Articles de revues : « 3D Runout Modeling »

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Xu, Xiaorong, Feng Jin, Qicheng Sun, Kenichi Soga et Gordon G. D. Zhou. « Three-dimensional material point method modeling of runout behavior of the Hongshiyan landslide ». Canadian Geotechnical Journal 56, n^o 9 (septembre 2019) : 1318–37. http://dx.doi.org/10.1139/cgj-2017-0638.

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This study presents a field-scale simulation of the Hongshiyan landslide in China. It uses an advanced numerical approach (material point method (MPM)) and a constitutive model (the Drucker–Prager model + μ(I) rheological relation) for the three-dimensional (3D) simulation. The performance of the developed MPM model is validated with laboratory-scale experimental data on granular collapse before being applied to field-scale analyses. ArcGIS data are used to create a 3D MPM model of the soil body with complicated geometry. Although the developed model can describe the multiple phases of granular flow, it focuses on the runout behavior of the landslide in this work. The landslide is assumed to have occurred suddenly due to an earthquake, and global sudden failure rather than progressive failure is modeled. The MPM simulation results match reasonably well with the measured post-earthquake topography (e.g., deposit height of about 120 m and stretch length of about 900 m in the river) and landslide duration of about 1 min. The velocity of the sliding mass increases rapidly during flow, especially in the first 20 s. The velocity profiles along the depth direction at different locations of the sliding body exhibit an exponential distribution similar to that of a Bagnold-type profile, indicating that the sliding body is fully mobilized. The rate-dependent dissipation parameter β used in the model significantly influences the runout behavior (e.g., flow speed, velocity distribution, and deposit shape).

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Tishchenko, Ilya, Gabor Tari, Mohammad Fallah et Jonathan Floodpage. « Submarine landslide origin of a tsunami at the Black Sea coast : Evidence based on swath bathymetry and 3D seismic reflection data ». Interpretation 9, n^o 2 (21 avril 2021) : SB67—SB78. http://dx.doi.org/10.1190/int-2020-0174.1.

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Tsunami waves were observed along the Bulgarian Black Sea coastline on 7 May 2007. The maximum rise and fall of the sea level were 1.2 and 2.0 m, respectively, with wave oscillations between 4 and 8 min. At first, submarine landsliding and then later on atmospheric disturbance were suggested as the cause of the tsunami. Numerical modeling, assuming a landslide displacing 30–60 million m3 material on the slope with a thickness range of more than 20–40 m, could reproduce the main characteristics of the recorded tsunami. In this early model, the landslide initiated on the shelf at a water depth of 100 m with a runout of approximately 20 km into 1000 m water depth. Subsequent and recent numerical modeling suggested that the failure may have initiated on the slope, anywhere between 200 and 1500 m seafloor depth. The runout of the transported sediments in these latest model was at 1850 m water depth. Just a few years after the tsunami, OMV and its joint venture partners, TOTAL and Repsol, acquired modern deepwater data sets in the same area where the submarine landsliding was assumed to occur. These data sets included multibeam swath bathymetry area and 3D reflection seismic data. These data sets offer a possibility to establish the presence of speculative submarine landslide responsible for the tsunami, with its geometry and nature. Our results provide direct evidence for the occurrence of large nonseismic catastrophic sediment failures along the Bulgarian coast. In this study, we illustrate Quaternary submarine landslides on 3D seismic reflection data immediately below the one responsible for the 2007 event; we also briefly point out the potential interpretation pitfall related to sediment waves and mass transport complexes.

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Stark, G. A., et K. S. Moon. « Modeling Surface Texture in the Peripheral Milling Process Using Neural Network, Spline, and Fractal Methods with Evidence of Chaos ». Journal of Manufacturing Science and Engineering 121, n^o 2 (1 mai 1999) : 251–56. http://dx.doi.org/10.1115/1.2831213.

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Modeling texture of milled surfaces using analytic methods requires explicit knowledge of a large number of variables some of which change during machining. These include dynamically changing tool runout, deflection, workpiece material properties, displacement of the workpiece within its fixture and others. Due to the complexity of all factors combined, an alternative approach is presented utilizing the ability of neural networks and fractals to implicitly account for these combined conditions. In the initial model, predicted surface points are first connected using splines to model 3D surface maps. Results are presented over varying several cutting parameters. Then, replacing splines, an improved fractal method is presented that determines fractal characteristics of milled surfaces to model more representative surface profiles on a small scale. The fractal character of surfaces as manifested by the fractal dimension provides evidence of chaos in milling.

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Wei, Li, Hualin Cheng et Zili Dai. « Propagation Modeling of Rainfall-Induced Landslides : A Case Study of the Shaziba Landslide in Enshi, China ». Water 15, n^o 3 (20 janvier 2023) : 424. http://dx.doi.org/10.3390/w15030424.

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Geological disasters, especially landslides, frequently occur in Enshi County, Hubei Province, China. On 21 July 2020, a large-scale landslide occurred in Enshi due to continuous rainfall. The landslide mass blocked the Qingjiang River, formed a dammed lake and caused great damage to surrounding roads and village buildings. In this study, the geomechanical properties of the landslide mass were obtained through field surveys. A three-dimensional topography model of the slope was established using the particle flow code (PFC) and the numerical parameters of the model were calibrated. A 3D discrete element model (DEM) was used to simulate the propagation of Shaziba landslide, and the dynamic behavior of the landslide was divided into five stages. The simulation results show that the landslide movement lasted approximately 1000 s. The maximum average velocity of the landslide reached up to 7.5 m/s and the average runout distance was about 1000 m. The simulated morphology of the landslide deposits was in good agreement with the field data. In addition, the influence of effective modulus on the calculation results was analyzed. The results indicate that the propagation behavior of a landslide and the morphology of landslide deposits are closely related to the effective modulus in the contact model of the PFC3D.

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Žabota, Barbara, Frédéric Berger et Milan Kobal. « The Potential of UAV-Acquired Photogrammetric and LiDAR-Point Clouds for Obtaining Rock Dimensions as Input Parameters for Modeling Rockfall Runout Zones ». Drones 7, n^o 2 (3 février 2023) : 104. http://dx.doi.org/10.3390/drones7020104.

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Rockfalls present a significant hazard to human activities; therefore, their identification and knowledge about potential spatial impacts are important in planning protection measures to reduce rockfall risk. Remote sensing with unmanned aerial vehicles (UAVs) has allowed for the accurate observation of slopes that are susceptible to rockfall activity via various methods and sensors with which it is possible to digitally collect information about the rockfall activity and spatial distributions. In this work, a three-dimensional (3D) reconstruction of rock deposits (width, length, and height) and their volumes are addressed, and the results are used in a rockfall trajectory simulation. Due to the availability of different sensors on the UAV, the aim was also to observe the possible differences in the dimension estimations between photogrammetric and LiDAR (light detection and ranging) point clouds, besides the most traditional method where rock deposit dimensions are measured on the field using a measuring tape. The motivation for reconstructing rock dimensions and volumes was solely for obtaining input parameters into a rockfall model. In order to study the differences between rock-measuring methods, rock dimensions were used as input parameters in a rockfall model, and additionally, modeling results such as propagation probability, maximum kinetic energies, and maximum passing heights were compared. The results show that there are no statistically significant differences between the measurement method with respect to rock dimensions and volumes and when modeling the propagation probability and maximum passing heights. On the other hand, large differences are present with maximum kinetic energies where LiDAR point cloud measurements achieved statistically significantly different results from the other two measurements. With this approach, an automated collection and measurement process of rock deposits is possible without the need for exposure to a risk of rockfall during fieldwork.

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Han, Shi Guo, Jun Zhao et Xiao Feng Zhang. « Surface Topography and Roughness Simulations for 5-Axis Ball-End Milling ». Advanced Materials Research 69-70 (mai 2009) : 471–75. http://dx.doi.org/10.4028/www.scientific.net/amr.69-70.471.

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In five-axis high speed milling of freeform surface with ball-end cutters, unwanted machining results are usually introduced by some error effects. Hence precise modeling and simulation of milled sculptured surfaces topography and roughness is the key to obtain optimal process parameters, satisfactory surface quality and high machining efficiency. In this paper, a predictive model for sculptured surface topography and roughness of ball-end milling is developed. Firstly, a mathematical model including both the relative motion of the cutter-workpiece couple and some influential factors on machined surface quality such as the tool runout, tool deflection and tool wear is proposed, and subsequently the analytical form of the tool swept envelope is derived by means of homogeneous coordinate transformation. Then the minimal z-values of the corresponding points lied in discrete cutting edges model and Z-map workpiece model are used to update the workpiece surface topography and to calculate 3D surface roughness. Finally, the simulation algorithm is realized with Matlab software. A series of machining tests on 3Cr2MoNi steel are conducted to validate the model, and the machined surface topography is found in good accordance with the simulation result.

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Gischig, Valentin S., Oldrich Hungr, Andrew Mitchell et Franck Bourrier. « Pierre3D : a 3D stochastic rockfall simulator based on random ground roughness and hyperbolic restitution factors ». Canadian Geotechnical Journal 52, n^o 9 (septembre 2015) : 1360–73. http://dx.doi.org/10.1139/cgj-2014-0312.

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The use of dynamic computational methods has become indispensable for addressing problems related to rockfall hazard. Although a number of models with various degrees of complexity are available, model parameters are rarely calibrated against observations from rockfall experiments. A major difficulty lies in reproducing the apparent randomness of the impact process related to both ground and block irregularities. Calibration of rigorous methods capable of explicitly modeling trajectories and impact physics of irregular blocks is difficult, as parameter spaces become too vast and the quality of model input and observation data are insufficient. The model presented here returns to the simple “lumped-mass” approach and simulates the characteristic randomness of rockfall impact as a stochastic process. Despite similarities to existing approaches, the model presented here incorporates several novel concepts: (i) ground roughness and particle roughness are represented as a random change of slope angle at impact; (ii) lateral deviations of rebound direction from the trajectory plane at impact are similarly accounted for by perturbing the ground orientation laterally, thus inducing scatter of run-out directions; and (iii) a hyperbolic relationship connects restitution factors to impact deformation energy. With these features, the model is capable of realistically accounting for the influence of particle mass on dynamic behaviour. The model only requires four input parameters, rendering it flexible for calibration against observed datasets. In this study, we calibrate the model against observations from the rockfall test site at Vaujany in France. The model is able to reproduce observed distributions of velocity, jump heights, and runout at observation points. In addition, the spatial distribution of the trajectories and landing points has been successfully simulated. Different parameter sets have been used for different ground materials such as an avalanche channel, a forest road, and a talus cone. Further calibration of the new model against a range of field datasets is essential. This study is part of an extensive calibration program that is still in progress at this first presentation of the method, and focuses on fine-tuning the details of the stochastic process implemented both in two-dimensional (2D) and three-dimensional (3D) versions of the model.

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Honek, David, Zuzana Németová, Silvia Kohnová et Monika Šulc Michalková. « Sensitivity analysis of soil parameters and their impact on runoff-erosion processes ». Pollack Periodica 15, n^o 1 (avril 2020) : 53–64. http://dx.doi.org/10.1556/606.2020.15.1.6.

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Abstract The modeling of soil erosion processes is affected by several factors that reflect the physical-geographic conditions of the study site together with the land use linkage. The soil parameters are significant in the modeling of erosion and also runoff processes. The correct determination of a soil's parameters becomes a crucial part of the model's calibration. This paper deals with a sensitivity analysis of seven soil input parameters to the physically-based Erosion 3D model. The results show the variable influence of each soil parameter. The Erosion 3D model is very sensitive to initial soil moisture, bulk density, and erodibility.

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Shrestha, P., M. Sulis, M. Masbou, S. Kollet et C. Simmer. « A Scale-Consistent Terrestrial Systems Modeling Platform Based on COSMO, CLM, and ParFlow ». Monthly Weather Review 142, n^o 9 (septembre 2014) : 3466–83. http://dx.doi.org/10.1175/mwr-d-14-00029.1.

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A highly modular and scale-consistent Terrestrial Systems Modeling Platform (TerrSysMP) is presented. The modeling platform consists of an atmospheric model (Consortium for Small-Scale Modeling; COSMO), a land surface model (the NCAR Community Land Model, version 3.5; CLM3.5), and a 3D variably saturated groundwater flow model (ParFlow). An external coupler (Ocean Atmosphere Sea Ice Soil, version 3.0; OASIS3) with multiple executable approaches is employed to couple the three independently developed component models, which intrinsically allows for a separation of temporal–spatial modeling scales and the coupling frequencies between the component models. Idealized TerrSysMP simulations are presented, which focus on the interaction of key hydrologic processes, like runoff production (excess rainfall and saturation) at different hydrological modeling scales and the drawdown of the water table through groundwater pumping, with processes in the atmospheric boundary layer. The results show a strong linkage between integrated surface–groundwater dynamics, biogeophysical processes, and boundary layer evolution. The use of the mosaic approach for the hydrological component model (to resolve subgrid-scale topography) impacts simulated runoff production, soil moisture redistribution, and boundary layer evolution, which demonstrates the importance of hydrological modeling scales and thus the advantages of the coupling approach used in this study. Real data simulations were carried out with TerrSysMP over the Rur catchment in Germany. The inclusion of the integrated surface–groundwater flow model results in systematic patterns in the root zone soil moisture, which influence exchange flux distributions and the ensuing atmospheric boundary layer development. In a first comparison to observations, the 3D model compared to the 1D model shows slightly improved predictions of surface fluxes and a strong sensitivity to the initial soil moisture content.

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Sala, Zac, D. Jean Hutchinson et Rob Harrap. « Simulation of fragmental rockfalls detected using terrestrial laser scans from rock slopes in south-central British Columbia, Canada ». Natural Hazards and Earth System Sciences 19, n^o 11 (30 octobre 2019) : 2385–404. http://dx.doi.org/10.5194/nhess-19-2385-2019.

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Abstract. Rockfall presents an ongoing challenge to the safe operation of transportation infrastructure, creating hazardous conditions which can result in damage to roads and railways, as well as loss of life. Rockfall risk assessment frameworks often involve the determination of rockfall runout in an attempt to understand the likelihood that rockfall debris will reach an element at risk. Rockfall modelling programs which simulate the trajectory of rockfall material are one method commonly used to assess potential runout. This study aims to demonstrate the effectiveness of a rockfall simulation prototype which uses the Unity 3D game engine. The technique is capable of simulating rockfall events comprised of many mobile fragments, a limitation of many industry standard rockfall modelling programs. Five fragmental rockfalls were simulated using the technique, with slope and rockfall geometries constructed from high-resolution terrestrial laser scans. Simulated change detection was produced for each of the events and compared to the actual change detection results for each rockfall as a basis for testing model performance. In each case the simulated change detection results aligned well with the actual observed change in terms of location and magnitude. An example of how the technique could be used to support the design of rockfall catchment ditches is shown. Suggestions are made for future development of the simulation technique with a focus on better informing simulated rockfall fragment size and the timing of fragmentation.

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Filipović, Vilim, Thomas Weninger, Lana Filipović, Andreas Schwen, Keith L. Bristow, Sophie Zechmeister-Boltenstern et Sonja Leitner. « Inverse estimation of soil hydraulic properties and water repellency following artificially induced drought stress ». Journal of Hydrology and Hydromechanics 66, n^o 2 (1 juin 2018) : 170–80. http://dx.doi.org/10.2478/johh-2018-0002.

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AbstractGlobal climate change is projected to continue and result in prolonged and more intense droughts, which can increase soil water repellency (SWR). To be able to estimate the consequences of SWR on vadose zone hydrology, it is important to determine soil hydraulic properties (SHP). Sequential modeling using HYDRUS (2D/3D) was performed on an experimental field site with artificially imposed drought scenarios (moderately M and severely S stressed) and a control plot. First, inverse modeling was performed for SHP estimation based on water and ethanol infiltration experimental data, followed by model validation on one selected irrigation event. Finally, hillslope modeling was performed to assess water balance for 2014. Results suggest that prolonged dry periods can increase soil water repellency. Inverse modeling was successfully performed for infiltrating liquids, water and ethanol, withR2and model efficiency (E) values both > 0.9. SHP derived from the ethanol measurements showed large differences in van Genuchten-Mualem (VGM) parameters for the M and S plots compared to water infiltration experiments. SWR resulted in large saturated hydraulic conductivity (Ks) decrease on the M and S scenarios. After validation of SHP on water content measurements during a selected irrigation event, one year simulations (2014) showed that water repellency increases surface runoff in non-structured soils at hillslopes.

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Gharechelou, Saeid, Ryutaro Tateishi et Brian A. Johnson. « A Simple Method for the Parameterization of Surface Roughness from Microwave Remote Sensing ». Remote Sensing 10, n^o 11 (30 octobre 2018) : 1711. http://dx.doi.org/10.3390/rs10111711.

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Generally, the characterization of land surface roughness is obtained from the analysis of height variations observed along transects (e.g., root mean square (RMS) height, correlation length, and autocorrelation function). These surface roughness measurements are then used as inputs for surface dynamics modeling, e.g., for soil erosion modeling, runoff estimation, and microwave remote sensing scattering modeling and calibration. In the past, researchers have suggested various methods for estimating roughness parameters based on ground measurements, e.g., using a pin profilometer, but these methods require physical contact with the land and can be time-consuming to conduct. The target of this research is to develop a technique for deriving surface roughness characteristics from digital camera images by applying photogrammetric and geographical information systems (GIS) analysis techniques. First, ground photos acquired by a digital camera in the field were used to create a point cloud and 3D digital terrain model (DTM). Then, the DTM was imported to a GIS environment to calculate the surface roughness parameter for each field site. The results of the roughness derivation can be integrated with soil moisture for backscattering simulation, e.g., for inversion modeling to retrieve the backscattering coefficient. The results show that the proposed method has a high potential for retrieving surface roughness parameters in a time- and cost-efficient manner. The selection of homogeneous fields and the increased spatial distribution of sites in the study area will show a better result for microwave backscattering modeling.

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Adhikary, Deepak P., Marc Elmouttie, Vincent Lemiale et Brett Poulsen. « Recent advances in the stability assessment of natural and engineered rock slopes ». Journal of Nepal Geological Society 50, n^o 1 (21 décembre 2016) : 65–72. http://dx.doi.org/10.3126/jngs.v50i1.22866.

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Science’s understanding of the failure mechanisms of large natural and engineered slopes has been improved considerably over the past 15 years. Significant improvements have been realized in innovative methods of data acquisition through field measurement and monitoring, as well as numerical modelling techniques. However, inadequate understanding of complex geology and landslide processes means that any interpretation of landslide data remains mostly subjective. This causes major uncertainty in landslide risk assessment. Over the past decade, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO; http://www.csiro.au/) has developed novel techniques to facilitate efficient assessment of rock slope stability. These include SirovisionTM, Siromodel, and three CSIRO numerical codes: CSIRO‑SPH, CSIRO‑DEM and CSIRO‑COSFLOW. SirovisionTM is a geological/geotechnical mapping and analysis system that generates accurate, scaled 3D images of rock faces from stereo photographs of exposed rock surfaces, allowing for rapid rock mass structural mapping. Siromodel is a polyhedral modelling system that reads the SirovisionTM data, generates discrete fracture networks (DFN) and performs polyhedral (rock block) modelling and a first‑pass stability analysis. CSIRO‑SPH, CSIRO‑DEM and CSIRO‑COSFLOW are all used for detailed stress‑deformation analysis of rock slopes; however, each code has its own problem‑specific advantage. CSIRO‑SPH is suited for large deformation problems, and can simulate large scale fluid flow problems, such as modelling a dam breakage. CSIRO‑DEM is suited for rock breakage process analysis, and assessment of the runout distance of failure debris. CSIRO‑COSFLOW is designed specifically for efficient, accurate stress‑deformation analysis of stability of structures on bedded sedimentary rocks, where failures along the preexisting bedding planes and through the intact rock layers occur simultaneously.

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Lu, Xiaohong, Chen Cong, Pengrong Hou, Kai Xv et Steven Y. Liang. « Improved Cutting Force Modelling in Micro-Milling Aluminum Alloy LF 21 Considering Tool Wear ». Applied Sciences 12, n^o 11 (25 mai 2022) : 5357. http://dx.doi.org/10.3390/app12115357.

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Aluminum alloy LF 21 has a strong ability to reflect electromagnetic waves. LF 21 waveguide slit array structure is widely used in waveguide radar antenna. The stiffness of the slit array structure is relatively weak. So, the structure is prone to deformation under the cutting force in the conventional milling process. Micro-milling technology can realize high-precision machining of mesoscale parts/structures and is a potential effective machining technology for the waveguide slit array structure. However, the diameter of the micro-milling cutter is small, and the feed per tooth is comparable to the arc radius of the cutting edge, so the micro-milling cutter is prone to wear. In addition, the effects of elastic recovery of material, the minimum cutting thickness and friction of cutting dead zone on micro-milling force cannot be ignored. A simulation model of micro-milling aluminum alloy LF 21 processes based on DEFORM 3D is built by combining the theory of cutting and the technology of process simulation. Prediction of tool wear is achieved. The quantitative relationship between the arc radius of the cutting edge and tool wear is clarified for the first time. The authors built an improved cutting force model in micro-milling LF 21 considering tool wear and cutter runout with the minimum cutting thickness as the boundary. The validity of the built micro-milling force model is verified by experiments.

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Robiati, Carlo, Giandomenico Mastrantoni, Mirko Francioni, Matthew Eyre, John Coggan et Paolo Mazzanti. « Contribution of High-Resolution Virtual Outcrop Models for the Definition of Rockfall Activity and Associated Hazard Modelling ». Land 12, n^o 1 (6 janvier 2023) : 191. http://dx.doi.org/10.3390/land12010191.

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The increased accessibility of drone technology and structure from motion 3D scene reconstruction have transformed the approach for mapping inaccessible slopes undergoing active rockfalls and generating virtual outcrop models (VOM). The Poggio Baldi landslide (Central Italy) and its natural laboratory offers the possibility to monitor and characterise the slope to define a workflow for rockfall hazard analysis. In this study, the analysis of multitemporal VOM (2016–2019) informed a rockfall trajectory analysis that was carried out with a physical-characteristic-based GIS model. The rockfall scenarios were reconstructed and then tested based on the remote sensing observations of the rock mass characteristics of both the main scarp and the rockfall fragment inventory deposited on the slope. The highest concentration of trajectory endpoints occurred at the very top of the debris talus, which was constrained by a narrow channel, while longer horizontal travel distances were allowed on the lower portion of the slope. To further improve the understanding of the Poggio Baldi landslide, a time-independent rockfall hazard analysis aiming to define the potential runout associated with several rock block volumetric classes is a critical component to any subsequent risk analysis in similar mountainous settings featuring marly–arenaceous multilayer sedimentary successions and reactivated main landslide scarps.

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Bentzen, T. R. « 3D modelling of transport, deposition and resuspension of highway deposited sediments in wet detention ponds ». Water Science and Technology 62, n^o 3 (1 août 2010) : 736–42. http://dx.doi.org/10.2166/wst.2010.363.

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The paper presents results from an experimental and numerical study of flows and transport of primarily particle bound pollutants in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to evaluate the quality of long term simulation based on historical rains series of the pollutant discharges from roads and highways. A three-dimensional hydrodynamic and mud transport model is used for the investigation. The transport model has been calibrated and validated on e.g. experiments in a 30 m long concrete channel with width of 0.8 m and a water depth of approximately 0.8 m and in circular flume experiments in order to reproduce near-bed specific processes such as resuspension and consolidation. With a fairly good agreement with measurements, modelling of hydrodynamics, transport of dissolved pollutants and particles in wet detention ponds is possible with application of a three dimensional RANS model and the advection/dispersion equation taken physical phenomena like wind, waves, deposition, erosion and consolidation of the bottom sediment into account.

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Mernild, Sebastian H., Glen E. Liston, Christopher A. Hiemstra et Konrad Steffen. « Surface Melt Area and Water Balance Modeling on the Greenland Ice Sheet 1995–2005 ». Journal of Hydrometeorology 9, n^o 6 (1 décembre 2008) : 1191–211. http://dx.doi.org/10.1175/2008jhm957.1.

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Abstract SnowModel, a physically based snow-evolution modeling system that includes four submodels—MicroMet, EnBal, SnowPack, and SnowTran-3D—was used to simulate variations in Greenland [including the Greenland Ice Sheet (GrIS)] surface snow and ice melt, as well as water balance components, for 1995–2005. Meteorological observations from 25 stations inside and outside the GrIS were used as model input. Winter and summer mass balance observations, spatial snow depth observations, and snowmelt depletion curves derived from time-lapse photography from the Mittivakkat and Zackenberg glacierized catchments in East Greenland were used to validate the performance of SnowModel. Model results compared well with observed values, confirming the robustness of the model. The yearly modeled GrIS interior nonmelt area differs from satellite observations by a maximum of ∼68 000 km2 (or ∼6%) in 2004, and the lowest uncertainties (<8000 km2, or <1%) occur for the years with the smallest (2005) and most extensive (1996) nonmelt areas. Modeled surface melt occurred at elevations reaching 2950 m MSL for 2005, while the equilibrium line altitude (ELA) fluctuates from 1640 to 600 m MSL. The modeled interannual variability in the nonmelt area also agrees with observation records (R2 = 0.96), yielding simulated GrIS nonmelt covers of 71% for 1996 and 50% for 2005. On average, the simulated nonmelt area decreased ∼6% from 1995 to 2005; this trend is similar to observed values. An average surface mass balance (SMB) storage of 138(±81) km3 yr−1, a GrIS loss of 257(±81) km3 yr−1, and a runoff contribution to the ocean of 392(±58) km3 yr−1 occurred for the period 1995–2005. Approximately 58% and 42% of the runoff came from the GrIS western and eastern drainage areas, respectively. The modeled average specific runoff from the GrIS was 6.71 s−1 km−2 yr−1, which, over the simulation period, represents a contribution of ∼1.1 mm yr−1 to global sea level rise.

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Wang, Gongwen, Shouting Zhang, Changhai Yan, Zhenshan Pang, Hongwei Wang, Zhankui Feng, Hong Dong et al. « Resource-environment joint forecasting using big data mining and 3D/4D modeling in Luanchuan mining district, China ». Earth sciences and subsoil use 44, n^o 3 (30 octobre 2021) : 219–42. http://dx.doi.org/10.21285/2686-9993-2021-44-3-219-242.

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The Fourth generation industrial age and 5G + intelligent communication in the "Fourth Paradigm of Science" in the 21st century provide a new opportunity for research on the relationship between mining development and environmental protection. This paper is based on the theory of metallogenic geodynamics background, metallogenic process and quantitative evaluation and chooses the Luanchuan district as a case study, using deep-level artificial intelligence mining and three/four-dimensional (3D/4D) multi-disciplinary, multi-parameter and multi-scale modeling technology platform of geoscience big data (including multi-dimensional and multi-scale geological, geophysical, geochemical, hyperspectral and highresolution remote sensing (multi-temporal) and real-time mining data), carrying out the construction of 3D geological model, metallogenic process model and quantitative exploration model from district to deposit scales and the quantitative prediction and evaluation of the regional Mo polymetallic mineral resources, the aim is to realize the dynamic evaluation of highprecision 3D geological (rock, structure, hydrology, soil, etc.) environment protection and comprehensive development and utilization of mineral resources in digital and wisdom mines, it provides scientific information for the sustainable development of mineral resources and mine environment in the study area. The research results are summarized as follows: (1) The geoscience big data related to mineral resource prediction and evaluation of district include mining data such as 3D geological modeling, geophysics interpretation, geochemistry, and remote sensing modeling, which are combined with GeoCube3.0 software. The optimization of deep targets and comprehensive evaluation of mineral resources in Luanchuan district (500 km2, 2.5 km deep) have been realized, including 6.5 million tons of Mo, 1.5 million tons of W, and 5 million tons of Pb-Zn-Ag. (2) The 3D geological modeling of geology, mineral deposit, and exploration targeting is related to the mine environment. The data of exploration and mining in the pits of Nannihu – Sandaozhuang – Shangfang deposits and the deep channels of Luotuoshan and Xigou deposits show a poor spatial correlation between the NW-trending porphyryskarn deposits and the ore bodies. The NE-trending faults are usually tensional or tensional-torsional structures formed in the post-metallogenic period, which is the migration pathway of hydrothermal fluid of the related Pb-Zn deposit. There is a risk of groundwater pollution in the high-altitude Pb-Zn mining zones, such as the Lengshui and Bailugou deposits controlled by NE-trending faults are developed outside of porphyry-skarn types of Mo (W) deposits in the Luanchuan area. (3) Construction of mineral resources and environmental assessment and decision-making in intelligent digital mines: 3D geological model is established in large mines and associated with ancient mining caves, pit, and deep roadway engineering in the mining areas to realize reasonable orientation and sustainable development of mining industry. The hyperspectral database is used to construct three-dimensional useful and harmful element models to realize the association of exploration, mining, and mineral processing mineralogy for the recovery of harmful elements (As, Sb, Hg, etc.). 0.5 m resolution Worldview2 images are used to identify the distribution of Fe in the wastewater and slag slurry of important tailings reservoirs, so as to protect surface runoff and soil pollution.

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Beitlerová, Hana, Jonas Lenz, Jan Devátý, Martin Mistr, Jiří Kapička, Arno Buchholz, Ilona Gerndtová et Anne Routschek. « Improved calibration of the Green–Ampt infiltration module in the EROSION-2D/3D model using a rainfall-runoff experiment database ». SOIL 7, n^o 1 (18 juin 2021) : 241–53. http://dx.doi.org/10.5194/soil-7-241-2021.

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Abstract. Soil infiltration is one of the key factors that has an influence on soil erosion caused by rainfall. Therefore, a well-represented infiltration process is a necessary precondition for successful soil erosion modelling. Complex natural conditions do not allow the full mathematical description of the infiltration process, and additional calibration parameters are required. The Green–Ampt-based infiltration module in the EROSION-2D/3D model introduces a calibration parameter “skinfactor” to adjust saturated hydraulic conductivity. Previous studies provide skinfactor values for several combinations of soil and vegetation conditions. However, their accuracies are questionable, and estimating the skinfactors for other than the measured conditions yields significant uncertainties in the model results. This study brings together an extensive database of rainfall simulation experiments, the state-of-the-art model parametrisation method and linear mixed-effect models to statistically analyse relationships between soil and vegetation conditions and the model calibration parameter skinfactor. New empirically based transfer functions for skinfactor estimation significantly improving the accuracy of the infiltration module and thus the overall EROSION-2D/3D model performance are provided in this study. Soil moisture and bulk density were identified as the most significant predictors explaining 82 % of the skinfactor variability, followed by the soil texture, vegetation cover and impact of previous rainfall events. The median absolute percentage error of the skinfactor prediction was improved from 71 % using the currently available method to 30 %–34 % using the presented transfer functions, which led to significant decrease in error propagation into the model results compared to the present method. The strong logarithmic relationship observed between the calibration parameter and soil moisture however indicates high overestimation of infiltration for dry soils by the algorithms implemented in EROSION-2D/3D and puts the state-of-the-art parametrisation method in question. An alternative parameter optimisation method including calibration of two Green–Ampt parameters' saturated hydraulic conductivity and water potential at the wetting front was tested and compared with the state-of-the-art method, which paves a new direction for future EROSION-2D/3D model parametrisation.

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Whitehurst, Daniel, Brianna Friedman, Kevin Kochersberger, Venkat Sridhar et James Weeks. « Drone-Based Community Assessment, Planning, and Disaster Risk Management for Sustainable Development ». Remote Sensing 13, n^o 9 (30 avril 2021) : 1739. http://dx.doi.org/10.3390/rs13091739.

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Accessible, low-cost technologies and tools are needed in the developing world to support community planning, disaster risk assessment, and land tenure. Enterprise-scale geographic information system (GIS) software and high-resolution aerial or satellite imagery are tools which are typically not available to or affordable for resource-limited communities. In this paper, we present a concept of aerial data collection, 3D cadastre modeling, and disaster risk assessment using low-cost drones and adapted open-source software. Computer vision/machine learning methods are used to create a classified 3D cadastre that contextualizes and quantifies potential natural disaster risk to existing or planned infrastructure. Building type and integrity are determined from aerial imagery. Potential flood damage risk to a building is evaluated as a function of three mechanisms: undermining (erosion) of the foundation, hydraulic pressure damage, and building collapse due to water load. Use of Soil and Water Assessment Tool (SWAT) provides water runoff estimates that are improved using classified land features (urban ecology, erosion marks) to improve flow direction estimates. A convolutional neural network (CNN) is trained to find these flood-induced erosion marks from high-resolution drone imagery. A flood damage potential metric scaled by property value estimates results in individual and community property risk assessments.

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Liste, Maria, Manel Grifoll, Ingrid Keupers, Jaak Monbaliu et Manuel Espino. « INCORPORATION OF CONTINENTAL AND URBAN RUN-OFF INTO A COASTAL CIRCULATION MODEL : APPLICATION TO THE CATALAN COAST ». Coastal Engineering Proceedings 1, n^o 33 (14 décembre 2012) : 40. http://dx.doi.org/10.9753/icce.v33.currents.40.

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A 3D hydrodynamical model has been set up to incorporate the continental and urban run-off into the Catalan Coastal waters. Particular attention was paid to introducing correctly the freshwater plumes and attention was also paid to determinate the influence of the land discharge profile with regard to the distributed continental run-off. The model domain includes a small part of the Catalan Coast where the combination of local land topography with torrential rainfall caused considerable local runoff on a short period of time with a large impact on the receiving coastal waters. The Regional Ocean Modeling System (ROMS) simulations were used to examine the dispersal to a freshwater delivery from two relevant event; a low river discharge typical of mean conditions during April 2011 and a high discharge representative of the storm event during March 2011 are considered. We have observed the plume responses to an abrupt change in river discharge. During the mean conditions, low salinity water is concentrated around the rivers mouth while during the flood event, the plume spread offshore in the direction of river water outflow and turned downstream close to the coast. The differences between a simulation including the river outflow as a land forcing and a simulation including river and urban runoff as a land forcing suggested that the urban runoff plays an important role in the spreading and shape of the river plume.

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Gatter, Ricarda, Marco Cavalli, Stefano Crema et Giulia Bossi. « Modelling the dynamics of a large rock landslide in the Dolomites (eastern Italian Alps) using multi-temporal DEMs ». PeerJ 6 (8 novembre 2018) : e5903. http://dx.doi.org/10.7717/peerj.5903.

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Latest advances in topographic data acquisition techniques have greatly enhanced the possibility to analyse landscapes in order to understand the processes that shaped them. High-resolution Digital Elevation Models (DEMs), such as LiDAR-derived ones, provide detailed topographic information. In particular, if multi-temporal DEMs are available, it is possible to carry out a detailed geomorphic change detection analysis. This analysis may provide information about the dynamics of large landslides and may thus, be useful for landslide risk assessments. However, LiDAR-derived DEMs are mostly available only as post-event surveys. The technique is relatively recent, and local or national authorities only started widespread surveys in the last decade. Therefore, it is of a certain interest to analyse the effectiveness of DEMs derived from technical cartography to produce reliable volumetric estimates related to large landslides. This study evaluates the use of a multi-source DEM of Difference (DoD) analysis for the investigation of a large landslide –Le Laste–, which occurred on November 12, 2014 on Mount Antelao (eastern Italian Alps). The landslide initiated as a 365,000 m3rockslide close to the summit of the mountain and transformed into a debris avalanche during its runout. The comparison of pre- and post-event DEMs allowed for the identification and quantification of erosion and deposition areas, and for the estimation of landslide volume. A sound back-analysis of the landslide with the 3D numerical model DAN3D was based on this comparison and on seismic records of the event. These seismic records proved to be remarkably useful, as they allowed for the calibration of the simulated landslide velocity. This ensured the reliability of the model notwithstanding the topographic datasets, intrinsic uncertainties. We found that using a pre-event DEM derived from technical cartography tends to slightly overestimate the volume with respect to the use of the more accurate LiDAR-derived DEM. In recent years, the landslide risk around Mt. Antelao has been increasing alongside the ever-growing population and human activities in the area. Sediment accumulations produced by the Le Laste landslide significantly amplified the debris flow hazard by providing new sediment sources. Therefore, it is crucial to delineate the distribution of this material to enable an adequate debris flow hazard assessment. The material properties derived from the back-analysis of the Le Laste landslide can be used to simulate the runout of possible future events, and to generate reliable hazard zone maps, which are necessary for effective risk mitigation.

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Pei, Qiantong, Jinyu Sheng et Kyoko Ohashi. « Numerical Study of Effects of Winds and Tides on Monthly-Mean Circulation and Hydrography over the Southwestern Scotian Shelf ». Journal of Marine Science and Engineering 10, n^o 11 (9 novembre 2022) : 1706. http://dx.doi.org/10.3390/jmse10111706.

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A nested-grid modelling system is used to quantify effects of winds and tides on the three-dimensional (3D) circulation and hydrography over the southwestern Scotian Shelf (swScS) and surrounding areas in 2018. The performance of the nested-grid modelling system is assessed by comparing model results with observations and reanalysis data. Analysis of model results demonstrates that both winds and tides enhance the vertical mixing and modify the 3D circulation over the swScS. In winter (summer), the wind-induced vertical mixing warms (significantly cools) the sea surface temperature (SST) over the Scotian Shelf (ScS). In addition to intense vertical mixing associated with winter convection, the wind-induced mixing raises the sea surface salinity (SSS) by entraining the relatively salty sub-surface waters with the surface waters. The effect of wind-induced vertical mixing is evident in the upper water columns of ~40 m (~15 m) in February (August) 2018 over the swScS, reflecting the typically stronger wind forcing in winter than in summer. The wind forcing also enhances the seaward spreading of river runoff. Strong tidal mixing and advection also play an important role in affecting the hydrography and density-driven currents over the Bay of Fundy (BoF), Georges Bank (GeB), and swScS. In summer, tides significantly reduce the SST, increase the SSS, and affect large density-driven currents over the BoF, GeB, and swScS. Winds and tides also modify the large-scale ocean circulation, eddies, meanders, and frontal structures in the deep waters off the swScS through the modulation of baroclinic hydrodynamics.

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Turunen, M., E. Turtola, M. T. Vaaja, J. Hyväluoma et H. Koivusalo. « Terrestrial laser scanning data combined with 3D hydrological modeling decipher the role of tillage in field water balance and runoff generation ». CATENA 187 (avril 2020) : 104363. http://dx.doi.org/10.1016/j.catena.2019.104363.

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Barros, Juliana Patrícia Fernandes Guedes, et Josiclêda Domiciano Galvíncio. « Caracterização fisiográfica das bacias hidrográficas do rio Una e Mundaú utilizando dados do LiDAR, Pernambuco 3D ». Revista Brasileira de Geografia Física 15, n^o 5 (14 septembre 2022) : 2671. http://dx.doi.org/10.26848/rbgf.v15.5.p2671-2688.

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Inundações e enchentes, decorrentes de inputs pluviométricos e ocupação desordenada das áreas de interflúvio de bacias hidrográficas, aliadas ao déficit estrutural urbano culminam em danos socias, políticos, econômicos e ambientais. As bacias do rio Una e Mundaú são ocupadas por áreas urbanas e agricultura, que degradam o solo e alteram as características naturais da dinâmica hídrica, desse modo o entendimento e caracterização fisiográfica de bacias com uso do solo propício ao desenvolvimento de problemática hídricas é de suma relevância para o gerenciamento e prevenção da propagação de enchentes e inundações. A construção de modelos hidrológicos que possibilitem a compreensão de como água flui através de uma área e como as mudanças nessa área podem afetar o fluxo, ou seja, padrões de escoamento, infiltração e fluxo de água nas bacias, são de suma importância nesse contexto. Utilizando modelagem hidrológica semiautomática com os dados do sensor LiDAR, imageado pelo projeto PE3D no ano de 2016, foi construído um modelo a fim de extrair informações hídricas utilizando a ferramenta Hydrology. Tendo objetivo de demonstrando a necessidade de modelagem hídrica atualiza, que disponibilize dados fidedignos para planejamento adequado e orientação das tomadas de decisão pelos comitês de bacia e poder público. Physiographic characterization of the Una and Mundaú river basins using data from LIDAR, Pernambuco 3DA B S T R A C TFloods and floods, arising from rainwater and/or occupation of the interfluvial areas of the basins, together with the urban structural deficit, culminate in social, political, economic and environmental damage. The Una and Mundaú river basins are occupied by urban areas and agriculture, which degrade the soil and change the natural characteristics of the water dynamics, thus the understanding and physiographic characterization of basins with land use conducive to the development of water problems is essential relevance to the management and prevention of the spread of floods and floods. The construction of hydrological models that enable the understanding of how water flows through an area and how changes in that area can affect the flow, ie, patterns of runoff, infiltration and water flow in the basins, are of paramount importance in this context. Using semi-automatic hydrological modeling with data from the Lidar sensor, imaged by the PE3D project, a model was built in order to extract water information using the Hydrology tool. Aiming at demonstrating the need for updated water modeling, which provides reliable data for proper planning and guidance in decision-making by basin committees and public authorities.Keywords: floods; hydrological modeling; water resources.

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Fransiska Sisilia Mukti et Nicholaus Wayong Kabelen. « PEMBUATAN DATASET ANIMASI BAHASA ISYARAT UNTUK APLIKASI UMKM DIGITAL BAGI MASYARAKAT TUNA RUNGU WICARA ». Jurnal Seni dan Reka Rancang : Jurnal Ilmiah Magister Desain 5, n^o 1 (1 novembre 2022) : 93–104. http://dx.doi.org/10.25105/jsrr.v5i1.15278.

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Abstract Sign language is the primary tool for people with speech impairment in communicating with the surrounding environment. However, the existence of sign language itself is not fully understood by the wider community, so the space for movement of people with hearing impairments is often limited. It takes a companion such as a sign language expert to be able to translate the surrounding information. Innovations are needed to make it easier for the deaf to communicate with their environment, especially in technology. This research explicitly presents the concept of making a sign language animation video that translates the body movements of experts into a 3D animation which will later be combined as one of the features of artificial intelligence in digital MSME applications using speech-to-text and text-to-animation technology. The process of making animation is carried out in four major stages: data collection (recording of sign language movements from experts), analysis, animation design (through pre-production, production and post-production stages), and evaluation of the results of making videos for users. A series of processes have been carried out, starting from character sketching, modeling, texturing, rigging, script conversion, and motion animation creation to the rendering process; the results obtained are animated characters that are adapted to the personal character of one of the experts and accurate sign language movements. Based on the evaluation results through the distribution of questionnaires to 40 user respondents, it was found that the animated video that had been made had a correctness quality factor value of 94%, a usability quality factor of 97.25%, and a flexibility quality factor of 95.75%. The evaluation results show that creating a sign language movement animation dataset has the appropriate function and purpose for feature development in digital MSME applications.Keywords: animation, sign language, speech deaf, MSME, AI dataset Abstrak Bahasa isyarat menjadi alat bantu utama bagi para penyandang disabilitas tuna rungu wicara dalam berkomunikasi dengan lingkungan sekitar. Namun, keberadaan bahasa isyarat sendiri tidak sepenuhnya dipahami oleh masyarakat luas, sehingga seringkali ruang gerak para penyandang tuna rungu wicara menjadi terbatas. Dibutuhkan adanya pendamping seperti tenaga ahli bahasa isyarat untuk dapat mentranslasikan informasi di sekitarnya. Inovasi baru dibutuhkan untuk menciptakan kemudahan bagi kalangan tuna rungu wicara dalam berkomunikasi dengan lingkungannya, khususnya dalam bidang teknologi. Penelitian ini secara khusus menghadirkan konsep pembuatan video animasi bahasa isyarat yang mentranslasikan gerakan tubuh para tenaga ahli menjadi sebuah animasi 3D yang nantinya akan digabungkan sebagai salah satu fitur kecerdasan buatan pada aplikasi UMKM digital dengan menggunakan teknologi speech-to-text and text-to-animation. Proses pembuatan animasi dikerjakan dalam empat tahapan besar yang meliputi pengumpulan data (perekaman gerakan bahasa isyarat dari tenaga ahli), analisis, perancangan animasi (melalui tahap pra produksi, produksi dan pasca produksi), serta evaluasi hasil pembuatan video kepada pengguna. Serangkaian proses telah dilakukan mulai dari pembuatan sketsa karakter, modelling, texturing, rigging, konversi naskah, pembuatan animasi gerakan hingga proses rendering, didapatkan hasil karakter animasi yang disesuaikan dengan personal karakter dari salah satu tenaga ahli dan gerakan bahasa isyarat yang sesungguhnya. Berdasarkan hasil evaluasi melalui penyebaran kuesioner terhadap 40 responden pengguna, didapatkan hasil bahwa video animasi yang telah dibuat memiliki nilai faktor kualitas correctness sebesar 94%, faktor kualitas usability sebesar 97,25% dan faktor kualitas flexibility sebesar 95,75%. Hasil evaluasi menunjukkan bahwa pembuatan dataset animasi gerakan bahasa isyarat memiliki kesesuaian fungsi dan tujuannya untuk pengembangan fitur pada aplikasi UMKM digital.Kata kunci: animasi, bahasa isyarat, rungu wicara, UMKM, dataset AI

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Bernhardt, M., U. Strasser, G. E. Liston et W. Mauser. « High resolution modelling of snow transport in complex terrain using simulated wind fields ». Cryosphere Discussions 2, n^o 4 (11 juillet 2008) : 513–56. http://dx.doi.org/10.5194/tcd-2-513-2008.

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Abstract. Snow transport is one of the most dominant processes influencing the snow cover accumulation and ablation in high alpine mountain environments. Hence, the spatial and temporal variability of the snow cover is significantly modified with respective consequences on the total amount of water in the snow pack, on the temporal dynamics of the runoff and on the energy balance of the surface. For the presented study we used the snow transport model SnowTran-3D in combination with MM5 (Penn State University – National Center for Atmospheric Research MM5 model) generated wind fields. In a first step the MM5 wind fields were downscaled by using a semi-empirical approach which accounts for the elevation difference of model and real topography, as well as aspect, inclination and vegetation. The target resolution of 30 m corresponds to the resolution of the best available DEM and land cover map. For the numerical modelling, data of six automatic meteorological stations were used, comprising the winter season (September–August) of 2003/04 and 2004/05. In addition we had automatic snow depth measurements and periodic manual measurements of snow courses available for the validation of the results. In this paper we describe the downscaling of the wind fields and discuss the results of the snow transport simulations with respect to the measurements and remotely sensed data.

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Hasholt, B., G. E. Liston et N. T. Knudsen. « Snow-Distribution Modelling in the Ammassalik Region, South East Greenland ». Hydrology Research 34, n^o 1-2 (1 février 2003) : 1–16. http://dx.doi.org/10.2166/nh.2003.0025.

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The Ammassalik region is characterized by a strong alpine relief, with altitudes up to 1,000 m. Glaciers are located mainly on the western side of ridges. The climate is low arctic, with annual precipitation amounts of more than 1,000 mm, which falls mainly as snow. Furthermore very strong storms occur frequently throughout the region. All together these factors support strong snow redistribution by wind, which likely explains the glacier locations, and also explains the observed regional runoff differences. The aim of this study is to apply the Liston & Sturm snow-transport model (SnowTran-3D) to elucidate the snow distribution according to the actual climatic conditions. A digital terrain model was used to determine the terrain forcing of the wind field. Precipitation data from the Ammassalik meteorological station were corrected for aerodynamic errors and orographic effects. Wind, temperature and humidity were obtained from a station located on a nunatak 515 m.a.s.l. at the equilibrium line on the Mittivakkat Glacier. The recorded winter accumulation (balance) of snow on the glacier was used for model calibration and testing. Significant snow transport from east-facing slopes to west-facing slopes was confirmed by the model. The drift accumulations were greatest at the head of the glacier, just on the lee side of the ridge east of the glacier. In some areas, as much as 10% of the precipitation was returned to the atmosphere by blowing-snow sublimation. An average snow water equivalent of 113 cm was obtained (not including some minor areas having snow depths as great as 4 m). These results compare well with glacier observations of 114 cm collected in May 1998 (during the field survey the 4 m areas are omitted because of crevasse hazards). Future work will use the model to test scenarios that include changes in wind regime. 1

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Raghavendra Kumar, R., et Rajiv Gupta. « Stability Analysis of Directional Tunnel in Sandy Soil ». IOP Conference Series : Materials Science and Engineering 1197, n^o 1 (1 novembre 2021) : 012008. http://dx.doi.org/10.1088/1757-899x/1197/1/012008.

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Abstract In recent times, water storage is becoming a confronting task because of the depletion of water resources worldwide. Domestic rainwater harvesting and human-made structures for water procurement achieved significance because of the increase in intermittent water accessibility. In turn, functional water infrastructures fetch prominence in the wake of constructive coordination among the communities in a locality. Low water security and losses through evaporation observed by practising different rainwater harvesting methods create a research gap to construct water infrastructure in rural areas to procure water productively. The current research work represents the model of a water storage structure, named directional tunnel (DT), which is placed below the ground level in a declination, as it reduces evaporation and temperature, thus storing rainwater for longer days. DT stores runoff and rainwater collected from the rooftop of multiple houses in a selected locality. The detailed working of the DT is discussed using Building Information Modelling (BIM) concept. Combined with the engineering geological characteristics, the DT’s stability during water storage comes into the picture as the whole structure interacts with the soil. The current study also focuses on the behaviour of DT with respect to sandy soil using PLAXIS 3D software, and the results are interpreted for practical viability.

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Guo, Qiang, Wenbo wang, Yan Jiang et Yuwen Sun. « 3D Surface Topography Prediction in the Five-Axis Milling of Plexiglas and Metal Using Cutters with Non-Uniform Helix and Pitch Angles Combining Runout ». Journal of Materials Processing Technology, janvier 2023, 117885. http://dx.doi.org/10.1016/j.jmatprotec.2023.117885.

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Liu, Yong, Xuejian Chen et Miao Hu. « Three-dimensional large deformation modelling of landslides in spatially variable and strain-softening soils subjected to seismic loads ». Canadian Geotechnical Journal, 1 septembre 2022. http://dx.doi.org/10.1139/cgj-2022-0106.

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Landslide is a common dynamic large-deformation disaster of mobilized soils, which poses a serious threat to the lives and economic properties of surrounding people. Both the strain-softening effect and spatial variability of soil are reported to have significant impacts on landslide behaviors. This study investigated the coupled effect of strain softening and spatial variability on the occurrence, evolution, and runout behavior of landslides induced by seismic loads, using three-dimensional (3D) large-deformation finite-element method. The results show that both the strain-softening behavior and spatial variability of soil dramatically affect the sliding velocity and runout distance. Their coupled effect further weakens the soil strength, resulting in a larger runout distance. Secondly, the runout distance in the 3D deterministic analysis is always smaller than the minimum value in the corresponding random analysis, which completely differs from the result from the two-dimensional (2D) analysis. This finding indicates that 2D analysis can result in a conservative estimation on the runout distance for spatially variable soils and highlights the advantages of 3D modelling on landslides. Thirdly, a linear formula was proposed to quantify the runout distance based on the horizontal peak acceleration, which can provide some guidelines for the safety design in practical slope engineering.

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Wang, Liang, Xue Zhang, Qinghua Lei, Stelios Panayides et Stefano Tinti. « A three-dimensional particle finite element model for simulating soil flow with elastoplasticity ». Acta Geotechnica, 28 juin 2022. http://dx.doi.org/10.1007/s11440-022-01618-1.

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AbstractSoil flow is involved in many earth surface processes such as debris flows and landslides. It is a very challenging task to model this large deformational phenomenon because of the extreme change in material configurations and properties when soil flows. Most of the existing models require a two-dimensional (2D) simplification of actual systems, which are however three-dimensional (3D). To overcome this issue, we develop a novel 3D particle finite element method (PFEM) for direct simulation of complex soil flows in 3D space. Our PFEM model implemented in a fully implicit solution framework based on a generalised Hellinger–Reissner variational principle permits the use of a large time step without compromising the numerical stability. A mixed quadratic-linear element is used to avoid volumetric locking issues and ensure computational accuracy. The correctness and robustness of our 3D PFEM formulation for modelling large deformational soil flow problems are demonstrated by a series of benchmarks against analytical or independent numerical solutions. Our model can serve as an effective tool to support the assessment of catastrophic soil slope failures and subsequent runout behaviours.

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Muftah, H., T. S. L. Rowan et A. P. Butler. « Towards open-source LOD2 modelling using convolutional neural networks ». Modeling Earth Systems and Environment, 13 mai 2021. http://dx.doi.org/10.1007/s40808-021-01159-8.

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AbstractThe aim of this paper is to classify and segment roofs using vertical aerial imagery to generate three-dimensional (3D) models. Such models can be used, for example, to evaluate the rainfall runoff from properties for rainwater harvesting and in assessing solar energy and roof insulation options. Aerial orthophotos and building footprints are used to extract individual roofs and bounding boxes, which are then fed into one neural network for classification and then another for segmentation. The approach initially implements transfer learning on a pre-trained VGG16 model. The first step achieves an accuracy of 95.39% as well as a F1 score of 95%. The classified images are segmented using a fully convolutional network semantic segmentation model. The mask of the segmented roof planes is used to extract the coordinates of the roof edges and the nexus points using the Harris corner detector algorithm. The coordinates of the corners are then used to plot a 3D Level of Detail 2 (LOD2) representation of the building and the roof height is determined by calculating the maximum and minimum height of a Digital Surface Model LiDAR point cloud and known building height data. Subsequently the wireframe plot can be used to compute the roof area. This model achieved an accuracy of 80.2%, 96.1%, 96.0%, 85.1% and 91.1% for flat, hip, gable, cross-hip and mansard roofs, respectively.

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Pesci, María Herminia, Kilian Mouris, Stefan Haun et Kristian Förster. « Assessment of uncertainties in a complex modeling chain for predicting reservoir sedimentation under changing climate ». Modeling Earth Systems and Environment, 11 février 2023. http://dx.doi.org/10.1007/s40808-023-01705-6.

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AbstractLong-term predictions of reservoir sedimentation require an objective consideration of the preceding catchment processes. In this study, we apply a complex modeling chain to predict sedimentation processes in the Banja reservoir (Albania). The modeling chain consists of the water balance model WaSiM, the soil erosion and sediment transport model combination RUSLE-SEDD, and the 3d hydro-morphodynamic reservoir model SSIIM2 to accurately represent all relevant physical processes. Furthermore, an ensemble of climate models is used to analyze future scenarios. Although the capabilities of each model enable us to obtain satisfying results, the propagation of uncertainties in the modeling chain cannot be neglected. Hence, approximate model parameter uncertainties are quantified with the First-Order Second-Moment (FOSM) method. Another source of uncertainty for long-term predictions is the spread of climate projections. Thus, we compared both sources of uncertainties and found that the uncertainties generated by climate projections are 408% (for runoff), 539% (for sediment yield), and 272% (for bed elevation in the reservoir) larger than the model parameter uncertainties. We conclude that (i) FOSM is a suitable method for quantifying approximate parameter uncertainties in a complex modeling chain, (ii) the model parameter uncertainties are smaller than the spread of climate projections, and (iii) these uncertainties are of the same order of magnitude as the change signal for the investigated low-emission scenario. Thus, the proposed method might support modelers to communicate different sources of uncertainty in complex modeling chains, including climate impact models.

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Irvine, Kim, Ho Huu (Josh) Loc, Chansopheaktra Sovann, Asan Suwanarit, Fa Likitswat, Ranjna Jindal, Thammarat Koottatep et al. « Bridging the Form and Function Gap in Urban Green Space Design through Environmental Systems Modeling ». Journal of Water Management Modeling, 2021. http://dx.doi.org/10.14796/jwmm.c476.

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Using a case study approach from past projects in Singapore, Australia, Cambodia, Thailand and Vietnam, we examine the benefits, but also some of the challenges, to implementing green space in urban design. Green space can have multiple physical and psychological wellbeing benefits, as well as environmental benefits, including urban runoff quantity and quality management, urban heat island abatement, air quality improvement, and noise reduction. Water sensitive urban design (WSUD) can be an important element of green space design and here we explore how modeling of ecosystem services and dynamic modeling of WSUD can help to facilitate sound planning and management decision making in support of green space implementation. As we illustrate with examples for Australia, Singapore and Cambodia, we believe that application of an urban ecosystem services modeling approach can elucidate environmental benefits of urban green space that otherwise may not be considered. Engineers may include dynamic modeling of WSUD in support of an urban master plan, or urban redevelopment, but generally urban planners are less conversant in applying models. We discuss some of the challenges to integrating multidisciplinary visioning and modeling of green space design and performance evaluation through our experience with a stormwater and wastewater design study for Cha Am, Thailand, that included landscape architecture and engineering classes at Thammasat University, Mahidol University, and AIT. Through a case study of Phnom Penh, we illustrate how modeling and 3D visualization can be used to effectively explore the benefits of green space. We conclude that a user-friendly decision support system is needed to integrate modeling and visualization tools and thereby bridge the gap between form and function in urban green space design.

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Dohnal, Michal, Jaromír Dušek, Tomáš Vogel, Milena Císlerová, Ľubomír Lichner et Vlasta Štekauerová. « Ponded infiltration into soil with biopores — field experiment and modeling ». Biologia 64, n^o 3 (1 janvier 2009). http://dx.doi.org/10.2478/s11756-009-0078-7.

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AbstractPreferential movement of water in macropores plays an important role when the process of ponded infiltration in natural porous systems is studied. For example, the detailed knowledge of water flow through macropores is of a major importance when predicting runoff responses to rainfall events. The main objectives of this study are to detect preferential movement of water in Chernozem soil and to employ numerical modeling to describe the variably saturated flow during a field ponded infiltration experiment. The infiltration experiment was performed at the Macov experimental station (Calcari-Haplic Chernozem in Danubian Lowland, Slovakia). The experiment involved single ring ponded infiltration. At the quasi steady state phase of the experiment dye tracer was added to the infiltrating water. Then the soil profile was excavated and the penetration pattern of the applied tracer was recorded. The abundance of biopores as a product of fauna and flora was found. To quantify the preferential flow effects during the infiltration experiment, three-dimensional axisymmetric simulations were carried out by a two-dimensional dual-continuum numerical model. The water flow simulations based on measured hydraulic characteristics without consideration of preferential flow effects failed to describe the infiltration experiment adequately. The 3D axisymmetric simulation based on dual-permeability approach provided relatively realistic space-time distribution of soil water pressure below the infiltration ring.

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« Using inverse modeling to estimate parameter values for three dimensional transport of contaminants in Lake Ontario ». Issue 1 16, n^o 1 (2 décembre 2013) : 124–35. http://dx.doi.org/10.30955/gnj.001076.

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<p>The Great Lakes form an important freshwater drinking source for many urban areas surrounding the Lakes but also provide a sink for pollutants and runoff. Consequently introducing new drinking water intakes into any of these water bodies requires investigation into local pollutant sources and their transport in order to determine the most appropriate location and depth of any new intake. Two methods involving the calibration of a 3D wind driven transport model, to spill data collected over a 4 week period, are described. The methods include the traditional trial and error approach and the application of a nonlinear inverse model to optimize parameter estimates. Results show that calibration using the inverse modeling approach was an improvement over the traditional trial and error approach by providing a clear quantitative analysis of parameter sensitivity and importance, and ultimately yielding a better fit between observed and simulated data. The calibrated three-dimensional model was ultimately applied to assess the impacts of a potential local pollutant source to several proposed new drinking water intakes located along the north shore of Lake Ontario.</p>

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Khayyun, Thair Sharif, et Hasan Hadi Mahdi. « Predicted Climate Change Impact on Groundwater Flow for the Upper Zone of Iraqi Aquifers ». Journal of Southwest Jiaotong University 55, n^o 2 (2020). http://dx.doi.org/10.35741/issn.0258-2724.55.2.17.

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A 3D groundwater steady-state flow conceptual model was built for all of Iraq using a MODFLOW package integrated with the Groundwater Modeling System to simulate the groundwater movement and flow direction for the upper zone of Iraq as well as to compute the water budget for all aquifer systems in Iraq. This model was run for seven scenarios of climate change conditions for the period of 2020–2050. A Representative Concentration Pathway model (RCP4.5) was used for the prediction of future rainfall over the next 31 years. The results showed that the decline in rainfall will be 6.247% due to climate change impacts. The decline in rainfall will cover two-thirds of the area of Iraq. Seven scenarios simulating groundwater flow behavior showed that decreased soil moisture content will significantly reduce groundwater recharge and increase runoff. A decline in groundwater levels by an average of 1.8–4.8 m will occur for the upper zone of Iraqi aquifers over the next 31 years. These results will help Iraqi decision-makers improve water resource management.

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ROȘCA,, Bogdan, Ionuț VASILINIUC et George TOPȘA. « Models for Estimating Soil Erosion in the Middle and Lower VasluieÅ£ Basin ». Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture 69, n^o 1 (11 décembre 2012). http://dx.doi.org/10.15835/buasvmcn-agr:8674.

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In this paper, several models of estimating soil erosion have been compared, with a special emphasis on pixel-based calculation of soil loss. The paper describes and analyzes the differences between USLE, RUSLE 3D and USPED models, with an accent on theÂ formula proposed by MoÅ£oc et alÂ Â . (1975). The materials used in the modeling process were the digital elevation model (DEM) at a 10m resolution, 1:10,000 soil maps created by OSPA Vaslui including the analytical data attached, ortophotoplans and LANDSAT images for C factor extraction. For each model, the necessary layers have been derived according to specifications provided by the original authors. Moreover, a review of the Romanian literature on the subject has been conducted. After calculating soil erosion according to each model, results were compared with the absolute values measured by various research centers and values obtained by other authors. It has been found that the values obtained are comparable with those of other authors, and even with those from runoff plots. The main conclusion of the paper is that the Romanian version of the USLE equation needs to be updated, and some factors such as rainfall erosivity and soil erodability re-evaluated. The use of such a version would make all the applicatÂ ionsâ€™ results comparable.

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Fissel, David B., Yuehua Lin, Alison Scoon, Jose Lim, Leslie Brown et Ryan Clouston. « The variability of the sediment plume and ocean circulation features of the Nass River Estuary, British Columbia ». Satellite Oceanography and Meteorology 2, n^o 2 (28 décembre 2017). http://dx.doi.org/10.18063/som.v2i2.316.

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The Nass River discharges into Nass Bay and Iceberg Bay, which are adjoining tidal inlets located within the northern inland waters of British Columbia, Canada. After the Skeena River, the Nass River is the second longest river within northern British Columbia, which discharges directly into Canadian waters of the Pacific Ocean. It is also supports one of the most productive salmon fisheries in northern British Columbia. The Nass River discharges into the eastern end of Nass Bay. Nass Bay, in turn feeds into Portland Canal and the fresh surface waters then flows westward to the Pacific Ocean via Dixon Entrance. The tides in Northern British Columbia are very large with a tidal height range of just over 7 m. Nass Bay is a shallow inlet of less than 10 km in length with typical water depths of than 10 m or less. The existing knowledge of oceanographic processes in Nass and Iceberg Bays was rudimentary until three years ago, when the first modern oceanographic measurements were obtained. In this study, the seasonal and tidal variability of the lateral extent of the Nass River surface plume is mapped from analyses of Landsat satellite data spanning the period from 2008 to 2015. A high resolution coupled three dimensional (3D) hydrodynamic model was developed and implemented, within the widely used and accepted Delft3D modeling framework, which was forced and validated using recent 2013-2016 in-situ oceanographic measurements. The combined satellite and numerical modeling methods are used to study the physical oceanographic and sediment transport regime of Nass and Iceberg Bays and the adjoining waters of Portland Inlet and Observatory Inlet. The ocean circulation of Nass and Iceberg Bays was found to be dominated by tidal currents, and by the highly seasonal and variable Nass River freshwater discharges. Complex lateral spatial patterns in the tidal currents occur due to the opening of the southwestern side of Nass Bay onto the deeper adjoining waters of Iceberg Bay. Surface winds are limited to a secondary role in the circulation variability. The sediment dynamics of the Nass Bay system features a very prominent surface sediment plume present from the time of freshet in mid-spring through to large rainfall runoff events in the fall. The time-varying turbidity distribution and transport paths of the Nass River sediment discharges in the study area were characterized using the model results combined with an analysis of several high-resolution multi-year Landsat satellite data sets.

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Neumann, Alexey, Feifei Dong, Yuko Shimoda, Carlos Arnillas, Aisha Javed, Diana Paredes, Cindy Yang et al. « A REVIEW OF THE CURRENT STATE OF PROCESS-BASED AND DATA-DRIVEN MODELLING : GUIDELINES FOR LAKE ERIE MANAGERS AND WATERSHED MODELLERS ». Environmental Reviews, 23 mars 2021. http://dx.doi.org/10.1139/er-2020-0070.

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We present a comprehensive evaluation of eleven process-based models to characterize the water cycle, nutrient fate and transport within a watershed context, and to find a robust and replicable way to optimize the modelling strategy for the Lake Erie watershed. Our primary objective is to review the conceptual/technical strengths and weaknesses of the individual models to reproduce surface runoff, groundwater, sediment transport, nutrient cycling, channel routing and collectively guide the management in Lake Erie Basin. Our analysis suggests that the available models either opted for simpler approximations of the multifaceted, non-linear dynamics of nutrient fate and transport and instead placed more emphasis on the advanced representation of the water cycle, or introduced a greater degree of biogeochemical complexity but simplified their strategies to recreate the role of critical hydrological processes. Notwithstanding its overparameterization problem, MIKE-SHE provides the most comprehensive 3D representation of the interplay between surface and subsurface hydrological processes with a fully dynamic description, whereby we can recreate the solute transport that infiltrates from the surface to the unsaturated soil layer and subsequently percolates into the saturated layer. Likewise, the physically based submodels designed to represent the sediment detachment and erosion/removal processes (DWSM, HBV-INCA, HSPF, HYPE and MIKE-SHE), offer a distinct alternative to USLE-type empirical strategies. The ability to explicitly simulate the daily plant growth (SWAT and APEX) coupled with a dynamic representation of soil P processes can be critical when evaluating the long-term watershed responses to various agricultural management strategies. While our propositions seem to favor the consideration of complex models that may lack the commensurate knowledge to properly characterize the underlying processes, we contend this issue can be counterbalanced by the joint consideration of simpler empirical models, under an ensemble framework, that can both constrain the plausible values of individual processes and validate macroscale patterns. Finally, our study discusses critical facets of the watershed modelling work in Lake Erie, such as the role of legacy P, the challenges in reproducing spring-freshet or event-flow conditions, and the dynamic characterization of water/nutrient cycles under the non-stationarity of a changing climate.

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