What does debris flow mean?

What is the meaning of debris flow?

Debris flows are fast-moving landslides that are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. They occur in a wide variety of environments throughout the world, including all 50 states and U.S. Territories.

Why do debris flows occur?

Debris flows can be triggered by intense rainfall or snowmelt, by dam-break or glacial outburst floods, or by landsliding that may or may not be associated with intense rain or earthquakes.

What is debris flow mud flow?

Debris and mud flows are a combination of fast moving water and a great volume of sediment and debris that surges down a slope with tremendous force. The consistency is similar to pancake batter. They are similar to flash floods and may occur suddenly without time for adequate warning.

Is an example of debris flow?

Here are a few examples: Addition of Moisture: A sudden flow of water from heavy rain, or rapid snowmelt, can be channeled over a steep valley filled with debris that is loose enough to be mobilized. The water soaks down into the debris, lubricates the material, adds weight, and triggers a flow.

Does debris flow have water?

A debris flow is a mixture of water and particles driven down a slope by gravity. They typically consist of unsteady, non-uniform surges of mixtures of muddy water and high concentrations of rock fragments of different shapes and sizes.

What is the difference between an earth flow and a debris flow?

A debris flow is the movement of a water-laden mass of loose mud, sand, soil, rock and debris down a slope. A debris flow can dash down the slope, reaching speeds of 100 miles per hour or greater. An earthflow is a flow of fine-grained material that typically develops at the lower end of a slope.

Is a slump fast or slow?

The speed of slump varies widely, ranging from meters per second, to meters per year. Sudden slumps usually occur after earthquakes or heavy continuing rains, and can stabilize within a few hours. Most slumps develop over comparatively longer periods, taking months or years to reach stability.

How is a slump formed?

slump, in geology, downward intermittent movement of rock debris, usually the consequence of removal of buttressing earth at the foot of a slope of unconsolidated material. It commonly involves a shear plane on which a back-tilting of the top of the slumped mass occurs.

What are the primary differences between a debris slide and a slump?

Landslides involve rock and debris moving downslope along a planar surface, whereas slumping usually occurs along a curved interface and as a single large unit. Slumps are commonly observed in large impact craters, including Giordano Bruno, Darwin C, Klute W, Milne N, and Steno Q.

What are 4 types of landslides?

Landslides are part of a more general erosion or surficial pro- cess known as mass wasting, which is simply the downslope movement of earth or surface materials due to gravity. They are classified into four main types: fall and toppling, slides (rotational and translational), flows and creep.

What are the 4 types of mass movement?

There are four different types of mass movement:

• Rockfall. Bits of rock fall off the cliff face, usually due to freeze-thaw weathering.
• Mudflow. Saturated soil (soil filled with water) flows down a slope.
• Landslide. Large blocks of rock slide downhill.
• Rotational slip. Saturated soil slumps down a curved surface.

How are sediment flows classified?

The rheology of a sediment gravity flow in its depositional phase is determined by three parameters: (I) the flow is either laminar or turbu- lent; (II) the concentration of the flow is either low or high; (III) the flow behavior is either fluidal (cohesionless) or plastic (cohesive).

What is debris slide?

Definition of debris-slide

: a mass of predominantly unconsolidated and incoherent soil and rock fragments that has slid or rolled rapidly down a steep slope when comparatively dry to form an irregular hummocky deposit — compare debris-avalanche.

How do sediment flows differ from slope failures?

Slope Failures – a sudden failure of the slope resulting in transport of debris down hill by sliding, rolling, falling, or slumping. Sediment Flows – debris flows down hill mixed with water or air.

What’s the movement of sediment?

Sediment moves from one place to another through the process of erosion. Erosion is the removal and transportation of rock or soil. Erosion can move sediment through water, ice, or wind. Water can wash sediment, such as gravel or pebbles, down from a creek, into a river, and eventually to that river’s delta.

What is sediment called?

Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter).

How is sediment transported in fluid?

The simplest definition of sediment transport is the transport of granular particles by fluids. The main agents by which sedimentary materials are moved include gravity (gravity transport), river and stream flow, ice, wind, and estuarine and ocean currents.