Disentangling anthropogenic signatures of the Anthropocene and the Great Acceleration from natural Holocene climatic oscillations requires high-resolution datasets and transparent computational workflows. This study introduces a "Geopython" ecosystem consisting of two original open-source applications: EssefiSedInterpreter and EssefiCyclo. EssefiSedInterpreter automates sedimentological characterization by integrating image-based morphoscopy (utilizing "Solidity" as a rigorous proxy for grain rugosity) and End-Member Mixing Analysis (EMMA) via Non-Negative Least Squares (NNLS) optimization. Performance validation against industry-standard FRITSCH laser granulometry across 11 samples from Bizerte Lagoon demonstrated a high degree of fidelity, with an average relative error of only 3.06%. EssefiCyclo effectively isolated the non-stationary industrial surges of the Chaffar exoreic system, identifying underlying solar (Schwabe, Hale, Suess), atmospheric (NAO, Mediterranean Oscillation), and oceanographic (AMO) cycles. This integrated ecosystem provides a robust, auditable alternative to proprietary "black-box" software, empowering researchers to transform noisy stratigraphic records into genetically meaningful paleoenvironmental histories. Furthermore, the tool addresses the "geochronological gap" in environments where radiometric dating is sparse. By applying Lomb-Scargle periodograms and a novel "Inverse Cyclostratigraphy" module, the software tunes stratigraphic depth to global deterministic clocks. Applying this to a 78-cm core from Sebkha Mhabeul (380 samples at 2-mm resolution), the tool successfully identified an optimal sedimentation rate of 6.58 years/sample. This enabled the construction of a continuous 2500-year age model, capturing distinct climatic intervals including the Little Ice Age, the Medieval Climate Anomaly, and the Roman Warm Period.
Transverse ribs are prominent bedforms in gravel-bed rivers on alluvial fans, playing a crucial role in maintaining riverbed stability and ecological diversity. Their decline, caused by human interventions such as channel excavation and altered sediment supply for flood control, is a growing concern. This study investigates transverse rib formation through two conceptual frameworks: antidune-type and keystone-type. Hydraulic experiments replicated both mechanisms. Antidune-type ribs formed via hydraulic jumps and standing waves, producing upstream-migrating bedforms. Keystone-type ribs resulted from coarse sediment accumulation in low-velocity zones induced by immobile keystone elements. Varying keystone spatial arrangements significantly influenced flow patterns, sediment transport, and rib development, with alternating lateral placements enhancing flow complexity and rib formation under specific spacing conditions. Grain size analyses showed coarse sediment concentrated in ribs for both types, compared to adjacent pools. The coexistence of both rib types suggests complementary roles in channel morphology shaping. These findings highlight the potential of keystone-based designs to promote natural transverse rib reformation in managed rivers. Establishing design principles for keystone arrangements can contribute to sustainable river engineering by enhancing morphological diversity and hydraulic functionality.
The hydrological and erosional impacts of dynamically decreasing deadwood cover in disturbed mountain forests are poorly understood. This study investigated hydrological-erosional responses to decreasing deadwood cover using the Water Erosion Prediction Project (WEPP) model, which was calibrated and validated with 4-year monitoring data from a 4.5 & times; 6.0 m plot in the Italian Alps. Three simulations were separately performed: uncalibrated (Sim #1); hydraulic conductivity and interrill erodibility calibrated (Sim #2); hydraulic conductivity, interrill erodibility, and residue cover parameter calibrated (Sim #3). Sim #1 significantly underpredicted runoff and sediment yield, highlighting the necessity of validation when extrapolating existing models to mountain forests. Sim #2 notably improved the prediction accuracy of both runoff (from 18.2% to 81.8%) and sediment yield (from 0% to 27.3%), whereas Sim #3 further improved runoff prediction accuracy to 90.9%, confirming the hydrological soundness of deadwood parameterization. Decreases in deadwood cover only marginally increased runoff and sediment yield (<1%) in grass-covered scenarios. Contrastingly, bare-soil conditions revealed dramatic increases (runoff: 13-263%, sediment yield: 139-3931%), emphasizing the protective role of vegetation cover. These results suggest that salvage logging can significantly accelerate runoff and erosion unless vegetation is restored, and properly calibrated models can inform low-impact deadwood management and post-windthrow recovery.
Flood being the most devastating natural hazard has caused loss to human lives and damage to infrastructure globally. This study makes an attempt to assess flood susceptibility in Upper Jhelum Sub-catchment, India. Effectiveness of multilayer perceptron (MLP), sequential minimal optimization (SMOreg), M5P and bagging ensembles (B-MLP, B-M5P, B-SMOreg) models were utilized for achieving accurate results of flood susceptibility. The results revealed that B-MLP model was found to be a more effective model based on assessors and validation (ROC-AUC: 0.936; correla-tion coefficient: 0.925; precision: 0.906; F1-score: 0.887; accuracy: 0.863; root mean square error: 0.043; relative absolute error: 2.078 and mean absolute error: 0.013). Thus, this paper integrates bag-ging (B-MLP) with geospatial analysis in the watersheds of the Sub- catchment for the prediction of flood susceptibility mapping. The results revealed high flood susceptibility was found in the watershed 1E1D2 (Rembaira) followed by 1E1D3 (Vishav) and 1E1D4 (Lidder). The watershed 1E1D3 (Vishav) experienced largest area under moderate flood susceptibility followed by 1E1D4 (Lidder) and 1E1D2 (Rembaira). The findings may help in enhancing flood prediction and devising effective management strategies. B-MLP model can effectively be utilized for flood susceptibility mapping in other geographical regions at spatial scales.
To study the influence of the valley topography effect and the geological effect of structural planes on the dynamic response characteristics and failure mechanisms of a steep rock slope, a time-frequency joint analysis method combining time, frequency and time-frequency domains analysis is proposed. Four models were created for dynamic analysis using FLAC3D. According to the time-frequency joint analysis, the dynamic response law of homogeneous high-steep slopes is that the acceleration amplification factor (AAF) varies periodically along the elevation with a certain pattern and is obviously amplified at the slope crest. The existence of structural planes reduces the velocity of wave propagation through rock masses while creating local amplification and attenuation of seismic waves. The valley topography has an amplifying effect on the dynamic response of the slopes but has less influence on the changing laws. Frequency domain analysis shows that the low-frequency and high-frequency components mainly cause overall deformation and local deformation of the slopes, respectively. Moreover, structural planes have a high-frequency filtering effect, and the influence of structural planes on the failure mechanism of slopes is significantly greater than that of valley topography. In addition, the relationship between the local deformation response of anti-dip slopes and the occurrence of landslides is determined. In addition, the dynamic response characteristics of the slope were analysed based on the Hilbert energy, and the ability of the seismic Hilbert energy spectrum to reflect the dynamic deformation characteristics of the slope was identified.
Land surface temperature is a key indicator of environmental conditions, and it is affected by both natural and anthropogenic activities. This study assessed the environmental determinants of land surface temperature (LST) within the Kaduna River Basin (KRB) using an integrated framework of machine learning and GeoDetector analysis. Using satellite-derived datasets, including MODIS (LST and NDVI), Sentinel-2 (LULC), and SRTM (elevation), this study quantifies regional and seasonal LST drivers. The results demonstrate significant seasonal shifts: the mean NDVI increased from 0.34 in the dry season to 0.51 in the wet season, whereas the mean LST decreased from 33.57 degrees C to 31.99 degrees C. Stacked ensemble machine learning (R-2 = 0.72 dry; 0.66 wet) and GeoDetector analysis identified vegetation (NDVI) and elevation as primary controls on the LST. Notably, the interaction between the NDVI and elevation was found to be more influential than individual factors, highlighting the synergistic role of topography and green cover in regulating basin-scale thermal dynamics. This study provides critical policy insights by stressing the importance of sustaining plant cover, particularly in specific topographical zones, in managing basin-scale thermal dynamics in the face of growing regional warming.
In 2000, the Government of India announced plans of eight hydro-power projects along the Nagavali river, one of the East-Indian River flows through Odisha and Andhra Pradesh before entering the Bay of Bengal. Of these, three projects have been implemented which is significantly altering the river's dynamics. This study evaluates anthropogenic impacts on fluvial processes of these sites, with particular emphasis on river avulsion, channel incision, and reservoir-induced geomorphic change. For detecting such changes, Google Earth Images of different time periods have been used and hydrological, meteorological, geologic-geomorphic, and lithological data were collected and analysed from different Govt. sources as well as from the detailed field study. At the Hathipahar Waterfall site, dam construction triggered a rapid avulsion, resulting in a westward channel shift of approximately 550 m, channel incision of similar to 45 m, and land loss of about 0.54 km(2) during a single flash-flood event, indicating severe geomorphic instability. At the Thotapalli Regulator, post-construction flood events caused substantial upstream channel widening (from similar to 500 m to similar to 1200 m) and reservoir expansion from 1.39 km(2) to 9.91 km(2) within nine years, reflecting strong backwater effects and sediment redistribution.
Mountain glaciers in central Chile are highly sensitive to climatic variability, yet glacier-specific, long-term assessments remain limited in transitional climatic zones. This study quantifies recent changes in the Universidad Glacier (central Chilean Andes) using a multi-decadal remote sensing approach integrated with atmospheric and hydrometeorological data. Glacier surface area was mapped from Landsat (1975-2025) and Sentinel-2 (2016-2025) imagery, while climate forcing was characterized using radiosonde temperature profiles, gridded precipitation products, and satellite-derived snow-cover data. Results indicate a sustained glacier retreat, with a net surface-area loss of approximately 5 km2 between 1990 and 2025 and accelerated shrinkage since the early 2000s. Mid-tropospheric warming and a rise in the annual mean zero-degree isotherm, frequently exceeding 4,000 m a.s.l. in recent years, coincide with declining winter precipitation and reduced snow cover. These changes have driven an upward shift of the equilibrium-line altitude of more than 400 m and a persistently negative surface mass balance. The findings demonstrate the value of combining long-term satellite observations with atmospheric data to diagnose climate-driven glacier change in data-sparse mountain regions.
The Parker Dunes, the only dune field in the Sonoran and Mojave Deserts of North America experiencing visible dune reddening, range in age from active to nearly 30,000 years before present. Different aerial and satellite remote sensing platforms reveal progressive reddening over time, as do redness ratings using Munsell color. X-ray dot maps of quartz sand grains indicate that iron X-rays are generated from coatings that cover progressively more grain area as the dunes age. Nanoscale transmission electron microscopy reveals that iron is incorporated into mixed-layered illite-montmorillonite clays, forming iron-rich "stringers" observable in back-scattered electron imagery at the micrometer scale. Light microscopy of ultrathin sections reveal these grain coatings to have an orange appearance. Our linking of iron-clay coatings at multiple-scales across multiple methodologies can only be considered preliminary because of the limited number of samples analyzed. Still, this research provides the first insight into dune color evolution in the Sonoran Desert.
Climate change is altering precipitation regimes and, consequently, debris-flow hazard patterns, increasing uncertainties in hazard assessments. In Europe, the absence of unified guidelines for hazard zone mapping further complicates regional comparability, underlining the need for rapid and standardized methods to identify hazard sources. This study explores a methodological framework combining sediment connectivity analyses with conventional process-based hazard modelling for efficient and transferable debris-flow hazard assessment. The study case was selected within a geologically complex Alpine catchment in Austria, which is affected by debris-flow processes. The methodology combines i) geomorphological mapping with sediment connectivity analyses, specifically, the Effective Catchment Area (ECA) and the Index of Connectivity (IC), to identify sediment sources and pathways, and ii) RAMMS:Debrisflow (RApid Mass Movement Simulation:Debrisflow) simulations implemented by connectivity delineations. Results show that ECA and IC have the potential to identify hazard-prone zones and support the identification of release areas for RAMMS modelling. In addition, statistical analysis reveals a relationship between IC and simulated flow parameters, supporting the identification of areas with more severe flow conditions. While absolute IC values are catchment-specific, the connectivity-hazard relationship can improve the spatial delineation of hazard zones and define a transferable methodological framework at the catchment scale.
Rapid glacier retreat across the Western Himalayas has led to the widespread expansion and deepening of proglacial lakes, increasing concerns over moraine stability and Glacial Lake Outburst Flood (GLOF) hazards. In this context, the present study investigates the coupled evolution of the Samudra Tapu glacier and its proglacial lake using multi-temporal Sentinel-1 SAR datasets spanning 2018-2024. The analysis focuses on lake-depth expansion toward the glacier snout and deformation of the moraine rim derived from InSAR-based techniques, enabling an assessment of their temporal interaction. Results indicate a progressive increase in lake depth from approximately 30 m during 2018-2020 to localized maxima of 60-69 m by 2023-2024. This evolution reflects enhanced and spatially variable meltwater inflow, subaqueous over-deepening, and alternating shallow-deep zones observed between 2020 and 2023. Concurrent InSAR-derived deformation patterns ranging from -0.52 m to +0.05 m correspond closely with periods of rapid lake deepening, suggesting moraine weakening driven by increased hydrostatic pressure. Notably, although lake depths appeared more balanced in 2024, deformation signals remained pronounced, indicating delayed mechanical responses of moraine materials to cumulative stress. Overall, integrating InSAR-based deformation mapping with satellite-derived bathymetry provides a robust framework for identifying instability zones and improving hazard assessment.
A regional-scale geomorphic analysis of Andalusian rivers was carried out with the objective of characterizing river conditions and morphological changes. For this aim, an assessment of the morphological conditions by the Hydro-Morphological Quality Index (HMQI) was initially performed. The HMQI has been applied to 356 river reaches, allowing to characterise the geomorphic conditions of the rivers and better evaluate the causes of alterations. Overall, approximately 54% of the river reaches are in moderate condition, 22% are in good condition, 16% are in poor condition, and few cases are classified as high or very poor (approximately 4.5% and 4%, respectively). The assessment of river conditions was followed by an analysis of changes in channel morphology and width from 1956-present carried out for most alluvial, unconfined or partly confined river segments. The analysis revealed that most segments have undergone moderate to intense channel narrowing, with only a few segments experiencing widening. The morphological channel pattern changed in approximately 37% of the cases. For the overall geomorphic conditions, the causes of these changes are associated with socioeconomic development, specifically the decline in bedload caused by dams, increasing agricultural activities adjacent to rivers, and the fixation of some reaches crossing urbanised areas.
Inundation of a scroll-plain of the Darling River during 2010-2011 illustrate flood processes of an arid zone river with sediments dominated by sodic smectites. Initial inundation progressed as much by subsurface flow as by surface, with the subsurface flow extending some metres in front of the surface flow via pipes and cracks. Collapse into cavities was common. Swales were submerged to a depth of 2.5 m and a higher terrace <0.5 m. Microrelief determined surface flow direction which could be 180o from that in the main channel. Flow crossed the scroll-plain during the flood peak parallel to the trend of the channel belt. The fastest flows deposited ripples of fine sand and coarse silt of quartz and clay pellets. The clay-rich surface of the scroll-plain trapped pools of water in low points as the flood fell. Little or no recharge of the shallow alluvial aquifer by floodwaters occurred, and any recharge must be by lateral bank recharge. As the surface dried, it was broken up by shallow cracking. Deeper cracks are expected to form with drying of the subsoil.
We analyzed physical properties, diatoms, and geochemistry in a 1500-year sediment profile from a small, mid-elevation lake in west central Costa Rica formed by a landslide. Laguna Arancibia occupies an area long affected by landslides, including large debris avalanches; in 2000 CE one of the largest debris avalanches recorded in Costa Rica passed within 300 m of the lake. A systematic archaeological survey provides context for the paleolimnological study, showing sparse human settlement during the Pavas archaeological phase (2250-1650 cal yr BP), a hiatus during the Curridabat phase (1650-950 cal yr BP), and repopulation during the Cartago phase (950-400 cal yr BP). Our record begins during the hiatus, when diatoms indicate a shallow lake. A major shift in diatoms followed by increased inorganic sedimentation suggests humans returned about 880 cal yr BP. Peaks in inorganic sediment influx during the Cartago phase document erosion from agricultural fields or landslides possibly triggered by forest clearance. However, stable carbon isotopes in n-alkanes of terrestrial leaf waxes indicate extensive C-3 forest since reoccupation, suggesting only moderate deforestation for agriculture by a small population. The Spanish Conquest may have further reduced, or completely destroyed, this population, but evidence in the sediment record is inconclusive.
Land directly transformed by humans now occupies much of the terrestrial surface and has a significant impact on the natural environment and natural hazards. Premodern man-made landforms such as hilltop castles affect landslide disasters, particularly in western Japan. This study compared the topographical features of 39 ridge sites modified into medieval castles and 39 unmodified natural ridges in a granite area of Hiroshima Prefecture, western Japan. Topographic attributes, including slope and profile/plan curvature, were calculated from airborne LiDAR digital elevation models (DEMs) with a resolution of 1 m. As a result, the standard deviations of slopes, profile curvature, and plan curvature were larger at the castle sites than at the unmodified natural ridges. These indices reflect the modified topography of a castle, which is composed of flat surfaces and steep slopes. We also proposed a method to classify ridge topography with combining these indices. The proposed method is potentially useful for finding unknown ridge transformation by premodern human activity and also for evaluating the potential of shallow landslides in castle sites.
The Gravity Recovery and Climate Experiment (GRACE) and its successor, GRACE Follow-On (GRACE-FO), have revolutionized our understanding of Earth's gravitational field and its changes over time, providing critical insights into climate change, water resource management, and sea-level rise. However, a gap of approximately one year between the end of the original GRACE mission and operationalization of GRACE-FO resulted in breaking the continuity of terrestrial water storage anomaly (TWSA) data and posed challenges for accurate monitoring. Utilizing a multilayer perceptron neural network (MLPNN), we aim to fill these data gaps and improve the efficiency of GRACE data in Iran plateau. Six features were used for training including latitude, longitude, time and three hydrological features - precipitation, evapotranspiration and runoff - derived from European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) dataset. Our findings reveal that the applied method can efficiently fill the temporal gaps. 10% of data were excluded from the training dataset to validate the reconstructed TWSA and an RMSE of 1.6 cm was obtained. Furthermore, the reconstructed values were compared with obtained TWSA from Global Land Data Assimilation System (GLDAS). Despite the inherent bias between GRACE TWSA and GLDAS TWSA, an average RMSE of 3.3 cm was obtained during the gap period.
Increasing frequency and intensity of extreme climate events are profoundly affecting agriculture and rural livelihoods in Ethiopia. However, there is limited empirical evidence on how these extremes vary across agroecological zones (AEZs) and what they mean for smallholder farming systems. This study investigates trends and patterns of extreme climate indices across three AEZs in the Sidama region of Ethiopia, highlighting their implications for smallholder farmers. Using daily precipitation and temperature data from 1985 to 2018, the analysis applied the Mann-Kendall trend test and Sen's slope estimator on indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). The results show a marked shift in climate extremes, with significant declines in precipitation indices such as total annual rainfall, maximum 1-day and 5-day precipitation and wet days, while consecutive dry days and warm spells have increased. Temperature-related extremes, including maximum and minimum temperatures, warm days and nights and warm spell duration have risen significantly, particularly in the highland and midland zones. Conversely, cold days and nights have decreased. These changes signal heightened exposure to droughts and erratic rainfall, posing threats such as reduced crop yields, increased crop failure, soil erosion, and biodiversity loss. Highland areas appear especially vulnerable due to their rapid warming. The study concludes by emphasizing the urgency of developing agroecology-specific climate adaptation strategies to support sustainable livelihoods and resilience among smallholder farmers facing growing climate risks in the Sidama region.
The Loess Plateau, a worldwide recognized ecologically sensitive region, with slope-gully systems (SGS) serving as primary sediment sources due to their unique erosion dynamics. However, quantifying the partitioning of sediment contributions between slope and gully subsystems remains poorly understood. This study examines erosion mechanisms and sediment budgets in a 26 km2 SGS watershed. We assessed slope erosion contributions using data from multiple sources, including remote sensing, field surveys, and historical records. Concurrently, the sediment-trapping capacities of five check dams were calculated using geotechnical field measurements, allowing gully erosion estimation. The results demonstrated differential erosion partitioning, with annual sediment yields of 10,550 t a-1 (30.8%) from slope systems and 23,735 t a-1 (69.2%) from gully systems, showing gully dominance in sediment production. Results show gully systems dominate sediment production (69.2%), with check dams reducing gully slope lengths by 18-32% and vegetation roots enhancing shear strength biome chanically. Furthermore, biomechanical reinforcement by arboreal vegetation within dam sediments was identified, with root structures that functionally emulate anti-slide pile systems. These findings establish vegetation restoration and strategic dam placement as complementary interventions for slope and gully erosion reduction, respectively, providing insights into soil erosion control strategies in the Loess Plateau's agricultural areas.
Reliable rainfall estimates are essential for understanding extreme rainfall patterns and supporting climate adaptation in vulnerable areas. In Ethiopia's Jemma sub-basin, limited surface weather observations challenge accurate characterization of rainfall extremes, necessitating the use of satellite and reanalysis products. We evaluated five rainfall datasets, CHIRPS v2.0, TAMSAT v3.1, ERA5, MERRA v2, and MSWEP v2.8, for their ability to replicate daily rainfall, detect rainfall events, and represent rainfall indices across sub-tropical and temperate agro-ecological zones (AEZs). A point to pixel evaluation approach was used, and statistical metrics including continuous metrics such as root mean square error (RMSE), percent bias (PBIAS), Kling Gupta efficiency (KGE), and correlation coefficient (R), and categorical metrics such as probability of detection (POD), false alarm ratio (FAR), critical success index (CSI), and frequency bias index (FBI) were used to assess performance and assign ranks using a comprehensive rating index (CRI). Results show that MSWEP v2.8 is most reliable for daily rainfall across both AEZs, while CHIRPS v2.0 excels in capturing extreme rainfall in the sub-tropical AEZ. MSWEP v2.8 also performs well in the temperate AEZ but shows limitations for indices like R20mm in sub-tropical AEZ. ERA5 and MERRA v2 exhibit higher biases, lower resolution, and weaker correlations. These findings highlight the importance of selecting rainfall products based on indices and regional conditions. MSWEP v2.8 and CHIRPS v2.0 are recommended for flood and drought forecasting, water management, and agricultural planning. Integrating multiple datasets with local observations and establishing additional meteorological stations can further enhance rainfall assessments and modeling.
