Landscape evolution model
Encyclopedia
A landscape evolution model is a physically based numerical model that simulates changing terrain over the course of time. This can be due to glacial
erosion and deposition; erosion
, sediment transport
, and deposition
in fluvial
systems such as river
s; regolith production
; the movement of material on hill
slopes; more intermittent events such as rockfall
s, debris flow
s, landslide
s, and other surface processes. This can also be due to surface uplift and/or subsidence
. A typical landscape evolution model takes many of these factors into account.
Landscape evolution models are used primarily in the field of geomorphology
. As they improve, they are beginning to be consulted by land managers
to aid in decision making.
The earliest of these models were developed in the 1970s. In these models, water was run across a mesh, and cell elevations were changed in response to calculated erosion.
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
erosion and deposition; erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
, sediment transport
Sediment transport
Sediment transport is the movement of solid particles , typically due to a combination of the force of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained...
, and deposition
Deposition (geology)
Deposition is the geological process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment flowing via gravity, transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of...
in fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...
systems such as river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s; regolith production
Soil production function
Soil production function refers to the rate of bedrock weathering into soil as a function of soil thickness.A general model suggested that the rate of physical weathering of bedrock can be represented as an exponential decline with soil thickness:...
; the movement of material on hill
Hill
A hill is a landform that extends above the surrounding terrain. Hills often have a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit A hill is a landform that extends above the surrounding terrain. Hills...
slopes; more intermittent events such as rockfall
Rockfall
Rockfall or rock-fall refers to quantities of rock falling freely from a cliff face. A rockfall is a fragment of rock detached by sliding, toppling, or falling, that falls along a vertical or sub-vertical cliff, proceeds down slope by bouncing and flying along ballistic trajectories or by rolling...
s, debris flow
Debris flow
A debris flow is a fast moving, liquefied landslide of unconsolidated, saturated debris that looks like flowing concrete. It is differentiated from a mudflow in terms of the viscosity and textural properties of the flow. Flows can carry material ranging in size from clay to boulders, and may...
s, landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
s, and other surface processes. This can also be due to surface uplift and/or subsidence
Subsidence
Subsidence is the motion of a surface as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation...
. A typical landscape evolution model takes many of these factors into account.
Landscape evolution models are used primarily in the field of geomorphology
Geomorphology
Geomorphology is the scientific study of landforms and the processes that shape them...
. As they improve, they are beginning to be consulted by land managers
Land management
Land management is the process of managing the use and development of land resources. Land resources are used for a variety of purposes which may include organic agriculture, reforestation, water resource management and eco-tourism projects.-See also:*Sustainable land management*Acreage...
to aid in decision making.
The earliest of these models were developed in the 1970s. In these models, water was run across a mesh, and cell elevations were changed in response to calculated erosion.