a fragmented expansion. This reflects the continuous strengthening of human intervention in the process of regional development. Under the jurisdiction of Hantai District, the biggest change in landscape pattern is in Hanzhong City and Qili Town. The improved economy and increasing population and urbanization rate were the main factors that cause these changes. This research could provide necessary information for understanding the evolution mechanism of land resources in mountainous human settlements for mountainous areas with significant geomorphic differentiation. [ABSTRACT FROM AUTHOR]

Cosmogenic nuclide (CN) applications offer methods to quantify rates of landscape change and of dating geomorphological deposits and surfaces. Over the past two decades, CNs have been used to determine denudation rates, constrain uplift rates and determine burial ages of sediments in different geomorphological settings across the Southern African landscape. Here, we first give an overview of the landscape evolution of Southern Africa and how CN-based studies have contributed to this subject. Then we give a compilation of CN denudation data from Southern Africa, which show that average erosion rates have decreased by an order of magnitude since the late Cenozoic. Finally, we present the state of CN infrastructure and capabilities in South Africa as well as envisaged future developments. An Accelerator Mass Spectrometer (AMS) has become operational for carbon-14, beryllium-10 and aluminium-26 measurements at the National Research Foundation (NRF) iThemba Laboratory for Accelerator Based Sciences (LABS) in Gauteng since 2017. The measurements' accuracy and precision compare well with other AMS laboratories internationally. Local sample preparation laboratories are currently available with limited capabilities and are mostly still under development. [ABSTRACT FROM AUTHOR]

Warming in the high Arctic is occurring at the fastest rate on the planet, raising concerns over how this global change driver will influence plant community composition, the timing of vegetation phenological events, and the wildlife that rely on them. In this region, as much as 50% of near-surface permafrost is composed of thermally sensitive ground ice that when melted produces substantial changes in topography and microbiome conditions. We take advantage of natural variations in permafrost melt to conduct a space-for-time study on Ellesmere Island in northern Canada. We demonstrate that phenological timing can be delayed in thermokarst areas when compared to stable ground, and that this change is a function of shifting species composition in these vegetation communities as well as delayed timing within species. These findings suggest that a warming climate could result in an overall broadening of blooming and leafing windows at the landscape level when these delayed timings are taken into consideration with the projected advance of phenological timings in ice-poor areas. We emphasize that the impacts of geomorphic processes on key phenological drivers are essential for enhancing our understanding of community response to climate warming in the high Arctic, with implications for ecosystem functioning and trophic interactions. [ABSTRACT FROM AUTHOR]

Two detailed geomorphological maps (1:2000) depicting landscape changes as a result of a glacial lake outburst flood were produced for the 2.1-km-long section of the Zackenberg river, NE Greenland. The maps document the riverscape before the flood (5 August 2017) and immediately after the flood (8 August 2017), illustrating changes to the riverbanks and morphology of the channel. A series of additional maps (1:800) represent case studies of different types of riverbank responses, emphasising the importance of the lateral thermo-erosion and bank collapsing as significant immediate effects of the flood. The average channel width increased from 40.75 m pre-flood to 44.59 m post-flood, whereas the length of active riverbanks decreased from 1729 to 1657 m. The new deposits related to 2017 flood covered 93,702 m2. The developed maps demonstrated the applicability of small Unmanned Aerial Vehicles (UAVs) for investigating the direct effects of floods, even in the harsh Arctic environment. [ABSTRACT FROM AUTHOR]

Landscape morphology reflects the spatial and temporal history of erosion. Erosion in turn embodies the competition between tectonic and climatic processes. Quantitative analysis of topography can therefore reveal the driving tectonic conditions that have influenced landscape development, when combined with theoretical understanding of erosion processes. Recent developments in the automated analysis of high-resolution (<10 m) topographic data mean that integrated analysis of hillslope and channel topographic metrics can provide understanding of the transient response of landscapes to changing boundary conditions. We perform high-resolution topographic analysis of hillslopes and channels in small (<3 km2) catchments spanning an inferred uplift gradient along the Bolinas Ridge, California, USA, revealing tight coupling between channel steepness and hillslope metrics thought to be proxies for erosion rates. We find that the concavity of channel longitudinal profiles varies inversely with uplift rates, although drainage density increases with uplift rates. Both of these results can be explained by the contribution of mass wasting processes to valley formation in steeper (high uplift rate) landscapes. At the catchment scale, hillslope and channel metrics for erosion are correlated, hillslopes and channels steepen in concert, and hilltops (ridges) get sharper with increased uplift rate. This broad agreement suggests that hillslopes are responding to erosion rates in the channel network, which implies that landscape uplift is relatively stable and prolonged. Hillslope morphology deviates systematically from the steady-state predictions of established geomorphic transport laws, suggesting that hillslope adjustment is ongoing and that relief is growing. • Hillslope and channel metrics for erosion rate tightly coupled across inferred uplift gradient. • Channel concavity inversely related to uplift rates. • Hillslope morphology indicates actively growing relief where uplift rates inferred to be highest. • Spatial distribution of hillslope properties consistent with channel steepness. [ABSTRACT FROM AUTHOR]

The paper discusses variances in the relief of erosional-denudational valleys that are scattered across the woodland areas of the threshold of the Carpathian foothill region - in the Wiśnicz Foothills. Relief in the study area was characterized via geomorphological mapping and analyses of cartographic materials such as a LIDAR DEM. The paper also discusses valley types and valley morphometry along with the diversity of morphogenetic processes occurring in the study area. Deposits forming the floors of the studied valleys were also characterized through the use of 12 geologic drilling sites. The resulting data included the deposit grain size range and degree of deposit sorting. In the section on the analysis of present-day relief and relief evolution, the research focuses on the joint action of landslides and fluvial erosion. The following sequence of valley types is discussed for the main valleys presented in the study: denudational trough or gully, active V-shaped valley, V-shaped valley with a flat accumulation floor - found near the mouth of the watercourse. Active V-shaped valleys are characterized by the presence of short but numerous valley sections featuring predominant downcutting erosion or small, local accumulation zones. In this case, the presence of these sections is determined by the intensity of landslides on hill slopes in the studied valley, influx of material from tributary valleys, erosional capacity of local streams, and the presence of woody or rock steps in stream channels. The characteristics of deposits composing valley floors, described in the present study, indicate large differences in deposition process energy and short-distance transport of mineral-type material in stream channels. Research has shown significant complexity of regional factors and local factors affecting the evolution of small erosional-denudational valleys in forested areas in the southern part of the Wiśnicz Foothills. The location of the study area in the Silesian unit overthrust associated with the presence of a visible morphologic threshold, the middle foothills threshold, leads to significant, local differences in elevation, high degree of hill slope fragmentation, high activity of morphogenetic processes, and also affects the impact of these processes on deposits forming the floor of the studied valley. [ABSTRACT FROM AUTHOR]

Contemporary changes in the natural environment in many mountain areas, especially those occurring above the upper tree line, are related to tourism. The Svydovets Massif, located in the Eastern Carpathians in Ukraine, is a good example of an area that is currently experiencing intense degradation. The highest, NE part of this area is crisscrossed with numerous paths, tourist routes, and ski trails. The strong human impact the area experiences is occurring simultaneously with the activity of natural geomorphologic processes. The processes occur with the greatest intensity above the upper tree line. The development of the discussed area has been occurring gradually since the early 20th century. It started when the region belonged to Austria-Hungary, then Czechoslovakia, and subsequently the USSR. Now that it belongs to independent Ukraine the level of tourism-related development has sharply increased. Comparing it to other mountain areas, such as the Tatras, the Alps, or the Monts Dore Massif in France, the Svydovets Massif is being reshaped much more rapidly due to the damage caused by human impact. [ABSTRACT FROM AUTHOR]

The Himalayan Range is subject to both tectonic forces and climatic variations, each operating on different time scales, as observed in Nepal. Through the use of repeated photos, we try to illustrate some examples of very rapid geomorphological evolution, especially over the last 10 years, showing both the intensity of the processes in action (landslides, floods) and their potential impacts on inhabited areas and infrastructures under construction. We selected four sites from the middle Kali Gandaki valley (Annapurna-Dhaulagiri Himal) where frequent natural hazards are threatening the two-lane highway under construction, and two more sites in the south of the Everest massif to illustrate the changes brought about by the last 2015 earthquake. [ABSTRACT FROM AUTHOR]

Since the first archaeological excavations undertaken in the 1970s/1980s, Tel Akko is known to have been an important trade city from the early 2nd millennium B.C. onwards. Even if the site has been intensively excavated, no paleoenvironmental studies looking to understand coastal changes near the tell since the Bronze Age had been undertaken until recently. Our research is based on the study of sediment cores drilled at the foot of the tell and in the Old City of Akko, 1,500 m west of the tell. We validate the coastal changes, already proposed by previous studies, while clarifying the chronology of these changes. We propose that the southern anchorage was located in the river mouth of the Na'aman until the early Persian period. This anchorage shifted to the "open" western coast of the tell during the Persian period before its subsequent relocation to the rocky promontory of Akko in Hellenistic times. We attempted to locate the Hellenistic harbor of Akko by coring in the Old City, in proximity to the modern harbor. At that time, a harbor lay in a semi‐protected pocket beach at the foot of the promontory. [ABSTRACT FROM AUTHOR]

Landscapes and soils evolve in non‐linear ways over millennia. Current knowledge is incomplete as only average denudation (or erosion) rates are normally estimated, neglecting the temporal discontinuities of these processes. The determination of regressive and progressive phases of soil evolution is important to our understanding of how soils and landscapes respond to environmental changes. The Sila Massif (Italy) provides a well‐defined geomorphological and geological setting to unravel temporal variations in soil redistribution rates. We used a combination of in situ cosmogenic radionuclide measurements (10Be) along tor (residual rock) height profiles, coupled with fallout radionuclides (239+240Pu) in soils, to model soil denudation rates over the last 100 ka. We measured rates prior to the Last Glacial Maximum (LGM) of ≤30 t km−2 yr−1 (~0.036 mm yr−1). Following the LGM, during the transition from the Pleistocene to the Holocene, these rates increased to ~150–200 t km−2 yr−1 and appeared to be above soil production rates, causing regressive soil evolution. For the last ~50 years, we even describe erosion rates of ≥1,000 t km−2 yr−1 (~1.23 mm yr−1) and consider human impact as the decisive factor for this development. Consequently, the natural soil production rates cannot cope with the current erosion rates. Thus, a distinct regressive phase of soil formation exists, which will give rise to shallowing of soils over time. Overall, our multimethod approach traced denudation and erosion histories over geologic and human timescales and made a new archive to soil science and geomorphology accessible. [ABSTRACT FROM AUTHOR]

The geomorphological changes in the Berbeşti Mining Basin have an impact on the environment by: excavating the mining mass and depositing the tailings in the waste dumps, the contrast between the black color of the coal with the general green landscape, the local damage to vegetation and fauna, the change of groundwater regime and aquifers, the exposure of the area to uncontrolled uses of land, affecting local communities. The impact of geomorphological changes in the Berbeşti Mining Basin on the land and the relief is manifested by the radical modification of the morphology of the land, the hydrological and hydrogeological regime, the vegetation, the fauna and the soil. In this paper beside the detailed description of the impacts mentioned before, for it's identification we have applied the impact networks method. [ABSTRACT FROM AUTHOR]

The paper is focused on identifying and evaluation of the processes in the cadastral areas forming a large part of the Ostrava-Karviná coalfield in the Czech Republic. Seven basic processes, that reflect the trends in the landscape changes in the area of interest, are traced at three levels: across the entire study area, on the level of three smaller parts of the coalfield, and in more detail on the level of individual cadastral areas. The most frequently occurring processes (urbanization and abandonment in each period; deforestation, intensification of agriculture and afforestation in one period) are described in more details. The research was based on the evaluation of temporal-spatial land cover changes over a long period of time, from the 1830s to the beginning of the 21st century. The multitemporal analysis of land cover in the study area was based on stable cadastral maps, historical aerial photographs and orthophotos. [ABSTRACT FROM AUTHOR]

This article presents analyses made in the first stage of research on determining landscape capacity of Sobotka municipality located in Lower Silesia in Poland, partially within Sleza Landscape Park and Bystrzyca Valley Landscape Park. The main objective of the study was to determine the level of change that took place in the high-value landscape of the analysed area in 1938-2016, and to identify the threat level of changes in the future. I began research by preparing maps showing the main elements of land cover for the three periods to be examined. Using of the maps, I developed a database of the surface of the main elements constituting the background landscape of the research area. I relied on available cartographic documents and aerial photographs from the years 1938, 1977, and 2014, plus field studies carried out in 2016. The data obtained made it possible to assess the level of change in two different periods by means of the landscape change index. The analysis helped identify areas where landscape changes were the highest and areas where changes were hardly noticeable. The last step was to identify to what degree the landscape is threatened with changes in the future, current spatial policy of the local authorities being the basis for it. [ABSTRACT FROM AUTHOR]

This research focuses on the reconstruction of the morphological modifications of the coastal floodplain of Rapallo (Eastern Liguria, NW Italy) due to human intervention since the eighteenth century. By the second half of the nineteenth century Rapallo became a popular tourist destination: as a consequence, the urban development of the floodplain started and became very intense after Second World War, strongly modifying former landforms. The study was carried out using multi-temporal cartographic and photographic comparison, the analysis of geo-thematic cartography and documentation from the Basin Master Plan and the town plan of Rapallo, the interpretation of cores from regional database and field data from direct urban surveys. Man-made landforms were mapped and classified using the new geomorphological legend which is in progress in the framework of the Working Groups on "Cartography" and "Urban Geomorphology" of the Italian Association of Physical Geography and Geomorphology (AIGEO). The main significant morphological changes were stream diversions and channeling, excavations and filling, quarry activities, embankments along the shoreline and overurbanization. Human interventions, in addition to local geomorphological and climate features, increased flood hazard and risk, which historically affected the city of Rapallo. [ABSTRACT FROM AUTHOR]

Remotely sensed data show details of the geomorphic features and landscape evolution west of the Nile. The detected features include remnants of paleochannels, flutes and rock-mass movements. Fused radar/optical data, altitudinal profiles and 3D perspective view provided evidences of massive landslides that fully blocked the earlier Nile channel near to the Western Desert plateau. This channel was ~30 km west of the present Nile at ~100 m above the present level of the Nile. Subsequently, the fluvial activities shifted about ~10 km eastward, leaving behind several remnants of paleochannels, fluvial deposits, ancient landscape and Nilotic fauna. The automatic extraction of stream networks clearly depicts the developments of paleochannels. Our results revealed that fluvial activity switched from the Gallaba plain to the present Nile course through a series of tectonic and climatic changes. Furthermore, integration of radar and optical images provided an explanation for causes of the undulated forms ‘flutes’. [ABSTRACT FROM AUTHOR]

Glacial forelands are harsh environments where incipient pedogenesis provides the basis for vegetation establishment and succession. The Easton Glacier foreland on Mount Baker, Washington, has till deposited during five time intervals over the last 100 years as determined from historic ground and air photos. A soil chronosequence was established on the different age surfaces to assess rates of pedogenesis. As hypothesized, all soil variables, except pH, showed increasing values on progressively older surfaces, with several orders of magnitude increase between the active till and the 100-year surface. Till on ice showed no vegetation cover, low organic matter (0.4 percent), little to no nitrogen content (maximum 0.001 percent), minimal carbon (maximum 0.0083 percent), and a carbon/nitrogen (C/N) ratio of 5.9. The 100-year-old surface has continuous vegetation cover, high organic matter (12.6 percent), 0.67 percent nitrogen, and 9.47 percent carbon, and the C/N ratio was at its highest (22.6). Organic matter content started higher than expected in fresh till and gradually increased before vegetation became established, suggesting aeolian deposition of detritus built soil fertility. We estimate that after about sixty years of exposure, till surfaces became fully covered with vegetation and soil organic matter increased by almost 2,800 percent (0.4–12.6 percent). This rapid rate of soil development, given a short growing season, is hypothesized to be related to several edaphic conditions (topographic setting relative to established vegetation, aspect, and andesitic parent material), rather than a normal condition for the Cascades Range as a whole, demonstrating that ongoing climate change is affecting many environmental processes. [ABSTRACT FROM AUTHOR]

In 1925, then-Captain AW Stevens of the US Army Air Corps took low-angle, oblique aerial photographs of the spectacular landscape of Glacier National Park, Montana (USA). Two of those photographs, of astonishing clarity, were used in a US Geological Survey Professional Paper published in 1959, but were subsequently assigned to the US National Archives and never utilized again. This paper advocates the usefulness of Stevens’ photographs for documenting landscape change from the early 20th century to the present. Stevens’ photographs illustrate the “state” of numerous Park glaciers in 1925, and are the first known aerial photographs of the Park glaciers. These photographs can be used in comparison to modern photographs to illustrate the extent of glacial recession that has occurred in the Park since 1925. [ABSTRACT FROM AUTHOR]

Geomorphological, geochronological and geoarchaeological analysis focusing on six tributaries of the Kura River provide valuable data concerning sedimentation rhythmicity and Holocene human settlement distribution at a regional scale. Seven new radiocarbon dates from the upstream part of these hydrosystems complemented the existing radiocarbon dataset (n = 32) obtained downstream. These data seem to indicate that upstream hydrosystems also reacted to marine regressions by powerful riverbed incisions and to transgression phases by thick valley infillings from at least as early as the Upper Pleistocene. The retroactive morphogenic effects were also perceived in intra-mountainous areas far from the Caspian shoreline. The land use patterns of the Caucasian societies dwelling in the valley of the Kura hydrosystem were affected by temporary river avulsions resulting in silty fans over the high terraces during the Neolithic–Chalcolithic periods. These river avulsions seem to be governed by local climate and base level changes linked to fluctuations of the Caspian Sea level over time. This is spatially and diachronically evidenced in settlement distribution, with almost exclusive localization on perched silty fans and river runoff from the key period of Neolithic development in the region. These new data must be considered in future geoarchaeological analyses concerning the Caspian Sea Basin and will contribute to the enhancement of the relative Caspian Sea level curve for the past 40 ka. [ABSTRACT FROM AUTHOR]

We have reconstructed landscape changes at a known obsidian source area in the central highland, Japan, using well dated pollen and micro-charcoal records, in order to better understand the difference in obsidian procurement between gathering in the Palaeolithic period (>30-16 ka cal bp) and mining in the Jomon period (16-2.9 ka cal bp). The pollen record at the site shows that alpine vegetation, such as patches of Pinus pumila (dwarf Siberian pine) and alpine meadows with rocky areas surrounded the area during the period 30-17 ka cal bp. The reconstructed Palaeolithic landscape implies that there was a favourable situation for gathering obsidian on the ground surface in the area. Subsequently, growth of woodland started at 17 ka cal bp due to a rise of the tree line elevation corresponding to the deglacial warming. The pollen record at the site shows that mixed woodland consisting of Betula (birch) and boreal conifers covered the area during the period 17-11.2 ka cal bp, and dense mixed oak woodlands flourished during the period 11.2-2.9 ka cal bp. From 17 ka cal bp, local conditions were unfavourable for gathering obsidian, and this probably caused the Jomon people to develop obsidian mining. We can suggest that the landscape changes between the Palaeolithic and Jomon periods strongly influenced the prehistoric exploitation of obsidian in the area. [ABSTRACT FROM AUTHOR]

As human interactions with Earth systems continue to intensify, understanding the complex relationships among human activity, landscape change, and societal responses to those changes becomes increasingly important. Interdisciplinary research centered on the theme of “feedbacks” in human–landscape systems serves as a promising focus for unraveling these interactions. This paper examines the specific case of the 2012 Waldo Canyon Fire of Colorado, where human responses after the fire to perceived threats of hydro-geomorphological hazards included construction of tall fences at the base of a burned watershed. These actions prompted feedbacks that promoted further landscape change that ultimately increased those hazards, rather than dampening the hydro-geomorphological effects of fire. Geomorphic analysis showed that the fences trapped particles that would naturally move through the system by flows with recurrence intervals greater than 3.3 years. With the particles blocked by the fences, the channel downstream became erosive, because it was devoid of large particles that produce substantial hydraulic resistance. Channel incision prompted a second human response to pave the eroding channel, which led to further incision downstream. This cycle of positive feedbacks between human decision-making and landscape change eventually led to a complete channelization of the stream channel downstream of the fences. The explanation for the transformation of the post-fire landscape therefore lies in the interacting human impacts and feedbacks, rather than the expected post-fire hydro-geomorphological adjustments. An initial agent-based model, capable of integrating social and hydro-geomorphological data, simulates these interacting impacts and feedbacks. Further refinement with more complete data input, especially pertaining to human decision making at individual or local levels, is required to fully demonstrate the utility and promise of this tool for application to geomorphic analysis. [ABSTRACT FROM AUTHOR]

Recent and future climate change may lead to landscape changes in geomorphic processes and process rates. Such modifications are likely to be widely distributed, making their direct measurement difficult and there are almost no such measurements at decadal intervals. Aerial imagery has been acquired by many national agencies since the 1950s and significant archives remain. Unlocking the information from these data sources is important because their timescale may inform significant unresolved hypotheses regarding the impact of rapid climate change on Alpine environments. However, such photogrammetric applications are challenging because of topographic complexity (including occlusions and large elevation ranges) and variations in image texture. A complete workflow is described from raw data to the treatment and interpretation of results. This is applied to imagery of Val d'Héréns, Switzerland, a landscape containing an assemblage of glacial, periglacial, hillslope and fluvial landforms across a height range of 1800 to 3600 m from the 1960s to the present. These changes reveal important characteristics of landscape scale erosion and deposition at the decadal scale. [ABSTRACT FROM AUTHOR]

This paper addresses a series of geomorphic questions relating to large-scale (> 1 km), long-term (100 - 1,000 years) coastal planshape evolution. Previous research on soft-cliff coasts has recognised the role of protective fronting beach volumes on reducing rates of cliff toe retreat. However, it is the maintenance of this critical threshold that ultimately determines two contrasting modes of shoreline behaviour: Mode A, in which there is little beach sediment and shoreline evolution is controlled by material strength; and, Mode B, when ample beach sediment means that shoreline evolution is controlled by longshore sediment transport. Here we use a numerical model (SCAPE) to investigate temporal and spatial changes in beach volume on a broader range of feedbacks than considered in previous models. The transition between Mode A and Mode B coasts is defined by relative sediment inputs to outputs and used to explore how these contrasting modes control the evolution of an initial linear frontage exhibiting longshore changes in cliff lithology (material resistance and the proportion of beach grade material in the eroded bedrock). Under Mode A, relative changes in material resistance result in long term heterogeneous rates of retreat, which result in the development of persistent headland and embayment features. However, under Mode B, feedbacks between coastal planshape, longshore sediment transport, beach volume and wave energy result in steady state retreat rates regardless of longshore variations in resistance. Results are compared and contrasted to previous simulations and site specific examples and a conceptual model of Mode A and Mode B interactions presented. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

What we see now in the landscape is the result of a long history of events with varying degrees of persistence. We have only limited access to much of that history and we know that many current events have only a minimal impact on what we see. Even rather extreme events may have impacts that are not very long-lasting but can have the effect of changing the antecedent states for future events. That means that sampling of sequences of events might be important in understanding the evolution of the catchments. In some cases, however, extreme events can have an impact on the system that persists over hundreds or thousands of years. Any evolution of the landscape is then constrained by those past events, however much it might be also constrained by self-organisational principles. It might be difficult to verify those principles given the epistemic uncertainties about past histories and system properties that are generic to the studies that are possible within a research project or career. These arguments are investigated in a simple slab model of landslip failures in a hillslope hollow subject to stochastic forcing over long periods of time. The complementarity of an event-persistence approach to hydro-eco-geomorphological systems is captured in suggestions for future research questions. [ABSTRACT FROM AUTHOR]

Stream morphology is affected by changes on the surrounding landscape. Understanding the effects of urbanization on stream morphology is a critical factor for land managers to maintain and improve vulnerable stream corridors in urbanizing landscapes. Stormwater practices are used in urban landscapes to manage runoff volumes and peak flows, potentially mitigating alterations to the flow regime that drive changes in channel morphology. However, there remains a paucity of long-term studies assessing watershed-scale relationships between urbanization and effects on stream morphology where green stormwater infrastructure exists in high densities. This paper evaluates the geomorphic changes across four headwater catchments in the Chesapeake Bay Watershed over the course of >10 yr and relates these changes to urban development. Annual cross-sectional surveys conducted from 2002 to 2019 in one forested catchment, one agricultural catchment, and two treatment catchments were used to understand the relationship between urbanization and changes in stream morphology. Six cross-sectional geomorphic metrics were calculated and compared with development timelines and high flow events. A channel evolution model was then used to understand the status of morphologic stability at sites within the study. Results suggest downstream environments in developing areas are more impacted during early phases of suburban construction. Channel change during construction could be a result of sediment and erosion control efforts' limitations on preventing and controlling overland sediment mobilization or of increased discharge causing widening and thus bank-derived sediment to move to the streambed. Results demonstrate that geomorphic metrics are highly variable within a small area and are not always accurate representations of broader landscape changes but rather of the more localized environment at a specific stream segment. Despite a high density of stormwater management facilities in urban catchments, substantial alterations to cross sections were found at multiple locations in each catchment including the controls. • Geomorphic metrics and CEM calculated at 32 cross sections annually over 17 years. • Contrasted change in forested, agricultural, and urbanizing catchments in Maryland. • All catchments have experienced change, typically greater in downstream areas. • Metrics highly variable within a small area in catchments. • Metrics suggest localized BMP impact on streams; may not represent broad effects. [ABSTRACT FROM AUTHOR]

ABSTRACT The archetypal badass is individualistic, non-conformist, and able to produce disproportionate results. The badass concept is applied here to geomorphology. The individualistic concept of landscape evolution (ICLE) is introduced, based on three propositions: excess evolution space, capacity of all landforms to change, and variable selection pressure from environmental factors within and encompassing landscapes. ICLE indicates that geomorphic systems are idiosyncratic to some extent, and that even where two systems are similar, this is a happenstance of similar environmental selection, not an attractor state. As geomorphic systems are all individualistic, those that are also non-conformist with respect to conventional wisdoms and have amplifier effects are considered badass. Development of meander bends on a section of the Kentucky River illustrates these ideas. The divergence of karst and fluvial forms on the inner and outer bends represents unstable amplifying effects. The divergence is also individualistic, as it can be explained only by combining general laws governing surface and subsurface flow partitioning with a specific geographical and environmental setting and the history of Quaternary downcutting of the Kentucky River. Landscape evolution there does not conform to any conventional theories or conceptual frameworks of geomorphology. The badass traits of many geomorphic systems have implications for the systems themselves, attitudes toward geomorphic practice, and appreciation of landforms. Badass geomorphology and the ICLE reflect a view, and approach to the study of, landforms as the outcome of the interplay of general laws, place-specific controls, and history. Badass geomorphology also implies a research style receptive to contraventional wisdoms. Aesthetically, amplifier effects and individualism guarantee an essentially infinite variety of landforms and landscapes that geoscientists can appreciate both artistically and scientifically. Non-conformity makes the interpretation and understanding of this variety more challenging - and while that increases the degree of difficulty, it also makes for more interesting and compelling professional challenges. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]