bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Precursors of Reading Development in Simultaneous Bilinguals: A Systematic Review and Meta-Analysis
Authors: Bhalloo Insiya , Molnar Monika
Published: August 2023

Purpose:

Literacy precursors are cognitive, linguistic, and oral-language skills that predict future reading skills in children as young as 4 years. Speech-language pathologists and educators utilize these precursors as assessment tools to identify children at risk for reading difficulties. Most current tools are developed based on monolinguals (predominantly in English), despite the significant percentage of bilinguals globally. As such, bilingual children are typically assessed on tools developed for monolinguals in research and clinical settings. Despite this common practice, there is a lack of comprehensive synthesis on whether these precursors are a reliable indicator of reading skills in bilingual children. Our article examines whether literacy precursors commonly used with monolinguals are associated with reading development in simultaneous bilinguals.

Method:

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane guidelines, our review includes four databases (Linguistics and Language Behavior Abstracts, Educational Resources Information Center, Modern Language Association, and PsycINFO), in addition to gray-literature and manual reference-list searches. To control for age of acquisition and language dominance variability, we included typically developing simultaneous bilinguals exposed to both languages before age 3 years (
N
= 5,942). We analyzed reported statistical associations between code-related or oral-language precursors and reading outcome measures, using correlational meta-analyses.

Results:

The 41 reports, which met inclusion/exclusion criteria, were published between 1977 and 2022. The average age at assessment was 7;5 (years;months; range: 3;0–11;0), with children speaking over 21 bilingual language combinations. Our meta-analysis demonstrated significant within-language correlations and cross-language transfer effects for code-related (e.g., phonological awareness) and oral-language (e.g., vocabulary and morphological awareness) precursors. Semantic awareness, however, was not a reliable predictor in bilinguals.

Conclusions:

Phonological awareness and vocabulary measures—even if originally developed for monolingual children—can form a meaningful component of early literacy assessment in simultaneous bilingual children: These precursors may be used as assessment tools across heritage and societal languages in research and clinical practice. Future research suggestions within this domain are also discussed.

Supplemental Material:

https://doi.org/10.23641/asha.23880465
DES Y3 cosmic shear down to small scales: Constraints on cosmology and baryons
Authors: Aricò Giovanni , Angulo Raul E. , Zennaro Matteo , Contreras Sergio , Chen Angela , Hernández-Monteagudo Carlos
Published: August 2023

We present the first analysis of cosmic shear measured in DES Y3 that employs the entire range of angular scales in the data. To achieve this, we built upon recent advances in the theoretical modelling of weak lensing provided by a combination of N-body simulations, physical models of baryonic processes, and neural networks. Specifically, we used BACCOemu to model the linear and non-linear matter power spectrum including baryonic physics, allowing us to robustly exploit scales smaller than those used by the DES Collaboration. We show that the additional data produce cosmological parameters that are tighter but consistent with those obtained from larger scales, while also constraining the distribution of baryons. In particular, we measured the mass scale at which haloes have lost half of their gas, log Mc = 14.38−0.56+0.60 log(h−1 M⊙), and a parameter that quantifies the weighted amplitudes of the present-day matter inhomogeneities, S8 = 0.799−0.015+0.023. Our constraint on S8 is statistically compatible with that inferred from the Planck satellite data at the 0.9σ level. We find instead a 1.4σ shift in comparison to that from the official DES Y3 cosmic shear, because of different choices in the modelling of intrinsic alignment, non-linearities, baryons, and lensing shear ratios. We conclude that small scales in cosmic shear data contain valuable astrophysical and cosmological information and thus should be included in standard analyses.
Binary masses and luminosities with Gaia DR3
Authors: Chevalier S. , Babusiaux C. , Merle T. , Arenou F.
Published: August 2023

Context. The recent third data release (DR3) of Gaia has brought some new exciting data about stellar binaries. It provides new opportunities to fully characterize more stellar systems and contributes to enriching our global knowledge of stellar behaviour.

Aims. By combining the new Gaia non-single stars catalogue with double-lined spectroscopic binaries (SB2), we can determine the individual masses and luminosities of the components. To fit an empirical mass-luminosity relation in the Gaia G band, lower-mass stars must be added. These masses can be derived using Gaia-resolved wide binaries combined with literature data.

Methods. Using the BINARYS tool, we combined the astrometric non-single star solutions in the Gaia DR3 with SB2 data from two other catalogues: the 9th Catalogue of Spectroscopic Binary orbits (SB9), and APOGEE. We also searched for low-mass stars that are resolved in Gaia with direct imaging and HIPPARCOS data or with a literature mass fraction.

Results. The combination of Gaia astrometric non-single star solutions with double-lined spectroscopic data enabled us to characterize 43 binary systems with SB9 and 13 systems with APOGEE. We furthermore derived the masses of 6 low-mass binaries that are resolved with Gaia. We then derived an empirical mass-luminosity relation in the Gaia G band down to 0.12 ℳ⊙.
Electronic spectroscopy of 1-cyanonaphthalene cation for astrochemical consideration
Authors: Daly Francis C. , Palotás Julianna , Jacovella Ugo , Campbell Ewen K.
Published: August 2023

Context. Polycyclic aromatic hydrocarbons (PAHs) are believed to be the carriers of the aromatic infrared bands and have been proposed as candidates to explain other astronomical phenomena such as diffuse interstellar bands (DIBs). The first aromatic structures possessing more than one ring, 1- and 2-cyanonaphthalene (CNN), were recently detected by rotational spectroscopy in the dense molecular cloud TMC-1. Laboratory investigations have indicated that due to fast and efficient relaxation through recurrent fluorescence (RF), CNN+ may be photostable in the harsh conditions of the lower density, more diffuse regions of the interstellar medium (ISM) exposed to ultraviolet (UV) radiation. As a result, it has been suggested that the widely held belief that small PAHs present in these regions are dissociated may need to be revisited. If 1-CNN+ is able to survive in the diffuse ISM it may contribute to the population of 1-CNN observed in TMC-1. To investigate the abundance of 1-CNN+ in diffuse clouds, laboratory spectroscopy is required. The present work concerns the electronic spectroscopy of 1-CNN+ in absorption and the search for its spectroscopic fingerprints in diffuse clouds.

Aims. The aim is to obtain laboratory data on the electronic transitions of gas-phase 1-CNN+ under conditions appropriate for comparison with DIBs and assess abundance in diffuse clouds.

Methods. Spectroscopic experiments are carried out using a cryogenic ion trapping apparatus in which gas-phase 1-CNN+ is cooled to temperatures below 10 K through buffer gas cooling. Calculations are carried out using time-dependent density-functional theory.

Results. Experimental and theoretical data on the D2 ← D0 and D3 ← D0 electronic transitions of 1-CNN+ are reported. The former transition has a calculated oscillator strength of f = 0.075 and possesses a pattern dominated by its origin band. The origin band is located at 7343 Å and has a full width at half maximum of 28 Å. In observational data, this falls in a region polluted by telluric water lines, hindering assessment of its abundance.

Conclusions. Space-based observations are required to search for the spectroscopic signatures of 1-CNN+ and evaluate the hypothesis that this small aromatic system, stabilised by RF, may be able to survive in regions of the ISM exposed to UV photons.
Particle size segregation and diffusion in saturated granular flows: Implications for grain sorting in debris flows
Authors: Cui Kahlil Fredrick , Zhou Gordon G.D. , Jing Lu , Xie Yunxu , Lu Xueqiang
Published: August 2023

Sorting of rocks, boulders, and silt/sand-sized particles according to their size is a characteristic feature of debris flow deposits and is an active process during flow which significantly affects the mobility. The degree at which size sorting occurs in debris flows depends on the relative magnitudes of granular processes such as particle size segregation and diffusion. Since debris flows are fluid-saturated phenomena, accurate modelling of size sorting requires the understanding of the influence of fluids on these processes, which have not been systematically studied. Here, we present simulation results and the associated empirical expressions for particle size segregation and diffusion which take into account fluid effects due to buoyant and drag forces. These expressions are developed through scaling analysis of data obtained from coupled granular-fluid simulations of saturated bi-disperse mixtures under simple shear. We further show that using these scaling relationships, an existing segregation-diffusion continuum equation can be extended to model particle sorting in debris flows with various types of fluids.
Numerical investigation of particle dynamic behaviours in geophysical flows considering solid-fluid interaction
Authors: Fang Jun , Cui Yifei , Li Xinyue , Tang Hui
Published: August 2023

Solid-fluid interaction vitally influences the flow dynamics of particles in a geophysical flow. A coupled computational fluid dynamics and discrete element method (CFD-DEM) is used in this study to model multiphase geophysical flow as a mixture of fluid and solid phases. The two non-Newtonian fluids (i.e., Bingham and Hershcel-Bulkley fluids) and water mixed with particles are considered in the simulation, while dry granular flow with the same volume is simulated as a control test. Results revealed that the solid-fluid interaction heavily governs the particle dynamic behaviours. Specifically, compared to dry case, particles in three multiphase cases are characterized by larger flow mobility and greater shear rate while smaller basal normal force. In addition, a power-law distribution with a crossover to a generalized Pareto Distribution is recommended to fit the distribution of normalized interparticle contact force.
The influence of particle size on the spread distance and angle of friction of granular materials
Authors: Jan Chyan-Deng , Dey Litan
Published: August 2023

To produce a hazard map and thus provide mitigation measures against natural catastrophic events such as landslides, avalanches, and debris flows, it is necessary to determine the spread distance of such flows. There is a well-documented relationship between the angle of friction and the debris flow volume, allowing one to determine the possible distance a debris flow can travel. However, the effect of mean particle size (d50) and the sorting coefficient (Sc) on the final spread distance (Df) has received mere attention. In this study, a mini conical-shaped mould was used to measure the final spread distance (Df) and angle of friction (αf) for various dry granular material samples both in air and in water. Experimental results indicated that a granular material sample with a smaller d50 travel a longer distance compared to a sample with a higher d50. However, a sample with a smaller d50 results in a smaller angle of friction than the one with a higher d50. Conversely, a well-sorted sample has a smaller spread distance and larger angle of friction. Results also indicated that the spread distance in air is slightly larger and the angle of friction is slightly smaller than in water.
Formation of dry granular fronts and watery tails in debris flows
Authors: Meng Xiannan , Johnson Chris G. , Gray John M.N.T.
Published: August 2023

Debris flows are particle-fluid mixtures that pose a significant hazard to many communities throughout the world. Bouldery debris flows are often characterized by a deep dry granular flow front, which is followed by a progressively thinner and increasingly watery tail. The formation of highly destructive bouldery wave fronts is usually attributed to particle-size segregation. However, the moving-bed flume experiments of Davies (N. Z. J. Hydrol., vol. 29, 1990, pp. 18-46) show that discrete surges with dry fronts and watery tails also form in monodisperse particle-fluid mixtures. These observations motivate the development of a new depth-averaged mixture theory for debris flows, which explicitly takes account of the differing granular and phreatic surfaces, velocity shear, and relative motion between grains and fluid to explain these phenomena. This poster presents the theory of Meng et al. (J. Fluid Mech., vol. 943, 2022, A19), which consists of four coupled conservation laws that describe the spatial and temporal evolution of the grain and water thicknesses and depth-averaged velocities. This system enables travelling wave solutions to be constructed that consist of (i) a large amplitude dry flow front that smoothly transitions to (ii) an under saturated body, (iii) an oversaturated region and then (iv) a pure water tail. It is shown that these solutions are in good quantitative agreement with Davies’ experiments at high bed speeds and slope inclinations. At lower bed speeds and inclinations, the theory produces travelling wave solutions that connect to a steady-uniform upstream flow, and may or may not have a bulbous flow front, consistent with Davies’ observations.
A dilatant two-phase debris flow model with erosion validated by full-scale field data from the Illgraben test station
Authors: Meyrat Guillaume , Bartelt Perry , McArdell Brian
Published: August 2023

We propose a dilatant, two-layer debris flow model validated by full scale density/saturation measurements obtained from the Swiss Illgraben test site. Like many existing models we suppose the debris flow consists of a matrix of solid particles (rocks, boulders) that is surrounded by muddy fluid. However, we split the muddy fluid into two fractions. One part, the inter-granular fluid, is bonded to the solid matrix and fills the void space between the solid particles. The combination of solid material and inter-granular fluid forms the first layer of the debris flow. The second part of the muddy fluid is not bonded to the solid matrix and can move independently from the first layer. This free fluid forms the second layer of the debris flow. During flow the rocky particulate material is sheared which induces dilatant motions that change the solid/fluid concentration of the first layer and then his density. As suggested by real data of Illgraben, the rheology used is not constant and uniform but a function of the flow composition/ density. The model is then compared to real debris flow data of Illgraben and tested on a real event in Ritigraben for which erosion data are available.
Debris flow susceptibility mapping in Colorado Front Range, USA: A comparison of physics-based and data-driven approaches
Authors: Pei Te , Qiu Tong
Published: August 2023

This study used an inventory of debris flow triggered by a storm event in Colorado Front Range as an example to compare the capability of data-driven and physics-based approaches for regional-scale debris flow susceptibility mapping (LSM). Nine debris flow contributing factors were collected for the present study based on the availability of geophysical data in the study area. These contributing factors represent hillslope geometries, surface hydrology, and soil conditions. For the physics-based approach, the infinite slope model was used to directly determine the debris flow susceptibility for the study area by calculating the factor of safety (FS) based on parameters derived from geophysical data. For the data-driven approach, an artificial neural network (ANN) was developed to predict debris flow susceptibility for the study area by learning relationships from the contributing factors using the debris flow inventory. The results showed that both physics-based and data-driven models predicted debris flow susceptibility in the study area with relatively high accuracy; the data-driven approach outperformed the physics-based approach as it could extract complex features which the physics-based approach did not consider.
Laboratory investigation of the effects of grain size on the dynamics of debris flows: Measurement of pore fluid pressure in an open channel
Authors: Sakai Yuichi , Hotta Norifumi
Published: August 2023

The dynamics of debris flow depend on internal stress components, such as particle–particle stress, the stress exerted by pore water, and interactions between particles and pore water. Although dominant internal stress components depend on the grain size composition, the effects of grain size on the dynamics of debris flow are not fully understood. To investigate the effects of grain size on the dynamics of debris flows, pore fluid pressures were measured in an open channel experiment. In the experiment, monodisperse debris flows were triggered for five different grain sizes: 0.2, 0.8, 1.3, 2.2, and 2.9 mm. The pore fluid pressures in debris flows of 0.2 mm grains had larger excess pressures over the hydrostatic pressure, and were close to the total normal stress, while those of other grain sizes had smaller excess pressures and were relatively close to the hydrostatic pressure. Comparing the measured friction factors and theoretical ones for stony debris flows, particle–particle stress dominated in debris flows, except for 0.2 mm grains, and the measured excess pore pressures could be explained by the Reynolds stress of pore fluid due to shear by particles in laminar motion. By contrast, particle–particle stress did not dominate in debris flows of grain size 0.2 mm, and a large portion of the particles was in suspension affected by turbulence. These differences in flow dynamics may correspond to the flow transition from laminar to turbulent flow described by the threshold of relative flow depth, which is the ratio of the flow depth to grain size.
Inferring spatial variations in velocity profiles and bed geometry of natural debris flows based on discharge estimates from high-frequency 3D LiDAR point clouds; Illgraben, Switzerland
Authors: Spielmann Raffaele , Aaron Jordan , McArdell Brian W.
Published: August 2023

More detailed field measurements are required for a better understanding of surging debris flows. In this work, we analyze a debris flow at the field-scale using timelapse point clouds from a high-resolution, high-frequency 3D LiDAR sensor, which has been installed over a check dam on the fan of the Illgraben catchment in Switzerland. In our investigations, we manually measured the front velocity and tracked individual features such as large boulders and woody debris over a 25 m long channel segment. We observed a change in the front velocity as well as a difference in the velocity of large boulders and woody debris (vboulder≈ 0.6vwood) during the second surge of the event. We also estimated the discharge for different closely spaced channel sections based on automated measurements of the cross-sectional area and the surface velocity, which enabled us to infer spatial variations in the bed geometry and the velocity profile. From the discharge estimates, we then derived the volume of this event. Over the course of the next year, the amount of field-scale LiDAR data from the Illgraben will increase substantially and allow for an even more detailed analysis of fundamental debris-flow processes.
How are fine sediments described in sediment sheet flow?
Authors: Uchida Taro , Nishiguchi Yuki , Niwa Satoshi , Kubo Takeshi , Gonda Yutaka , Satofuka Yoshifumi
Published: August 2023

Stony debris flow transits to sediment sheet flow when the river bed gradient becomes gentle. The sediment sheet flow consists of a water flow layer and a sediment moving layer. Fine sediments are expected to behave as a part of the fluid rather than a solid phase in the sediment moving layer. Further, it can be thought that a part of fine sediment can be suspended in the water flow layer. However, it was not possible to physically express whether the fine sediment behaves as a solid phase or a fluid phase in the numerical simulation model. Here we physically modeled fine sediment behavior in sediment sheet flow. We confirmed the applicability of the new model to describe the longitudinal deposited sediment gradient in flume experiments.
Impact of a dry granular flow against a rigid wall: MPM simulations with a new constitutive approach
Authors: di Prisco Claudio , Marveggio Pietro , Redaelli Irene , Zerbi Matteo
Published: August 2023

The dynamic interaction between granular flowing masses and obstacles is a very complex phenomenon involving large displacements and high strain rates. To simulate the event in a continuum-based framework both advanced numerical tools and constitutive relationships are required. In this work, the impact of a dry granular mass against a rigid wall is numerically simulated using the open-source Material Point Method code ANURA3D, while the constitutive model proposed by Marveggio et al., 2021 is adopted for the granular mass. The model accounts for rate and grain packing dependence, which have been shown to be crucial to reproduce the propagation of compression and rarefaction waves inside the mass. The model is capable of reproducing “solidification” and “liquefaction” phenomena observed in the DEM impact tests results already available in the literature.
Growth of Debris Flows by Soil Bed Erosion: Effects of Frictional and Hydrodynamic Shear Stresses
Authors: Song Pengjia , Choi Clarence
Published: August 2023

Debris flows are complex solid-fluid mixtures, which travel downslope under the influence of gravity. The destructive potential of a debris flow is governed by its volume and speed, both of which can be significantly enhanced by the erosion of soil bed material along the flow path. Existing friction-induced erosion theories simplify a debris flow as an equivalent fluid that induces frictional shear stress on a soil bed. Erosion occurs when the frictional stress exceeds the soil strength. Research also shows the importance of hydrodynamic stresses on the erosion of soil beds. However, the mechanism of soil bed failure under the influence of frictional and hydrodynamic shear stresses is not clear. In this extended abstract, some experimental flume test results are presented. The tests simulate the erosion of soil beds by dry sand flow and water flow to evaluate the effects of frictional and hydrodynamic shear stresses imposed on a soil bed, respectively. Findings from this research can be used to improve estimates of erosion of debris flows in mountainous regions, which will strengthen hazard assessments.
Mixture theory-based SPH model for submerged landslide
Authors: Zhu Chengwei , Peng Chong , Wu Wei
Published: August 2023

A novel SPH model aimed at solving the coupled water-soil problems is proposed based on the mixture theory. This method is featured with the spatially overlapped dual continua for both fluid and solid phases. The water phase is modeled as a weakly-compressible Newtonian fluid, and the soil phase is modeled using an elastoplastic constitutive model. The benchmark problem, fully submerged soil subjected to gravity, is examined to validate this SPH model. Finally, a submerged landslide is simulated to demonstrate the capability of the proposed SPH model in solving the dynamic soil–water coupling problems.
A new real-time debris flow and avalanches detection system based on optical fiber sensing
Authors: Aiassa Santina , Antolini Francesco , Barla Marco , Insana Alessandra , Gaudino Roberto , Rizzelli Martella Giuseppe , Pellegrini Saverio
Published: August 2023

The real-time detection of potentially destructive water, earth and snow mixtures such as debris flow and avalanches is a topic of growing interest to mitigate the risk in anthropized areas such as the Alpine region. In view of this, a new cutting-edge debris flow and avalanche detection system, called OPTIALP, was developed. The proposed system exploits the polarization variations induced on the fiber by mechanical vibrations, for the automatic detection along their propagation path of potentially destructive snow and soil-water mixtures. One of the main values-add of the OPTIALP system is the “quasi distributed” and spatially continuous detection along the whole fiber which improves the current monitoring technologies relying on “discrete” monitoring points and sensors. The OPTIALP system was designed and thoroughly tested in the laboratory environment by means of a specific setup. Over 650 tests were carried out and a new signal processing algorithm developed in Matlab environment capable to interpret the data acquired was created. The results showed that the OPTIALP system is able to correctly identify the signals produced by lab-scale mass movements.
Keynote lecture. Landslide Early Warning Systems: Resources or Problems?
Authors: Guzzetti Fausto
Published: August 2023

Recent estimates suggest that landslides occur in about 17.1% of the landmasses, that about 8.2% of the global population live in landslide prone areas, and that population exposure to landslides is expected to increase. It is threfore not surprising that landslide early warning is gaining attention in the scientific and the technical literature, and among decision makers. Thanks to important scientific and technological advancements, landslide prediction and early warning are now possible, and landslide early warning systems (LEWSs) are becoming valuable resources for risk mitigation. A review of geographical LEWSs examined 26 regional, national and global systems in the 44.5-year period from January 1977 to June 2019. The study relevaled that only five nations, 13 regions, and four metropolitan areas benefited from operational LEWSs, and that large areas where landslide risk to the population is high lack LEWS coverage. The review also revealed that the rate of LEWSs deployment has increased in the recent years, but remains low, and that reniewed efforts are needed to accelerate the deployment of LEWSs. Building on the review, recommendations for the further development and improvement of geographical LEWSs are proposed. The recommendations cover six areas, including design, deployment, and operation of LEWS; collection and analysis of landslide and rainfall data used to design, operate, and validate LEWSs; landslide forecast models and advisories used in LEWSs; LEWSs evaluation and performance assessment; operation and management; and communication and dissemination. LEWSs are complex and multi-faceted systems that require care in their design, implementation and operation. To avoid failures that can lead to loss of credibility and liability consequences, it is critical that the community of scientists and professionals who design, implement and operate LEWSs takes all necessary precautions, guided by rigorous scientific practices.
Initiation and runout characteristics of partially saturated debris flows in Ohya landslide scar, Japan
Authors: Imaizumi Fumitoshi , Oya Shunsuke , Takayama Shoki
Published: August 2023

A partially saturated flow, which has an unsaturated layer in its upper part, has been monitored in the steep initiation zones of debris flows. Understanding the initiation and runout characteristics of partially saturated flows is essential for predicting the timing and magnitude of downstream debris flows. Monitoring performed using time-lapse cameras and water pressure sensors in the Ohya landslide scar in central Japan allowed us to obtain data on a series of partially saturated debris flow surges from initiation to termination on July 6, 2020, and July 13, 2021. Debris flow surges were mainly induced by repetitive mass movement of sediment deposit caused by the overland flow erosion of channel deposits, channel deposit slides, and water and sediment supply from channel banks and tributaries. The excess pore water pressure in a partially saturated flow on July 6, 2020, was clearly higher than that on July 13, 2021. Rainfall patterns, which control the water content in channel deposits, and the flow height likely affect the magnitude of the excess pore water pressure in partially saturated flows.
Continuous debris flow monitoring using DFLP and LVP on Sakura-jima Island
Authors: Itoh Takahiro , Iwao Tadaaki , Kubo Seiki , Tsurumoto Takaya , Tagata Satoshi , Furuya Misa , Mizuyama Takahisa
Published: August 2023

Since 2010, numerous debris flows have occurred on Sakura-jima Island due to rainfall events that occurred after extensive ash deposition associated with volcanic activity. The study area included the Nojiri and Arimura rivers in the southwestern and southeastern parts of Sakura-jima, respectively. Debris flow monitoring systems consisting of loadcell and pressure sensor (DFLP) were installed to evaluate characteristics of moving weight and so on during debris flows. The systems were installed at the Arimura River No. 3 sabo dam in June in 2012 and at the Nojiri River No. 1 sabo dam in 2014. In addition, LVP (Load, Vibration and Pressure) sensors consisting of loadcells and accelerometers for measuring vibration and pressure were installed on the riverbed for debris flow detection. Modified LVP systems were installed at the Nojiri River No. 7 sabo dam in February in 2015, and at the Arimura River No. 3 sabo dam in October in 2016. Interesting characteristics of debris flows were obtained by the DFLP and LVP systems. The findings showed that the sediment concentrations of both the coarse and the suspended and liquid phases could be estimated by the DFLP systems, and several patterns of debris flows were observed by the LVP systems.
Triggering rainfall intensities for post-wildfire debris flows in the Sonoran Desertscrub plant community
Authors: McGuire Luke , Youberg Ann , Gorr Alexander , Beers Rebecca
Published: August 2023

Wildfire makes landscapes more vulnerable to debris flows by reducing soil infiltration capacity and decreasing vegetation cover. The extent to which fire affects debris-flow processes depends on the severity of the fire, the climatology of intense rainfall, the pre-fire plant community, and sediment supply, among other factors. As fire expands into new plant communities and geographic regions, there is a corresponding need to expand efforts to document fire-induced changes and their impacts on debris-flow processes. In recent years, several large wildfires have impacted portions of the Sonoran Desertscrub plant community in Arizona, USA, a plant community where fire has been historically infrequent. Following two of these fires, we monitored debris-flow activity at the watershed scale and quantified wildfire-driven changes in soil hydraulic properties using in-situ measurements with mini disk tension infiltrometers. Results indicate that rainfall intensity-duration thresholds for the initiation of post-fire debris flows in recently burned watersheds within the Sonoran Desertscrub plant community are substantially greater than those in nearby areas dominated by other plant communities, such as chaparral. Results provide insight into the impact of fire on debris-flow processes in a plant community where it is likely to be more impactful in the future and help expand existing post-fire debris flow databases into a plant community where there is a paucity of observations.
Reconstruction of debris flow in the Gerkhozhan-Su river valley based on the chain modeling
Authors: Iudina (Kurovskaia) Viktoriia , Chernomorets Sergey , Krylenko Inna , Vinodradova Tatyana , Zaporozhchenko Eduard
Published: August 2023

The paper presents the reconstruction of the most catastrophic debris flows in the Gerkhozhan-Su river valley (North Caucasus, Russia) based on a chain of mathematical models. Transport-shift model was applied for 6 sections of debris flow formation or intense material increment, while for the rest the FLO-2D hydrodynamic model was used. A number of numerical experiments were carried out in the transport-shift model for a section of a debris flow origination site with a change in the parameters of a potential debris flow-forming soils, such as initial moisture content and density. According to the simulation results, with a rise in moisture content, the maximum debris flow discharge can increase by about 2.8 times. Modeling of debris flow in the Gerkhozhan-Su river valley was conducted for the case of low density debris flow. Based on the results, debris flow wave hydrographs were obtained at 12 sections. The results of modeling are in general agreement with the commonly accepted reconstructed pattern of the debris flow in 2000 and values obtained by videomaterials.
Proposal of Hazard Connectivity Index for debris flow disaster management
Authors: Kobiyama Masato , Franck Alessandro Gustavo
Published: August 2023

The concept of connectivity and its index have been widely discussed and applied to environmental studies such as ecology, hydrology, geomorphology and hydrosedimentology. Supposing that this concept is very useful also in disaster risk management, we define the hazard connectivity associated to debris flows as the connectivity degree between the debris flow occurrence (trajectory) and the point of interest (location of house, person, and so on). Based on this definition, the Hazard Connectivity Index (HCI) associated to debris flow is proposed as: HCI = L/(x+L), where x is the shortest distance between the debris flow trajectory and the point of interest; and L is the runout distance of the debris flow or just mass movement. The HCI value varies from 0 to 1, being that its higher value indicates larger hazard condition. The HCI application to one case study showed that it can be useful in the analysis of the debris flow related hazard.
Debris flows and debris avalanches initiation and runout susceptibility assessment in Campania region (Italy)
Authors: Tufano Rita , Mazza Davide , Guadagno Francesco Maria , De Vita Pantaleone , Russo Giacomo , Revellino Paola
Published: August 2023

Sectors of the Campania region (southern Italy), where pyroclastic airfall deposits cover carbonate slopes, have frequently experienced debris avalanches and debris flows. These landslides are triggered by heavy rainfall and in the last century caused severe destruction and hundreds of deaths. Their occurrence is controlled by the interaction of several factors, both natural and human induced. The initial failure is linked with the presence of morphological discontinuities such as rocky scarps and road cuts, which interrupt the stratigraphical continuity of an “infinite slope”. Here the main criteria for susceptibility analysis are defined trying to develop a procedure for identify highly-susceptible sources, runout and invasion areas.
Keynote lecture. Modelling flow-landslides impact against protection structures
Authors: Cuomo Sabatino
Published: August 2023

Dynamic impact of flow-like landslides against protection structures calls for a sound understanding of the interaction mechanisms. In fact, despite a large variety of flow-landslides, there is also a significant availability of several types of protection works and many different modelling approaches, which have been customized to the specific classes of flow-landslides and protection structurers. Some remarks are reported below in a design-oriented engineering framework.
Effect of multiple debris flow countermeasures on flow characteristics and topographic changes through real-scale experiment
Authors: Jang Woojae , Kim Beom-Jun , Choi Shin-Kyu , Kwon Tae-Hyuk , Yune Chan-Young
Published: August 2023

In this study, to investigate the effect of multiple countermeasure on the flow characteristics of debris flows, a real-scale experiment was conducted in a natural gully by reproducing a debris flow with a installation of multiple countermeasures. In addition, the topographic changes before and after experiment by debris flow were investigated using UAV-LiDAR. Based on the experiment results, the effect of multiple countermeasures and the topographic changes against the gully erosion and deposition caused by debris flow were also analyzed. The installation of multiple countermeasures significantly decreased the frontal velocity of debris flow. Furthermore, the countermeasure induced the deposition of debris material on the back of the countermeasure.
Coupled Eulerian-Lagrangian Debris Flow Model with Flexible Barrier
Authors: Sha Shiyin , Dyson Ashley P. , Kefayati Gholamreza , Tolooiyan Ali
Published: August 2023

Natural hazards such as large debris flow events can have catastrophic effects on the environment and critical infrastructure, posing a significant threat to human life. Debris flows often exhibit high velocity, high-pressure discharges due to their bulk volume, and the capacity to transport considerable volumes of large rocks, boulders, and woody debris. Although debris flow run-out simulations are commonly performed using hydraulic modelling software, these environments are seldom capable of assessing the interaction between the debris fluid, transported material, and protective structures. In this research, large deformation numerical models are calibrated using input parameters from hydraulic modelling software. Due to the computational cost of the large deformation models involving fluid-solid-structure simulation with flexible net barriers, an equivalent stiffness method is implemented to provide comparable performance through a membrane structure. The Coupled Eulerian-Lagrangian Finite Element method is used to model the impact forces of rocky boulders on the membrane, exhibiting damage characteristics consistent with flexible ring-net protective structures. The Coupled Eulerian-Lagrangian model results highlight the performance of the simplified membrane, as shown through a benchmark simulation of debris flow with boulders.
A new statistical method to assess potential debris flow erosion
Authors: Bertoldi Gabriele , Baggio Tommaso , Bettella Francesco , D’Agostino Vincenzo
Published: August 2023

Debris-flow erosion patterns were investigated for two adjacent catchments, Molinara and Val del Lago creeks (Eastern Alps, Trento Province, Italy), where two debris flows were triggered by an intense storm in the summer of 2010. Both basins have been inactive over the last two centuries. The debris flows were activated by channel and bank erosion under stable bed conditions before the event. The erosive process was analysed by combining a field campaign (two hundred cross sections were surveyed along the creeks) and pre- and post-event LiDAR surveys. Data were analysed by selecting morphologically-homogenous channel reaches and deriving for each reach: erosion depth, creek width, eroded volume and peak discharge. Investigating the frequency distribution of the erosion depth we found out that it follows an EV1 probability distribution. On this basis, a new approach has been proposed to predict event volumes when the expected maximum potential depth erosion is known. The procedure would be of high interest in predicting debris flow volume in mountain channels characterized by long silent periods.
Debris Flow Hazard Mapping Along Linear Infrastructure: An Agent Based Model and GIS Approach
Authors: Knibbs Graham , Guthrie Richard , Wasklewicz Thad
Published: August 2023

Often linear infrastructure, including rail, highways, and pipelines, span large geographic areas intersecting a variety of terrain, predisposing infrastructure to a higher likelihood of geohazard interaction. Debris flow models can be particularly advantageous in remote hazard and risk mapping along linear infrastructure as runout from susceptible slopes may extend considerable distance downslope to a receptor. In this sentiment, a method is developed using an agent-based model, DebrisFlow Predictor, in combination with geographic information software (GIS), to produce regional debris flow hazard and risk profiles along widespread corridors. Thousands of debris flows upslope of a receptor(s) are simulated in the model environment (i.e., model scenarios). Outputs of the modelled scenarios provide probabilistic spatial attributes of debris flow runout and depth across a digital elevation model at a 5m resolution. The outputs of multiple scenarios are mosaiced and corrected to in-situ temporal and spatial debris flow initiation conditions in GIS. The corrected scenario outputs provide a comprehensive hazard profile along the infrastructure alignment, that in turn can facilitate quantified vulnerability and risk calculations. Thousands of modelled debris flows throughout several physiographic regions of Canada and the United States of America, calibrated to local conditions, provide substantive support for a novel methodology to identify key hazard and risk locations to major linear infrastructure.
The contributions of space geodesy to the construction of sustainable cities in Africa and around the world
Authors: Adjagan Kêmy Elary Mahugnon , Adelakoun Jean Raphaël
Published: August 2023

The accelerate urbanisation African cities caused by the massive rural exodus contributed to the demographic boom of these cities. Our cities barely breathe. The swamps of yesterday have become the habitats of today, the marine areas become a refuge by excellence for families newly arrived in the city. This is the birth of precarious neighborhoods with growing land insecurity. The disappearance of marine and coastal biodiversity, the increase in pollution in all its forms; this is where space geodesy comes in. Recognized as one of the great revolutions of Navigation. Space geodesy has made available to territories and continents including the oceans a set of techniques that in their applications participate in the construction and management of sustainable cities in Africa and in the world; it participates through its fields of application in atmospheric monitoring, marine environment monitoring, territorial, climatological to ensure a better life on land, underground, in water and under water. These techniques and application are an urban decision support for the construction and management of sustainable cities; precise geodetic measurements make it possible to assess topography, identify flood zones, with facilitates the installation of resilient infrastructure.
The effect of sustainable and smart planning framework on urban logistics and mobility
Authors: Amar Sara , Amar Youssef Haddou , Hammouche Hicham , Arrihioui Karim
Published: August 2023

Urban planning and design have witnessed an exceptional transformation following the rapid development of information and communication technologies (ICTs). This new era paved the way for the rise of new technical concepts and methods in urban planning where human-computer interaction is at the centre of interest. However, despite this fast evolution, there remains a significant research gap that needs to be addressed. It is essential for urban planners and designers to keep pace with technological advancements while simultaneously securing environment-friendly outcomes and fostering environmental sustainability. In this context, our work focuses on the challenges encountered by urban designers as they seek to transition toward smart, sustainable industrialized cities. Of a special concern is the inclusion of mobility, logistics features and digitalization of city supply chain management, where we consider the management pf physical, information and financial flows in modern urban areas.
Preventing urban traffic congestion using VANET technology in urban area
Authors: Toulni Hamza , Miyara Mounia , Filali Youssef , Koumétio Tékouabou Stéphane Cédric
Published: August 2023

Urban mobility is one of the most important factors in the development of any nation and can act as a strong stimulant for economic expansion. Moreover, the rapid urban population growth in recent years has resulted in a substantial rise in the number of urban vehicles. But, the infrastructure on urban routes frequently isn’t adequate for a big number of urban vehicles. This inadequacy leads to several problems, including road insecurity, time loss and pollution. Congestion is one of the biggest issues and a significant hindrance to the road transportation system. In order to maximize the efficiency of the existing road network infrastructure, one idea is to leverage modern communication technologies to transmit traffic data, including the locations of accidents and risky road conditions. As a result, the congestion prevention system (CPS) presented in this study can assist drivers in improving their travel. CPS would be the best option for cutting down on travel time and fuel usage, avoiding traffic jams and lines, and ensuring that the current road infrastructure is used more effectively. The CPS is based on a methodology that examines accurate and valuable real-time traffic data. Experimental results for reducing urban traffic congestion have been highly encouraging according to the simulation of the system under various scenarios. We intend to include artificial intelligence in our system in future studies to improve it.
Land Use and Urban Sprawl in the Case of the City of Rabat in Morocco: An Integrated Approach Using Remote Sensing, Geospatial Modeling, and Machine Learning
Authors: Boulmani Soufiane , Saadane Abderrahme
Published: August 2023

This document is produced as part of a project of mapping, monitoring and prediction of urban sprawl in the city of Rabat, using algorithms of machine Learning, remote sensing and geographic information system. It therefore aims to determine and monitor the urban sprawl of the city of Rabat, using new Geo-spatial technologies, this socio-economic mechanism is theoretically based on the increase in the horizontal area of the city, and a decrease in population density. On the contrary, the city of Rabat is characterized by a negative growth rate between the years 2004-2014 at about -0.79% different from 1.2% at the national level, and defined by a higher population density of 255 inhabitants per km2, these statistics were directed to a hypothesis that indicates a horizontal confinement of the city of Rabat and reverse immigration to per-urban territories. In addition, this project is mainly aimed at the implementation of a computerized simulation model for the characterization and prediction of the urban expansion of the city of Rabat for 40 years (1990, 2000, 2010, 2020, 2030). To conclude, the city of Rabat has experienced a very slow urban sprawl, thanks to the green belt put in 1971, and the modernization strategy that has been adapted in recent years to eliminate informal housing, in addition to the development of roads and the new TGV railway line, and also to the lack of land use, of which many large villas of several hectares were built. Although this mechanism is moving very slowly, the city of Rabat has had negative consequences on the territory and the environment. So, local authorities need a creative, innovative and intelligent urban planning programme to both eliminate the effects of this mechanism, and build the pillars of the functional city (smart city).