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TITAN2D
TITAN2D is a geoflow simulation software application, intended for geological researchers. It is distributed as free software. Overview TITAN2D is a free software application developed by the Geophysical Mass Flow Group at the State University of New York (SUNY) at Buffalo. TITAN2D was developed for the purpose of simulating granular flows (primarily geological mass flows such as debris avalanches and landslides) over digital elevation models (DEM)s of natural terrain. The code is designed to help scientists and civil protection authorities assess the risk of, and mitigate, hazards due to dry debris flows and avalanches. TITAN2D combines numerical simulations of a flow with digital elevation data of natural terrain supported through a Geographical Information System (GIS) interface such as GRASS. TITAN2D is capable of multiprocessor runs. A Message Passing Interface (MPI) Application Programming Interface (API) allows for parallel computing on multiple processors, which ef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titan2d-mod
Titan2d-mod (titan 3.1.1, 2016) is a free open source code to simulate dry granular avalanche flows over natural terrain, modified from an early version (titan 3.0.0, 2011) of TITAN2D code. It is available in the contributor's home page http://lsec.cc.ac.cn/~lyuan/code.html, or searchable in th Sourceforgewebsite. Overview The code allows for several variants of the shallow granular flow model,A.K. Patra, A.C. Bauer, C.C. Nichita, E.B. Pitman, M.F. Sheridan, M. Bursik, B. Rupp, A. Webber, A. Stinton, L. Namikawa, and C. Renschler, ''Journal of Volcanology and Geophysical Research'', 139 (2005) 1-21. and the governing equations are discretized on Cartesian meshes and solved with the Davis predictor-corrector Godunov type method. The code structures and usage are the same as earlier TITAN2D versions (see user's manual [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lahar
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extremely destructive: they can flow tens of metres per second, they have been known to be up to deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the latter of which killed thousands of people in the town of Armero. Etymology The word ''lahar'' is of Javanese origin. Berend George Escher introduced it as a geological term in 1922. Description The word ''lahar'' is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and 60% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colima (volcano)
Colima (), officially the Free and Sovereign State of Colima ( es, Estado Libre y Soberano de Colima), is one of the 31 states that make up the 32 Federal Entities of Mexico. It shares its name with its capital and main city, Colima. Colima is a small state of Western Mexico on the central Pacific coast, and includes the four oceanic Revillagigedo Islands. Mainland Colima shares borders with the states of Jalisco and Michoacán. In addition to the capital city of Colima, the main cities are Manzanillo and Tecomán. Colima is the fourth smallest state in Mexico and has the second smallest population, but has one of Mexico's highest standards of living and the lowest unemployment. However, Colima is also the state with the highest murder rate per capita and one of the highest crime rates, due to its ports being a contested area for cartels. Geography The state covers a territory of 5,455 km2 and is the fourth smallest federal entity after Tlaxcala, Morelos and the Fede ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Mesh Refinement
In numerical analysis, adaptive mesh refinement (AMR) is a method of adapting the accuracy of a solution within certain sensitive or turbulent regions of simulation, dynamically and during the time the solution is being calculated. When solutions are calculated numerically, they are often limited to pre-determined quantified grids as in the Cartesian plane which constitute the computational grid, or 'mesh'. Many problems in numerical analysis, however, do not require a uniform precision in the numerical grids used for graph plotting or computational simulation, and would be better suited if specific areas of graphs which needed precision could be refined in quantification only in the regions requiring the added precision. Adaptive mesh refinement provides such a dynamic programming environment for adapting the precision of the numerical computation based on the requirements of a computation problem in specific areas of multi-dimensional graphs which need precision while leaving the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landslides
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides. Gravity is the primary driving force for a landslide to occur, but there are other factors affecting slope stability that produce specific conditions that make a slope prone to failure. In many cases, the landslide is triggered by a specific event (such as a heavy rainfall, an earthquake, a slope cut to build a road, and many others), although this is not always identifiable. Causes Landslides occur when the slope (or a portion of it) undergoes some processes that change its condition from stable to unstable. This is essentially due to a decrease in the shear strength of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debris Flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally have bulk densities comparable to those of rock avalanches and other types of landslides (roughly 2000 kilograms per cubic meter), but owing to widespread sediment liquefaction caused by high pore-fluid pressures, they can flow almost as fluidly as water. Debris flows descending steep channels commonly attain speeds that surpass 10 m/s (36 km/h), although some large flows can reach speeds that are much greater. Debris flows with volumes ranging up to about 100,000 cubic meters occur frequently in mountainous regions worldwide. The largest prehistoric flows have had volumes exceeding 1 billion cubic meters (i.e., 1 cubic kilometer). As a result of their high sediment concentrations and mobility, debris flows can be very des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of but is capable of reaching speeds up to . The gases and tephra can reach temperatures of about . Pyroclastic flows are the most deadly of all volcanic hazards and are produced as a result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Origin of term The word ''pyroclast'' is derived from the Greek (''pýr''), meaning "fire", and (''klastós''), meaning "broken in pieces". A name for pyroclastic flows which glow red in the dark is (French, "burning cloud"); this was notably used to describe the disastrous 1902 eruption of Mount Pelée on Martinique, a French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Hazards
A geologic hazard or geohazard is an adverse geologic condition capable of causing widespread damage or loss of property and life. These hazards are geological and environmental conditions and involve long-term or short-term geological processes. Geohazards can be relatively small features, but they can also attain huge dimensions (e.g., submarine or surface landslide) and affect local and regional socio-economics to a large extent (e.g., tsunamis). Sometimes the hazard is instigated by the careless location of developments or construction in which the conditions were not taken into account. Human activities, such as drilling through overpressured zones, could result in significant risk, and as such mitigation and prevention are paramount, through improved understanding of geohazards, their preconditions, causes and implications. In other cases, particularly in montane regions, natural processes can cause catalytic events of a complex nature, such as an avalanche hitting a lak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Godunov's Scheme
In numerical analysis and computational fluid dynamics, Godunov's scheme is a conservative numerical scheme, suggested by S. K. Godunov in 1959, for solving partial differential equations. One can think of this method as a conservative finite-volume method which solves exact, or approximate Riemann problems at each inter-cell boundary. In its basic form, Godunov's method is first order accurate in both space and time, yet can be used as a base scheme for developing higher-order methods. Basic scheme Following the classical finite-volume method framework, we seek to track a finite set of discrete unknowns, : Q^_i = \frac \int_ ^ q(t^n, x)\, dx where the x_ = x_ + \left( i - 1/2 \right) \Delta x and t^n = n \Delta t form a discrete set of points for the hyperbolic problem: : q_t + ( f( q ) )_x = 0, where the indices t and x indicate the derivations in time and space, respectively. If we integrate the hyperbolic problem over a control volume _, x_ we obtain a me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperbolic Partial Differential Equation
In mathematics, a hyperbolic partial differential equation of order n is a partial differential equation (PDE) that, roughly speaking, has a well-posed initial value problem for the first n-1 derivatives. More precisely, the Cauchy problem can be locally solved for arbitrary initial data along any non-characteristic hypersurface. Many of the equations of mechanics are hyperbolic, and so the study of hyperbolic equations is of substantial contemporary interest. The model hyperbolic equation is the wave equation. In one spatial dimension, this is : \frac = c^2 \frac The equation has the property that, if ''u'' and its first time derivative are arbitrarily specified initial data on the line (with sufficient smoothness properties), then there exists a solution for all time ''t''. The solutions of hyperbolic equations are "wave-like". If a disturbance is made in the initial data of a hyperbolic differential equation, then not every point of space feels the disturbance at once. Rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Computing
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling.S.V. Adve ''et al.'' (November 2008)"Parallel Computing Research at Illinois: The UPCRC Agenda" (PDF). Parallel@Illinois, University of Illinois at Urbana-Champaign. "The main techniques for these performance benefits—increased clock frequency and smarter but increasingly complex architectures—are now hitting the so-called power wall. The computer industry has accepted that future performance increases must largely come from increasing the number of processors (or cores) on a die, rather than m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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