Field Investigation Research Articles

Annual Coastal Boulder Mobility Detected in 2017–2021 Remote Sensing Imagery and Its Relation to Marine Storms (Gulf of Taranto, Mediterranean Sea)

Landward displacements of coastal boulders are geomorphological signatures of sea flooding and erosion processes. In this study, using open-access resources that do not require the integration of specialist software, the 2017 to 2021 annual mobility of medium, coarse, and very coarse boulders spread over about 100 km of the eastern coast of the Gulf of Taranto (Italy, Mediterranean Sea) was explored. The boulder displacement data obtained from remote sensing imagery were verified and refined by means of geomorphological field investigation. The main results are the following: (1) A large interannual variability in the boulder mobility was found; (2) storm Detlef, which crossed over the Mediterranean during 11–13 November 2019, was recognized as the cause of a massive displacement phenomenon; and (3) the marine weather conditions driving the investigated morphodynamic process were inferred.

The voice of society in designing public recreational spaces (PRS) in an urban environment

Global urban population growth, climate change, and the energy crisis pose significant challenges for the local authorities and encourage a shift in local policy-making towards sustainable development. Local governments have to cater to public needs and expectations regarding recreational spaces and environmental protection by implementing innovative infrastructure solutions, including those based on renewable energy sources. In recent years, the debate on urban planning has centred on the placemaking approach and the implementation of the 15-minute city and smart city concepts. This novel approach promotes sustainable urban development that relies on the links between the natural environment, the economy, and society. The aim of this study was to explore the possibilities of urban planning solutions and the components of urban infrastructure that contribute to sustainable urban development in the context of improving the quality of local life. Local community needs were identified in a questionnaire survey and during a field investigation. The study was conducted in a medium-sized Polish city where public recreational spaces were redesigned in line with the principles of sustainable urban development. The results were used to propose universal urban development projects that address local needs and rely on renewable energy sources to create a sustainable future for society, the natural environment, and the climate.

Enhancing in situ remediation of clayey soils contaminated with total petroleum hydrocarbons by combining pneumatic fracturing, plasma blasting, and vacuum extraction: A comprehensive field investigation

Oxidant injection technology is widely used in soil remediation; however, subsurface conditions, including soil properties and permeability, significantly influence its effectiveness. In this study, the potential of the combination of pneumatic fracturing, plasma discharge, and vacuum extraction (PPV) in enhancing soil permeability and remediating field-scale silt/clayey soils contaminated by total petroleum hydrocarbon (TPH) was studied. Improved soil permeability was assessed by measuring the chlorine and H2O2 concentrations in soil samples, and the remediation efficiency of PPV was evaluated by analyzing the TPH concentrations in the soil samples. The initial highest TPH concentration was 6922 mg kg−1; after a 42-day operation period, the TPH levels decreased to 541 mg kg−1. The economic assessment of PPV revealed it to be cost-effective, with a total operating cost of US$ 3077 for remediating 265 m³ of contaminated soil, equating to US$ 11.6 per ton of soil. Since PPV requires a short operational period, is inexpensive, and is suitable for purifying low-permeability soil, it is a promising and economically advantageous approach for soil purification. Overall, PPV demonstrated the ability to enhance oxidizing agent transfer by increasing soil permeability, suggesting its potential for efficient and targeted soil remediation.

A conjugated structure discloses interaction between two fault systems in eastern Taiwan during 2022 Guangfu earthquake

The Longitudinal Valley (LV) in the eastern Taiwan is located at the convergent boundary between the Philippine Sea Plate and the Eurasian Plate. Within the LV, two significant fault systems, the Longitudinal Valley Fault (LVF) in the eastern part and the Central Range Fault (CeRF) in the western part, have been recognized. However, understanding the precise mechanisms and spatial relationships of the two fault systems in the middle segment of the LV has remained a challenge. In this study, we integrate various data sources, including geodetic measurements, seismic data, field investigations, and simulation results, all obtained during the 2022 Guangfu earthquake event. Our goal is to shed light on the complex structural interactions between the two fault systems. We introduce a coupled structural model consisting of a main fault plane and a coupled ramp plane. The deep-seated fault plane is constrained using seismic data, while the shallow ramp plane is determined through field investigations. Geodetic measurements are utilized to constrain the surface deformation resulting from dislocation model. The simulation outcomes reveal that the 2022 Guangfu earthquake was primarily triggered by the activity along the CeRF. The CeRF experienced an eastward reverse slip of approximately 58 cm along the fault plane. This fault not only intersects the LVF beneath the Coastal Range but also initiates the development of a ramp plane along pre-existing fault planes of the LVF. This intricate interplay results in approximately 20 cm of vertical surface deformation within the Coastal Range. The linear connection observed in the simulation residuals is associated with pre-existing faults within the LVF system. This alignment corresponds to the ground distribution of ramp plane, suggesting that older fault systems within this area exhibit characteristics of reactivation in response to earthquake-induced processes. Our study not only pinpoints the potential location of the CeRF intersecting with the LVF in the middle segment of the LV but also provides insight into one of the interaction mechanisms between the CeRF and the LVF. These findings hold significant implications for assessing seismogenic structural activity and enhancing the mitigation of regional earthquake hazards in the future.

Semiquantitative Risk Evaluation Reveals Drivers of African Swine Fever Virus Transmission in Smallholder Pig Farms and Gaps in Biosecurity, Tanzania.

African swine fever (ASF) has remained persistent in Tanzania since the early 2000s. Between 2020 and 2021, pig farms in twelve districts in Tanzania were infected with ASF, and ≥4,804 pigs reportedly died directly due to the disease with disruption to livelihoods. We conducted semiquantitative field investigations and rapid risk assessment (RRA) to understand the risk factors and drivers of ASF virus (ASFV) amplification and transmission in smallholder pig farms, and determine the gaps in biosecurity through hazard profiling, focus group discussions and expert opinion. Outbreaks were connected by road and aligned along the pig product value chain and reported in the northern, central, and southern parts of Tanzania. The patterns of outbreaks and impacts differed among districts, but cases of ASF appeared to be self-limiting following significant mortality of pigs in farms. Movement of infected pigs, movement of contaminated pig products, and fomites associated with service providers, vehicles, and equipment, as well as the inadvertent risks associated with movements of animal health practitioners, visitors, and scavengers were the riskiest pathways to introduce ASFV into smallholder pig farms. Identified drivers and facilitators of risk of ASFV infection in smallholder pig farms were traders in whole pigs, middlemen, pig farmers, transporters, unauthorized animal health service providers, and traders in pork. All identified pig groups were susceptible to ASFV, particularly shared adult boars, pregnant and lactating sows, and other adult females. The risk of ASF for smallholder pig farms in Tanzania remains very high based on a systematic risk classification. The majority of the farms had poor biosecurity and no single farm implemented all identified biosecurity measures. Risky practices and breaches of biosecurity in the pig value chain in Tanzania are profit driven and are extremely difficult to change. Behavioural change communication must target identified drivers of infections, attitudes, and practices.

Global Survey of Energetic Electron Precipitation at Low Earth Orbit Observed by ELFIN

AbstractWe statistically evaluate the global distribution and energy spectrum of electron precipitation at low‐Earth‐orbit, using unprecedented pitch‐angle and energy resolved data from the Electron Losses and Fields INvestigation CubeSats. Our statistical results indicate that during active conditions, the ∼63 keV electron precipitation ratio peaks at L > 6 at midnight, whereas the spatial distribution of precipitating energy flux peaks between the dawn and noon sectors. ∼1 MeV electron precipitation ratio peaks near midnight at L > ∼6 but is enhanced near dusk during active times. The energy spectrum of the precipitation ratio shows reversal points indicating energy dispersion as a function of L shell in both the slot region and at L > ∼6, consistent with hiss‐driven precipitation and current sheet scattering, respectively. Our findings provide accurate quantification of electron precipitation at various energies in a broad region of the Earth's magnetosphere, which is critical for magnetosphere‐ionosphere coupling.

Drivers of plant diversification along an altitudinal gradient in the alpine desert grassland, Northern Tibetan Plateau

Revealing alpine plant diversity patterns can contribute to conserving mountain plant diversity. However, the spatial variation in the ecological niche and diversity patterns of the plant community and the mechanism by which it maintains itself in alpine desert grasslands remain poorly understood. Here, we conducted a field investigation across altitudinal gradients (3093, 3296, 3549, and 3790 m) in the northern Tibetan Plateau and compared species composition, diversity indices, Levins' niche breadth, and Pianka's niche overlap. The results showed that perennial herbs replaced semi-shrubs and xermesophytes and mesophytes replaced xerophytes with increasing altitude. The plant community heights decreased with altitude. The cover of the herb layer increased with altitude, whereas that of the shrub layer was hump-shaped. Species diversity indices (Patrick, Pielou, Shannon-Wiener, and Simpson) increased with increasing altitude. Sympegma regelii (1.05), Leymus chinensis (1.03), and Reaumuria kaschgarica (0.94) had larger niche breadths and were widespread. Species with a high niche overlap occupied a considerable proportion at higher altitudes, indicating strong interactions among species. The redundancy analysis revealed that altitude, soil water content, soil organic matter content, and pH were the main factors driving changes in plant diversity (P = 0.036, F = 3.7). Our study illustrated that environmental filtering and biotic interactions jointly shape plant composition and diversity in alpine desert grasslands along altitudinal gradients.

Facile construction of graphene oxide and iron organic frameworks decorated biopolymeric hybrid materials for fluoride uptake from water

The widespread excess level of fluoride in water causes a possible risk to human health. Herein, graphene oxide (GO) and iron-type metal–organic frameworks namely iron-benzene-1,4-dicarboxylate (Fe-BDC) supported material namely GO/Fe-BDC was employed to remove fluoride in water. Because of powder form, GO/Fe-BDC creates pressure drop during filtration. To overcome such troubles and improve fluoride adsorption capacity, GO/Fe-BDC integrated alginate (Alg) and chitosan (CS) biopolymer-based hybrid material namely GO/Fe-BDC/Alg-CS beads was developed for fluoride removal. Defluoridation properties of GO/Fe-BDC and GO/Fe-BDC/Alg-CS beads were evaluated under numerous influencing conditions namely pH, contact time, variable fluoride concentration, co-ions, dosage and temperature studies. The GO/Fe-BDC and GO/Fe-BDC/Alg-CS beads were revealed finer fluoride adsorption ability and also had high fluoride selectivity in complexed atmosphere with several co-ions. The element composition, crystalline nature and material morphology of GO/Fe-BDC and GO/Fe-BDC/Alg-CS beads were characterized using SEM, XRD, FTIR and EDAX analysis. The order and nature of defluoridation was examined with kinetics, thermodynamic and isotherm analysis. The highest r values and lowest sd values exhibit that Langmuir adsorption isotherm and pseudo-second-order (PSO) models were consider as best fit models for fluoride adsorption process onto GO/Fe-BDC and GO/Fe-BDC/Alg-CS beads. The thermodynamic results illustrate that fluoride adsorption was spontaneous, chemical adsorption with endothermic nature . Electrostatic interaction and complexation were found as the primary defluoridation mechanism of GO/Fe-BDC and GO/Fe-BDC/Alg-CS beads. The renewal and field investigations of GO/Fe-BDC and GO/Fe-BDC/Alg-CS beads were explored to check their regeneration ability and field suitability nature.

Meandering Streamflows across Landscapes and Scales: a Review and Discussion

Abstract The study of meandering patterns created by geophysical flows is important for a number of fundamental and applied research topics, including stream and wetland restoration, land management, infrastructure design, oil exploration and production, carbon sequestration, flood-hazard mitigation, and planetary paleoenvironmental reconstructions. This volume, Meandering Streamflows: Patterns and Processes across Landscapes and Scales , contains 13 papers that present field, laboratory, and numerical investigations of meandering channels found in distinct environmental and geological contexts, and focus on how the interactions of different autogenic and allogenic processes, both in the horizontal and the vertical dimension, affect meander kinematics and the resulting morphology, sedimentology, and stratigraphic architecture. In this introductory chapter, we offer an overview of the evolution of scientific research on meandering streams over time, aiming to review and discuss meandering patterns in both fluvial and non-fluvial settings. Additionally, we present a new compilation of data on meander morphological features, drawn from both existing literature and novel sources, encompassing over 8000 meander bends discovered across a diverse array of environments.

Exploring the impact of high-power infrared lasers on electro-optical systems performance: A field study with different wavelengths

The performance of different electro-optical (EO) and infrared (IR) imaging systems under the impact of high-power pulsed infrared lasers has been well evaluated and studied. The infrared lasers operating at 1.06 µm, 3.7–4.2 µm, and 9.6 μm wavelengths, including short-wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared (LWIR) sensors used in television, infrared imaging, and tracking systems. Our research is focused on the intended waveband of the infrared imagers at significant distances relevant to tactical security operations, with a range of 6 km–10 km. The study compares the effects of both dazzling and damaging laser radiation on EO systems using a straightforward theoretical framework supported by atmospheric modeling. It was observed that increased humidity and temperature diminish both dazzling and damage distances, with less impact at 1.06 µm and more significant at 9.6 µm, compared to 3.7–4.2 µm. The effect of atmospheric conditions on IR laser energy was studied using MODTRAN software to determine the effective laser parameters for EO imaging systems at different distances. The study also investigates the critical parameters of practical high-power pulsed infrared laser wavelengths to dazzle and damage imaging systems at different distances. Field investigations revealed that dazzling on TV seekers can extend beyond 10 km by 1.06 µm, with damages up to 8 km, depending on the sensor field of view, laser source pulse frequency, and environmental conditions. Lasers with wavelengths of 3.7–4.2 μm can produce high-dazzling spots at the center of images of MWIR seekers up to 6 km. Lasers with wavelengths of 9.6 μm can rapidly damage LWIR seekers’ pixels due to their varied energy outputs and pulse frequency-range responses up to 8 km. System functions were lost under the dazzling and damaging effects. The study revealed a strong correlation between experimental results and predictions, with a strong agreement between experimental and theoretical effective distances under similar environmental and atmospheric conditions.

Thermal and Entropic analyses of free convection of nanofluid in a partially heterogeneous porous chamber using the two-phase mixture model

Entropy generation and convection heat transfer in a partially porous chamber with different side wall temperatures using CuO–H2O have been investigated. The importance of this issue is wide application of the results in solar collectors, thermal extrusion systems, heat exchangers, bio-medicine, nuclear waste disposal, etc. The innovation of the present work is related to the investigation of fluid and heat fields and entropy generation by using a matrix with subordination of porosity to the vertical axis and permeability, thermal conductivity, and viscosity with subordination of porosity. To obtain accurate results, the two-phase mixture model was used, and thermal conductivity and viscosity of nanofluid were simulated by experimental models by temperature and volume fraction dependence. Governing equations are solved by the FVM. The main findings indicate that the best and worst optimization factor will occur in the porous matrix ε = ε(y2) and ε = -ε(y2), respectively, which is 113 % and 86 % of NH of the homogeneous matrix, respectively. Also increasing the filling of the cavity, highly improves NH, so that the NH will reach from 1.19 to 1.82 with the increase of S from 0.25 to 1.

Regional difference and prevention strategy of farmland erosion induced by extreme rainstorms in the Loess area and Rocky mountain area of Northern China

AbstractElucidating the mechanism of soil erosion caused by extreme rainstorms could improve agroecosystems' resilience to the extreme climate. However, less attention has been paid to the regional difference of soil erosion during extreme rainstorms through multiple field investigations. Using six field surveys of extreme rainstorms, soil erosion and its driving mechanism were investigated on farmland in the Loess area and the Rocky mountain area. Conclusions are as follows: (1) Farmland was severely eroded in comparison with abandoned land and forest–grass land. The erosion modulus of farmland in the Loess area (51 606.51 t/km2) was greater than that in the Rocky mountain area (2582.75 t/km2). (2) In both the Loess area and the Rocky mountain area, the main erosion types on sloped cropland and terraced land were rills/gullies and embankment failure, respectively. Terracing is an appropriate measure that can effectively control farmland erosion in rainstorm events. (3) Concentrated flow is a major driver of soil erosion, with nearly all rills/gullies occurring in the flow paths. Drainage measures can prevent the formation of concentrated flow, weakening rills/gullies erosion in farmland. (4) Building bio‐embankment, planting high‐coverage crops, and implementing local protection measures could reduce the farmland erosion influenced by extremely heavy rainfall. Combining drainage and agronomic measures is the common strategy to combat extreme rainstorm events for reducing farmland erosion in the two regions. These results can be applied to improve the ability of agricultural systems to cope with extreme rainstorms.

On the Provenance of Field Reports of the 1886 Charleston, South Carolina, Earthquake: A Seismo-Historical Whodunnit

Abstract Much of what is known about the effects of the 1886 Charleston, South Carolina, earthquake throughout the epicentral region can be attributed to meticulous field investigations by an individual with training in geology and engineering, Earle Sloan (Clendenin, 1926). In a recent study, Bilham and Hough (2024) undertook a detailed analysis of the effects of the earthquake on railroads in the Charleston region, drawing heavily from Sloan’s reports. This exercise identified several inconsistencies in Sloan’s field reports, including understandable measurement imprecision, inferred data entry mistakes, and transcription errors. The study also begged the question, where was Sloan at the time of the mainshock and over the following week? And to what extent did he draw from secondhand information in compiling his reports? On this question Sloan’s reports were sometimes enigmatic, lending themselves to misinterpretation in contemporaneous as well as modern interpretations. Beyond the details that were germane for, and briefly summarized by, the studies of Bilham and Hough (2023, 2024), in this report we don our historical seismologist caps to chronicle Sloan’s activities following the earthquake. We summarize our inferences here for the benefit of future scholars who might attempt to retrace either Sloan’s footsteps or our own. This study also serves to highlight Sloan’s singular contributions to earthquake science, which were never published separately.

Use of Ethnoveterinary Medicinal Plants to Treat Cattle Diseases by the Oulad Heriz Farmers in the Chaouia Region, Northwest of Morocco

Using medicinal plants for healthcare practices in indigenous communities presents a chance to discover natural remedies. This study aims to provide a detailed account of the ethnoveterinary knowledge of medicinal plants utilized for therapeutic purposes. From December 2020 to December 2021, a field investigation was carried out within the Oulad Heriz tribes. Two hundred local farmers were interviewed using open-ended, semi-structured discussions, free listing and focus groups. A total of one hundred medicinal plants belonging to 87 genera and 33 families were discovered to be employed for ethnoveterinary purposes. Rosmarinus officinalis L. was the most frequently utilized ethnoveterinary plant species in the study area (70 citations). Leaves are shown to be the most commonly employed plant parts (55%). However, digestive disorders were the most often mentioned ailment (33 medicinal plants, 599 citations), and most herbal medicines were made by infusion (46.2%). According to the current investigation findings, local farmers in Oulad Heriz have continuous knowledge of ethnoveterinary plants. This ethnoveterinary medicinal heritage needs to be incorporated with contemporary medicine to use plants and their products as potentially viable medications for various cattle illnesses.

Segment Cracking and Damage Mechanism of Curved Shield Tunnels During Construction by Field Investigation and Modeling

This study was based on the field statistical results of segment cracking and damage of a curved shield tunnel engineering. Combined with the collected data of 11 related tunneling parameters of 120 segments in the curve section, the one-way analysis of the variance method was used to reveal the main tunneling parameters that affect the cracking and damage state of the segment. Then, the finite element analysis model was established to analyze the mechanism of jack thrust and yawing angle affecting segment cracking and damage. The main results are as follows: (1) The phenomenon of segment cracking and damage gradually becomes serious from the crown to the invert. (2) The jack thrust and shield machine yawing angle are the main factors affecting the cracking and damage state of the segment. For larger values of yawing angle and jack thrust difference, the cracking and damage state of the segment is more serious. (3) The first three segments near the jack are significantly affected by the jack offset angle and uneven jack thrust. During the construction of a curved shield tunnel, under the action of the jack offset angle and uneven jack thrust, the segment spring line is more likely to incur tensile cracking. (4) To ensure the normal stress state of the segment during construction, it is suggested to control the jack offset angle at not more than 0.5° and the jack thrust non-uniform coefficient [Formula: see text] of the left- and right-hand sides within 0.75.

The use of ASTER and landsat remote sensing data for exploring hydrothermal mineral in Arabian-Nubian Shield

Multispectral remote sensing data provided valuable information for hydrothermal minerals exploration. In this article, Landsat-8 Operational Land Imager (OLI) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data were processed and analyzed using band ratio and principal component techniques to demarcate areas of hydrothermal mineral resources by highlighting the most influenced zone of hydrothermal alteration (high-grade) in Egypt. The area is a part of the Arabian-Nubian Shield, covering 1068 km2, and comprises wide varieties of Pre- and Pan-African rock assemblages. Preparing and integrating thematic layers consisting of the grade of hydrothermal intensity in a GIS technique supported generating a hydrothermal mineral predictive map (HMPM) using a multi-criteria decision-making technique. The plausible zone of very high mineral resources covers about 6.57 %. Analysis of ASTER data revealed that this zone is reliable with phyllic and argillic minerals and iron-oxides. The results of OLI data helped in demarcating potential areas of hydrothermal alteration areas (Al–OH) mixed with iron oxides. Field observations and investigations enabled the validation of the HMPM. The spatial distribution of hydrothermal zones throughout the study was reliable to that observed in the mine areas. Field and ore microscopic examination verified the existence of Au-sulfide minerals connected with hydrothermal alteration zones (HAZs) in different areas e.g., Abu-Marawat, Gidami, Semna, Abu-Gaharish, and Hamama mines. Overall, integrating multi-spectral data through overlay analysis techniques can provide valuable information about hydrothermal mineral resources in an accurate and cost-effective approach.

Harmonization of Authority in the Investigation of the Financial Services Sector in Indonesia

The rapid growth of the financial services sector in Indonesia demonstrates its strategic role in the national economy. However, harmonizing investigative authorities in this sector poses a challenge that needs to be addressed to maintain stability and public trust. This paper aims to investigate the issue of harmonizing investigative authorities in the Indonesian financial services sector, focusing on regulatory frameworks, case developments, and potential harmonization models. The evolution of investigative authority regulations in the financial services sector is outlined, identifying weaknesses in the system that need to be addressed. Case studies provide a concrete overview of the challenges faced in field investigations. A harmonization model for investigative authorities is proposed as a solution to enhance the effectiveness and efficiency of investigations. Under this harmonization model, OJK investigators are not the sole authority to conduct investigations in the financial services sector, but their authority must be elaborated with that of the POLRI or PPNS investigators as regulated in the Criminal Procedure Code (KUHAP). Article 49 paragraph (5) of Law No. 4 of 2023 concerning Financial Services Sector (P2SK Law), which essentially states that criminal investigations in the financial services sector can only be conducted by OJK investigators through a harmonization model of investigative authority in the financial services sector in Indonesia, should be elaborated so that investigative authority in the financial services sector can be carried out by POLRI or PPNS with the assistance of OJK investigators.

Formulaic Sequences Used in Academic Writing Register

The identification of formulaic sequences through a corpus-driven methodology is regarded as a fundamental aspect of achieving smooth linguistic expression and successful communication. The present study examined a prominent category of formulaic language known as lexical bundles. This research endeavors to examine the utilization of lexical bundles as formulaic structures in academic abstracts, introductions, and conclusions. Through the examination of 150 abstracts, introductions, and conclusions, 50 each, sourced from peer-reviewed articles within the domain of Language and Literacy, the quantity of formulaic language, specifically lexical bundles, is quantified and their pragmatic functions are analyzed. The Antconc software was utilized to produce formulaic sets consisting of two-word, three-word, four-word, and five-word lexical bundles, including a few six-word structures. Subsequently, the outcomes are juxtaposed with prior investigations in the respective field. The research indicates that lexical bundles, which are a type of formulaic language, exhibit a slightly lower frequency of usage in introductions and conclusions compared to abstracts.

Timescales of tree‐covered island dynamics on the mixed bedrock‐alluvial anabranching Vaal River, South Africa

AbstractPrevious research on mixed bedrock‐alluvial anabranching rivers has documented how alluvial islands commonly grow under vegetation influences atop slowly eroding bedrock templates, but timescales of island dynamics remain poorly constrained. We focus on the Vaal River near Parys, South Africa, and combine field investigations, aerial image analyses and optically stimulated luminescence (OSL) dating to establish timescales of initiation, growth and erosion for nine bedrock‐cored, tree‐covered, alluvial islands. For each island, two OSL samples were collected in vertical succession from sand‐rich exposures up to 4 m in thickness to establish minimum ages for island initiation (~1802 to 243 years) and to estimate local vertical aggradation rates (~0.20 to 1.8 cm year−1). The diachronous lower ages and lack of systematic upstream‐downstream trend in island age support an interpretation of patchwork initiation, growth, and erosion of islands throughout the late Holocene. Following island initiation, vertical island aggradation occurs in association with establishment of reeds, shrubs and trees, but erosion of island margins or dissection by cross‐cutting channels also can occur. Observations during and after recent large floods (peak discharges >3000 m3 s−1) provide further insights into island dynamics, including the influence of exotic trees (e.g., Eucalyptus spp.) that have colonised many islands in the postcolonial era (last ~150 years). Our findings extend previous conceptual models by constraining timescales of island dynamics and providing new insights into island stability and longevity in mixed bedrock‐alluvial anabranching rivers. Improved communication of findings regarding island geomorphology, ecology and stability can benefit local community engagement, geo/eco‐tourism and education activities, and land use planning.

Stratigraphic and U-Pb zircon age constraints on the timing of the Yanliao Biota in northern China

The Yanliao Biota from northern China is one of the most famous Mesozoic terrestrial lagerstätten in the world, with well-preserved fossil records in the Jurassic volcanic-sedimentary Ningcheng and Jianchang basins. However, the temporal evolution of the Yanliao Biota remains controversial, mainly due to the confusing stratigraphic framework and the unclear age of fossiliferous deposits in the Ningcheng basin. To address this issue, we carried out detailed field investigations and secondary ion mass spectrometry (SIMS) U-Pb age dating of zircons on fossiliferous and related strata in the southern part of the Ningcheng basin. The Jurassic infill of this area is composed of, in ascending order, fossil-bearing tuffaceous clastic rocks (unit 1), andesite and pyroclastic rocks (unit 2), fossil-bearing clastic rocks interlayered with minor volcanic rocks (unit 3), and andesite and pyroclastic rocks (unit 4). Integration of stratigraphic and geochronological data indicates that the Yanliao Biota in the Ningcheng basin appeared no later than ca. 163 Ma and lasted until ca. 156 Ma. A comparison with other analogous basins in northern China (e.g., the Luanping, Jianchang, and Beipiao basins) leads to the conclusion that the Yanliao Biota evolved in two phases and lasted for more than 11 m.y.: the first phase from ca. 167 Ma to ca. 163 Ma in the middle Bathonian to middle Callovian, followed by the second phase between ca. 161 Ma and ca. 156 Ma in the lower and middle Oxfordian.